1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since version 3.6.18, SQLite source code has been stored in the 112** <a href="http://www.fossil-scm.org/">Fossil configuration management 113** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 114** a string which identifies a particular check-in of SQLite 115** within its configuration management system. ^The SQLITE_SOURCE_ID 116** string contains the date and time of the check-in (UTC) and an SHA1 117** hash of the entire source tree. 118** 119** See also: [sqlite3_libversion()], 120** [sqlite3_libversion_number()], [sqlite3_sourceid()], 121** [sqlite_version()] and [sqlite_source_id()]. 122*/ 123#define SQLITE_VERSION "3.14.1" 124#define SQLITE_VERSION_NUMBER 3014001 125#define SQLITE_SOURCE_ID "2016-08-11 18:53:32 a12d8059770df4bca59e321c266410344242bf7b" 126 127/* 128** CAPI3REF: Run-Time Library Version Numbers 129** KEYWORDS: sqlite3_version, sqlite3_sourceid 130** 131** These interfaces provide the same information as the [SQLITE_VERSION], 132** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 133** but are associated with the library instead of the header file. ^(Cautious 134** programmers might include assert() statements in their application to 135** verify that values returned by these interfaces match the macros in 136** the header, and thus ensure that the application is 137** compiled with matching library and header files. 138** 139** <blockquote><pre> 140** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 141** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 142** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 143** </pre></blockquote>)^ 144** 145** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 146** macro. ^The sqlite3_libversion() function returns a pointer to the 147** to the sqlite3_version[] string constant. The sqlite3_libversion() 148** function is provided for use in DLLs since DLL users usually do not have 149** direct access to string constants within the DLL. ^The 150** sqlite3_libversion_number() function returns an integer equal to 151** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 152** a pointer to a string constant whose value is the same as the 153** [SQLITE_SOURCE_ID] C preprocessor macro. 154** 155** See also: [sqlite_version()] and [sqlite_source_id()]. 156*/ 157SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 158SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 159SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 160SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 161 162/* 163** CAPI3REF: Run-Time Library Compilation Options Diagnostics 164** 165** ^The sqlite3_compileoption_used() function returns 0 or 1 166** indicating whether the specified option was defined at 167** compile time. ^The SQLITE_ prefix may be omitted from the 168** option name passed to sqlite3_compileoption_used(). 169** 170** ^The sqlite3_compileoption_get() function allows iterating 171** over the list of options that were defined at compile time by 172** returning the N-th compile time option string. ^If N is out of range, 173** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 174** prefix is omitted from any strings returned by 175** sqlite3_compileoption_get(). 176** 177** ^Support for the diagnostic functions sqlite3_compileoption_used() 178** and sqlite3_compileoption_get() may be omitted by specifying the 179** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 180** 181** See also: SQL functions [sqlite_compileoption_used()] and 182** [sqlite_compileoption_get()] and the [compile_options pragma]. 183*/ 184#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 185SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 186SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 187#endif 188 189/* 190** CAPI3REF: Test To See If The Library Is Threadsafe 191** 192** ^The sqlite3_threadsafe() function returns zero if and only if 193** SQLite was compiled with mutexing code omitted due to the 194** [SQLITE_THREADSAFE] compile-time option being set to 0. 195** 196** SQLite can be compiled with or without mutexes. When 197** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 198** are enabled and SQLite is threadsafe. When the 199** [SQLITE_THREADSAFE] macro is 0, 200** the mutexes are omitted. Without the mutexes, it is not safe 201** to use SQLite concurrently from more than one thread. 202** 203** Enabling mutexes incurs a measurable performance penalty. 204** So if speed is of utmost importance, it makes sense to disable 205** the mutexes. But for maximum safety, mutexes should be enabled. 206** ^The default behavior is for mutexes to be enabled. 207** 208** This interface can be used by an application to make sure that the 209** version of SQLite that it is linking against was compiled with 210** the desired setting of the [SQLITE_THREADSAFE] macro. 211** 212** This interface only reports on the compile-time mutex setting 213** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 214** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 215** can be fully or partially disabled using a call to [sqlite3_config()] 216** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 217** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 218** sqlite3_threadsafe() function shows only the compile-time setting of 219** thread safety, not any run-time changes to that setting made by 220** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 221** is unchanged by calls to sqlite3_config().)^ 222** 223** See the [threading mode] documentation for additional information. 224*/ 225SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 226 227/* 228** CAPI3REF: Database Connection Handle 229** KEYWORDS: {database connection} {database connections} 230** 231** Each open SQLite database is represented by a pointer to an instance of 232** the opaque structure named "sqlite3". It is useful to think of an sqlite3 233** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 234** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 235** and [sqlite3_close_v2()] are its destructors. There are many other 236** interfaces (such as 237** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 238** [sqlite3_busy_timeout()] to name but three) that are methods on an 239** sqlite3 object. 240*/ 241typedef struct sqlite3 sqlite3; 242 243/* 244** CAPI3REF: 64-Bit Integer Types 245** KEYWORDS: sqlite_int64 sqlite_uint64 246** 247** Because there is no cross-platform way to specify 64-bit integer types 248** SQLite includes typedefs for 64-bit signed and unsigned integers. 249** 250** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 251** The sqlite_int64 and sqlite_uint64 types are supported for backwards 252** compatibility only. 253** 254** ^The sqlite3_int64 and sqlite_int64 types can store integer values 255** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 256** sqlite3_uint64 and sqlite_uint64 types can store integer values 257** between 0 and +18446744073709551615 inclusive. 258*/ 259#ifdef SQLITE_INT64_TYPE 260 typedef SQLITE_INT64_TYPE sqlite_int64; 261 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 262#elif defined(_MSC_VER) || defined(__BORLANDC__) 263 typedef __int64 sqlite_int64; 264 typedef unsigned __int64 sqlite_uint64; 265#else 266 typedef long long int sqlite_int64; 267 typedef unsigned long long int sqlite_uint64; 268#endif 269typedef sqlite_int64 sqlite3_int64; 270typedef sqlite_uint64 sqlite3_uint64; 271 272/* 273** If compiling for a processor that lacks floating point support, 274** substitute integer for floating-point. 275*/ 276#ifdef SQLITE_OMIT_FLOATING_POINT 277# define double sqlite3_int64 278#endif 279 280/* 281** CAPI3REF: Closing A Database Connection 282** DESTRUCTOR: sqlite3 283** 284** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 285** for the [sqlite3] object. 286** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 287** the [sqlite3] object is successfully destroyed and all associated 288** resources are deallocated. 289** 290** ^If the database connection is associated with unfinalized prepared 291** statements or unfinished sqlite3_backup objects then sqlite3_close() 292** will leave the database connection open and return [SQLITE_BUSY]. 293** ^If sqlite3_close_v2() is called with unfinalized prepared statements 294** and/or unfinished sqlite3_backups, then the database connection becomes 295** an unusable "zombie" which will automatically be deallocated when the 296** last prepared statement is finalized or the last sqlite3_backup is 297** finished. The sqlite3_close_v2() interface is intended for use with 298** host languages that are garbage collected, and where the order in which 299** destructors are called is arbitrary. 300** 301** Applications should [sqlite3_finalize | finalize] all [prepared statements], 302** [sqlite3_blob_close | close] all [BLOB handles], and 303** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 304** with the [sqlite3] object prior to attempting to close the object. ^If 305** sqlite3_close_v2() is called on a [database connection] that still has 306** outstanding [prepared statements], [BLOB handles], and/or 307** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 308** of resources is deferred until all [prepared statements], [BLOB handles], 309** and [sqlite3_backup] objects are also destroyed. 310** 311** ^If an [sqlite3] object is destroyed while a transaction is open, 312** the transaction is automatically rolled back. 313** 314** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 315** must be either a NULL 316** pointer or an [sqlite3] object pointer obtained 317** from [sqlite3_open()], [sqlite3_open16()], or 318** [sqlite3_open_v2()], and not previously closed. 319** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 320** argument is a harmless no-op. 321*/ 322SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 323SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 324 325/* 326** The type for a callback function. 327** This is legacy and deprecated. It is included for historical 328** compatibility and is not documented. 329*/ 330typedef int (*sqlite3_callback)(void*,int,char**, char**); 331 332/* 333** CAPI3REF: One-Step Query Execution Interface 334** METHOD: sqlite3 335** 336** The sqlite3_exec() interface is a convenience wrapper around 337** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 338** that allows an application to run multiple statements of SQL 339** without having to use a lot of C code. 340** 341** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 342** semicolon-separate SQL statements passed into its 2nd argument, 343** in the context of the [database connection] passed in as its 1st 344** argument. ^If the callback function of the 3rd argument to 345** sqlite3_exec() is not NULL, then it is invoked for each result row 346** coming out of the evaluated SQL statements. ^The 4th argument to 347** sqlite3_exec() is relayed through to the 1st argument of each 348** callback invocation. ^If the callback pointer to sqlite3_exec() 349** is NULL, then no callback is ever invoked and result rows are 350** ignored. 351** 352** ^If an error occurs while evaluating the SQL statements passed into 353** sqlite3_exec(), then execution of the current statement stops and 354** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 355** is not NULL then any error message is written into memory obtained 356** from [sqlite3_malloc()] and passed back through the 5th parameter. 357** To avoid memory leaks, the application should invoke [sqlite3_free()] 358** on error message strings returned through the 5th parameter of 359** sqlite3_exec() after the error message string is no longer needed. 360** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 361** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 362** NULL before returning. 363** 364** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 365** routine returns SQLITE_ABORT without invoking the callback again and 366** without running any subsequent SQL statements. 367** 368** ^The 2nd argument to the sqlite3_exec() callback function is the 369** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 370** callback is an array of pointers to strings obtained as if from 371** [sqlite3_column_text()], one for each column. ^If an element of a 372** result row is NULL then the corresponding string pointer for the 373** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 374** sqlite3_exec() callback is an array of pointers to strings where each 375** entry represents the name of corresponding result column as obtained 376** from [sqlite3_column_name()]. 377** 378** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 379** to an empty string, or a pointer that contains only whitespace and/or 380** SQL comments, then no SQL statements are evaluated and the database 381** is not changed. 382** 383** Restrictions: 384** 385** <ul> 386** <li> The application must ensure that the 1st parameter to sqlite3_exec() 387** is a valid and open [database connection]. 388** <li> The application must not close the [database connection] specified by 389** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 390** <li> The application must not modify the SQL statement text passed into 391** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 392** </ul> 393*/ 394SQLITE_API int SQLITE_STDCALL sqlite3_exec( 395 sqlite3*, /* An open database */ 396 const char *sql, /* SQL to be evaluated */ 397 int (*callback)(void*,int,char**,char**), /* Callback function */ 398 void *, /* 1st argument to callback */ 399 char **errmsg /* Error msg written here */ 400); 401 402/* 403** CAPI3REF: Result Codes 404** KEYWORDS: {result code definitions} 405** 406** Many SQLite functions return an integer result code from the set shown 407** here in order to indicate success or failure. 408** 409** New error codes may be added in future versions of SQLite. 410** 411** See also: [extended result code definitions] 412*/ 413#define SQLITE_OK 0 /* Successful result */ 414/* beginning-of-error-codes */ 415#define SQLITE_ERROR 1 /* SQL error or missing database */ 416#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 417#define SQLITE_PERM 3 /* Access permission denied */ 418#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 419#define SQLITE_BUSY 5 /* The database file is locked */ 420#define SQLITE_LOCKED 6 /* A table in the database is locked */ 421#define SQLITE_NOMEM 7 /* A malloc() failed */ 422#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 423#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 424#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 425#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 426#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 427#define SQLITE_FULL 13 /* Insertion failed because database is full */ 428#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 429#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 430#define SQLITE_EMPTY 16 /* Database is empty */ 431#define SQLITE_SCHEMA 17 /* The database schema changed */ 432#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 433#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 434#define SQLITE_MISMATCH 20 /* Data type mismatch */ 435#define SQLITE_MISUSE 21 /* Library used incorrectly */ 436#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 437#define SQLITE_AUTH 23 /* Authorization denied */ 438#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 439#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 440#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 441#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 442#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 443#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 444#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 445/* end-of-error-codes */ 446 447/* 448** CAPI3REF: Extended Result Codes 449** KEYWORDS: {extended result code definitions} 450** 451** In its default configuration, SQLite API routines return one of 30 integer 452** [result codes]. However, experience has shown that many of 453** these result codes are too coarse-grained. They do not provide as 454** much information about problems as programmers might like. In an effort to 455** address this, newer versions of SQLite (version 3.3.8 and later) include 456** support for additional result codes that provide more detailed information 457** about errors. These [extended result codes] are enabled or disabled 458** on a per database connection basis using the 459** [sqlite3_extended_result_codes()] API. Or, the extended code for 460** the most recent error can be obtained using 461** [sqlite3_extended_errcode()]. 462*/ 463#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 464#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 465#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 466#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 467#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 468#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 469#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 470#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 471#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 472#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 473#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 474#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 475#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 476#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 477#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 478#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 479#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 480#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 481#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 482#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 483#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 484#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 485#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 486#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 487#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 488#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 489#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 490#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 491#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 492#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 493#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 494#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 495#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 496#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 497#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 498#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 499#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 500#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 501#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 502#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 503#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 504#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 505#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 506#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 507#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 508#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 509#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 510#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 511#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 512#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 513#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 514#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 515#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 516#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 517#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 518#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 519 520/* 521** CAPI3REF: Flags For File Open Operations 522** 523** These bit values are intended for use in the 524** 3rd parameter to the [sqlite3_open_v2()] interface and 525** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 526*/ 527#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 528#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 529#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 530#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 531#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 532#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 533#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 536#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 537#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 538#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 539#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 540#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 541#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 542#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 543#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 544#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 545#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 546#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 547 548/* Reserved: 0x00F00000 */ 549 550/* 551** CAPI3REF: Device Characteristics 552** 553** The xDeviceCharacteristics method of the [sqlite3_io_methods] 554** object returns an integer which is a vector of these 555** bit values expressing I/O characteristics of the mass storage 556** device that holds the file that the [sqlite3_io_methods] 557** refers to. 558** 559** The SQLITE_IOCAP_ATOMIC property means that all writes of 560** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 561** mean that writes of blocks that are nnn bytes in size and 562** are aligned to an address which is an integer multiple of 563** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 564** that when data is appended to a file, the data is appended 565** first then the size of the file is extended, never the other 566** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 567** information is written to disk in the same order as calls 568** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 569** after reboot following a crash or power loss, the only bytes in a 570** file that were written at the application level might have changed 571** and that adjacent bytes, even bytes within the same sector are 572** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 573** flag indicate that a file cannot be deleted when open. The 574** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 575** read-only media and cannot be changed even by processes with 576** elevated privileges. 577*/ 578#define SQLITE_IOCAP_ATOMIC 0x00000001 579#define SQLITE_IOCAP_ATOMIC512 0x00000002 580#define SQLITE_IOCAP_ATOMIC1K 0x00000004 581#define SQLITE_IOCAP_ATOMIC2K 0x00000008 582#define SQLITE_IOCAP_ATOMIC4K 0x00000010 583#define SQLITE_IOCAP_ATOMIC8K 0x00000020 584#define SQLITE_IOCAP_ATOMIC16K 0x00000040 585#define SQLITE_IOCAP_ATOMIC32K 0x00000080 586#define SQLITE_IOCAP_ATOMIC64K 0x00000100 587#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 588#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 589#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 590#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 591#define SQLITE_IOCAP_IMMUTABLE 0x00002000 592 593/* 594** CAPI3REF: File Locking Levels 595** 596** SQLite uses one of these integer values as the second 597** argument to calls it makes to the xLock() and xUnlock() methods 598** of an [sqlite3_io_methods] object. 599*/ 600#define SQLITE_LOCK_NONE 0 601#define SQLITE_LOCK_SHARED 1 602#define SQLITE_LOCK_RESERVED 2 603#define SQLITE_LOCK_PENDING 3 604#define SQLITE_LOCK_EXCLUSIVE 4 605 606/* 607** CAPI3REF: Synchronization Type Flags 608** 609** When SQLite invokes the xSync() method of an 610** [sqlite3_io_methods] object it uses a combination of 611** these integer values as the second argument. 612** 613** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 614** sync operation only needs to flush data to mass storage. Inode 615** information need not be flushed. If the lower four bits of the flag 616** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 617** If the lower four bits equal SQLITE_SYNC_FULL, that means 618** to use Mac OS X style fullsync instead of fsync(). 619** 620** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 621** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 622** settings. The [synchronous pragma] determines when calls to the 623** xSync VFS method occur and applies uniformly across all platforms. 624** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 625** energetic or rigorous or forceful the sync operations are and 626** only make a difference on Mac OSX for the default SQLite code. 627** (Third-party VFS implementations might also make the distinction 628** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 629** operating systems natively supported by SQLite, only Mac OSX 630** cares about the difference.) 631*/ 632#define SQLITE_SYNC_NORMAL 0x00002 633#define SQLITE_SYNC_FULL 0x00003 634#define SQLITE_SYNC_DATAONLY 0x00010 635 636/* 637** CAPI3REF: OS Interface Open File Handle 638** 639** An [sqlite3_file] object represents an open file in the 640** [sqlite3_vfs | OS interface layer]. Individual OS interface 641** implementations will 642** want to subclass this object by appending additional fields 643** for their own use. The pMethods entry is a pointer to an 644** [sqlite3_io_methods] object that defines methods for performing 645** I/O operations on the open file. 646*/ 647typedef struct sqlite3_file sqlite3_file; 648struct sqlite3_file { 649 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 650}; 651 652/* 653** CAPI3REF: OS Interface File Virtual Methods Object 654** 655** Every file opened by the [sqlite3_vfs.xOpen] method populates an 656** [sqlite3_file] object (or, more commonly, a subclass of the 657** [sqlite3_file] object) with a pointer to an instance of this object. 658** This object defines the methods used to perform various operations 659** against the open file represented by the [sqlite3_file] object. 660** 661** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 662** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 663** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 664** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 665** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 666** to NULL. 667** 668** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 669** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 670** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 671** flag may be ORed in to indicate that only the data of the file 672** and not its inode needs to be synced. 673** 674** The integer values to xLock() and xUnlock() are one of 675** <ul> 676** <li> [SQLITE_LOCK_NONE], 677** <li> [SQLITE_LOCK_SHARED], 678** <li> [SQLITE_LOCK_RESERVED], 679** <li> [SQLITE_LOCK_PENDING], or 680** <li> [SQLITE_LOCK_EXCLUSIVE]. 681** </ul> 682** xLock() increases the lock. xUnlock() decreases the lock. 683** The xCheckReservedLock() method checks whether any database connection, 684** either in this process or in some other process, is holding a RESERVED, 685** PENDING, or EXCLUSIVE lock on the file. It returns true 686** if such a lock exists and false otherwise. 687** 688** The xFileControl() method is a generic interface that allows custom 689** VFS implementations to directly control an open file using the 690** [sqlite3_file_control()] interface. The second "op" argument is an 691** integer opcode. The third argument is a generic pointer intended to 692** point to a structure that may contain arguments or space in which to 693** write return values. Potential uses for xFileControl() might be 694** functions to enable blocking locks with timeouts, to change the 695** locking strategy (for example to use dot-file locks), to inquire 696** about the status of a lock, or to break stale locks. The SQLite 697** core reserves all opcodes less than 100 for its own use. 698** A [file control opcodes | list of opcodes] less than 100 is available. 699** Applications that define a custom xFileControl method should use opcodes 700** greater than 100 to avoid conflicts. VFS implementations should 701** return [SQLITE_NOTFOUND] for file control opcodes that they do not 702** recognize. 703** 704** The xSectorSize() method returns the sector size of the 705** device that underlies the file. The sector size is the 706** minimum write that can be performed without disturbing 707** other bytes in the file. The xDeviceCharacteristics() 708** method returns a bit vector describing behaviors of the 709** underlying device: 710** 711** <ul> 712** <li> [SQLITE_IOCAP_ATOMIC] 713** <li> [SQLITE_IOCAP_ATOMIC512] 714** <li> [SQLITE_IOCAP_ATOMIC1K] 715** <li> [SQLITE_IOCAP_ATOMIC2K] 716** <li> [SQLITE_IOCAP_ATOMIC4K] 717** <li> [SQLITE_IOCAP_ATOMIC8K] 718** <li> [SQLITE_IOCAP_ATOMIC16K] 719** <li> [SQLITE_IOCAP_ATOMIC32K] 720** <li> [SQLITE_IOCAP_ATOMIC64K] 721** <li> [SQLITE_IOCAP_SAFE_APPEND] 722** <li> [SQLITE_IOCAP_SEQUENTIAL] 723** </ul> 724** 725** The SQLITE_IOCAP_ATOMIC property means that all writes of 726** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 727** mean that writes of blocks that are nnn bytes in size and 728** are aligned to an address which is an integer multiple of 729** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 730** that when data is appended to a file, the data is appended 731** first then the size of the file is extended, never the other 732** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 733** information is written to disk in the same order as calls 734** to xWrite(). 735** 736** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 737** in the unread portions of the buffer with zeros. A VFS that 738** fails to zero-fill short reads might seem to work. However, 739** failure to zero-fill short reads will eventually lead to 740** database corruption. 741*/ 742typedef struct sqlite3_io_methods sqlite3_io_methods; 743struct sqlite3_io_methods { 744 int iVersion; 745 int (*xClose)(sqlite3_file*); 746 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 747 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 748 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 749 int (*xSync)(sqlite3_file*, int flags); 750 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 751 int (*xLock)(sqlite3_file*, int); 752 int (*xUnlock)(sqlite3_file*, int); 753 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 754 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 755 int (*xSectorSize)(sqlite3_file*); 756 int (*xDeviceCharacteristics)(sqlite3_file*); 757 /* Methods above are valid for version 1 */ 758 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 759 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 760 void (*xShmBarrier)(sqlite3_file*); 761 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 762 /* Methods above are valid for version 2 */ 763 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 764 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 765 /* Methods above are valid for version 3 */ 766 /* Additional methods may be added in future releases */ 767}; 768 769/* 770** CAPI3REF: Standard File Control Opcodes 771** KEYWORDS: {file control opcodes} {file control opcode} 772** 773** These integer constants are opcodes for the xFileControl method 774** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 775** interface. 776** 777** <ul> 778** <li>[[SQLITE_FCNTL_LOCKSTATE]] 779** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 780** opcode causes the xFileControl method to write the current state of 781** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 782** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 783** into an integer that the pArg argument points to. This capability 784** is used during testing and is only available when the SQLITE_TEST 785** compile-time option is used. 786** 787** <li>[[SQLITE_FCNTL_SIZE_HINT]] 788** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 789** layer a hint of how large the database file will grow to be during the 790** current transaction. This hint is not guaranteed to be accurate but it 791** is often close. The underlying VFS might choose to preallocate database 792** file space based on this hint in order to help writes to the database 793** file run faster. 794** 795** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 796** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 797** extends and truncates the database file in chunks of a size specified 798** by the user. The fourth argument to [sqlite3_file_control()] should 799** point to an integer (type int) containing the new chunk-size to use 800** for the nominated database. Allocating database file space in large 801** chunks (say 1MB at a time), may reduce file-system fragmentation and 802** improve performance on some systems. 803** 804** <li>[[SQLITE_FCNTL_FILE_POINTER]] 805** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 806** to the [sqlite3_file] object associated with a particular database 807** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 808** 809** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 810** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 811** to the [sqlite3_file] object associated with the journal file (either 812** the [rollback journal] or the [write-ahead log]) for a particular database 813** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 814** 815** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 816** No longer in use. 817** 818** <li>[[SQLITE_FCNTL_SYNC]] 819** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 820** sent to the VFS immediately before the xSync method is invoked on a 821** database file descriptor. Or, if the xSync method is not invoked 822** because the user has configured SQLite with 823** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 824** of the xSync method. In most cases, the pointer argument passed with 825** this file-control is NULL. However, if the database file is being synced 826** as part of a multi-database commit, the argument points to a nul-terminated 827** string containing the transactions master-journal file name. VFSes that 828** do not need this signal should silently ignore this opcode. Applications 829** should not call [sqlite3_file_control()] with this opcode as doing so may 830** disrupt the operation of the specialized VFSes that do require it. 831** 832** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 833** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 834** and sent to the VFS after a transaction has been committed immediately 835** but before the database is unlocked. VFSes that do not need this signal 836** should silently ignore this opcode. Applications should not call 837** [sqlite3_file_control()] with this opcode as doing so may disrupt the 838** operation of the specialized VFSes that do require it. 839** 840** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 841** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 842** retry counts and intervals for certain disk I/O operations for the 843** windows [VFS] in order to provide robustness in the presence of 844** anti-virus programs. By default, the windows VFS will retry file read, 845** file write, and file delete operations up to 10 times, with a delay 846** of 25 milliseconds before the first retry and with the delay increasing 847** by an additional 25 milliseconds with each subsequent retry. This 848** opcode allows these two values (10 retries and 25 milliseconds of delay) 849** to be adjusted. The values are changed for all database connections 850** within the same process. The argument is a pointer to an array of two 851** integers where the first integer i the new retry count and the second 852** integer is the delay. If either integer is negative, then the setting 853** is not changed but instead the prior value of that setting is written 854** into the array entry, allowing the current retry settings to be 855** interrogated. The zDbName parameter is ignored. 856** 857** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 858** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 859** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 860** write ahead log and shared memory files used for transaction control 861** are automatically deleted when the latest connection to the database 862** closes. Setting persistent WAL mode causes those files to persist after 863** close. Persisting the files is useful when other processes that do not 864** have write permission on the directory containing the database file want 865** to read the database file, as the WAL and shared memory files must exist 866** in order for the database to be readable. The fourth parameter to 867** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 868** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 869** WAL mode. If the integer is -1, then it is overwritten with the current 870** WAL persistence setting. 871** 872** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 873** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 874** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 875** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 876** xDeviceCharacteristics methods. The fourth parameter to 877** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 878** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 879** mode. If the integer is -1, then it is overwritten with the current 880** zero-damage mode setting. 881** 882** <li>[[SQLITE_FCNTL_OVERWRITE]] 883** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 884** a write transaction to indicate that, unless it is rolled back for some 885** reason, the entire database file will be overwritten by the current 886** transaction. This is used by VACUUM operations. 887** 888** <li>[[SQLITE_FCNTL_VFSNAME]] 889** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 890** all [VFSes] in the VFS stack. The names are of all VFS shims and the 891** final bottom-level VFS are written into memory obtained from 892** [sqlite3_malloc()] and the result is stored in the char* variable 893** that the fourth parameter of [sqlite3_file_control()] points to. 894** The caller is responsible for freeing the memory when done. As with 895** all file-control actions, there is no guarantee that this will actually 896** do anything. Callers should initialize the char* variable to a NULL 897** pointer in case this file-control is not implemented. This file-control 898** is intended for diagnostic use only. 899** 900** <li>[[SQLITE_FCNTL_VFS_POINTER]] 901** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 902** [VFSes] currently in use. ^(The argument X in 903** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 904** of type "[sqlite3_vfs] **". This opcodes will set *X 905** to a pointer to the top-level VFS.)^ 906** ^When there are multiple VFS shims in the stack, this opcode finds the 907** upper-most shim only. 908** 909** <li>[[SQLITE_FCNTL_PRAGMA]] 910** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 911** file control is sent to the open [sqlite3_file] object corresponding 912** to the database file to which the pragma statement refers. ^The argument 913** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 914** pointers to strings (char**) in which the second element of the array 915** is the name of the pragma and the third element is the argument to the 916** pragma or NULL if the pragma has no argument. ^The handler for an 917** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 918** of the char** argument point to a string obtained from [sqlite3_mprintf()] 919** or the equivalent and that string will become the result of the pragma or 920** the error message if the pragma fails. ^If the 921** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 922** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 923** file control returns [SQLITE_OK], then the parser assumes that the 924** VFS has handled the PRAGMA itself and the parser generates a no-op 925** prepared statement if result string is NULL, or that returns a copy 926** of the result string if the string is non-NULL. 927** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 928** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 929** that the VFS encountered an error while handling the [PRAGMA] and the 930** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 931** file control occurs at the beginning of pragma statement analysis and so 932** it is able to override built-in [PRAGMA] statements. 933** 934** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 935** ^The [SQLITE_FCNTL_BUSYHANDLER] 936** file-control may be invoked by SQLite on the database file handle 937** shortly after it is opened in order to provide a custom VFS with access 938** to the connections busy-handler callback. The argument is of type (void **) 939** - an array of two (void *) values. The first (void *) actually points 940** to a function of type (int (*)(void *)). In order to invoke the connections 941** busy-handler, this function should be invoked with the second (void *) in 942** the array as the only argument. If it returns non-zero, then the operation 943** should be retried. If it returns zero, the custom VFS should abandon the 944** current operation. 945** 946** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 947** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 948** to have SQLite generate a 949** temporary filename using the same algorithm that is followed to generate 950** temporary filenames for TEMP tables and other internal uses. The 951** argument should be a char** which will be filled with the filename 952** written into memory obtained from [sqlite3_malloc()]. The caller should 953** invoke [sqlite3_free()] on the result to avoid a memory leak. 954** 955** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 956** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 957** maximum number of bytes that will be used for memory-mapped I/O. 958** The argument is a pointer to a value of type sqlite3_int64 that 959** is an advisory maximum number of bytes in the file to memory map. The 960** pointer is overwritten with the old value. The limit is not changed if 961** the value originally pointed to is negative, and so the current limit 962** can be queried by passing in a pointer to a negative number. This 963** file-control is used internally to implement [PRAGMA mmap_size]. 964** 965** <li>[[SQLITE_FCNTL_TRACE]] 966** The [SQLITE_FCNTL_TRACE] file control provides advisory information 967** to the VFS about what the higher layers of the SQLite stack are doing. 968** This file control is used by some VFS activity tracing [shims]. 969** The argument is a zero-terminated string. Higher layers in the 970** SQLite stack may generate instances of this file control if 971** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 972** 973** <li>[[SQLITE_FCNTL_HAS_MOVED]] 974** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 975** pointer to an integer and it writes a boolean into that integer depending 976** on whether or not the file has been renamed, moved, or deleted since it 977** was first opened. 978** 979** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 980** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 981** opcode causes the xFileControl method to swap the file handle with the one 982** pointed to by the pArg argument. This capability is used during testing 983** and only needs to be supported when SQLITE_TEST is defined. 984** 985** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 986** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 987** be advantageous to block on the next WAL lock if the lock is not immediately 988** available. The WAL subsystem issues this signal during rare 989** circumstances in order to fix a problem with priority inversion. 990** Applications should <em>not</em> use this file-control. 991** 992** <li>[[SQLITE_FCNTL_ZIPVFS]] 993** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 994** VFS should return SQLITE_NOTFOUND for this opcode. 995** 996** <li>[[SQLITE_FCNTL_RBU]] 997** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 998** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 999** this opcode. 1000** </ul> 1001*/ 1002#define SQLITE_FCNTL_LOCKSTATE 1 1003#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1004#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1005#define SQLITE_FCNTL_LAST_ERRNO 4 1006#define SQLITE_FCNTL_SIZE_HINT 5 1007#define SQLITE_FCNTL_CHUNK_SIZE 6 1008#define SQLITE_FCNTL_FILE_POINTER 7 1009#define SQLITE_FCNTL_SYNC_OMITTED 8 1010#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1011#define SQLITE_FCNTL_PERSIST_WAL 10 1012#define SQLITE_FCNTL_OVERWRITE 11 1013#define SQLITE_FCNTL_VFSNAME 12 1014#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1015#define SQLITE_FCNTL_PRAGMA 14 1016#define SQLITE_FCNTL_BUSYHANDLER 15 1017#define SQLITE_FCNTL_TEMPFILENAME 16 1018#define SQLITE_FCNTL_MMAP_SIZE 18 1019#define SQLITE_FCNTL_TRACE 19 1020#define SQLITE_FCNTL_HAS_MOVED 20 1021#define SQLITE_FCNTL_SYNC 21 1022#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1023#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1024#define SQLITE_FCNTL_WAL_BLOCK 24 1025#define SQLITE_FCNTL_ZIPVFS 25 1026#define SQLITE_FCNTL_RBU 26 1027#define SQLITE_FCNTL_VFS_POINTER 27 1028#define SQLITE_FCNTL_JOURNAL_POINTER 28 1029 1030/* deprecated names */ 1031#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1032#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1033#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1034 1035 1036/* 1037** CAPI3REF: Mutex Handle 1038** 1039** The mutex module within SQLite defines [sqlite3_mutex] to be an 1040** abstract type for a mutex object. The SQLite core never looks 1041** at the internal representation of an [sqlite3_mutex]. It only 1042** deals with pointers to the [sqlite3_mutex] object. 1043** 1044** Mutexes are created using [sqlite3_mutex_alloc()]. 1045*/ 1046typedef struct sqlite3_mutex sqlite3_mutex; 1047 1048/* 1049** CAPI3REF: Loadable Extension Thunk 1050** 1051** A pointer to the opaque sqlite3_api_routines structure is passed as 1052** the third parameter to entry points of [loadable extensions]. This 1053** structure must be typedefed in order to work around compiler warnings 1054** on some platforms. 1055*/ 1056typedef struct sqlite3_api_routines sqlite3_api_routines; 1057 1058/* 1059** CAPI3REF: OS Interface Object 1060** 1061** An instance of the sqlite3_vfs object defines the interface between 1062** the SQLite core and the underlying operating system. The "vfs" 1063** in the name of the object stands for "virtual file system". See 1064** the [VFS | VFS documentation] for further information. 1065** 1066** The value of the iVersion field is initially 1 but may be larger in 1067** future versions of SQLite. Additional fields may be appended to this 1068** object when the iVersion value is increased. Note that the structure 1069** of the sqlite3_vfs object changes in the transaction between 1070** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1071** modified. 1072** 1073** The szOsFile field is the size of the subclassed [sqlite3_file] 1074** structure used by this VFS. mxPathname is the maximum length of 1075** a pathname in this VFS. 1076** 1077** Registered sqlite3_vfs objects are kept on a linked list formed by 1078** the pNext pointer. The [sqlite3_vfs_register()] 1079** and [sqlite3_vfs_unregister()] interfaces manage this list 1080** in a thread-safe way. The [sqlite3_vfs_find()] interface 1081** searches the list. Neither the application code nor the VFS 1082** implementation should use the pNext pointer. 1083** 1084** The pNext field is the only field in the sqlite3_vfs 1085** structure that SQLite will ever modify. SQLite will only access 1086** or modify this field while holding a particular static mutex. 1087** The application should never modify anything within the sqlite3_vfs 1088** object once the object has been registered. 1089** 1090** The zName field holds the name of the VFS module. The name must 1091** be unique across all VFS modules. 1092** 1093** [[sqlite3_vfs.xOpen]] 1094** ^SQLite guarantees that the zFilename parameter to xOpen 1095** is either a NULL pointer or string obtained 1096** from xFullPathname() with an optional suffix added. 1097** ^If a suffix is added to the zFilename parameter, it will 1098** consist of a single "-" character followed by no more than 1099** 11 alphanumeric and/or "-" characters. 1100** ^SQLite further guarantees that 1101** the string will be valid and unchanged until xClose() is 1102** called. Because of the previous sentence, 1103** the [sqlite3_file] can safely store a pointer to the 1104** filename if it needs to remember the filename for some reason. 1105** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1106** must invent its own temporary name for the file. ^Whenever the 1107** xFilename parameter is NULL it will also be the case that the 1108** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1109** 1110** The flags argument to xOpen() includes all bits set in 1111** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1112** or [sqlite3_open16()] is used, then flags includes at least 1113** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1114** If xOpen() opens a file read-only then it sets *pOutFlags to 1115** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1116** 1117** ^(SQLite will also add one of the following flags to the xOpen() 1118** call, depending on the object being opened: 1119** 1120** <ul> 1121** <li> [SQLITE_OPEN_MAIN_DB] 1122** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1123** <li> [SQLITE_OPEN_TEMP_DB] 1124** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1125** <li> [SQLITE_OPEN_TRANSIENT_DB] 1126** <li> [SQLITE_OPEN_SUBJOURNAL] 1127** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1128** <li> [SQLITE_OPEN_WAL] 1129** </ul>)^ 1130** 1131** The file I/O implementation can use the object type flags to 1132** change the way it deals with files. For example, an application 1133** that does not care about crash recovery or rollback might make 1134** the open of a journal file a no-op. Writes to this journal would 1135** also be no-ops, and any attempt to read the journal would return 1136** SQLITE_IOERR. Or the implementation might recognize that a database 1137** file will be doing page-aligned sector reads and writes in a random 1138** order and set up its I/O subsystem accordingly. 1139** 1140** SQLite might also add one of the following flags to the xOpen method: 1141** 1142** <ul> 1143** <li> [SQLITE_OPEN_DELETEONCLOSE] 1144** <li> [SQLITE_OPEN_EXCLUSIVE] 1145** </ul> 1146** 1147** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1148** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1149** will be set for TEMP databases and their journals, transient 1150** databases, and subjournals. 1151** 1152** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1153** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1154** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1155** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1156** SQLITE_OPEN_CREATE, is used to indicate that file should always 1157** be created, and that it is an error if it already exists. 1158** It is <i>not</i> used to indicate the file should be opened 1159** for exclusive access. 1160** 1161** ^At least szOsFile bytes of memory are allocated by SQLite 1162** to hold the [sqlite3_file] structure passed as the third 1163** argument to xOpen. The xOpen method does not have to 1164** allocate the structure; it should just fill it in. Note that 1165** the xOpen method must set the sqlite3_file.pMethods to either 1166** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1167** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1168** element will be valid after xOpen returns regardless of the success 1169** or failure of the xOpen call. 1170** 1171** [[sqlite3_vfs.xAccess]] 1172** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1173** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1174** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1175** to test whether a file is at least readable. The file can be a 1176** directory. 1177** 1178** ^SQLite will always allocate at least mxPathname+1 bytes for the 1179** output buffer xFullPathname. The exact size of the output buffer 1180** is also passed as a parameter to both methods. If the output buffer 1181** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1182** handled as a fatal error by SQLite, vfs implementations should endeavor 1183** to prevent this by setting mxPathname to a sufficiently large value. 1184** 1185** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1186** interfaces are not strictly a part of the filesystem, but they are 1187** included in the VFS structure for completeness. 1188** The xRandomness() function attempts to return nBytes bytes 1189** of good-quality randomness into zOut. The return value is 1190** the actual number of bytes of randomness obtained. 1191** The xSleep() method causes the calling thread to sleep for at 1192** least the number of microseconds given. ^The xCurrentTime() 1193** method returns a Julian Day Number for the current date and time as 1194** a floating point value. 1195** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1196** Day Number multiplied by 86400000 (the number of milliseconds in 1197** a 24-hour day). 1198** ^SQLite will use the xCurrentTimeInt64() method to get the current 1199** date and time if that method is available (if iVersion is 2 or 1200** greater and the function pointer is not NULL) and will fall back 1201** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1202** 1203** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1204** are not used by the SQLite core. These optional interfaces are provided 1205** by some VFSes to facilitate testing of the VFS code. By overriding 1206** system calls with functions under its control, a test program can 1207** simulate faults and error conditions that would otherwise be difficult 1208** or impossible to induce. The set of system calls that can be overridden 1209** varies from one VFS to another, and from one version of the same VFS to the 1210** next. Applications that use these interfaces must be prepared for any 1211** or all of these interfaces to be NULL or for their behavior to change 1212** from one release to the next. Applications must not attempt to access 1213** any of these methods if the iVersion of the VFS is less than 3. 1214*/ 1215typedef struct sqlite3_vfs sqlite3_vfs; 1216typedef void (*sqlite3_syscall_ptr)(void); 1217struct sqlite3_vfs { 1218 int iVersion; /* Structure version number (currently 3) */ 1219 int szOsFile; /* Size of subclassed sqlite3_file */ 1220 int mxPathname; /* Maximum file pathname length */ 1221 sqlite3_vfs *pNext; /* Next registered VFS */ 1222 const char *zName; /* Name of this virtual file system */ 1223 void *pAppData; /* Pointer to application-specific data */ 1224 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1225 int flags, int *pOutFlags); 1226 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1227 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1228 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1229 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1230 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1231 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1232 void (*xDlClose)(sqlite3_vfs*, void*); 1233 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1234 int (*xSleep)(sqlite3_vfs*, int microseconds); 1235 int (*xCurrentTime)(sqlite3_vfs*, double*); 1236 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1237 /* 1238 ** The methods above are in version 1 of the sqlite_vfs object 1239 ** definition. Those that follow are added in version 2 or later 1240 */ 1241 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1242 /* 1243 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1244 ** Those below are for version 3 and greater. 1245 */ 1246 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1247 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1248 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1249 /* 1250 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1251 ** New fields may be appended in future versions. The iVersion 1252 ** value will increment whenever this happens. 1253 */ 1254}; 1255 1256/* 1257** CAPI3REF: Flags for the xAccess VFS method 1258** 1259** These integer constants can be used as the third parameter to 1260** the xAccess method of an [sqlite3_vfs] object. They determine 1261** what kind of permissions the xAccess method is looking for. 1262** With SQLITE_ACCESS_EXISTS, the xAccess method 1263** simply checks whether the file exists. 1264** With SQLITE_ACCESS_READWRITE, the xAccess method 1265** checks whether the named directory is both readable and writable 1266** (in other words, if files can be added, removed, and renamed within 1267** the directory). 1268** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1269** [temp_store_directory pragma], though this could change in a future 1270** release of SQLite. 1271** With SQLITE_ACCESS_READ, the xAccess method 1272** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1273** currently unused, though it might be used in a future release of 1274** SQLite. 1275*/ 1276#define SQLITE_ACCESS_EXISTS 0 1277#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1278#define SQLITE_ACCESS_READ 2 /* Unused */ 1279 1280/* 1281** CAPI3REF: Flags for the xShmLock VFS method 1282** 1283** These integer constants define the various locking operations 1284** allowed by the xShmLock method of [sqlite3_io_methods]. The 1285** following are the only legal combinations of flags to the 1286** xShmLock method: 1287** 1288** <ul> 1289** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1290** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1291** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1292** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1293** </ul> 1294** 1295** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1296** was given on the corresponding lock. 1297** 1298** The xShmLock method can transition between unlocked and SHARED or 1299** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1300** and EXCLUSIVE. 1301*/ 1302#define SQLITE_SHM_UNLOCK 1 1303#define SQLITE_SHM_LOCK 2 1304#define SQLITE_SHM_SHARED 4 1305#define SQLITE_SHM_EXCLUSIVE 8 1306 1307/* 1308** CAPI3REF: Maximum xShmLock index 1309** 1310** The xShmLock method on [sqlite3_io_methods] may use values 1311** between 0 and this upper bound as its "offset" argument. 1312** The SQLite core will never attempt to acquire or release a 1313** lock outside of this range 1314*/ 1315#define SQLITE_SHM_NLOCK 8 1316 1317 1318/* 1319** CAPI3REF: Initialize The SQLite Library 1320** 1321** ^The sqlite3_initialize() routine initializes the 1322** SQLite library. ^The sqlite3_shutdown() routine 1323** deallocates any resources that were allocated by sqlite3_initialize(). 1324** These routines are designed to aid in process initialization and 1325** shutdown on embedded systems. Workstation applications using 1326** SQLite normally do not need to invoke either of these routines. 1327** 1328** A call to sqlite3_initialize() is an "effective" call if it is 1329** the first time sqlite3_initialize() is invoked during the lifetime of 1330** the process, or if it is the first time sqlite3_initialize() is invoked 1331** following a call to sqlite3_shutdown(). ^(Only an effective call 1332** of sqlite3_initialize() does any initialization. All other calls 1333** are harmless no-ops.)^ 1334** 1335** A call to sqlite3_shutdown() is an "effective" call if it is the first 1336** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1337** an effective call to sqlite3_shutdown() does any deinitialization. 1338** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1339** 1340** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1341** is not. The sqlite3_shutdown() interface must only be called from a 1342** single thread. All open [database connections] must be closed and all 1343** other SQLite resources must be deallocated prior to invoking 1344** sqlite3_shutdown(). 1345** 1346** Among other things, ^sqlite3_initialize() will invoke 1347** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1348** will invoke sqlite3_os_end(). 1349** 1350** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1351** ^If for some reason, sqlite3_initialize() is unable to initialize 1352** the library (perhaps it is unable to allocate a needed resource such 1353** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1354** 1355** ^The sqlite3_initialize() routine is called internally by many other 1356** SQLite interfaces so that an application usually does not need to 1357** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1358** calls sqlite3_initialize() so the SQLite library will be automatically 1359** initialized when [sqlite3_open()] is called if it has not be initialized 1360** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1361** compile-time option, then the automatic calls to sqlite3_initialize() 1362** are omitted and the application must call sqlite3_initialize() directly 1363** prior to using any other SQLite interface. For maximum portability, 1364** it is recommended that applications always invoke sqlite3_initialize() 1365** directly prior to using any other SQLite interface. Future releases 1366** of SQLite may require this. In other words, the behavior exhibited 1367** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1368** default behavior in some future release of SQLite. 1369** 1370** The sqlite3_os_init() routine does operating-system specific 1371** initialization of the SQLite library. The sqlite3_os_end() 1372** routine undoes the effect of sqlite3_os_init(). Typical tasks 1373** performed by these routines include allocation or deallocation 1374** of static resources, initialization of global variables, 1375** setting up a default [sqlite3_vfs] module, or setting up 1376** a default configuration using [sqlite3_config()]. 1377** 1378** The application should never invoke either sqlite3_os_init() 1379** or sqlite3_os_end() directly. The application should only invoke 1380** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1381** interface is called automatically by sqlite3_initialize() and 1382** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1383** implementations for sqlite3_os_init() and sqlite3_os_end() 1384** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1385** When [custom builds | built for other platforms] 1386** (using the [SQLITE_OS_OTHER=1] compile-time 1387** option) the application must supply a suitable implementation for 1388** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1389** implementation of sqlite3_os_init() or sqlite3_os_end() 1390** must return [SQLITE_OK] on success and some other [error code] upon 1391** failure. 1392*/ 1393SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1394SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1395SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1396SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1397 1398/* 1399** CAPI3REF: Configuring The SQLite Library 1400** 1401** The sqlite3_config() interface is used to make global configuration 1402** changes to SQLite in order to tune SQLite to the specific needs of 1403** the application. The default configuration is recommended for most 1404** applications and so this routine is usually not necessary. It is 1405** provided to support rare applications with unusual needs. 1406** 1407** <b>The sqlite3_config() interface is not threadsafe. The application 1408** must ensure that no other SQLite interfaces are invoked by other 1409** threads while sqlite3_config() is running.</b> 1410** 1411** The sqlite3_config() interface 1412** may only be invoked prior to library initialization using 1413** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1414** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1415** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1416** Note, however, that ^sqlite3_config() can be called as part of the 1417** implementation of an application-defined [sqlite3_os_init()]. 1418** 1419** The first argument to sqlite3_config() is an integer 1420** [configuration option] that determines 1421** what property of SQLite is to be configured. Subsequent arguments 1422** vary depending on the [configuration option] 1423** in the first argument. 1424** 1425** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1426** ^If the option is unknown or SQLite is unable to set the option 1427** then this routine returns a non-zero [error code]. 1428*/ 1429SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1430 1431/* 1432** CAPI3REF: Configure database connections 1433** METHOD: sqlite3 1434** 1435** The sqlite3_db_config() interface is used to make configuration 1436** changes to a [database connection]. The interface is similar to 1437** [sqlite3_config()] except that the changes apply to a single 1438** [database connection] (specified in the first argument). 1439** 1440** The second argument to sqlite3_db_config(D,V,...) is the 1441** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1442** that indicates what aspect of the [database connection] is being configured. 1443** Subsequent arguments vary depending on the configuration verb. 1444** 1445** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1446** the call is considered successful. 1447*/ 1448SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1449 1450/* 1451** CAPI3REF: Memory Allocation Routines 1452** 1453** An instance of this object defines the interface between SQLite 1454** and low-level memory allocation routines. 1455** 1456** This object is used in only one place in the SQLite interface. 1457** A pointer to an instance of this object is the argument to 1458** [sqlite3_config()] when the configuration option is 1459** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1460** By creating an instance of this object 1461** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1462** during configuration, an application can specify an alternative 1463** memory allocation subsystem for SQLite to use for all of its 1464** dynamic memory needs. 1465** 1466** Note that SQLite comes with several [built-in memory allocators] 1467** that are perfectly adequate for the overwhelming majority of applications 1468** and that this object is only useful to a tiny minority of applications 1469** with specialized memory allocation requirements. This object is 1470** also used during testing of SQLite in order to specify an alternative 1471** memory allocator that simulates memory out-of-memory conditions in 1472** order to verify that SQLite recovers gracefully from such 1473** conditions. 1474** 1475** The xMalloc, xRealloc, and xFree methods must work like the 1476** malloc(), realloc() and free() functions from the standard C library. 1477** ^SQLite guarantees that the second argument to 1478** xRealloc is always a value returned by a prior call to xRoundup. 1479** 1480** xSize should return the allocated size of a memory allocation 1481** previously obtained from xMalloc or xRealloc. The allocated size 1482** is always at least as big as the requested size but may be larger. 1483** 1484** The xRoundup method returns what would be the allocated size of 1485** a memory allocation given a particular requested size. Most memory 1486** allocators round up memory allocations at least to the next multiple 1487** of 8. Some allocators round up to a larger multiple or to a power of 2. 1488** Every memory allocation request coming in through [sqlite3_malloc()] 1489** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1490** that causes the corresponding memory allocation to fail. 1491** 1492** The xInit method initializes the memory allocator. For example, 1493** it might allocate any require mutexes or initialize internal data 1494** structures. The xShutdown method is invoked (indirectly) by 1495** [sqlite3_shutdown()] and should deallocate any resources acquired 1496** by xInit. The pAppData pointer is used as the only parameter to 1497** xInit and xShutdown. 1498** 1499** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1500** the xInit method, so the xInit method need not be threadsafe. The 1501** xShutdown method is only called from [sqlite3_shutdown()] so it does 1502** not need to be threadsafe either. For all other methods, SQLite 1503** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1504** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1505** it is by default) and so the methods are automatically serialized. 1506** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1507** methods must be threadsafe or else make their own arrangements for 1508** serialization. 1509** 1510** SQLite will never invoke xInit() more than once without an intervening 1511** call to xShutdown(). 1512*/ 1513typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1514struct sqlite3_mem_methods { 1515 void *(*xMalloc)(int); /* Memory allocation function */ 1516 void (*xFree)(void*); /* Free a prior allocation */ 1517 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1518 int (*xSize)(void*); /* Return the size of an allocation */ 1519 int (*xRoundup)(int); /* Round up request size to allocation size */ 1520 int (*xInit)(void*); /* Initialize the memory allocator */ 1521 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1522 void *pAppData; /* Argument to xInit() and xShutdown() */ 1523}; 1524 1525/* 1526** CAPI3REF: Configuration Options 1527** KEYWORDS: {configuration option} 1528** 1529** These constants are the available integer configuration options that 1530** can be passed as the first argument to the [sqlite3_config()] interface. 1531** 1532** New configuration options may be added in future releases of SQLite. 1533** Existing configuration options might be discontinued. Applications 1534** should check the return code from [sqlite3_config()] to make sure that 1535** the call worked. The [sqlite3_config()] interface will return a 1536** non-zero [error code] if a discontinued or unsupported configuration option 1537** is invoked. 1538** 1539** <dl> 1540** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1541** <dd>There are no arguments to this option. ^This option sets the 1542** [threading mode] to Single-thread. In other words, it disables 1543** all mutexing and puts SQLite into a mode where it can only be used 1544** by a single thread. ^If SQLite is compiled with 1545** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1546** it is not possible to change the [threading mode] from its default 1547** value of Single-thread and so [sqlite3_config()] will return 1548** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1549** configuration option.</dd> 1550** 1551** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1552** <dd>There are no arguments to this option. ^This option sets the 1553** [threading mode] to Multi-thread. In other words, it disables 1554** mutexing on [database connection] and [prepared statement] objects. 1555** The application is responsible for serializing access to 1556** [database connections] and [prepared statements]. But other mutexes 1557** are enabled so that SQLite will be safe to use in a multi-threaded 1558** environment as long as no two threads attempt to use the same 1559** [database connection] at the same time. ^If SQLite is compiled with 1560** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1561** it is not possible to set the Multi-thread [threading mode] and 1562** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1563** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1564** 1565** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1566** <dd>There are no arguments to this option. ^This option sets the 1567** [threading mode] to Serialized. In other words, this option enables 1568** all mutexes including the recursive 1569** mutexes on [database connection] and [prepared statement] objects. 1570** In this mode (which is the default when SQLite is compiled with 1571** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1572** to [database connections] and [prepared statements] so that the 1573** application is free to use the same [database connection] or the 1574** same [prepared statement] in different threads at the same time. 1575** ^If SQLite is compiled with 1576** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1577** it is not possible to set the Serialized [threading mode] and 1578** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1579** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1580** 1581** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1582** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1583** a pointer to an instance of the [sqlite3_mem_methods] structure. 1584** The argument specifies 1585** alternative low-level memory allocation routines to be used in place of 1586** the memory allocation routines built into SQLite.)^ ^SQLite makes 1587** its own private copy of the content of the [sqlite3_mem_methods] structure 1588** before the [sqlite3_config()] call returns.</dd> 1589** 1590** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1591** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1592** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1593** The [sqlite3_mem_methods] 1594** structure is filled with the currently defined memory allocation routines.)^ 1595** This option can be used to overload the default memory allocation 1596** routines with a wrapper that simulations memory allocation failure or 1597** tracks memory usage, for example. </dd> 1598** 1599** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1600** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1601** interpreted as a boolean, which enables or disables the collection of 1602** memory allocation statistics. ^(When memory allocation statistics are 1603** disabled, the following SQLite interfaces become non-operational: 1604** <ul> 1605** <li> [sqlite3_memory_used()] 1606** <li> [sqlite3_memory_highwater()] 1607** <li> [sqlite3_soft_heap_limit64()] 1608** <li> [sqlite3_status64()] 1609** </ul>)^ 1610** ^Memory allocation statistics are enabled by default unless SQLite is 1611** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1612** allocation statistics are disabled by default. 1613** </dd> 1614** 1615** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1616** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1617** that SQLite can use for scratch memory. ^(There are three arguments 1618** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1619** aligned memory buffer from which the scratch allocations will be 1620** drawn, the size of each scratch allocation (sz), 1621** and the maximum number of scratch allocations (N).)^ 1622** The first argument must be a pointer to an 8-byte aligned buffer 1623** of at least sz*N bytes of memory. 1624** ^SQLite will not use more than one scratch buffers per thread. 1625** ^SQLite will never request a scratch buffer that is more than 6 1626** times the database page size. 1627** ^If SQLite needs needs additional 1628** scratch memory beyond what is provided by this configuration option, then 1629** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1630** ^When the application provides any amount of scratch memory using 1631** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1632** [sqlite3_malloc|heap allocations]. 1633** This can help [Robson proof|prevent memory allocation failures] due to heap 1634** fragmentation in low-memory embedded systems. 1635** </dd> 1636** 1637** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1638** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1639** that SQLite can use for the database page cache with the default page 1640** cache implementation. 1641** This configuration option is a no-op if an application-define page 1642** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1643** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1644** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1645** and the number of cache lines (N). 1646** The sz argument should be the size of the largest database page 1647** (a power of two between 512 and 65536) plus some extra bytes for each 1648** page header. ^The number of extra bytes needed by the page header 1649** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1650** ^It is harmless, apart from the wasted memory, 1651** for the sz parameter to be larger than necessary. The pMem 1652** argument must be either a NULL pointer or a pointer to an 8-byte 1653** aligned block of memory of at least sz*N bytes, otherwise 1654** subsequent behavior is undefined. 1655** ^When pMem is not NULL, SQLite will strive to use the memory provided 1656** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1657** a page cache line is larger than sz bytes or if all of the pMem buffer 1658** is exhausted. 1659** ^If pMem is NULL and N is non-zero, then each database connection 1660** does an initial bulk allocation for page cache memory 1661** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1662** of -1024*N bytes if N is negative, . ^If additional 1663** page cache memory is needed beyond what is provided by the initial 1664** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1665** additional cache line. </dd> 1666** 1667** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1668** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1669** that SQLite will use for all of its dynamic memory allocation needs 1670** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1671** [SQLITE_CONFIG_PAGECACHE]. 1672** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1673** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1674** [SQLITE_ERROR] if invoked otherwise. 1675** ^There are three arguments to SQLITE_CONFIG_HEAP: 1676** An 8-byte aligned pointer to the memory, 1677** the number of bytes in the memory buffer, and the minimum allocation size. 1678** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1679** to using its default memory allocator (the system malloc() implementation), 1680** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1681** memory pointer is not NULL then the alternative memory 1682** allocator is engaged to handle all of SQLites memory allocation needs. 1683** The first pointer (the memory pointer) must be aligned to an 8-byte 1684** boundary or subsequent behavior of SQLite will be undefined. 1685** The minimum allocation size is capped at 2**12. Reasonable values 1686** for the minimum allocation size are 2**5 through 2**8.</dd> 1687** 1688** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1689** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1690** pointer to an instance of the [sqlite3_mutex_methods] structure. 1691** The argument specifies alternative low-level mutex routines to be used 1692** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1693** the content of the [sqlite3_mutex_methods] structure before the call to 1694** [sqlite3_config()] returns. ^If SQLite is compiled with 1695** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1696** the entire mutexing subsystem is omitted from the build and hence calls to 1697** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1698** return [SQLITE_ERROR].</dd> 1699** 1700** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1701** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1702** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1703** [sqlite3_mutex_methods] 1704** structure is filled with the currently defined mutex routines.)^ 1705** This option can be used to overload the default mutex allocation 1706** routines with a wrapper used to track mutex usage for performance 1707** profiling or testing, for example. ^If SQLite is compiled with 1708** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1709** the entire mutexing subsystem is omitted from the build and hence calls to 1710** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1711** return [SQLITE_ERROR].</dd> 1712** 1713** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1714** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1715** the default size of lookaside memory on each [database connection]. 1716** The first argument is the 1717** size of each lookaside buffer slot and the second is the number of 1718** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1719** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1720** option to [sqlite3_db_config()] can be used to change the lookaside 1721** configuration on individual connections.)^ </dd> 1722** 1723** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1724** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1725** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1726** the interface to a custom page cache implementation.)^ 1727** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1728** 1729** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1730** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1731** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1732** the current page cache implementation into that object.)^ </dd> 1733** 1734** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1735** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1736** global [error log]. 1737** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1738** function with a call signature of void(*)(void*,int,const char*), 1739** and a pointer to void. ^If the function pointer is not NULL, it is 1740** invoked by [sqlite3_log()] to process each logging event. ^If the 1741** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1742** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1743** passed through as the first parameter to the application-defined logger 1744** function whenever that function is invoked. ^The second parameter to 1745** the logger function is a copy of the first parameter to the corresponding 1746** [sqlite3_log()] call and is intended to be a [result code] or an 1747** [extended result code]. ^The third parameter passed to the logger is 1748** log message after formatting via [sqlite3_snprintf()]. 1749** The SQLite logging interface is not reentrant; the logger function 1750** supplied by the application must not invoke any SQLite interface. 1751** In a multi-threaded application, the application-defined logger 1752** function must be threadsafe. </dd> 1753** 1754** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1755** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1756** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1757** then URI handling is globally disabled.)^ ^If URI handling is globally 1758** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1759** [sqlite3_open16()] or 1760** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1761** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1762** connection is opened. ^If it is globally disabled, filenames are 1763** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1764** database connection is opened. ^(By default, URI handling is globally 1765** disabled. The default value may be changed by compiling with the 1766** [SQLITE_USE_URI] symbol defined.)^ 1767** 1768** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1769** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1770** argument which is interpreted as a boolean in order to enable or disable 1771** the use of covering indices for full table scans in the query optimizer. 1772** ^The default setting is determined 1773** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1774** if that compile-time option is omitted. 1775** The ability to disable the use of covering indices for full table scans 1776** is because some incorrectly coded legacy applications might malfunction 1777** when the optimization is enabled. Providing the ability to 1778** disable the optimization allows the older, buggy application code to work 1779** without change even with newer versions of SQLite. 1780** 1781** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1782** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1783** <dd> These options are obsolete and should not be used by new code. 1784** They are retained for backwards compatibility but are now no-ops. 1785** </dd> 1786** 1787** [[SQLITE_CONFIG_SQLLOG]] 1788** <dt>SQLITE_CONFIG_SQLLOG 1789** <dd>This option is only available if sqlite is compiled with the 1790** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1791** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1792** The second should be of type (void*). The callback is invoked by the library 1793** in three separate circumstances, identified by the value passed as the 1794** fourth parameter. If the fourth parameter is 0, then the database connection 1795** passed as the second argument has just been opened. The third argument 1796** points to a buffer containing the name of the main database file. If the 1797** fourth parameter is 1, then the SQL statement that the third parameter 1798** points to has just been executed. Or, if the fourth parameter is 2, then 1799** the connection being passed as the second parameter is being closed. The 1800** third parameter is passed NULL In this case. An example of using this 1801** configuration option can be seen in the "test_sqllog.c" source file in 1802** the canonical SQLite source tree.</dd> 1803** 1804** [[SQLITE_CONFIG_MMAP_SIZE]] 1805** <dt>SQLITE_CONFIG_MMAP_SIZE 1806** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1807** that are the default mmap size limit (the default setting for 1808** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1809** ^The default setting can be overridden by each database connection using 1810** either the [PRAGMA mmap_size] command, or by using the 1811** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1812** will be silently truncated if necessary so that it does not exceed the 1813** compile-time maximum mmap size set by the 1814** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1815** ^If either argument to this option is negative, then that argument is 1816** changed to its compile-time default. 1817** 1818** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1819** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1820** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1821** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1822** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1823** that specifies the maximum size of the created heap. 1824** 1825** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1826** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1827** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1828** is a pointer to an integer and writes into that integer the number of extra 1829** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1830** The amount of extra space required can change depending on the compiler, 1831** target platform, and SQLite version. 1832** 1833** [[SQLITE_CONFIG_PMASZ]] 1834** <dt>SQLITE_CONFIG_PMASZ 1835** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1836** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1837** sorter to that integer. The default minimum PMA Size is set by the 1838** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1839** to help with sort operations when multithreaded sorting 1840** is enabled (using the [PRAGMA threads] command) and the amount of content 1841** to be sorted exceeds the page size times the minimum of the 1842** [PRAGMA cache_size] setting and this value. 1843** 1844** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1845** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1846** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1847** becomes the [statement journal] spill-to-disk threshold. 1848** [Statement journals] are held in memory until their size (in bytes) 1849** exceeds this threshold, at which point they are written to disk. 1850** Or if the threshold is -1, statement journals are always held 1851** exclusively in memory. 1852** Since many statement journals never become large, setting the spill 1853** threshold to a value such as 64KiB can greatly reduce the amount of 1854** I/O required to support statement rollback. 1855** The default value for this setting is controlled by the 1856** [SQLITE_STMTJRNL_SPILL] compile-time option. 1857** </dl> 1858*/ 1859#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1860#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1861#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1862#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1863#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1864#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1865#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1866#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1867#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1868#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1869#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1870/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1871#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1872#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1873#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1874#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1875#define SQLITE_CONFIG_URI 17 /* int */ 1876#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1877#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1878#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1879#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1880#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1881#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1882#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1883#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1884#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1885 1886/* 1887** CAPI3REF: Database Connection Configuration Options 1888** 1889** These constants are the available integer configuration options that 1890** can be passed as the second argument to the [sqlite3_db_config()] interface. 1891** 1892** New configuration options may be added in future releases of SQLite. 1893** Existing configuration options might be discontinued. Applications 1894** should check the return code from [sqlite3_db_config()] to make sure that 1895** the call worked. ^The [sqlite3_db_config()] interface will return a 1896** non-zero [error code] if a discontinued or unsupported configuration option 1897** is invoked. 1898** 1899** <dl> 1900** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1901** <dd> ^This option takes three additional arguments that determine the 1902** [lookaside memory allocator] configuration for the [database connection]. 1903** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1904** pointer to a memory buffer to use for lookaside memory. 1905** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1906** may be NULL in which case SQLite will allocate the 1907** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1908** size of each lookaside buffer slot. ^The third argument is the number of 1909** slots. The size of the buffer in the first argument must be greater than 1910** or equal to the product of the second and third arguments. The buffer 1911** must be aligned to an 8-byte boundary. ^If the second argument to 1912** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1913** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1914** configuration for a database connection can only be changed when that 1915** connection is not currently using lookaside memory, or in other words 1916** when the "current value" returned by 1917** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1918** Any attempt to change the lookaside memory configuration when lookaside 1919** memory is in use leaves the configuration unchanged and returns 1920** [SQLITE_BUSY].)^</dd> 1921** 1922** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1923** <dd> ^This option is used to enable or disable the enforcement of 1924** [foreign key constraints]. There should be two additional arguments. 1925** The first argument is an integer which is 0 to disable FK enforcement, 1926** positive to enable FK enforcement or negative to leave FK enforcement 1927** unchanged. The second parameter is a pointer to an integer into which 1928** is written 0 or 1 to indicate whether FK enforcement is off or on 1929** following this call. The second parameter may be a NULL pointer, in 1930** which case the FK enforcement setting is not reported back. </dd> 1931** 1932** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1933** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1934** There should be two additional arguments. 1935** The first argument is an integer which is 0 to disable triggers, 1936** positive to enable triggers or negative to leave the setting unchanged. 1937** The second parameter is a pointer to an integer into which 1938** is written 0 or 1 to indicate whether triggers are disabled or enabled 1939** following this call. The second parameter may be a NULL pointer, in 1940** which case the trigger setting is not reported back. </dd> 1941** 1942** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1943** <dd> ^This option is used to enable or disable the two-argument 1944** version of the [fts3_tokenizer()] function which is part of the 1945** [FTS3] full-text search engine extension. 1946** There should be two additional arguments. 1947** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1948** positive to enable fts3_tokenizer() or negative to leave the setting 1949** unchanged. 1950** The second parameter is a pointer to an integer into which 1951** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1952** following this call. The second parameter may be a NULL pointer, in 1953** which case the new setting is not reported back. </dd> 1954** 1955** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1956** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1957** interface independently of the [load_extension()] SQL function. 1958** The [sqlite3_enable_load_extension()] API enables or disables both the 1959** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1960** There should be two additional arguments. 1961** When the first argument to this interface is 1, then only the C-API is 1962** enabled and the SQL function remains disabled. If the first argument to 1963** this interface is 0, then both the C-API and the SQL function are disabled. 1964** If the first argument is -1, then no changes are made to state of either the 1965** C-API or the SQL function. 1966** The second parameter is a pointer to an integer into which 1967** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1968** is disabled or enabled following this call. The second parameter may 1969** be a NULL pointer, in which case the new setting is not reported back. 1970** </dd> 1971** 1972** </dl> 1973*/ 1974#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1975#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1976#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1977#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1978#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 1979 1980 1981/* 1982** CAPI3REF: Enable Or Disable Extended Result Codes 1983** METHOD: sqlite3 1984** 1985** ^The sqlite3_extended_result_codes() routine enables or disables the 1986** [extended result codes] feature of SQLite. ^The extended result 1987** codes are disabled by default for historical compatibility. 1988*/ 1989SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1990 1991/* 1992** CAPI3REF: Last Insert Rowid 1993** METHOD: sqlite3 1994** 1995** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1996** has a unique 64-bit signed 1997** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1998** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1999** names are not also used by explicitly declared columns. ^If 2000** the table has a column of type [INTEGER PRIMARY KEY] then that column 2001** is another alias for the rowid. 2002** 2003** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2004** most recent successful [INSERT] into a rowid table or [virtual table] 2005** on database connection D. 2006** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2007** ^If no successful [INSERT]s into rowid tables 2008** have ever occurred on the database connection D, 2009** then sqlite3_last_insert_rowid(D) returns zero. 2010** 2011** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2012** method, then this routine will return the [rowid] of the inserted 2013** row as long as the trigger or virtual table method is running. 2014** But once the trigger or virtual table method ends, the value returned 2015** by this routine reverts to what it was before the trigger or virtual 2016** table method began.)^ 2017** 2018** ^An [INSERT] that fails due to a constraint violation is not a 2019** successful [INSERT] and does not change the value returned by this 2020** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2021** and INSERT OR ABORT make no changes to the return value of this 2022** routine when their insertion fails. ^(When INSERT OR REPLACE 2023** encounters a constraint violation, it does not fail. The 2024** INSERT continues to completion after deleting rows that caused 2025** the constraint problem so INSERT OR REPLACE will always change 2026** the return value of this interface.)^ 2027** 2028** ^For the purposes of this routine, an [INSERT] is considered to 2029** be successful even if it is subsequently rolled back. 2030** 2031** This function is accessible to SQL statements via the 2032** [last_insert_rowid() SQL function]. 2033** 2034** If a separate thread performs a new [INSERT] on the same 2035** database connection while the [sqlite3_last_insert_rowid()] 2036** function is running and thus changes the last insert [rowid], 2037** then the value returned by [sqlite3_last_insert_rowid()] is 2038** unpredictable and might not equal either the old or the new 2039** last insert [rowid]. 2040*/ 2041SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 2042 2043/* 2044** CAPI3REF: Count The Number Of Rows Modified 2045** METHOD: sqlite3 2046** 2047** ^This function returns the number of rows modified, inserted or 2048** deleted by the most recently completed INSERT, UPDATE or DELETE 2049** statement on the database connection specified by the only parameter. 2050** ^Executing any other type of SQL statement does not modify the value 2051** returned by this function. 2052** 2053** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2054** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2055** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2056** 2057** Changes to a view that are intercepted by 2058** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2059** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2060** DELETE statement run on a view is always zero. Only changes made to real 2061** tables are counted. 2062** 2063** Things are more complicated if the sqlite3_changes() function is 2064** executed while a trigger program is running. This may happen if the 2065** program uses the [changes() SQL function], or if some other callback 2066** function invokes sqlite3_changes() directly. Essentially: 2067** 2068** <ul> 2069** <li> ^(Before entering a trigger program the value returned by 2070** sqlite3_changes() function is saved. After the trigger program 2071** has finished, the original value is restored.)^ 2072** 2073** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2074** statement sets the value returned by sqlite3_changes() 2075** upon completion as normal. Of course, this value will not include 2076** any changes performed by sub-triggers, as the sqlite3_changes() 2077** value will be saved and restored after each sub-trigger has run.)^ 2078** </ul> 2079** 2080** ^This means that if the changes() SQL function (or similar) is used 2081** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2082** returns the value as set when the calling statement began executing. 2083** ^If it is used by the second or subsequent such statement within a trigger 2084** program, the value returned reflects the number of rows modified by the 2085** previous INSERT, UPDATE or DELETE statement within the same trigger. 2086** 2087** See also the [sqlite3_total_changes()] interface, the 2088** [count_changes pragma], and the [changes() SQL function]. 2089** 2090** If a separate thread makes changes on the same database connection 2091** while [sqlite3_changes()] is running then the value returned 2092** is unpredictable and not meaningful. 2093*/ 2094SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 2095 2096/* 2097** CAPI3REF: Total Number Of Rows Modified 2098** METHOD: sqlite3 2099** 2100** ^This function returns the total number of rows inserted, modified or 2101** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2102** since the database connection was opened, including those executed as 2103** part of trigger programs. ^Executing any other type of SQL statement 2104** does not affect the value returned by sqlite3_total_changes(). 2105** 2106** ^Changes made as part of [foreign key actions] are included in the 2107** count, but those made as part of REPLACE constraint resolution are 2108** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2109** are not counted. 2110** 2111** See also the [sqlite3_changes()] interface, the 2112** [count_changes pragma], and the [total_changes() SQL function]. 2113** 2114** If a separate thread makes changes on the same database connection 2115** while [sqlite3_total_changes()] is running then the value 2116** returned is unpredictable and not meaningful. 2117*/ 2118SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2119 2120/* 2121** CAPI3REF: Interrupt A Long-Running Query 2122** METHOD: sqlite3 2123** 2124** ^This function causes any pending database operation to abort and 2125** return at its earliest opportunity. This routine is typically 2126** called in response to a user action such as pressing "Cancel" 2127** or Ctrl-C where the user wants a long query operation to halt 2128** immediately. 2129** 2130** ^It is safe to call this routine from a thread different from the 2131** thread that is currently running the database operation. But it 2132** is not safe to call this routine with a [database connection] that 2133** is closed or might close before sqlite3_interrupt() returns. 2134** 2135** ^If an SQL operation is very nearly finished at the time when 2136** sqlite3_interrupt() is called, then it might not have an opportunity 2137** to be interrupted and might continue to completion. 2138** 2139** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2140** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2141** that is inside an explicit transaction, then the entire transaction 2142** will be rolled back automatically. 2143** 2144** ^The sqlite3_interrupt(D) call is in effect until all currently running 2145** SQL statements on [database connection] D complete. ^Any new SQL statements 2146** that are started after the sqlite3_interrupt() call and before the 2147** running statements reaches zero are interrupted as if they had been 2148** running prior to the sqlite3_interrupt() call. ^New SQL statements 2149** that are started after the running statement count reaches zero are 2150** not effected by the sqlite3_interrupt(). 2151** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2152** SQL statements is a no-op and has no effect on SQL statements 2153** that are started after the sqlite3_interrupt() call returns. 2154** 2155** If the database connection closes while [sqlite3_interrupt()] 2156** is running then bad things will likely happen. 2157*/ 2158SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2159 2160/* 2161** CAPI3REF: Determine If An SQL Statement Is Complete 2162** 2163** These routines are useful during command-line input to determine if the 2164** currently entered text seems to form a complete SQL statement or 2165** if additional input is needed before sending the text into 2166** SQLite for parsing. ^These routines return 1 if the input string 2167** appears to be a complete SQL statement. ^A statement is judged to be 2168** complete if it ends with a semicolon token and is not a prefix of a 2169** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2170** string literals or quoted identifier names or comments are not 2171** independent tokens (they are part of the token in which they are 2172** embedded) and thus do not count as a statement terminator. ^Whitespace 2173** and comments that follow the final semicolon are ignored. 2174** 2175** ^These routines return 0 if the statement is incomplete. ^If a 2176** memory allocation fails, then SQLITE_NOMEM is returned. 2177** 2178** ^These routines do not parse the SQL statements thus 2179** will not detect syntactically incorrect SQL. 2180** 2181** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2182** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2183** automatically by sqlite3_complete16(). If that initialization fails, 2184** then the return value from sqlite3_complete16() will be non-zero 2185** regardless of whether or not the input SQL is complete.)^ 2186** 2187** The input to [sqlite3_complete()] must be a zero-terminated 2188** UTF-8 string. 2189** 2190** The input to [sqlite3_complete16()] must be a zero-terminated 2191** UTF-16 string in native byte order. 2192*/ 2193SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2194SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2195 2196/* 2197** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2198** KEYWORDS: {busy-handler callback} {busy handler} 2199** METHOD: sqlite3 2200** 2201** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2202** that might be invoked with argument P whenever 2203** an attempt is made to access a database table associated with 2204** [database connection] D when another thread 2205** or process has the table locked. 2206** The sqlite3_busy_handler() interface is used to implement 2207** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2208** 2209** ^If the busy callback is NULL, then [SQLITE_BUSY] 2210** is returned immediately upon encountering the lock. ^If the busy callback 2211** is not NULL, then the callback might be invoked with two arguments. 2212** 2213** ^The first argument to the busy handler is a copy of the void* pointer which 2214** is the third argument to sqlite3_busy_handler(). ^The second argument to 2215** the busy handler callback is the number of times that the busy handler has 2216** been invoked previously for the same locking event. ^If the 2217** busy callback returns 0, then no additional attempts are made to 2218** access the database and [SQLITE_BUSY] is returned 2219** to the application. 2220** ^If the callback returns non-zero, then another attempt 2221** is made to access the database and the cycle repeats. 2222** 2223** The presence of a busy handler does not guarantee that it will be invoked 2224** when there is lock contention. ^If SQLite determines that invoking the busy 2225** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2226** to the application instead of invoking the 2227** busy handler. 2228** Consider a scenario where one process is holding a read lock that 2229** it is trying to promote to a reserved lock and 2230** a second process is holding a reserved lock that it is trying 2231** to promote to an exclusive lock. The first process cannot proceed 2232** because it is blocked by the second and the second process cannot 2233** proceed because it is blocked by the first. If both processes 2234** invoke the busy handlers, neither will make any progress. Therefore, 2235** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2236** will induce the first process to release its read lock and allow 2237** the second process to proceed. 2238** 2239** ^The default busy callback is NULL. 2240** 2241** ^(There can only be a single busy handler defined for each 2242** [database connection]. Setting a new busy handler clears any 2243** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2244** or evaluating [PRAGMA busy_timeout=N] will change the 2245** busy handler and thus clear any previously set busy handler. 2246** 2247** The busy callback should not take any actions which modify the 2248** database connection that invoked the busy handler. In other words, 2249** the busy handler is not reentrant. Any such actions 2250** result in undefined behavior. 2251** 2252** A busy handler must not close the database connection 2253** or [prepared statement] that invoked the busy handler. 2254*/ 2255SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2256 2257/* 2258** CAPI3REF: Set A Busy Timeout 2259** METHOD: sqlite3 2260** 2261** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2262** for a specified amount of time when a table is locked. ^The handler 2263** will sleep multiple times until at least "ms" milliseconds of sleeping 2264** have accumulated. ^After at least "ms" milliseconds of sleeping, 2265** the handler returns 0 which causes [sqlite3_step()] to return 2266** [SQLITE_BUSY]. 2267** 2268** ^Calling this routine with an argument less than or equal to zero 2269** turns off all busy handlers. 2270** 2271** ^(There can only be a single busy handler for a particular 2272** [database connection] at any given moment. If another busy handler 2273** was defined (using [sqlite3_busy_handler()]) prior to calling 2274** this routine, that other busy handler is cleared.)^ 2275** 2276** See also: [PRAGMA busy_timeout] 2277*/ 2278SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2279 2280/* 2281** CAPI3REF: Convenience Routines For Running Queries 2282** METHOD: sqlite3 2283** 2284** This is a legacy interface that is preserved for backwards compatibility. 2285** Use of this interface is not recommended. 2286** 2287** Definition: A <b>result table</b> is memory data structure created by the 2288** [sqlite3_get_table()] interface. A result table records the 2289** complete query results from one or more queries. 2290** 2291** The table conceptually has a number of rows and columns. But 2292** these numbers are not part of the result table itself. These 2293** numbers are obtained separately. Let N be the number of rows 2294** and M be the number of columns. 2295** 2296** A result table is an array of pointers to zero-terminated UTF-8 strings. 2297** There are (N+1)*M elements in the array. The first M pointers point 2298** to zero-terminated strings that contain the names of the columns. 2299** The remaining entries all point to query results. NULL values result 2300** in NULL pointers. All other values are in their UTF-8 zero-terminated 2301** string representation as returned by [sqlite3_column_text()]. 2302** 2303** A result table might consist of one or more memory allocations. 2304** It is not safe to pass a result table directly to [sqlite3_free()]. 2305** A result table should be deallocated using [sqlite3_free_table()]. 2306** 2307** ^(As an example of the result table format, suppose a query result 2308** is as follows: 2309** 2310** <blockquote><pre> 2311** Name | Age 2312** ----------------------- 2313** Alice | 43 2314** Bob | 28 2315** Cindy | 21 2316** </pre></blockquote> 2317** 2318** There are two column (M==2) and three rows (N==3). Thus the 2319** result table has 8 entries. Suppose the result table is stored 2320** in an array names azResult. Then azResult holds this content: 2321** 2322** <blockquote><pre> 2323** azResult[0] = "Name"; 2324** azResult[1] = "Age"; 2325** azResult[2] = "Alice"; 2326** azResult[3] = "43"; 2327** azResult[4] = "Bob"; 2328** azResult[5] = "28"; 2329** azResult[6] = "Cindy"; 2330** azResult[7] = "21"; 2331** </pre></blockquote>)^ 2332** 2333** ^The sqlite3_get_table() function evaluates one or more 2334** semicolon-separated SQL statements in the zero-terminated UTF-8 2335** string of its 2nd parameter and returns a result table to the 2336** pointer given in its 3rd parameter. 2337** 2338** After the application has finished with the result from sqlite3_get_table(), 2339** it must pass the result table pointer to sqlite3_free_table() in order to 2340** release the memory that was malloced. Because of the way the 2341** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2342** function must not try to call [sqlite3_free()] directly. Only 2343** [sqlite3_free_table()] is able to release the memory properly and safely. 2344** 2345** The sqlite3_get_table() interface is implemented as a wrapper around 2346** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2347** to any internal data structures of SQLite. It uses only the public 2348** interface defined here. As a consequence, errors that occur in the 2349** wrapper layer outside of the internal [sqlite3_exec()] call are not 2350** reflected in subsequent calls to [sqlite3_errcode()] or 2351** [sqlite3_errmsg()]. 2352*/ 2353SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2354 sqlite3 *db, /* An open database */ 2355 const char *zSql, /* SQL to be evaluated */ 2356 char ***pazResult, /* Results of the query */ 2357 int *pnRow, /* Number of result rows written here */ 2358 int *pnColumn, /* Number of result columns written here */ 2359 char **pzErrmsg /* Error msg written here */ 2360); 2361SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2362 2363/* 2364** CAPI3REF: Formatted String Printing Functions 2365** 2366** These routines are work-alikes of the "printf()" family of functions 2367** from the standard C library. 2368** These routines understand most of the common K&R formatting options, 2369** plus some additional non-standard formats, detailed below. 2370** Note that some of the more obscure formatting options from recent 2371** C-library standards are omitted from this implementation. 2372** 2373** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2374** results into memory obtained from [sqlite3_malloc()]. 2375** The strings returned by these two routines should be 2376** released by [sqlite3_free()]. ^Both routines return a 2377** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2378** memory to hold the resulting string. 2379** 2380** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2381** the standard C library. The result is written into the 2382** buffer supplied as the second parameter whose size is given by 2383** the first parameter. Note that the order of the 2384** first two parameters is reversed from snprintf().)^ This is an 2385** historical accident that cannot be fixed without breaking 2386** backwards compatibility. ^(Note also that sqlite3_snprintf() 2387** returns a pointer to its buffer instead of the number of 2388** characters actually written into the buffer.)^ We admit that 2389** the number of characters written would be a more useful return 2390** value but we cannot change the implementation of sqlite3_snprintf() 2391** now without breaking compatibility. 2392** 2393** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2394** guarantees that the buffer is always zero-terminated. ^The first 2395** parameter "n" is the total size of the buffer, including space for 2396** the zero terminator. So the longest string that can be completely 2397** written will be n-1 characters. 2398** 2399** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2400** 2401** These routines all implement some additional formatting 2402** options that are useful for constructing SQL statements. 2403** All of the usual printf() formatting options apply. In addition, there 2404** is are "%q", "%Q", "%w" and "%z" options. 2405** 2406** ^(The %q option works like %s in that it substitutes a nul-terminated 2407** string from the argument list. But %q also doubles every '\'' character. 2408** %q is designed for use inside a string literal.)^ By doubling each '\'' 2409** character it escapes that character and allows it to be inserted into 2410** the string. 2411** 2412** For example, assume the string variable zText contains text as follows: 2413** 2414** <blockquote><pre> 2415** char *zText = "It's a happy day!"; 2416** </pre></blockquote> 2417** 2418** One can use this text in an SQL statement as follows: 2419** 2420** <blockquote><pre> 2421** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2422** sqlite3_exec(db, zSQL, 0, 0, 0); 2423** sqlite3_free(zSQL); 2424** </pre></blockquote> 2425** 2426** Because the %q format string is used, the '\'' character in zText 2427** is escaped and the SQL generated is as follows: 2428** 2429** <blockquote><pre> 2430** INSERT INTO table1 VALUES('It''s a happy day!') 2431** </pre></blockquote> 2432** 2433** This is correct. Had we used %s instead of %q, the generated SQL 2434** would have looked like this: 2435** 2436** <blockquote><pre> 2437** INSERT INTO table1 VALUES('It's a happy day!'); 2438** </pre></blockquote> 2439** 2440** This second example is an SQL syntax error. As a general rule you should 2441** always use %q instead of %s when inserting text into a string literal. 2442** 2443** ^(The %Q option works like %q except it also adds single quotes around 2444** the outside of the total string. Additionally, if the parameter in the 2445** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2446** single quotes).)^ So, for example, one could say: 2447** 2448** <blockquote><pre> 2449** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2450** sqlite3_exec(db, zSQL, 0, 0, 0); 2451** sqlite3_free(zSQL); 2452** </pre></blockquote> 2453** 2454** The code above will render a correct SQL statement in the zSQL 2455** variable even if the zText variable is a NULL pointer. 2456** 2457** ^(The "%w" formatting option is like "%q" except that it expects to 2458** be contained within double-quotes instead of single quotes, and it 2459** escapes the double-quote character instead of the single-quote 2460** character.)^ The "%w" formatting option is intended for safely inserting 2461** table and column names into a constructed SQL statement. 2462** 2463** ^(The "%z" formatting option works like "%s" but with the 2464** addition that after the string has been read and copied into 2465** the result, [sqlite3_free()] is called on the input string.)^ 2466*/ 2467SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2468SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2469SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2470SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2471 2472/* 2473** CAPI3REF: Memory Allocation Subsystem 2474** 2475** The SQLite core uses these three routines for all of its own 2476** internal memory allocation needs. "Core" in the previous sentence 2477** does not include operating-system specific VFS implementation. The 2478** Windows VFS uses native malloc() and free() for some operations. 2479** 2480** ^The sqlite3_malloc() routine returns a pointer to a block 2481** of memory at least N bytes in length, where N is the parameter. 2482** ^If sqlite3_malloc() is unable to obtain sufficient free 2483** memory, it returns a NULL pointer. ^If the parameter N to 2484** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2485** a NULL pointer. 2486** 2487** ^The sqlite3_malloc64(N) routine works just like 2488** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2489** of a signed 32-bit integer. 2490** 2491** ^Calling sqlite3_free() with a pointer previously returned 2492** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2493** that it might be reused. ^The sqlite3_free() routine is 2494** a no-op if is called with a NULL pointer. Passing a NULL pointer 2495** to sqlite3_free() is harmless. After being freed, memory 2496** should neither be read nor written. Even reading previously freed 2497** memory might result in a segmentation fault or other severe error. 2498** Memory corruption, a segmentation fault, or other severe error 2499** might result if sqlite3_free() is called with a non-NULL pointer that 2500** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2501** 2502** ^The sqlite3_realloc(X,N) interface attempts to resize a 2503** prior memory allocation X to be at least N bytes. 2504** ^If the X parameter to sqlite3_realloc(X,N) 2505** is a NULL pointer then its behavior is identical to calling 2506** sqlite3_malloc(N). 2507** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2508** negative then the behavior is exactly the same as calling 2509** sqlite3_free(X). 2510** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2511** of at least N bytes in size or NULL if insufficient memory is available. 2512** ^If M is the size of the prior allocation, then min(N,M) bytes 2513** of the prior allocation are copied into the beginning of buffer returned 2514** by sqlite3_realloc(X,N) and the prior allocation is freed. 2515** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2516** prior allocation is not freed. 2517** 2518** ^The sqlite3_realloc64(X,N) interfaces works the same as 2519** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2520** of a 32-bit signed integer. 2521** 2522** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2523** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2524** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2525** ^The value returned by sqlite3_msize(X) might be larger than the number 2526** of bytes requested when X was allocated. ^If X is a NULL pointer then 2527** sqlite3_msize(X) returns zero. If X points to something that is not 2528** the beginning of memory allocation, or if it points to a formerly 2529** valid memory allocation that has now been freed, then the behavior 2530** of sqlite3_msize(X) is undefined and possibly harmful. 2531** 2532** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2533** sqlite3_malloc64(), and sqlite3_realloc64() 2534** is always aligned to at least an 8 byte boundary, or to a 2535** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2536** option is used. 2537** 2538** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2539** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2540** implementation of these routines to be omitted. That capability 2541** is no longer provided. Only built-in memory allocators can be used. 2542** 2543** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2544** the system malloc() and free() directly when converting 2545** filenames between the UTF-8 encoding used by SQLite 2546** and whatever filename encoding is used by the particular Windows 2547** installation. Memory allocation errors were detected, but 2548** they were reported back as [SQLITE_CANTOPEN] or 2549** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2550** 2551** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2552** must be either NULL or else pointers obtained from a prior 2553** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2554** not yet been released. 2555** 2556** The application must not read or write any part of 2557** a block of memory after it has been released using 2558** [sqlite3_free()] or [sqlite3_realloc()]. 2559*/ 2560SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2561SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2562SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2563SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2564SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2565SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2566 2567/* 2568** CAPI3REF: Memory Allocator Statistics 2569** 2570** SQLite provides these two interfaces for reporting on the status 2571** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2572** routines, which form the built-in memory allocation subsystem. 2573** 2574** ^The [sqlite3_memory_used()] routine returns the number of bytes 2575** of memory currently outstanding (malloced but not freed). 2576** ^The [sqlite3_memory_highwater()] routine returns the maximum 2577** value of [sqlite3_memory_used()] since the high-water mark 2578** was last reset. ^The values returned by [sqlite3_memory_used()] and 2579** [sqlite3_memory_highwater()] include any overhead 2580** added by SQLite in its implementation of [sqlite3_malloc()], 2581** but not overhead added by the any underlying system library 2582** routines that [sqlite3_malloc()] may call. 2583** 2584** ^The memory high-water mark is reset to the current value of 2585** [sqlite3_memory_used()] if and only if the parameter to 2586** [sqlite3_memory_highwater()] is true. ^The value returned 2587** by [sqlite3_memory_highwater(1)] is the high-water mark 2588** prior to the reset. 2589*/ 2590SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2591SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2592 2593/* 2594** CAPI3REF: Pseudo-Random Number Generator 2595** 2596** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2597** select random [ROWID | ROWIDs] when inserting new records into a table that 2598** already uses the largest possible [ROWID]. The PRNG is also used for 2599** the build-in random() and randomblob() SQL functions. This interface allows 2600** applications to access the same PRNG for other purposes. 2601** 2602** ^A call to this routine stores N bytes of randomness into buffer P. 2603** ^The P parameter can be a NULL pointer. 2604** 2605** ^If this routine has not been previously called or if the previous 2606** call had N less than one or a NULL pointer for P, then the PRNG is 2607** seeded using randomness obtained from the xRandomness method of 2608** the default [sqlite3_vfs] object. 2609** ^If the previous call to this routine had an N of 1 or more and a 2610** non-NULL P then the pseudo-randomness is generated 2611** internally and without recourse to the [sqlite3_vfs] xRandomness 2612** method. 2613*/ 2614SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2615 2616/* 2617** CAPI3REF: Compile-Time Authorization Callbacks 2618** METHOD: sqlite3 2619** 2620** ^This routine registers an authorizer callback with a particular 2621** [database connection], supplied in the first argument. 2622** ^The authorizer callback is invoked as SQL statements are being compiled 2623** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2624** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2625** points during the compilation process, as logic is being created 2626** to perform various actions, the authorizer callback is invoked to 2627** see if those actions are allowed. ^The authorizer callback should 2628** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2629** specific action but allow the SQL statement to continue to be 2630** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2631** rejected with an error. ^If the authorizer callback returns 2632** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2633** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2634** the authorizer will fail with an error message. 2635** 2636** When the callback returns [SQLITE_OK], that means the operation 2637** requested is ok. ^When the callback returns [SQLITE_DENY], the 2638** [sqlite3_prepare_v2()] or equivalent call that triggered the 2639** authorizer will fail with an error message explaining that 2640** access is denied. 2641** 2642** ^The first parameter to the authorizer callback is a copy of the third 2643** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2644** to the callback is an integer [SQLITE_COPY | action code] that specifies 2645** the particular action to be authorized. ^The third through sixth parameters 2646** to the callback are zero-terminated strings that contain additional 2647** details about the action to be authorized. 2648** 2649** ^If the action code is [SQLITE_READ] 2650** and the callback returns [SQLITE_IGNORE] then the 2651** [prepared statement] statement is constructed to substitute 2652** a NULL value in place of the table column that would have 2653** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2654** return can be used to deny an untrusted user access to individual 2655** columns of a table. 2656** ^If the action code is [SQLITE_DELETE] and the callback returns 2657** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2658** [truncate optimization] is disabled and all rows are deleted individually. 2659** 2660** An authorizer is used when [sqlite3_prepare | preparing] 2661** SQL statements from an untrusted source, to ensure that the SQL statements 2662** do not try to access data they are not allowed to see, or that they do not 2663** try to execute malicious statements that damage the database. For 2664** example, an application may allow a user to enter arbitrary 2665** SQL queries for evaluation by a database. But the application does 2666** not want the user to be able to make arbitrary changes to the 2667** database. An authorizer could then be put in place while the 2668** user-entered SQL is being [sqlite3_prepare | prepared] that 2669** disallows everything except [SELECT] statements. 2670** 2671** Applications that need to process SQL from untrusted sources 2672** might also consider lowering resource limits using [sqlite3_limit()] 2673** and limiting database size using the [max_page_count] [PRAGMA] 2674** in addition to using an authorizer. 2675** 2676** ^(Only a single authorizer can be in place on a database connection 2677** at a time. Each call to sqlite3_set_authorizer overrides the 2678** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2679** The authorizer is disabled by default. 2680** 2681** The authorizer callback must not do anything that will modify 2682** the database connection that invoked the authorizer callback. 2683** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2684** database connections for the meaning of "modify" in this paragraph. 2685** 2686** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2687** statement might be re-prepared during [sqlite3_step()] due to a 2688** schema change. Hence, the application should ensure that the 2689** correct authorizer callback remains in place during the [sqlite3_step()]. 2690** 2691** ^Note that the authorizer callback is invoked only during 2692** [sqlite3_prepare()] or its variants. Authorization is not 2693** performed during statement evaluation in [sqlite3_step()], unless 2694** as stated in the previous paragraph, sqlite3_step() invokes 2695** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2696*/ 2697SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2698 sqlite3*, 2699 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2700 void *pUserData 2701); 2702 2703/* 2704** CAPI3REF: Authorizer Return Codes 2705** 2706** The [sqlite3_set_authorizer | authorizer callback function] must 2707** return either [SQLITE_OK] or one of these two constants in order 2708** to signal SQLite whether or not the action is permitted. See the 2709** [sqlite3_set_authorizer | authorizer documentation] for additional 2710** information. 2711** 2712** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2713** returned from the [sqlite3_vtab_on_conflict()] interface. 2714*/ 2715#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2716#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2717 2718/* 2719** CAPI3REF: Authorizer Action Codes 2720** 2721** The [sqlite3_set_authorizer()] interface registers a callback function 2722** that is invoked to authorize certain SQL statement actions. The 2723** second parameter to the callback is an integer code that specifies 2724** what action is being authorized. These are the integer action codes that 2725** the authorizer callback may be passed. 2726** 2727** These action code values signify what kind of operation is to be 2728** authorized. The 3rd and 4th parameters to the authorization 2729** callback function will be parameters or NULL depending on which of these 2730** codes is used as the second parameter. ^(The 5th parameter to the 2731** authorizer callback is the name of the database ("main", "temp", 2732** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2733** is the name of the inner-most trigger or view that is responsible for 2734** the access attempt or NULL if this access attempt is directly from 2735** top-level SQL code. 2736*/ 2737/******************************************* 3rd ************ 4th ***********/ 2738#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2739#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2740#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2741#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2742#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2743#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2744#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2745#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2746#define SQLITE_DELETE 9 /* Table Name NULL */ 2747#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2748#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2749#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2750#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2751#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2752#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2753#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2754#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2755#define SQLITE_INSERT 18 /* Table Name NULL */ 2756#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2757#define SQLITE_READ 20 /* Table Name Column Name */ 2758#define SQLITE_SELECT 21 /* NULL NULL */ 2759#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2760#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2761#define SQLITE_ATTACH 24 /* Filename NULL */ 2762#define SQLITE_DETACH 25 /* Database Name NULL */ 2763#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2764#define SQLITE_REINDEX 27 /* Index Name NULL */ 2765#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2766#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2767#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2768#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2769#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2770#define SQLITE_COPY 0 /* No longer used */ 2771#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2772 2773/* 2774** CAPI3REF: Tracing And Profiling Functions 2775** METHOD: sqlite3 2776** 2777** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2778** instead of the routines described here. 2779** 2780** These routines register callback functions that can be used for 2781** tracing and profiling the execution of SQL statements. 2782** 2783** ^The callback function registered by sqlite3_trace() is invoked at 2784** various times when an SQL statement is being run by [sqlite3_step()]. 2785** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2786** SQL statement text as the statement first begins executing. 2787** ^(Additional sqlite3_trace() callbacks might occur 2788** as each triggered subprogram is entered. The callbacks for triggers 2789** contain a UTF-8 SQL comment that identifies the trigger.)^ 2790** 2791** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2792** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2793** 2794** ^The callback function registered by sqlite3_profile() is invoked 2795** as each SQL statement finishes. ^The profile callback contains 2796** the original statement text and an estimate of wall-clock time 2797** of how long that statement took to run. ^The profile callback 2798** time is in units of nanoseconds, however the current implementation 2799** is only capable of millisecond resolution so the six least significant 2800** digits in the time are meaningless. Future versions of SQLite 2801** might provide greater resolution on the profiler callback. The 2802** sqlite3_profile() function is considered experimental and is 2803** subject to change in future versions of SQLite. 2804*/ 2805SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_trace(sqlite3*, 2806 void(*xTrace)(void*,const char*), void*); 2807SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2808 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2809 2810/* 2811** CAPI3REF: SQL Trace Event Codes 2812** KEYWORDS: SQLITE_TRACE 2813** 2814** These constants identify classes of events that can be monitored 2815** using the [sqlite3_trace_v2()] tracing logic. The third argument 2816** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2817** the following constants. ^The first argument to the trace callback 2818** is one of the following constants. 2819** 2820** New tracing constants may be added in future releases. 2821** 2822** ^A trace callback has four arguments: xCallback(T,C,P,X). 2823** ^The T argument is one of the integer type codes above. 2824** ^The C argument is a copy of the context pointer passed in as the 2825** fourth argument to [sqlite3_trace_v2()]. 2826** The P and X arguments are pointers whose meanings depend on T. 2827** 2828** <dl> 2829** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2830** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2831** first begins running and possibly at other times during the 2832** execution of the prepared statement, such as at the start of each 2833** trigger subprogram. ^The P argument is a pointer to the 2834** [prepared statement]. ^The X argument is a pointer to a string which 2835** is the unexpanded SQL text of the prepared statement or an SQL comment 2836** that indicates the invocation of a trigger. ^The callback can compute 2837** the same text that would have been returned by the legacy [sqlite3_trace()] 2838** interface by using the X argument when X begins with "--" and invoking 2839** [sqlite3_expanded_sql(P)] otherwise. 2840** 2841** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2842** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2843** information as is provided by the [sqlite3_profile()] callback. 2844** ^The P argument is a pointer to the [prepared statement] and the 2845** X argument points to a 64-bit integer which is the estimated of 2846** the number of nanosecond that the prepared statement took to run. 2847** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2848** 2849** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2850** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2851** statement generates a single row of result. 2852** ^The P argument is a pointer to the [prepared statement] and the 2853** X argument is unused. 2854** 2855** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2856** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2857** connection closes. 2858** ^The P argument is a pointer to the [database connection] object 2859** and the X argument is unused. 2860** </dl> 2861*/ 2862#define SQLITE_TRACE_STMT 0x01 2863#define SQLITE_TRACE_PROFILE 0x02 2864#define SQLITE_TRACE_ROW 0x04 2865#define SQLITE_TRACE_CLOSE 0x08 2866 2867/* 2868** CAPI3REF: SQL Trace Hook 2869** METHOD: sqlite3 2870** 2871** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2872** function X against [database connection] D, using property mask M 2873** and context pointer P. ^If the X callback is 2874** NULL or if the M mask is zero, then tracing is disabled. The 2875** M argument should be the bitwise OR-ed combination of 2876** zero or more [SQLITE_TRACE] constants. 2877** 2878** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2879** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2880** 2881** ^The X callback is invoked whenever any of the events identified by 2882** mask M occur. ^The integer return value from the callback is currently 2883** ignored, though this may change in future releases. Callback 2884** implementations should return zero to ensure future compatibility. 2885** 2886** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2887** ^The T argument is one of the [SQLITE_TRACE] 2888** constants to indicate why the callback was invoked. 2889** ^The C argument is a copy of the context pointer. 2890** The P and X arguments are pointers whose meanings depend on T. 2891** 2892** The sqlite3_trace_v2() interface is intended to replace the legacy 2893** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2894** are deprecated. 2895*/ 2896SQLITE_API int SQLITE_STDCALL sqlite3_trace_v2( 2897 sqlite3*, 2898 unsigned uMask, 2899 int(*xCallback)(unsigned,void*,void*,void*), 2900 void *pCtx 2901); 2902 2903/* 2904** CAPI3REF: Query Progress Callbacks 2905** METHOD: sqlite3 2906** 2907** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2908** function X to be invoked periodically during long running calls to 2909** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2910** database connection D. An example use for this 2911** interface is to keep a GUI updated during a large query. 2912** 2913** ^The parameter P is passed through as the only parameter to the 2914** callback function X. ^The parameter N is the approximate number of 2915** [virtual machine instructions] that are evaluated between successive 2916** invocations of the callback X. ^If N is less than one then the progress 2917** handler is disabled. 2918** 2919** ^Only a single progress handler may be defined at one time per 2920** [database connection]; setting a new progress handler cancels the 2921** old one. ^Setting parameter X to NULL disables the progress handler. 2922** ^The progress handler is also disabled by setting N to a value less 2923** than 1. 2924** 2925** ^If the progress callback returns non-zero, the operation is 2926** interrupted. This feature can be used to implement a 2927** "Cancel" button on a GUI progress dialog box. 2928** 2929** The progress handler callback must not do anything that will modify 2930** the database connection that invoked the progress handler. 2931** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2932** database connections for the meaning of "modify" in this paragraph. 2933** 2934*/ 2935SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2936 2937/* 2938** CAPI3REF: Opening A New Database Connection 2939** CONSTRUCTOR: sqlite3 2940** 2941** ^These routines open an SQLite database file as specified by the 2942** filename argument. ^The filename argument is interpreted as UTF-8 for 2943** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2944** order for sqlite3_open16(). ^(A [database connection] handle is usually 2945** returned in *ppDb, even if an error occurs. The only exception is that 2946** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2947** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2948** object.)^ ^(If the database is opened (and/or created) successfully, then 2949** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2950** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2951** an English language description of the error following a failure of any 2952** of the sqlite3_open() routines. 2953** 2954** ^The default encoding will be UTF-8 for databases created using 2955** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2956** created using sqlite3_open16() will be UTF-16 in the native byte order. 2957** 2958** Whether or not an error occurs when it is opened, resources 2959** associated with the [database connection] handle should be released by 2960** passing it to [sqlite3_close()] when it is no longer required. 2961** 2962** The sqlite3_open_v2() interface works like sqlite3_open() 2963** except that it accepts two additional parameters for additional control 2964** over the new database connection. ^(The flags parameter to 2965** sqlite3_open_v2() can take one of 2966** the following three values, optionally combined with the 2967** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2968** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2969** 2970** <dl> 2971** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2972** <dd>The database is opened in read-only mode. If the database does not 2973** already exist, an error is returned.</dd>)^ 2974** 2975** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2976** <dd>The database is opened for reading and writing if possible, or reading 2977** only if the file is write protected by the operating system. In either 2978** case the database must already exist, otherwise an error is returned.</dd>)^ 2979** 2980** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2981** <dd>The database is opened for reading and writing, and is created if 2982** it does not already exist. This is the behavior that is always used for 2983** sqlite3_open() and sqlite3_open16().</dd>)^ 2984** </dl> 2985** 2986** If the 3rd parameter to sqlite3_open_v2() is not one of the 2987** combinations shown above optionally combined with other 2988** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2989** then the behavior is undefined. 2990** 2991** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2992** opens in the multi-thread [threading mode] as long as the single-thread 2993** mode has not been set at compile-time or start-time. ^If the 2994** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2995** in the serialized [threading mode] unless single-thread was 2996** previously selected at compile-time or start-time. 2997** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2998** eligible to use [shared cache mode], regardless of whether or not shared 2999** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3000** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3001** participate in [shared cache mode] even if it is enabled. 3002** 3003** ^The fourth parameter to sqlite3_open_v2() is the name of the 3004** [sqlite3_vfs] object that defines the operating system interface that 3005** the new database connection should use. ^If the fourth parameter is 3006** a NULL pointer then the default [sqlite3_vfs] object is used. 3007** 3008** ^If the filename is ":memory:", then a private, temporary in-memory database 3009** is created for the connection. ^This in-memory database will vanish when 3010** the database connection is closed. Future versions of SQLite might 3011** make use of additional special filenames that begin with the ":" character. 3012** It is recommended that when a database filename actually does begin with 3013** a ":" character you should prefix the filename with a pathname such as 3014** "./" to avoid ambiguity. 3015** 3016** ^If the filename is an empty string, then a private, temporary 3017** on-disk database will be created. ^This private database will be 3018** automatically deleted as soon as the database connection is closed. 3019** 3020** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3021** 3022** ^If [URI filename] interpretation is enabled, and the filename argument 3023** begins with "file:", then the filename is interpreted as a URI. ^URI 3024** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3025** set in the fourth argument to sqlite3_open_v2(), or if it has 3026** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3027** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3028** As of SQLite version 3.7.7, URI filename interpretation is turned off 3029** by default, but future releases of SQLite might enable URI filename 3030** interpretation by default. See "[URI filenames]" for additional 3031** information. 3032** 3033** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3034** authority, then it must be either an empty string or the string 3035** "localhost". ^If the authority is not an empty string or "localhost", an 3036** error is returned to the caller. ^The fragment component of a URI, if 3037** present, is ignored. 3038** 3039** ^SQLite uses the path component of the URI as the name of the disk file 3040** which contains the database. ^If the path begins with a '/' character, 3041** then it is interpreted as an absolute path. ^If the path does not begin 3042** with a '/' (meaning that the authority section is omitted from the URI) 3043** then the path is interpreted as a relative path. 3044** ^(On windows, the first component of an absolute path 3045** is a drive specification (e.g. "C:").)^ 3046** 3047** [[core URI query parameters]] 3048** The query component of a URI may contain parameters that are interpreted 3049** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3050** SQLite and its built-in [VFSes] interpret the 3051** following query parameters: 3052** 3053** <ul> 3054** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3055** a VFS object that provides the operating system interface that should 3056** be used to access the database file on disk. ^If this option is set to 3057** an empty string the default VFS object is used. ^Specifying an unknown 3058** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3059** present, then the VFS specified by the option takes precedence over 3060** the value passed as the fourth parameter to sqlite3_open_v2(). 3061** 3062** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3063** "rwc", or "memory". Attempting to set it to any other value is 3064** an error)^. 3065** ^If "ro" is specified, then the database is opened for read-only 3066** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3067** third argument to sqlite3_open_v2(). ^If the mode option is set to 3068** "rw", then the database is opened for read-write (but not create) 3069** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3070** been set. ^Value "rwc" is equivalent to setting both 3071** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3072** set to "memory" then a pure [in-memory database] that never reads 3073** or writes from disk is used. ^It is an error to specify a value for 3074** the mode parameter that is less restrictive than that specified by 3075** the flags passed in the third parameter to sqlite3_open_v2(). 3076** 3077** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3078** "private". ^Setting it to "shared" is equivalent to setting the 3079** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3080** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3081** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3082** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3083** a URI filename, its value overrides any behavior requested by setting 3084** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3085** 3086** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3087** [powersafe overwrite] property does or does not apply to the 3088** storage media on which the database file resides. 3089** 3090** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3091** which if set disables file locking in rollback journal modes. This 3092** is useful for accessing a database on a filesystem that does not 3093** support locking. Caution: Database corruption might result if two 3094** or more processes write to the same database and any one of those 3095** processes uses nolock=1. 3096** 3097** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3098** parameter that indicates that the database file is stored on 3099** read-only media. ^When immutable is set, SQLite assumes that the 3100** database file cannot be changed, even by a process with higher 3101** privilege, and so the database is opened read-only and all locking 3102** and change detection is disabled. Caution: Setting the immutable 3103** property on a database file that does in fact change can result 3104** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3105** See also: [SQLITE_IOCAP_IMMUTABLE]. 3106** 3107** </ul> 3108** 3109** ^Specifying an unknown parameter in the query component of a URI is not an 3110** error. Future versions of SQLite might understand additional query 3111** parameters. See "[query parameters with special meaning to SQLite]" for 3112** additional information. 3113** 3114** [[URI filename examples]] <h3>URI filename examples</h3> 3115** 3116** <table border="1" align=center cellpadding=5> 3117** <tr><th> URI filenames <th> Results 3118** <tr><td> file:data.db <td> 3119** Open the file "data.db" in the current directory. 3120** <tr><td> file:/home/fred/data.db<br> 3121** file:///home/fred/data.db <br> 3122** file://localhost/home/fred/data.db <br> <td> 3123** Open the database file "/home/fred/data.db". 3124** <tr><td> file://darkstar/home/fred/data.db <td> 3125** An error. "darkstar" is not a recognized authority. 3126** <tr><td style="white-space:nowrap"> 3127** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3128** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3129** C:. Note that the %20 escaping in this example is not strictly 3130** necessary - space characters can be used literally 3131** in URI filenames. 3132** <tr><td> file:data.db?mode=ro&cache=private <td> 3133** Open file "data.db" in the current directory for read-only access. 3134** Regardless of whether or not shared-cache mode is enabled by 3135** default, use a private cache. 3136** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3137** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3138** that uses dot-files in place of posix advisory locking. 3139** <tr><td> file:data.db?mode=readonly <td> 3140** An error. "readonly" is not a valid option for the "mode" parameter. 3141** </table> 3142** 3143** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3144** query components of a URI. A hexadecimal escape sequence consists of a 3145** percent sign - "%" - followed by exactly two hexadecimal digits 3146** specifying an octet value. ^Before the path or query components of a 3147** URI filename are interpreted, they are encoded using UTF-8 and all 3148** hexadecimal escape sequences replaced by a single byte containing the 3149** corresponding octet. If this process generates an invalid UTF-8 encoding, 3150** the results are undefined. 3151** 3152** <b>Note to Windows users:</b> The encoding used for the filename argument 3153** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3154** codepage is currently defined. Filenames containing international 3155** characters must be converted to UTF-8 prior to passing them into 3156** sqlite3_open() or sqlite3_open_v2(). 3157** 3158** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3159** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3160** features that require the use of temporary files may fail. 3161** 3162** See also: [sqlite3_temp_directory] 3163*/ 3164SQLITE_API int SQLITE_STDCALL sqlite3_open( 3165 const char *filename, /* Database filename (UTF-8) */ 3166 sqlite3 **ppDb /* OUT: SQLite db handle */ 3167); 3168SQLITE_API int SQLITE_STDCALL sqlite3_open16( 3169 const void *filename, /* Database filename (UTF-16) */ 3170 sqlite3 **ppDb /* OUT: SQLite db handle */ 3171); 3172SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 3173 const char *filename, /* Database filename (UTF-8) */ 3174 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3175 int flags, /* Flags */ 3176 const char *zVfs /* Name of VFS module to use */ 3177); 3178 3179/* 3180** CAPI3REF: Obtain Values For URI Parameters 3181** 3182** These are utility routines, useful to VFS implementations, that check 3183** to see if a database file was a URI that contained a specific query 3184** parameter, and if so obtains the value of that query parameter. 3185** 3186** If F is the database filename pointer passed into the xOpen() method of 3187** a VFS implementation when the flags parameter to xOpen() has one or 3188** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3189** P is the name of the query parameter, then 3190** sqlite3_uri_parameter(F,P) returns the value of the P 3191** parameter if it exists or a NULL pointer if P does not appear as a 3192** query parameter on F. If P is a query parameter of F 3193** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3194** a pointer to an empty string. 3195** 3196** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3197** parameter and returns true (1) or false (0) according to the value 3198** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3199** value of query parameter P is one of "yes", "true", or "on" in any 3200** case or if the value begins with a non-zero number. The 3201** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3202** query parameter P is one of "no", "false", or "off" in any case or 3203** if the value begins with a numeric zero. If P is not a query 3204** parameter on F or if the value of P is does not match any of the 3205** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3206** 3207** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3208** 64-bit signed integer and returns that integer, or D if P does not 3209** exist. If the value of P is something other than an integer, then 3210** zero is returned. 3211** 3212** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3213** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3214** is not a database file pathname pointer that SQLite passed into the xOpen 3215** VFS method, then the behavior of this routine is undefined and probably 3216** undesirable. 3217*/ 3218SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3219SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3220SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3221 3222 3223/* 3224** CAPI3REF: Error Codes And Messages 3225** METHOD: sqlite3 3226** 3227** ^If the most recent sqlite3_* API call associated with 3228** [database connection] D failed, then the sqlite3_errcode(D) interface 3229** returns the numeric [result code] or [extended result code] for that 3230** API call. 3231** If the most recent API call was successful, 3232** then the return value from sqlite3_errcode() is undefined. 3233** ^The sqlite3_extended_errcode() 3234** interface is the same except that it always returns the 3235** [extended result code] even when extended result codes are 3236** disabled. 3237** 3238** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3239** text that describes the error, as either UTF-8 or UTF-16 respectively. 3240** ^(Memory to hold the error message string is managed internally. 3241** The application does not need to worry about freeing the result. 3242** However, the error string might be overwritten or deallocated by 3243** subsequent calls to other SQLite interface functions.)^ 3244** 3245** ^The sqlite3_errstr() interface returns the English-language text 3246** that describes the [result code], as UTF-8. 3247** ^(Memory to hold the error message string is managed internally 3248** and must not be freed by the application)^. 3249** 3250** When the serialized [threading mode] is in use, it might be the 3251** case that a second error occurs on a separate thread in between 3252** the time of the first error and the call to these interfaces. 3253** When that happens, the second error will be reported since these 3254** interfaces always report the most recent result. To avoid 3255** this, each thread can obtain exclusive use of the [database connection] D 3256** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3257** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3258** all calls to the interfaces listed here are completed. 3259** 3260** If an interface fails with SQLITE_MISUSE, that means the interface 3261** was invoked incorrectly by the application. In that case, the 3262** error code and message may or may not be set. 3263*/ 3264SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3265SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3266SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3267SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3268SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3269 3270/* 3271** CAPI3REF: Prepared Statement Object 3272** KEYWORDS: {prepared statement} {prepared statements} 3273** 3274** An instance of this object represents a single SQL statement that 3275** has been compiled into binary form and is ready to be evaluated. 3276** 3277** Think of each SQL statement as a separate computer program. The 3278** original SQL text is source code. A prepared statement object 3279** is the compiled object code. All SQL must be converted into a 3280** prepared statement before it can be run. 3281** 3282** The life-cycle of a prepared statement object usually goes like this: 3283** 3284** <ol> 3285** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3286** <li> Bind values to [parameters] using the sqlite3_bind_*() 3287** interfaces. 3288** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3289** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3290** to step 2. Do this zero or more times. 3291** <li> Destroy the object using [sqlite3_finalize()]. 3292** </ol> 3293*/ 3294typedef struct sqlite3_stmt sqlite3_stmt; 3295 3296/* 3297** CAPI3REF: Run-time Limits 3298** METHOD: sqlite3 3299** 3300** ^(This interface allows the size of various constructs to be limited 3301** on a connection by connection basis. The first parameter is the 3302** [database connection] whose limit is to be set or queried. The 3303** second parameter is one of the [limit categories] that define a 3304** class of constructs to be size limited. The third parameter is the 3305** new limit for that construct.)^ 3306** 3307** ^If the new limit is a negative number, the limit is unchanged. 3308** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3309** [limits | hard upper bound] 3310** set at compile-time by a C preprocessor macro called 3311** [limits | SQLITE_MAX_<i>NAME</i>]. 3312** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3313** ^Attempts to increase a limit above its hard upper bound are 3314** silently truncated to the hard upper bound. 3315** 3316** ^Regardless of whether or not the limit was changed, the 3317** [sqlite3_limit()] interface returns the prior value of the limit. 3318** ^Hence, to find the current value of a limit without changing it, 3319** simply invoke this interface with the third parameter set to -1. 3320** 3321** Run-time limits are intended for use in applications that manage 3322** both their own internal database and also databases that are controlled 3323** by untrusted external sources. An example application might be a 3324** web browser that has its own databases for storing history and 3325** separate databases controlled by JavaScript applications downloaded 3326** off the Internet. The internal databases can be given the 3327** large, default limits. Databases managed by external sources can 3328** be given much smaller limits designed to prevent a denial of service 3329** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3330** interface to further control untrusted SQL. The size of the database 3331** created by an untrusted script can be contained using the 3332** [max_page_count] [PRAGMA]. 3333** 3334** New run-time limit categories may be added in future releases. 3335*/ 3336SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3337 3338/* 3339** CAPI3REF: Run-Time Limit Categories 3340** KEYWORDS: {limit category} {*limit categories} 3341** 3342** These constants define various performance limits 3343** that can be lowered at run-time using [sqlite3_limit()]. 3344** The synopsis of the meanings of the various limits is shown below. 3345** Additional information is available at [limits | Limits in SQLite]. 3346** 3347** <dl> 3348** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3349** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3350** 3351** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3352** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3353** 3354** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3355** <dd>The maximum number of columns in a table definition or in the 3356** result set of a [SELECT] or the maximum number of columns in an index 3357** or in an ORDER BY or GROUP BY clause.</dd>)^ 3358** 3359** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3360** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3361** 3362** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3363** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3364** 3365** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3366** <dd>The maximum number of instructions in a virtual machine program 3367** used to implement an SQL statement. This limit is not currently 3368** enforced, though that might be added in some future release of 3369** SQLite.</dd>)^ 3370** 3371** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3372** <dd>The maximum number of arguments on a function.</dd>)^ 3373** 3374** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3375** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3376** 3377** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3378** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3379** <dd>The maximum length of the pattern argument to the [LIKE] or 3380** [GLOB] operators.</dd>)^ 3381** 3382** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3383** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3384** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3385** 3386** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3387** <dd>The maximum depth of recursion for triggers.</dd>)^ 3388** 3389** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3390** <dd>The maximum number of auxiliary worker threads that a single 3391** [prepared statement] may start.</dd>)^ 3392** </dl> 3393*/ 3394#define SQLITE_LIMIT_LENGTH 0 3395#define SQLITE_LIMIT_SQL_LENGTH 1 3396#define SQLITE_LIMIT_COLUMN 2 3397#define SQLITE_LIMIT_EXPR_DEPTH 3 3398#define SQLITE_LIMIT_COMPOUND_SELECT 4 3399#define SQLITE_LIMIT_VDBE_OP 5 3400#define SQLITE_LIMIT_FUNCTION_ARG 6 3401#define SQLITE_LIMIT_ATTACHED 7 3402#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3403#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3404#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3405#define SQLITE_LIMIT_WORKER_THREADS 11 3406 3407/* 3408** CAPI3REF: Compiling An SQL Statement 3409** KEYWORDS: {SQL statement compiler} 3410** METHOD: sqlite3 3411** CONSTRUCTOR: sqlite3_stmt 3412** 3413** To execute an SQL query, it must first be compiled into a byte-code 3414** program using one of these routines. 3415** 3416** The first argument, "db", is a [database connection] obtained from a 3417** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3418** [sqlite3_open16()]. The database connection must not have been closed. 3419** 3420** The second argument, "zSql", is the statement to be compiled, encoded 3421** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3422** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3423** use UTF-16. 3424** 3425** ^If the nByte argument is negative, then zSql is read up to the 3426** first zero terminator. ^If nByte is positive, then it is the 3427** number of bytes read from zSql. ^If nByte is zero, then no prepared 3428** statement is generated. 3429** If the caller knows that the supplied string is nul-terminated, then 3430** there is a small performance advantage to passing an nByte parameter that 3431** is the number of bytes in the input string <i>including</i> 3432** the nul-terminator. 3433** 3434** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3435** past the end of the first SQL statement in zSql. These routines only 3436** compile the first statement in zSql, so *pzTail is left pointing to 3437** what remains uncompiled. 3438** 3439** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3440** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3441** to NULL. ^If the input text contains no SQL (if the input is an empty 3442** string or a comment) then *ppStmt is set to NULL. 3443** The calling procedure is responsible for deleting the compiled 3444** SQL statement using [sqlite3_finalize()] after it has finished with it. 3445** ppStmt may not be NULL. 3446** 3447** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3448** otherwise an [error code] is returned. 3449** 3450** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3451** recommended for all new programs. The two older interfaces are retained 3452** for backwards compatibility, but their use is discouraged. 3453** ^In the "v2" interfaces, the prepared statement 3454** that is returned (the [sqlite3_stmt] object) contains a copy of the 3455** original SQL text. This causes the [sqlite3_step()] interface to 3456** behave differently in three ways: 3457** 3458** <ol> 3459** <li> 3460** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3461** always used to do, [sqlite3_step()] will automatically recompile the SQL 3462** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3463** retries will occur before sqlite3_step() gives up and returns an error. 3464** </li> 3465** 3466** <li> 3467** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3468** [error codes] or [extended error codes]. ^The legacy behavior was that 3469** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3470** and the application would have to make a second call to [sqlite3_reset()] 3471** in order to find the underlying cause of the problem. With the "v2" prepare 3472** interfaces, the underlying reason for the error is returned immediately. 3473** </li> 3474** 3475** <li> 3476** ^If the specific value bound to [parameter | host parameter] in the 3477** WHERE clause might influence the choice of query plan for a statement, 3478** then the statement will be automatically recompiled, as if there had been 3479** a schema change, on the first [sqlite3_step()] call following any change 3480** to the [sqlite3_bind_text | bindings] of that [parameter]. 3481** ^The specific value of WHERE-clause [parameter] might influence the 3482** choice of query plan if the parameter is the left-hand side of a [LIKE] 3483** or [GLOB] operator or if the parameter is compared to an indexed column 3484** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3485** </li> 3486** </ol> 3487*/ 3488SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3489 sqlite3 *db, /* Database handle */ 3490 const char *zSql, /* SQL statement, UTF-8 encoded */ 3491 int nByte, /* Maximum length of zSql in bytes. */ 3492 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3493 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3494); 3495SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3496 sqlite3 *db, /* Database handle */ 3497 const char *zSql, /* SQL statement, UTF-8 encoded */ 3498 int nByte, /* Maximum length of zSql in bytes. */ 3499 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3500 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3501); 3502SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3503 sqlite3 *db, /* Database handle */ 3504 const void *zSql, /* SQL statement, UTF-16 encoded */ 3505 int nByte, /* Maximum length of zSql in bytes. */ 3506 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3507 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3508); 3509SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3510 sqlite3 *db, /* Database handle */ 3511 const void *zSql, /* SQL statement, UTF-16 encoded */ 3512 int nByte, /* Maximum length of zSql in bytes. */ 3513 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3514 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3515); 3516 3517/* 3518** CAPI3REF: Retrieving Statement SQL 3519** METHOD: sqlite3_stmt 3520** 3521** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3522** SQL text used to create [prepared statement] P if P was 3523** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3524** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3525** string containing the SQL text of prepared statement P with 3526** [bound parameters] expanded. 3527** 3528** ^(For example, if a prepared statement is created using the SQL 3529** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3530** and parameter :xyz is unbound, then sqlite3_sql() will return 3531** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3532** will return "SELECT 2345,NULL".)^ 3533** 3534** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3535** is available to hold the result, or if the result would exceed the 3536** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3537** 3538** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3539** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3540** option causes sqlite3_expanded_sql() to always return NULL. 3541** 3542** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3543** automatically freed when the prepared statement is finalized. 3544** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3545** is obtained from [sqlite3_malloc()] and must be free by the application 3546** by passing it to [sqlite3_free()]. 3547*/ 3548SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3549SQLITE_API char *SQLITE_STDCALL sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3550 3551/* 3552** CAPI3REF: Determine If An SQL Statement Writes The Database 3553** METHOD: sqlite3_stmt 3554** 3555** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3556** and only if the [prepared statement] X makes no direct changes to 3557** the content of the database file. 3558** 3559** Note that [application-defined SQL functions] or 3560** [virtual tables] might change the database indirectly as a side effect. 3561** ^(For example, if an application defines a function "eval()" that 3562** calls [sqlite3_exec()], then the following SQL statement would 3563** change the database file through side-effects: 3564** 3565** <blockquote><pre> 3566** SELECT eval('DELETE FROM t1') FROM t2; 3567** </pre></blockquote> 3568** 3569** But because the [SELECT] statement does not change the database file 3570** directly, sqlite3_stmt_readonly() would still return true.)^ 3571** 3572** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3573** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3574** since the statements themselves do not actually modify the database but 3575** rather they control the timing of when other statements modify the 3576** database. ^The [ATTACH] and [DETACH] statements also cause 3577** sqlite3_stmt_readonly() to return true since, while those statements 3578** change the configuration of a database connection, they do not make 3579** changes to the content of the database files on disk. 3580*/ 3581SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3582 3583/* 3584** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3585** METHOD: sqlite3_stmt 3586** 3587** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3588** [prepared statement] S has been stepped at least once using 3589** [sqlite3_step(S)] but has neither run to completion (returned 3590** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3591** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3592** interface returns false if S is a NULL pointer. If S is not a 3593** NULL pointer and is not a pointer to a valid [prepared statement] 3594** object, then the behavior is undefined and probably undesirable. 3595** 3596** This interface can be used in combination [sqlite3_next_stmt()] 3597** to locate all prepared statements associated with a database 3598** connection that are in need of being reset. This can be used, 3599** for example, in diagnostic routines to search for prepared 3600** statements that are holding a transaction open. 3601*/ 3602SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3603 3604/* 3605** CAPI3REF: Dynamically Typed Value Object 3606** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3607** 3608** SQLite uses the sqlite3_value object to represent all values 3609** that can be stored in a database table. SQLite uses dynamic typing 3610** for the values it stores. ^Values stored in sqlite3_value objects 3611** can be integers, floating point values, strings, BLOBs, or NULL. 3612** 3613** An sqlite3_value object may be either "protected" or "unprotected". 3614** Some interfaces require a protected sqlite3_value. Other interfaces 3615** will accept either a protected or an unprotected sqlite3_value. 3616** Every interface that accepts sqlite3_value arguments specifies 3617** whether or not it requires a protected sqlite3_value. The 3618** [sqlite3_value_dup()] interface can be used to construct a new 3619** protected sqlite3_value from an unprotected sqlite3_value. 3620** 3621** The terms "protected" and "unprotected" refer to whether or not 3622** a mutex is held. An internal mutex is held for a protected 3623** sqlite3_value object but no mutex is held for an unprotected 3624** sqlite3_value object. If SQLite is compiled to be single-threaded 3625** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3626** or if SQLite is run in one of reduced mutex modes 3627** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3628** then there is no distinction between protected and unprotected 3629** sqlite3_value objects and they can be used interchangeably. However, 3630** for maximum code portability it is recommended that applications 3631** still make the distinction between protected and unprotected 3632** sqlite3_value objects even when not strictly required. 3633** 3634** ^The sqlite3_value objects that are passed as parameters into the 3635** implementation of [application-defined SQL functions] are protected. 3636** ^The sqlite3_value object returned by 3637** [sqlite3_column_value()] is unprotected. 3638** Unprotected sqlite3_value objects may only be used with 3639** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3640** The [sqlite3_value_blob | sqlite3_value_type()] family of 3641** interfaces require protected sqlite3_value objects. 3642*/ 3643typedef struct Mem sqlite3_value; 3644 3645/* 3646** CAPI3REF: SQL Function Context Object 3647** 3648** The context in which an SQL function executes is stored in an 3649** sqlite3_context object. ^A pointer to an sqlite3_context object 3650** is always first parameter to [application-defined SQL functions]. 3651** The application-defined SQL function implementation will pass this 3652** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3653** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3654** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3655** and/or [sqlite3_set_auxdata()]. 3656*/ 3657typedef struct sqlite3_context sqlite3_context; 3658 3659/* 3660** CAPI3REF: Binding Values To Prepared Statements 3661** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3662** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3663** METHOD: sqlite3_stmt 3664** 3665** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3666** literals may be replaced by a [parameter] that matches one of following 3667** templates: 3668** 3669** <ul> 3670** <li> ? 3671** <li> ?NNN 3672** <li> :VVV 3673** <li> @VVV 3674** <li> $VVV 3675** </ul> 3676** 3677** In the templates above, NNN represents an integer literal, 3678** and VVV represents an alphanumeric identifier.)^ ^The values of these 3679** parameters (also called "host parameter names" or "SQL parameters") 3680** can be set using the sqlite3_bind_*() routines defined here. 3681** 3682** ^The first argument to the sqlite3_bind_*() routines is always 3683** a pointer to the [sqlite3_stmt] object returned from 3684** [sqlite3_prepare_v2()] or its variants. 3685** 3686** ^The second argument is the index of the SQL parameter to be set. 3687** ^The leftmost SQL parameter has an index of 1. ^When the same named 3688** SQL parameter is used more than once, second and subsequent 3689** occurrences have the same index as the first occurrence. 3690** ^The index for named parameters can be looked up using the 3691** [sqlite3_bind_parameter_index()] API if desired. ^The index 3692** for "?NNN" parameters is the value of NNN. 3693** ^The NNN value must be between 1 and the [sqlite3_limit()] 3694** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3695** 3696** ^The third argument is the value to bind to the parameter. 3697** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3698** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3699** is ignored and the end result is the same as sqlite3_bind_null(). 3700** 3701** ^(In those routines that have a fourth argument, its value is the 3702** number of bytes in the parameter. To be clear: the value is the 3703** number of <u>bytes</u> in the value, not the number of characters.)^ 3704** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3705** is negative, then the length of the string is 3706** the number of bytes up to the first zero terminator. 3707** If the fourth parameter to sqlite3_bind_blob() is negative, then 3708** the behavior is undefined. 3709** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3710** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3711** that parameter must be the byte offset 3712** where the NUL terminator would occur assuming the string were NUL 3713** terminated. If any NUL characters occur at byte offsets less than 3714** the value of the fourth parameter then the resulting string value will 3715** contain embedded NULs. The result of expressions involving strings 3716** with embedded NULs is undefined. 3717** 3718** ^The fifth argument to the BLOB and string binding interfaces 3719** is a destructor used to dispose of the BLOB or 3720** string after SQLite has finished with it. ^The destructor is called 3721** to dispose of the BLOB or string even if the call to bind API fails. 3722** ^If the fifth argument is 3723** the special value [SQLITE_STATIC], then SQLite assumes that the 3724** information is in static, unmanaged space and does not need to be freed. 3725** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3726** SQLite makes its own private copy of the data immediately, before 3727** the sqlite3_bind_*() routine returns. 3728** 3729** ^The sixth argument to sqlite3_bind_text64() must be one of 3730** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3731** to specify the encoding of the text in the third parameter. If 3732** the sixth argument to sqlite3_bind_text64() is not one of the 3733** allowed values shown above, or if the text encoding is different 3734** from the encoding specified by the sixth parameter, then the behavior 3735** is undefined. 3736** 3737** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3738** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3739** (just an integer to hold its size) while it is being processed. 3740** Zeroblobs are intended to serve as placeholders for BLOBs whose 3741** content is later written using 3742** [sqlite3_blob_open | incremental BLOB I/O] routines. 3743** ^A negative value for the zeroblob results in a zero-length BLOB. 3744** 3745** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3746** for the [prepared statement] or with a prepared statement for which 3747** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3748** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3749** routine is passed a [prepared statement] that has been finalized, the 3750** result is undefined and probably harmful. 3751** 3752** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3753** ^Unbound parameters are interpreted as NULL. 3754** 3755** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3756** [error code] if anything goes wrong. 3757** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3758** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3759** [SQLITE_MAX_LENGTH]. 3760** ^[SQLITE_RANGE] is returned if the parameter 3761** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3762** 3763** See also: [sqlite3_bind_parameter_count()], 3764** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3765*/ 3766SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3767SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3768 void(*)(void*)); 3769SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3770SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3771SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3772SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3773SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3774SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3775SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3776 void(*)(void*), unsigned char encoding); 3777SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3778SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3779SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3780 3781/* 3782** CAPI3REF: Number Of SQL Parameters 3783** METHOD: sqlite3_stmt 3784** 3785** ^This routine can be used to find the number of [SQL parameters] 3786** in a [prepared statement]. SQL parameters are tokens of the 3787** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3788** placeholders for values that are [sqlite3_bind_blob | bound] 3789** to the parameters at a later time. 3790** 3791** ^(This routine actually returns the index of the largest (rightmost) 3792** parameter. For all forms except ?NNN, this will correspond to the 3793** number of unique parameters. If parameters of the ?NNN form are used, 3794** there may be gaps in the list.)^ 3795** 3796** See also: [sqlite3_bind_blob|sqlite3_bind()], 3797** [sqlite3_bind_parameter_name()], and 3798** [sqlite3_bind_parameter_index()]. 3799*/ 3800SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3801 3802/* 3803** CAPI3REF: Name Of A Host Parameter 3804** METHOD: sqlite3_stmt 3805** 3806** ^The sqlite3_bind_parameter_name(P,N) interface returns 3807** the name of the N-th [SQL parameter] in the [prepared statement] P. 3808** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3809** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3810** respectively. 3811** In other words, the initial ":" or "$" or "@" or "?" 3812** is included as part of the name.)^ 3813** ^Parameters of the form "?" without a following integer have no name 3814** and are referred to as "nameless" or "anonymous parameters". 3815** 3816** ^The first host parameter has an index of 1, not 0. 3817** 3818** ^If the value N is out of range or if the N-th parameter is 3819** nameless, then NULL is returned. ^The returned string is 3820** always in UTF-8 encoding even if the named parameter was 3821** originally specified as UTF-16 in [sqlite3_prepare16()] or 3822** [sqlite3_prepare16_v2()]. 3823** 3824** See also: [sqlite3_bind_blob|sqlite3_bind()], 3825** [sqlite3_bind_parameter_count()], and 3826** [sqlite3_bind_parameter_index()]. 3827*/ 3828SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3829 3830/* 3831** CAPI3REF: Index Of A Parameter With A Given Name 3832** METHOD: sqlite3_stmt 3833** 3834** ^Return the index of an SQL parameter given its name. ^The 3835** index value returned is suitable for use as the second 3836** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3837** is returned if no matching parameter is found. ^The parameter 3838** name must be given in UTF-8 even if the original statement 3839** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3840** 3841** See also: [sqlite3_bind_blob|sqlite3_bind()], 3842** [sqlite3_bind_parameter_count()], and 3843** [sqlite3_bind_parameter_name()]. 3844*/ 3845SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3846 3847/* 3848** CAPI3REF: Reset All Bindings On A Prepared Statement 3849** METHOD: sqlite3_stmt 3850** 3851** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3852** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3853** ^Use this routine to reset all host parameters to NULL. 3854*/ 3855SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3856 3857/* 3858** CAPI3REF: Number Of Columns In A Result Set 3859** METHOD: sqlite3_stmt 3860** 3861** ^Return the number of columns in the result set returned by the 3862** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3863** statement that does not return data (for example an [UPDATE]). 3864** 3865** See also: [sqlite3_data_count()] 3866*/ 3867SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3868 3869/* 3870** CAPI3REF: Column Names In A Result Set 3871** METHOD: sqlite3_stmt 3872** 3873** ^These routines return the name assigned to a particular column 3874** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3875** interface returns a pointer to a zero-terminated UTF-8 string 3876** and sqlite3_column_name16() returns a pointer to a zero-terminated 3877** UTF-16 string. ^The first parameter is the [prepared statement] 3878** that implements the [SELECT] statement. ^The second parameter is the 3879** column number. ^The leftmost column is number 0. 3880** 3881** ^The returned string pointer is valid until either the [prepared statement] 3882** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3883** reprepared by the first call to [sqlite3_step()] for a particular run 3884** or until the next call to 3885** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3886** 3887** ^If sqlite3_malloc() fails during the processing of either routine 3888** (for example during a conversion from UTF-8 to UTF-16) then a 3889** NULL pointer is returned. 3890** 3891** ^The name of a result column is the value of the "AS" clause for 3892** that column, if there is an AS clause. If there is no AS clause 3893** then the name of the column is unspecified and may change from 3894** one release of SQLite to the next. 3895*/ 3896SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3897SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3898 3899/* 3900** CAPI3REF: Source Of Data In A Query Result 3901** METHOD: sqlite3_stmt 3902** 3903** ^These routines provide a means to determine the database, table, and 3904** table column that is the origin of a particular result column in 3905** [SELECT] statement. 3906** ^The name of the database or table or column can be returned as 3907** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3908** the database name, the _table_ routines return the table name, and 3909** the origin_ routines return the column name. 3910** ^The returned string is valid until the [prepared statement] is destroyed 3911** using [sqlite3_finalize()] or until the statement is automatically 3912** reprepared by the first call to [sqlite3_step()] for a particular run 3913** or until the same information is requested 3914** again in a different encoding. 3915** 3916** ^The names returned are the original un-aliased names of the 3917** database, table, and column. 3918** 3919** ^The first argument to these interfaces is a [prepared statement]. 3920** ^These functions return information about the Nth result column returned by 3921** the statement, where N is the second function argument. 3922** ^The left-most column is column 0 for these routines. 3923** 3924** ^If the Nth column returned by the statement is an expression or 3925** subquery and is not a column value, then all of these functions return 3926** NULL. ^These routine might also return NULL if a memory allocation error 3927** occurs. ^Otherwise, they return the name of the attached database, table, 3928** or column that query result column was extracted from. 3929** 3930** ^As with all other SQLite APIs, those whose names end with "16" return 3931** UTF-16 encoded strings and the other functions return UTF-8. 3932** 3933** ^These APIs are only available if the library was compiled with the 3934** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3935** 3936** If two or more threads call one or more of these routines against the same 3937** prepared statement and column at the same time then the results are 3938** undefined. 3939** 3940** If two or more threads call one or more 3941** [sqlite3_column_database_name | column metadata interfaces] 3942** for the same [prepared statement] and result column 3943** at the same time then the results are undefined. 3944*/ 3945SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3946SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3947SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3948SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3949SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3950SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3951 3952/* 3953** CAPI3REF: Declared Datatype Of A Query Result 3954** METHOD: sqlite3_stmt 3955** 3956** ^(The first parameter is a [prepared statement]. 3957** If this statement is a [SELECT] statement and the Nth column of the 3958** returned result set of that [SELECT] is a table column (not an 3959** expression or subquery) then the declared type of the table 3960** column is returned.)^ ^If the Nth column of the result set is an 3961** expression or subquery, then a NULL pointer is returned. 3962** ^The returned string is always UTF-8 encoded. 3963** 3964** ^(For example, given the database schema: 3965** 3966** CREATE TABLE t1(c1 VARIANT); 3967** 3968** and the following statement to be compiled: 3969** 3970** SELECT c1 + 1, c1 FROM t1; 3971** 3972** this routine would return the string "VARIANT" for the second result 3973** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3974** 3975** ^SQLite uses dynamic run-time typing. ^So just because a column 3976** is declared to contain a particular type does not mean that the 3977** data stored in that column is of the declared type. SQLite is 3978** strongly typed, but the typing is dynamic not static. ^Type 3979** is associated with individual values, not with the containers 3980** used to hold those values. 3981*/ 3982SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3983SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3984 3985/* 3986** CAPI3REF: Evaluate An SQL Statement 3987** METHOD: sqlite3_stmt 3988** 3989** After a [prepared statement] has been prepared using either 3990** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3991** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3992** must be called one or more times to evaluate the statement. 3993** 3994** The details of the behavior of the sqlite3_step() interface depend 3995** on whether the statement was prepared using the newer "v2" interface 3996** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3997** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3998** new "v2" interface is recommended for new applications but the legacy 3999** interface will continue to be supported. 4000** 4001** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4002** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4003** ^With the "v2" interface, any of the other [result codes] or 4004** [extended result codes] might be returned as well. 4005** 4006** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4007** database locks it needs to do its job. ^If the statement is a [COMMIT] 4008** or occurs outside of an explicit transaction, then you can retry the 4009** statement. If the statement is not a [COMMIT] and occurs within an 4010** explicit transaction then you should rollback the transaction before 4011** continuing. 4012** 4013** ^[SQLITE_DONE] means that the statement has finished executing 4014** successfully. sqlite3_step() should not be called again on this virtual 4015** machine without first calling [sqlite3_reset()] to reset the virtual 4016** machine back to its initial state. 4017** 4018** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4019** is returned each time a new row of data is ready for processing by the 4020** caller. The values may be accessed using the [column access functions]. 4021** sqlite3_step() is called again to retrieve the next row of data. 4022** 4023** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4024** violation) has occurred. sqlite3_step() should not be called again on 4025** the VM. More information may be found by calling [sqlite3_errmsg()]. 4026** ^With the legacy interface, a more specific error code (for example, 4027** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4028** can be obtained by calling [sqlite3_reset()] on the 4029** [prepared statement]. ^In the "v2" interface, 4030** the more specific error code is returned directly by sqlite3_step(). 4031** 4032** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4033** Perhaps it was called on a [prepared statement] that has 4034** already been [sqlite3_finalize | finalized] or on one that had 4035** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4036** be the case that the same database connection is being used by two or 4037** more threads at the same moment in time. 4038** 4039** For all versions of SQLite up to and including 3.6.23.1, a call to 4040** [sqlite3_reset()] was required after sqlite3_step() returned anything 4041** other than [SQLITE_ROW] before any subsequent invocation of 4042** sqlite3_step(). Failure to reset the prepared statement using 4043** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4044** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 4045** calling [sqlite3_reset()] automatically in this circumstance rather 4046** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4047** break because any application that ever receives an SQLITE_MISUSE error 4048** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4049** can be used to restore the legacy behavior. 4050** 4051** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4052** API always returns a generic error code, [SQLITE_ERROR], following any 4053** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4054** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4055** specific [error codes] that better describes the error. 4056** We admit that this is a goofy design. The problem has been fixed 4057** with the "v2" interface. If you prepare all of your SQL statements 4058** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4059** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4060** then the more specific [error codes] are returned directly 4061** by sqlite3_step(). The use of the "v2" interface is recommended. 4062*/ 4063SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 4064 4065/* 4066** CAPI3REF: Number of columns in a result set 4067** METHOD: sqlite3_stmt 4068** 4069** ^The sqlite3_data_count(P) interface returns the number of columns in the 4070** current row of the result set of [prepared statement] P. 4071** ^If prepared statement P does not have results ready to return 4072** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4073** interfaces) then sqlite3_data_count(P) returns 0. 4074** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4075** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4076** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4077** will return non-zero if previous call to [sqlite3_step](P) returned 4078** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4079** where it always returns zero since each step of that multi-step 4080** pragma returns 0 columns of data. 4081** 4082** See also: [sqlite3_column_count()] 4083*/ 4084SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 4085 4086/* 4087** CAPI3REF: Fundamental Datatypes 4088** KEYWORDS: SQLITE_TEXT 4089** 4090** ^(Every value in SQLite has one of five fundamental datatypes: 4091** 4092** <ul> 4093** <li> 64-bit signed integer 4094** <li> 64-bit IEEE floating point number 4095** <li> string 4096** <li> BLOB 4097** <li> NULL 4098** </ul>)^ 4099** 4100** These constants are codes for each of those types. 4101** 4102** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4103** for a completely different meaning. Software that links against both 4104** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4105** SQLITE_TEXT. 4106*/ 4107#define SQLITE_INTEGER 1 4108#define SQLITE_FLOAT 2 4109#define SQLITE_BLOB 4 4110#define SQLITE_NULL 5 4111#ifdef SQLITE_TEXT 4112# undef SQLITE_TEXT 4113#else 4114# define SQLITE_TEXT 3 4115#endif 4116#define SQLITE3_TEXT 3 4117 4118/* 4119** CAPI3REF: Result Values From A Query 4120** KEYWORDS: {column access functions} 4121** METHOD: sqlite3_stmt 4122** 4123** ^These routines return information about a single column of the current 4124** result row of a query. ^In every case the first argument is a pointer 4125** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4126** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4127** and the second argument is the index of the column for which information 4128** should be returned. ^The leftmost column of the result set has the index 0. 4129** ^The number of columns in the result can be determined using 4130** [sqlite3_column_count()]. 4131** 4132** If the SQL statement does not currently point to a valid row, or if the 4133** column index is out of range, the result is undefined. 4134** These routines may only be called when the most recent call to 4135** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4136** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4137** If any of these routines are called after [sqlite3_reset()] or 4138** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4139** something other than [SQLITE_ROW], the results are undefined. 4140** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4141** are called from a different thread while any of these routines 4142** are pending, then the results are undefined. 4143** 4144** ^The sqlite3_column_type() routine returns the 4145** [SQLITE_INTEGER | datatype code] for the initial data type 4146** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4147** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4148** returned by sqlite3_column_type() is only meaningful if no type 4149** conversions have occurred as described below. After a type conversion, 4150** the value returned by sqlite3_column_type() is undefined. Future 4151** versions of SQLite may change the behavior of sqlite3_column_type() 4152** following a type conversion. 4153** 4154** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4155** routine returns the number of bytes in that BLOB or string. 4156** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4157** the string to UTF-8 and then returns the number of bytes. 4158** ^If the result is a numeric value then sqlite3_column_bytes() uses 4159** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4160** the number of bytes in that string. 4161** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4162** 4163** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4164** routine returns the number of bytes in that BLOB or string. 4165** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4166** the string to UTF-16 and then returns the number of bytes. 4167** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4168** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4169** the number of bytes in that string. 4170** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4171** 4172** ^The values returned by [sqlite3_column_bytes()] and 4173** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4174** of the string. ^For clarity: the values returned by 4175** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4176** bytes in the string, not the number of characters. 4177** 4178** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4179** even empty strings, are always zero-terminated. ^The return 4180** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4181** 4182** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4183** [unprotected sqlite3_value] object. In a multithreaded environment, 4184** an unprotected sqlite3_value object may only be used safely with 4185** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4186** If the [unprotected sqlite3_value] object returned by 4187** [sqlite3_column_value()] is used in any other way, including calls 4188** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4189** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4190** 4191** These routines attempt to convert the value where appropriate. ^For 4192** example, if the internal representation is FLOAT and a text result 4193** is requested, [sqlite3_snprintf()] is used internally to perform the 4194** conversion automatically. ^(The following table details the conversions 4195** that are applied: 4196** 4197** <blockquote> 4198** <table border="1"> 4199** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4200** 4201** <tr><td> NULL <td> INTEGER <td> Result is 0 4202** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4203** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4204** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4205** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4206** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4207** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4208** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4209** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4210** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4211** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4212** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4213** <tr><td> TEXT <td> BLOB <td> No change 4214** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4215** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4216** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4217** </table> 4218** </blockquote>)^ 4219** 4220** Note that when type conversions occur, pointers returned by prior 4221** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4222** sqlite3_column_text16() may be invalidated. 4223** Type conversions and pointer invalidations might occur 4224** in the following cases: 4225** 4226** <ul> 4227** <li> The initial content is a BLOB and sqlite3_column_text() or 4228** sqlite3_column_text16() is called. A zero-terminator might 4229** need to be added to the string.</li> 4230** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4231** sqlite3_column_text16() is called. The content must be converted 4232** to UTF-16.</li> 4233** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4234** sqlite3_column_text() is called. The content must be converted 4235** to UTF-8.</li> 4236** </ul> 4237** 4238** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4239** not invalidate a prior pointer, though of course the content of the buffer 4240** that the prior pointer references will have been modified. Other kinds 4241** of conversion are done in place when it is possible, but sometimes they 4242** are not possible and in those cases prior pointers are invalidated. 4243** 4244** The safest policy is to invoke these routines 4245** in one of the following ways: 4246** 4247** <ul> 4248** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4249** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4250** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4251** </ul> 4252** 4253** In other words, you should call sqlite3_column_text(), 4254** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4255** into the desired format, then invoke sqlite3_column_bytes() or 4256** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4257** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4258** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4259** with calls to sqlite3_column_bytes(). 4260** 4261** ^The pointers returned are valid until a type conversion occurs as 4262** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4263** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4264** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4265** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4266** [sqlite3_free()]. 4267** 4268** ^(If a memory allocation error occurs during the evaluation of any 4269** of these routines, a default value is returned. The default value 4270** is either the integer 0, the floating point number 0.0, or a NULL 4271** pointer. Subsequent calls to [sqlite3_errcode()] will return 4272** [SQLITE_NOMEM].)^ 4273*/ 4274SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4275SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4276SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4277SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4278SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4279SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4280SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4281SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4282SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4283SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4284 4285/* 4286** CAPI3REF: Destroy A Prepared Statement Object 4287** DESTRUCTOR: sqlite3_stmt 4288** 4289** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4290** ^If the most recent evaluation of the statement encountered no errors 4291** or if the statement is never been evaluated, then sqlite3_finalize() returns 4292** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4293** sqlite3_finalize(S) returns the appropriate [error code] or 4294** [extended error code]. 4295** 4296** ^The sqlite3_finalize(S) routine can be called at any point during 4297** the life cycle of [prepared statement] S: 4298** before statement S is ever evaluated, after 4299** one or more calls to [sqlite3_reset()], or after any call 4300** to [sqlite3_step()] regardless of whether or not the statement has 4301** completed execution. 4302** 4303** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4304** 4305** The application must finalize every [prepared statement] in order to avoid 4306** resource leaks. It is a grievous error for the application to try to use 4307** a prepared statement after it has been finalized. Any use of a prepared 4308** statement after it has been finalized can result in undefined and 4309** undesirable behavior such as segfaults and heap corruption. 4310*/ 4311SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4312 4313/* 4314** CAPI3REF: Reset A Prepared Statement Object 4315** METHOD: sqlite3_stmt 4316** 4317** The sqlite3_reset() function is called to reset a [prepared statement] 4318** object back to its initial state, ready to be re-executed. 4319** ^Any SQL statement variables that had values bound to them using 4320** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4321** Use [sqlite3_clear_bindings()] to reset the bindings. 4322** 4323** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4324** back to the beginning of its program. 4325** 4326** ^If the most recent call to [sqlite3_step(S)] for the 4327** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4328** or if [sqlite3_step(S)] has never before been called on S, 4329** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4330** 4331** ^If the most recent call to [sqlite3_step(S)] for the 4332** [prepared statement] S indicated an error, then 4333** [sqlite3_reset(S)] returns an appropriate [error code]. 4334** 4335** ^The [sqlite3_reset(S)] interface does not change the values 4336** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4337*/ 4338SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4339 4340/* 4341** CAPI3REF: Create Or Redefine SQL Functions 4342** KEYWORDS: {function creation routines} 4343** KEYWORDS: {application-defined SQL function} 4344** KEYWORDS: {application-defined SQL functions} 4345** METHOD: sqlite3 4346** 4347** ^These functions (collectively known as "function creation routines") 4348** are used to add SQL functions or aggregates or to redefine the behavior 4349** of existing SQL functions or aggregates. The only differences between 4350** these routines are the text encoding expected for 4351** the second parameter (the name of the function being created) 4352** and the presence or absence of a destructor callback for 4353** the application data pointer. 4354** 4355** ^The first parameter is the [database connection] to which the SQL 4356** function is to be added. ^If an application uses more than one database 4357** connection then application-defined SQL functions must be added 4358** to each database connection separately. 4359** 4360** ^The second parameter is the name of the SQL function to be created or 4361** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4362** representation, exclusive of the zero-terminator. ^Note that the name 4363** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4364** ^Any attempt to create a function with a longer name 4365** will result in [SQLITE_MISUSE] being returned. 4366** 4367** ^The third parameter (nArg) 4368** is the number of arguments that the SQL function or 4369** aggregate takes. ^If this parameter is -1, then the SQL function or 4370** aggregate may take any number of arguments between 0 and the limit 4371** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4372** parameter is less than -1 or greater than 127 then the behavior is 4373** undefined. 4374** 4375** ^The fourth parameter, eTextRep, specifies what 4376** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4377** its parameters. The application should set this parameter to 4378** [SQLITE_UTF16LE] if the function implementation invokes 4379** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4380** implementation invokes [sqlite3_value_text16be()] on an input, or 4381** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4382** otherwise. ^The same SQL function may be registered multiple times using 4383** different preferred text encodings, with different implementations for 4384** each encoding. 4385** ^When multiple implementations of the same function are available, SQLite 4386** will pick the one that involves the least amount of data conversion. 4387** 4388** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4389** to signal that the function will always return the same result given 4390** the same inputs within a single SQL statement. Most SQL functions are 4391** deterministic. The built-in [random()] SQL function is an example of a 4392** function that is not deterministic. The SQLite query planner is able to 4393** perform additional optimizations on deterministic functions, so use 4394** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4395** 4396** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4397** function can gain access to this pointer using [sqlite3_user_data()].)^ 4398** 4399** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4400** pointers to C-language functions that implement the SQL function or 4401** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4402** callback only; NULL pointers must be passed as the xStep and xFinal 4403** parameters. ^An aggregate SQL function requires an implementation of xStep 4404** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4405** SQL function or aggregate, pass NULL pointers for all three function 4406** callbacks. 4407** 4408** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4409** then it is destructor for the application data pointer. 4410** The destructor is invoked when the function is deleted, either by being 4411** overloaded or when the database connection closes.)^ 4412** ^The destructor is also invoked if the call to 4413** sqlite3_create_function_v2() fails. 4414** ^When the destructor callback of the tenth parameter is invoked, it 4415** is passed a single argument which is a copy of the application data 4416** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4417** 4418** ^It is permitted to register multiple implementations of the same 4419** functions with the same name but with either differing numbers of 4420** arguments or differing preferred text encodings. ^SQLite will use 4421** the implementation that most closely matches the way in which the 4422** SQL function is used. ^A function implementation with a non-negative 4423** nArg parameter is a better match than a function implementation with 4424** a negative nArg. ^A function where the preferred text encoding 4425** matches the database encoding is a better 4426** match than a function where the encoding is different. 4427** ^A function where the encoding difference is between UTF16le and UTF16be 4428** is a closer match than a function where the encoding difference is 4429** between UTF8 and UTF16. 4430** 4431** ^Built-in functions may be overloaded by new application-defined functions. 4432** 4433** ^An application-defined function is permitted to call other 4434** SQLite interfaces. However, such calls must not 4435** close the database connection nor finalize or reset the prepared 4436** statement in which the function is running. 4437*/ 4438SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4439 sqlite3 *db, 4440 const char *zFunctionName, 4441 int nArg, 4442 int eTextRep, 4443 void *pApp, 4444 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4445 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4446 void (*xFinal)(sqlite3_context*) 4447); 4448SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4449 sqlite3 *db, 4450 const void *zFunctionName, 4451 int nArg, 4452 int eTextRep, 4453 void *pApp, 4454 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4455 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4456 void (*xFinal)(sqlite3_context*) 4457); 4458SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4459 sqlite3 *db, 4460 const char *zFunctionName, 4461 int nArg, 4462 int eTextRep, 4463 void *pApp, 4464 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4465 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4466 void (*xFinal)(sqlite3_context*), 4467 void(*xDestroy)(void*) 4468); 4469 4470/* 4471** CAPI3REF: Text Encodings 4472** 4473** These constant define integer codes that represent the various 4474** text encodings supported by SQLite. 4475*/ 4476#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4477#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4478#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4479#define SQLITE_UTF16 4 /* Use native byte order */ 4480#define SQLITE_ANY 5 /* Deprecated */ 4481#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4482 4483/* 4484** CAPI3REF: Function Flags 4485** 4486** These constants may be ORed together with the 4487** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4488** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4489** [sqlite3_create_function_v2()]. 4490*/ 4491#define SQLITE_DETERMINISTIC 0x800 4492 4493/* 4494** CAPI3REF: Deprecated Functions 4495** DEPRECATED 4496** 4497** These functions are [deprecated]. In order to maintain 4498** backwards compatibility with older code, these functions continue 4499** to be supported. However, new applications should avoid 4500** the use of these functions. To encourage programmers to avoid 4501** these functions, we will not explain what they do. 4502*/ 4503#ifndef SQLITE_OMIT_DEPRECATED 4504SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4505SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4506SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4507SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4508SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4509SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4510 void*,sqlite3_int64); 4511#endif 4512 4513/* 4514** CAPI3REF: Obtaining SQL Values 4515** METHOD: sqlite3_value 4516** 4517** The C-language implementation of SQL functions and aggregates uses 4518** this set of interface routines to access the parameter values on 4519** the function or aggregate. 4520** 4521** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4522** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4523** define callbacks that implement the SQL functions and aggregates. 4524** The 3rd parameter to these callbacks is an array of pointers to 4525** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4526** each parameter to the SQL function. These routines are used to 4527** extract values from the [sqlite3_value] objects. 4528** 4529** These routines work only with [protected sqlite3_value] objects. 4530** Any attempt to use these routines on an [unprotected sqlite3_value] 4531** object results in undefined behavior. 4532** 4533** ^These routines work just like the corresponding [column access functions] 4534** except that these routines take a single [protected sqlite3_value] object 4535** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4536** 4537** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4538** in the native byte-order of the host machine. ^The 4539** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4540** extract UTF-16 strings as big-endian and little-endian respectively. 4541** 4542** ^(The sqlite3_value_numeric_type() interface attempts to apply 4543** numeric affinity to the value. This means that an attempt is 4544** made to convert the value to an integer or floating point. If 4545** such a conversion is possible without loss of information (in other 4546** words, if the value is a string that looks like a number) 4547** then the conversion is performed. Otherwise no conversion occurs. 4548** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4549** 4550** Please pay particular attention to the fact that the pointer returned 4551** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4552** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4553** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4554** or [sqlite3_value_text16()]. 4555** 4556** These routines must be called from the same thread as 4557** the SQL function that supplied the [sqlite3_value*] parameters. 4558*/ 4559SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4560SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4561SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4562SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4563SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4564SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4565SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4566SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4567SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4568SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4569SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4570SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4571 4572/* 4573** CAPI3REF: Finding The Subtype Of SQL Values 4574** METHOD: sqlite3_value 4575** 4576** The sqlite3_value_subtype(V) function returns the subtype for 4577** an [application-defined SQL function] argument V. The subtype 4578** information can be used to pass a limited amount of context from 4579** one SQL function to another. Use the [sqlite3_result_subtype()] 4580** routine to set the subtype for the return value of an SQL function. 4581** 4582** SQLite makes no use of subtype itself. It merely passes the subtype 4583** from the result of one [application-defined SQL function] into the 4584** input of another. 4585*/ 4586SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); 4587 4588/* 4589** CAPI3REF: Copy And Free SQL Values 4590** METHOD: sqlite3_value 4591** 4592** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4593** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4594** is a [protected sqlite3_value] object even if the input is not. 4595** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4596** memory allocation fails. 4597** 4598** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4599** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4600** then sqlite3_value_free(V) is a harmless no-op. 4601*/ 4602SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); 4603SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); 4604 4605/* 4606** CAPI3REF: Obtain Aggregate Function Context 4607** METHOD: sqlite3_context 4608** 4609** Implementations of aggregate SQL functions use this 4610** routine to allocate memory for storing their state. 4611** 4612** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4613** for a particular aggregate function, SQLite 4614** allocates N of memory, zeroes out that memory, and returns a pointer 4615** to the new memory. ^On second and subsequent calls to 4616** sqlite3_aggregate_context() for the same aggregate function instance, 4617** the same buffer is returned. Sqlite3_aggregate_context() is normally 4618** called once for each invocation of the xStep callback and then one 4619** last time when the xFinal callback is invoked. ^(When no rows match 4620** an aggregate query, the xStep() callback of the aggregate function 4621** implementation is never called and xFinal() is called exactly once. 4622** In those cases, sqlite3_aggregate_context() might be called for the 4623** first time from within xFinal().)^ 4624** 4625** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4626** when first called if N is less than or equal to zero or if a memory 4627** allocate error occurs. 4628** 4629** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4630** determined by the N parameter on first successful call. Changing the 4631** value of N in subsequent call to sqlite3_aggregate_context() within 4632** the same aggregate function instance will not resize the memory 4633** allocation.)^ Within the xFinal callback, it is customary to set 4634** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4635** pointless memory allocations occur. 4636** 4637** ^SQLite automatically frees the memory allocated by 4638** sqlite3_aggregate_context() when the aggregate query concludes. 4639** 4640** The first parameter must be a copy of the 4641** [sqlite3_context | SQL function context] that is the first parameter 4642** to the xStep or xFinal callback routine that implements the aggregate 4643** function. 4644** 4645** This routine must be called from the same thread in which 4646** the aggregate SQL function is running. 4647*/ 4648SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4649 4650/* 4651** CAPI3REF: User Data For Functions 4652** METHOD: sqlite3_context 4653** 4654** ^The sqlite3_user_data() interface returns a copy of 4655** the pointer that was the pUserData parameter (the 5th parameter) 4656** of the [sqlite3_create_function()] 4657** and [sqlite3_create_function16()] routines that originally 4658** registered the application defined function. 4659** 4660** This routine must be called from the same thread in which 4661** the application-defined function is running. 4662*/ 4663SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4664 4665/* 4666** CAPI3REF: Database Connection For Functions 4667** METHOD: sqlite3_context 4668** 4669** ^The sqlite3_context_db_handle() interface returns a copy of 4670** the pointer to the [database connection] (the 1st parameter) 4671** of the [sqlite3_create_function()] 4672** and [sqlite3_create_function16()] routines that originally 4673** registered the application defined function. 4674*/ 4675SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4676 4677/* 4678** CAPI3REF: Function Auxiliary Data 4679** METHOD: sqlite3_context 4680** 4681** These functions may be used by (non-aggregate) SQL functions to 4682** associate metadata with argument values. If the same value is passed to 4683** multiple invocations of the same SQL function during query execution, under 4684** some circumstances the associated metadata may be preserved. An example 4685** of where this might be useful is in a regular-expression matching 4686** function. The compiled version of the regular expression can be stored as 4687** metadata associated with the pattern string. 4688** Then as long as the pattern string remains the same, 4689** the compiled regular expression can be reused on multiple 4690** invocations of the same function. 4691** 4692** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4693** associated by the sqlite3_set_auxdata() function with the Nth argument 4694** value to the application-defined function. ^If there is no metadata 4695** associated with the function argument, this sqlite3_get_auxdata() interface 4696** returns a NULL pointer. 4697** 4698** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4699** argument of the application-defined function. ^Subsequent 4700** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4701** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4702** NULL if the metadata has been discarded. 4703** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4704** SQLite will invoke the destructor function X with parameter P exactly 4705** once, when the metadata is discarded. 4706** SQLite is free to discard the metadata at any time, including: <ul> 4707** <li> ^(when the corresponding function parameter changes)^, or 4708** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4709** SQL statement)^, or 4710** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4711** parameter)^, or 4712** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4713** allocation error occurs.)^ </ul> 4714** 4715** Note the last bullet in particular. The destructor X in 4716** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4717** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4718** should be called near the end of the function implementation and the 4719** function implementation should not make any use of P after 4720** sqlite3_set_auxdata() has been called. 4721** 4722** ^(In practice, metadata is preserved between function calls for 4723** function parameters that are compile-time constants, including literal 4724** values and [parameters] and expressions composed from the same.)^ 4725** 4726** These routines must be called from the same thread in which 4727** the SQL function is running. 4728*/ 4729SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4730SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4731 4732 4733/* 4734** CAPI3REF: Constants Defining Special Destructor Behavior 4735** 4736** These are special values for the destructor that is passed in as the 4737** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4738** argument is SQLITE_STATIC, it means that the content pointer is constant 4739** and will never change. It does not need to be destroyed. ^The 4740** SQLITE_TRANSIENT value means that the content will likely change in 4741** the near future and that SQLite should make its own private copy of 4742** the content before returning. 4743** 4744** The typedef is necessary to work around problems in certain 4745** C++ compilers. 4746*/ 4747typedef void (*sqlite3_destructor_type)(void*); 4748#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4749#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4750 4751/* 4752** CAPI3REF: Setting The Result Of An SQL Function 4753** METHOD: sqlite3_context 4754** 4755** These routines are used by the xFunc or xFinal callbacks that 4756** implement SQL functions and aggregates. See 4757** [sqlite3_create_function()] and [sqlite3_create_function16()] 4758** for additional information. 4759** 4760** These functions work very much like the [parameter binding] family of 4761** functions used to bind values to host parameters in prepared statements. 4762** Refer to the [SQL parameter] documentation for additional information. 4763** 4764** ^The sqlite3_result_blob() interface sets the result from 4765** an application-defined function to be the BLOB whose content is pointed 4766** to by the second parameter and which is N bytes long where N is the 4767** third parameter. 4768** 4769** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4770** interfaces set the result of the application-defined function to be 4771** a BLOB containing all zero bytes and N bytes in size. 4772** 4773** ^The sqlite3_result_double() interface sets the result from 4774** an application-defined function to be a floating point value specified 4775** by its 2nd argument. 4776** 4777** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4778** cause the implemented SQL function to throw an exception. 4779** ^SQLite uses the string pointed to by the 4780** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4781** as the text of an error message. ^SQLite interprets the error 4782** message string from sqlite3_result_error() as UTF-8. ^SQLite 4783** interprets the string from sqlite3_result_error16() as UTF-16 in native 4784** byte order. ^If the third parameter to sqlite3_result_error() 4785** or sqlite3_result_error16() is negative then SQLite takes as the error 4786** message all text up through the first zero character. 4787** ^If the third parameter to sqlite3_result_error() or 4788** sqlite3_result_error16() is non-negative then SQLite takes that many 4789** bytes (not characters) from the 2nd parameter as the error message. 4790** ^The sqlite3_result_error() and sqlite3_result_error16() 4791** routines make a private copy of the error message text before 4792** they return. Hence, the calling function can deallocate or 4793** modify the text after they return without harm. 4794** ^The sqlite3_result_error_code() function changes the error code 4795** returned by SQLite as a result of an error in a function. ^By default, 4796** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4797** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4798** 4799** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4800** error indicating that a string or BLOB is too long to represent. 4801** 4802** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4803** error indicating that a memory allocation failed. 4804** 4805** ^The sqlite3_result_int() interface sets the return value 4806** of the application-defined function to be the 32-bit signed integer 4807** value given in the 2nd argument. 4808** ^The sqlite3_result_int64() interface sets the return value 4809** of the application-defined function to be the 64-bit signed integer 4810** value given in the 2nd argument. 4811** 4812** ^The sqlite3_result_null() interface sets the return value 4813** of the application-defined function to be NULL. 4814** 4815** ^The sqlite3_result_text(), sqlite3_result_text16(), 4816** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4817** set the return value of the application-defined function to be 4818** a text string which is represented as UTF-8, UTF-16 native byte order, 4819** UTF-16 little endian, or UTF-16 big endian, respectively. 4820** ^The sqlite3_result_text64() interface sets the return value of an 4821** application-defined function to be a text string in an encoding 4822** specified by the fifth (and last) parameter, which must be one 4823** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4824** ^SQLite takes the text result from the application from 4825** the 2nd parameter of the sqlite3_result_text* interfaces. 4826** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4827** is negative, then SQLite takes result text from the 2nd parameter 4828** through the first zero character. 4829** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4830** is non-negative, then as many bytes (not characters) of the text 4831** pointed to by the 2nd parameter are taken as the application-defined 4832** function result. If the 3rd parameter is non-negative, then it 4833** must be the byte offset into the string where the NUL terminator would 4834** appear if the string where NUL terminated. If any NUL characters occur 4835** in the string at a byte offset that is less than the value of the 3rd 4836** parameter, then the resulting string will contain embedded NULs and the 4837** result of expressions operating on strings with embedded NULs is undefined. 4838** ^If the 4th parameter to the sqlite3_result_text* interfaces 4839** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4840** function as the destructor on the text or BLOB result when it has 4841** finished using that result. 4842** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4843** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4844** assumes that the text or BLOB result is in constant space and does not 4845** copy the content of the parameter nor call a destructor on the content 4846** when it has finished using that result. 4847** ^If the 4th parameter to the sqlite3_result_text* interfaces 4848** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4849** then SQLite makes a copy of the result into space obtained from 4850** from [sqlite3_malloc()] before it returns. 4851** 4852** ^The sqlite3_result_value() interface sets the result of 4853** the application-defined function to be a copy of the 4854** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4855** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4856** so that the [sqlite3_value] specified in the parameter may change or 4857** be deallocated after sqlite3_result_value() returns without harm. 4858** ^A [protected sqlite3_value] object may always be used where an 4859** [unprotected sqlite3_value] object is required, so either 4860** kind of [sqlite3_value] object can be used with this interface. 4861** 4862** If these routines are called from within the different thread 4863** than the one containing the application-defined function that received 4864** the [sqlite3_context] pointer, the results are undefined. 4865*/ 4866SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4867SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4868 sqlite3_uint64,void(*)(void*)); 4869SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4870SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4871SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4872SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4873SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4874SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4875SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4876SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4877SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4878SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4879SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4880 void(*)(void*), unsigned char encoding); 4881SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4882SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4883SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4884SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4885SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4886SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4887 4888 4889/* 4890** CAPI3REF: Setting The Subtype Of An SQL Function 4891** METHOD: sqlite3_context 4892** 4893** The sqlite3_result_subtype(C,T) function causes the subtype of 4894** the result from the [application-defined SQL function] with 4895** [sqlite3_context] C to be the value T. Only the lower 8 bits 4896** of the subtype T are preserved in current versions of SQLite; 4897** higher order bits are discarded. 4898** The number of subtype bytes preserved by SQLite might increase 4899** in future releases of SQLite. 4900*/ 4901SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); 4902 4903/* 4904** CAPI3REF: Define New Collating Sequences 4905** METHOD: sqlite3 4906** 4907** ^These functions add, remove, or modify a [collation] associated 4908** with the [database connection] specified as the first argument. 4909** 4910** ^The name of the collation is a UTF-8 string 4911** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4912** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4913** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4914** considered to be the same name. 4915** 4916** ^(The third argument (eTextRep) must be one of the constants: 4917** <ul> 4918** <li> [SQLITE_UTF8], 4919** <li> [SQLITE_UTF16LE], 4920** <li> [SQLITE_UTF16BE], 4921** <li> [SQLITE_UTF16], or 4922** <li> [SQLITE_UTF16_ALIGNED]. 4923** </ul>)^ 4924** ^The eTextRep argument determines the encoding of strings passed 4925** to the collating function callback, xCallback. 4926** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4927** force strings to be UTF16 with native byte order. 4928** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4929** on an even byte address. 4930** 4931** ^The fourth argument, pArg, is an application data pointer that is passed 4932** through as the first argument to the collating function callback. 4933** 4934** ^The fifth argument, xCallback, is a pointer to the collating function. 4935** ^Multiple collating functions can be registered using the same name but 4936** with different eTextRep parameters and SQLite will use whichever 4937** function requires the least amount of data transformation. 4938** ^If the xCallback argument is NULL then the collating function is 4939** deleted. ^When all collating functions having the same name are deleted, 4940** that collation is no longer usable. 4941** 4942** ^The collating function callback is invoked with a copy of the pArg 4943** application data pointer and with two strings in the encoding specified 4944** by the eTextRep argument. The collating function must return an 4945** integer that is negative, zero, or positive 4946** if the first string is less than, equal to, or greater than the second, 4947** respectively. A collating function must always return the same answer 4948** given the same inputs. If two or more collating functions are registered 4949** to the same collation name (using different eTextRep values) then all 4950** must give an equivalent answer when invoked with equivalent strings. 4951** The collating function must obey the following properties for all 4952** strings A, B, and C: 4953** 4954** <ol> 4955** <li> If A==B then B==A. 4956** <li> If A==B and B==C then A==C. 4957** <li> If A<B THEN B>A. 4958** <li> If A<B and B<C then A<C. 4959** </ol> 4960** 4961** If a collating function fails any of the above constraints and that 4962** collating function is registered and used, then the behavior of SQLite 4963** is undefined. 4964** 4965** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4966** with the addition that the xDestroy callback is invoked on pArg when 4967** the collating function is deleted. 4968** ^Collating functions are deleted when they are overridden by later 4969** calls to the collation creation functions or when the 4970** [database connection] is closed using [sqlite3_close()]. 4971** 4972** ^The xDestroy callback is <u>not</u> called if the 4973** sqlite3_create_collation_v2() function fails. Applications that invoke 4974** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4975** check the return code and dispose of the application data pointer 4976** themselves rather than expecting SQLite to deal with it for them. 4977** This is different from every other SQLite interface. The inconsistency 4978** is unfortunate but cannot be changed without breaking backwards 4979** compatibility. 4980** 4981** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4982*/ 4983SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4984 sqlite3*, 4985 const char *zName, 4986 int eTextRep, 4987 void *pArg, 4988 int(*xCompare)(void*,int,const void*,int,const void*) 4989); 4990SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4991 sqlite3*, 4992 const char *zName, 4993 int eTextRep, 4994 void *pArg, 4995 int(*xCompare)(void*,int,const void*,int,const void*), 4996 void(*xDestroy)(void*) 4997); 4998SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4999 sqlite3*, 5000 const void *zName, 5001 int eTextRep, 5002 void *pArg, 5003 int(*xCompare)(void*,int,const void*,int,const void*) 5004); 5005 5006/* 5007** CAPI3REF: Collation Needed Callbacks 5008** METHOD: sqlite3 5009** 5010** ^To avoid having to register all collation sequences before a database 5011** can be used, a single callback function may be registered with the 5012** [database connection] to be invoked whenever an undefined collation 5013** sequence is required. 5014** 5015** ^If the function is registered using the sqlite3_collation_needed() API, 5016** then it is passed the names of undefined collation sequences as strings 5017** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5018** the names are passed as UTF-16 in machine native byte order. 5019** ^A call to either function replaces the existing collation-needed callback. 5020** 5021** ^(When the callback is invoked, the first argument passed is a copy 5022** of the second argument to sqlite3_collation_needed() or 5023** sqlite3_collation_needed16(). The second argument is the database 5024** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5025** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5026** sequence function required. The fourth parameter is the name of the 5027** required collation sequence.)^ 5028** 5029** The callback function should register the desired collation using 5030** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5031** [sqlite3_create_collation_v2()]. 5032*/ 5033SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 5034 sqlite3*, 5035 void*, 5036 void(*)(void*,sqlite3*,int eTextRep,const char*) 5037); 5038SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 5039 sqlite3*, 5040 void*, 5041 void(*)(void*,sqlite3*,int eTextRep,const void*) 5042); 5043 5044#ifdef SQLITE_HAS_CODEC 5045/* 5046** Specify the key for an encrypted database. This routine should be 5047** called right after sqlite3_open(). 5048** 5049** The code to implement this API is not available in the public release 5050** of SQLite. 5051*/ 5052SQLITE_API int SQLITE_STDCALL sqlite3_key( 5053 sqlite3 *db, /* Database to be rekeyed */ 5054 const void *pKey, int nKey /* The key */ 5055); 5056SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 5057 sqlite3 *db, /* Database to be rekeyed */ 5058 const char *zDbName, /* Name of the database */ 5059 const void *pKey, int nKey /* The key */ 5060); 5061 5062/* 5063** Change the key on an open database. If the current database is not 5064** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5065** database is decrypted. 5066** 5067** The code to implement this API is not available in the public release 5068** of SQLite. 5069*/ 5070SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 5071 sqlite3 *db, /* Database to be rekeyed */ 5072 const void *pKey, int nKey /* The new key */ 5073); 5074SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 5075 sqlite3 *db, /* Database to be rekeyed */ 5076 const char *zDbName, /* Name of the database */ 5077 const void *pKey, int nKey /* The new key */ 5078); 5079 5080/* 5081** Specify the activation key for a SEE database. Unless 5082** activated, none of the SEE routines will work. 5083*/ 5084SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 5085 const char *zPassPhrase /* Activation phrase */ 5086); 5087#endif 5088 5089#ifdef SQLITE_ENABLE_CEROD 5090/* 5091** Specify the activation key for a CEROD database. Unless 5092** activated, none of the CEROD routines will work. 5093*/ 5094SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 5095 const char *zPassPhrase /* Activation phrase */ 5096); 5097#endif 5098 5099/* 5100** CAPI3REF: Suspend Execution For A Short Time 5101** 5102** The sqlite3_sleep() function causes the current thread to suspend execution 5103** for at least a number of milliseconds specified in its parameter. 5104** 5105** If the operating system does not support sleep requests with 5106** millisecond time resolution, then the time will be rounded up to 5107** the nearest second. The number of milliseconds of sleep actually 5108** requested from the operating system is returned. 5109** 5110** ^SQLite implements this interface by calling the xSleep() 5111** method of the default [sqlite3_vfs] object. If the xSleep() method 5112** of the default VFS is not implemented correctly, or not implemented at 5113** all, then the behavior of sqlite3_sleep() may deviate from the description 5114** in the previous paragraphs. 5115*/ 5116SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 5117 5118/* 5119** CAPI3REF: Name Of The Folder Holding Temporary Files 5120** 5121** ^(If this global variable is made to point to a string which is 5122** the name of a folder (a.k.a. directory), then all temporary files 5123** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5124** will be placed in that directory.)^ ^If this variable 5125** is a NULL pointer, then SQLite performs a search for an appropriate 5126** temporary file directory. 5127** 5128** Applications are strongly discouraged from using this global variable. 5129** It is required to set a temporary folder on Windows Runtime (WinRT). 5130** But for all other platforms, it is highly recommended that applications 5131** neither read nor write this variable. This global variable is a relic 5132** that exists for backwards compatibility of legacy applications and should 5133** be avoided in new projects. 5134** 5135** It is not safe to read or modify this variable in more than one 5136** thread at a time. It is not safe to read or modify this variable 5137** if a [database connection] is being used at the same time in a separate 5138** thread. 5139** It is intended that this variable be set once 5140** as part of process initialization and before any SQLite interface 5141** routines have been called and that this variable remain unchanged 5142** thereafter. 5143** 5144** ^The [temp_store_directory pragma] may modify this variable and cause 5145** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5146** the [temp_store_directory pragma] always assumes that any string 5147** that this variable points to is held in memory obtained from 5148** [sqlite3_malloc] and the pragma may attempt to free that memory 5149** using [sqlite3_free]. 5150** Hence, if this variable is modified directly, either it should be 5151** made NULL or made to point to memory obtained from [sqlite3_malloc] 5152** or else the use of the [temp_store_directory pragma] should be avoided. 5153** Except when requested by the [temp_store_directory pragma], SQLite 5154** does not free the memory that sqlite3_temp_directory points to. If 5155** the application wants that memory to be freed, it must do 5156** so itself, taking care to only do so after all [database connection] 5157** objects have been destroyed. 5158** 5159** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5160** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5161** features that require the use of temporary files may fail. Here is an 5162** example of how to do this using C++ with the Windows Runtime: 5163** 5164** <blockquote><pre> 5165** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5166** TemporaryFolder->Path->Data(); 5167** char zPathBuf[MAX_PATH + 1]; 5168** memset(zPathBuf, 0, sizeof(zPathBuf)); 5169** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5170** NULL, NULL); 5171** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5172** </pre></blockquote> 5173*/ 5174SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5175 5176/* 5177** CAPI3REF: Name Of The Folder Holding Database Files 5178** 5179** ^(If this global variable is made to point to a string which is 5180** the name of a folder (a.k.a. directory), then all database files 5181** specified with a relative pathname and created or accessed by 5182** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5183** to be relative to that directory.)^ ^If this variable is a NULL 5184** pointer, then SQLite assumes that all database files specified 5185** with a relative pathname are relative to the current directory 5186** for the process. Only the windows VFS makes use of this global 5187** variable; it is ignored by the unix VFS. 5188** 5189** Changing the value of this variable while a database connection is 5190** open can result in a corrupt database. 5191** 5192** It is not safe to read or modify this variable in more than one 5193** thread at a time. It is not safe to read or modify this variable 5194** if a [database connection] is being used at the same time in a separate 5195** thread. 5196** It is intended that this variable be set once 5197** as part of process initialization and before any SQLite interface 5198** routines have been called and that this variable remain unchanged 5199** thereafter. 5200** 5201** ^The [data_store_directory pragma] may modify this variable and cause 5202** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5203** the [data_store_directory pragma] always assumes that any string 5204** that this variable points to is held in memory obtained from 5205** [sqlite3_malloc] and the pragma may attempt to free that memory 5206** using [sqlite3_free]. 5207** Hence, if this variable is modified directly, either it should be 5208** made NULL or made to point to memory obtained from [sqlite3_malloc] 5209** or else the use of the [data_store_directory pragma] should be avoided. 5210*/ 5211SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5212 5213/* 5214** CAPI3REF: Test For Auto-Commit Mode 5215** KEYWORDS: {autocommit mode} 5216** METHOD: sqlite3 5217** 5218** ^The sqlite3_get_autocommit() interface returns non-zero or 5219** zero if the given database connection is or is not in autocommit mode, 5220** respectively. ^Autocommit mode is on by default. 5221** ^Autocommit mode is disabled by a [BEGIN] statement. 5222** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5223** 5224** If certain kinds of errors occur on a statement within a multi-statement 5225** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5226** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5227** transaction might be rolled back automatically. The only way to 5228** find out whether SQLite automatically rolled back the transaction after 5229** an error is to use this function. 5230** 5231** If another thread changes the autocommit status of the database 5232** connection while this routine is running, then the return value 5233** is undefined. 5234*/ 5235SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 5236 5237/* 5238** CAPI3REF: Find The Database Handle Of A Prepared Statement 5239** METHOD: sqlite3_stmt 5240** 5241** ^The sqlite3_db_handle interface returns the [database connection] handle 5242** to which a [prepared statement] belongs. ^The [database connection] 5243** returned by sqlite3_db_handle is the same [database connection] 5244** that was the first argument 5245** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5246** create the statement in the first place. 5247*/ 5248SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 5249 5250/* 5251** CAPI3REF: Return The Filename For A Database Connection 5252** METHOD: sqlite3 5253** 5254** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5255** associated with database N of connection D. ^The main database file 5256** has the name "main". If there is no attached database N on the database 5257** connection D, or if database N is a temporary or in-memory database, then 5258** a NULL pointer is returned. 5259** 5260** ^The filename returned by this function is the output of the 5261** xFullPathname method of the [VFS]. ^In other words, the filename 5262** will be an absolute pathname, even if the filename used 5263** to open the database originally was a URI or relative pathname. 5264*/ 5265SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5266 5267/* 5268** CAPI3REF: Determine if a database is read-only 5269** METHOD: sqlite3 5270** 5271** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5272** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5273** the name of a database on connection D. 5274*/ 5275SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5276 5277/* 5278** CAPI3REF: Find the next prepared statement 5279** METHOD: sqlite3 5280** 5281** ^This interface returns a pointer to the next [prepared statement] after 5282** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5283** then this interface returns a pointer to the first prepared statement 5284** associated with the database connection pDb. ^If no prepared statement 5285** satisfies the conditions of this routine, it returns NULL. 5286** 5287** The [database connection] pointer D in a call to 5288** [sqlite3_next_stmt(D,S)] must refer to an open database 5289** connection and in particular must not be a NULL pointer. 5290*/ 5291SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5292 5293/* 5294** CAPI3REF: Commit And Rollback Notification Callbacks 5295** METHOD: sqlite3 5296** 5297** ^The sqlite3_commit_hook() interface registers a callback 5298** function to be invoked whenever a transaction is [COMMIT | committed]. 5299** ^Any callback set by a previous call to sqlite3_commit_hook() 5300** for the same database connection is overridden. 5301** ^The sqlite3_rollback_hook() interface registers a callback 5302** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5303** ^Any callback set by a previous call to sqlite3_rollback_hook() 5304** for the same database connection is overridden. 5305** ^The pArg argument is passed through to the callback. 5306** ^If the callback on a commit hook function returns non-zero, 5307** then the commit is converted into a rollback. 5308** 5309** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5310** return the P argument from the previous call of the same function 5311** on the same [database connection] D, or NULL for 5312** the first call for each function on D. 5313** 5314** The commit and rollback hook callbacks are not reentrant. 5315** The callback implementation must not do anything that will modify 5316** the database connection that invoked the callback. Any actions 5317** to modify the database connection must be deferred until after the 5318** completion of the [sqlite3_step()] call that triggered the commit 5319** or rollback hook in the first place. 5320** Note that running any other SQL statements, including SELECT statements, 5321** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5322** the database connections for the meaning of "modify" in this paragraph. 5323** 5324** ^Registering a NULL function disables the callback. 5325** 5326** ^When the commit hook callback routine returns zero, the [COMMIT] 5327** operation is allowed to continue normally. ^If the commit hook 5328** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5329** ^The rollback hook is invoked on a rollback that results from a commit 5330** hook returning non-zero, just as it would be with any other rollback. 5331** 5332** ^For the purposes of this API, a transaction is said to have been 5333** rolled back if an explicit "ROLLBACK" statement is executed, or 5334** an error or constraint causes an implicit rollback to occur. 5335** ^The rollback callback is not invoked if a transaction is 5336** automatically rolled back because the database connection is closed. 5337** 5338** See also the [sqlite3_update_hook()] interface. 5339*/ 5340SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5341SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5342 5343/* 5344** CAPI3REF: Data Change Notification Callbacks 5345** METHOD: sqlite3 5346** 5347** ^The sqlite3_update_hook() interface registers a callback function 5348** with the [database connection] identified by the first argument 5349** to be invoked whenever a row is updated, inserted or deleted in 5350** a [rowid table]. 5351** ^Any callback set by a previous call to this function 5352** for the same database connection is overridden. 5353** 5354** ^The second argument is a pointer to the function to invoke when a 5355** row is updated, inserted or deleted in a rowid table. 5356** ^The first argument to the callback is a copy of the third argument 5357** to sqlite3_update_hook(). 5358** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5359** or [SQLITE_UPDATE], depending on the operation that caused the callback 5360** to be invoked. 5361** ^The third and fourth arguments to the callback contain pointers to the 5362** database and table name containing the affected row. 5363** ^The final callback parameter is the [rowid] of the row. 5364** ^In the case of an update, this is the [rowid] after the update takes place. 5365** 5366** ^(The update hook is not invoked when internal system tables are 5367** modified (i.e. sqlite_master and sqlite_sequence).)^ 5368** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5369** 5370** ^In the current implementation, the update hook 5371** is not invoked when duplication rows are deleted because of an 5372** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5373** invoked when rows are deleted using the [truncate optimization]. 5374** The exceptions defined in this paragraph might change in a future 5375** release of SQLite. 5376** 5377** The update hook implementation must not do anything that will modify 5378** the database connection that invoked the update hook. Any actions 5379** to modify the database connection must be deferred until after the 5380** completion of the [sqlite3_step()] call that triggered the update hook. 5381** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5382** database connections for the meaning of "modify" in this paragraph. 5383** 5384** ^The sqlite3_update_hook(D,C,P) function 5385** returns the P argument from the previous call 5386** on the same [database connection] D, or NULL for 5387** the first call on D. 5388** 5389** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5390** and [sqlite3_preupdate_hook()] interfaces. 5391*/ 5392SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5393 sqlite3*, 5394 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5395 void* 5396); 5397 5398/* 5399** CAPI3REF: Enable Or Disable Shared Pager Cache 5400** 5401** ^(This routine enables or disables the sharing of the database cache 5402** and schema data structures between [database connection | connections] 5403** to the same database. Sharing is enabled if the argument is true 5404** and disabled if the argument is false.)^ 5405** 5406** ^Cache sharing is enabled and disabled for an entire process. 5407** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5408** sharing was enabled or disabled for each thread separately. 5409** 5410** ^(The cache sharing mode set by this interface effects all subsequent 5411** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5412** Existing database connections continue use the sharing mode 5413** that was in effect at the time they were opened.)^ 5414** 5415** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5416** successfully. An [error code] is returned otherwise.)^ 5417** 5418** ^Shared cache is disabled by default. But this might change in 5419** future releases of SQLite. Applications that care about shared 5420** cache setting should set it explicitly. 5421** 5422** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5423** and will always return SQLITE_MISUSE. On those systems, 5424** shared cache mode should be enabled per-database connection via 5425** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5426** 5427** This interface is threadsafe on processors where writing a 5428** 32-bit integer is atomic. 5429** 5430** See Also: [SQLite Shared-Cache Mode] 5431*/ 5432SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5433 5434/* 5435** CAPI3REF: Attempt To Free Heap Memory 5436** 5437** ^The sqlite3_release_memory() interface attempts to free N bytes 5438** of heap memory by deallocating non-essential memory allocations 5439** held by the database library. Memory used to cache database 5440** pages to improve performance is an example of non-essential memory. 5441** ^sqlite3_release_memory() returns the number of bytes actually freed, 5442** which might be more or less than the amount requested. 5443** ^The sqlite3_release_memory() routine is a no-op returning zero 5444** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5445** 5446** See also: [sqlite3_db_release_memory()] 5447*/ 5448SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5449 5450/* 5451** CAPI3REF: Free Memory Used By A Database Connection 5452** METHOD: sqlite3 5453** 5454** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5455** memory as possible from database connection D. Unlike the 5456** [sqlite3_release_memory()] interface, this interface is in effect even 5457** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5458** omitted. 5459** 5460** See also: [sqlite3_release_memory()] 5461*/ 5462SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5463 5464/* 5465** CAPI3REF: Impose A Limit On Heap Size 5466** 5467** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5468** soft limit on the amount of heap memory that may be allocated by SQLite. 5469** ^SQLite strives to keep heap memory utilization below the soft heap 5470** limit by reducing the number of pages held in the page cache 5471** as heap memory usages approaches the limit. 5472** ^The soft heap limit is "soft" because even though SQLite strives to stay 5473** below the limit, it will exceed the limit rather than generate 5474** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5475** is advisory only. 5476** 5477** ^The return value from sqlite3_soft_heap_limit64() is the size of 5478** the soft heap limit prior to the call, or negative in the case of an 5479** error. ^If the argument N is negative 5480** then no change is made to the soft heap limit. Hence, the current 5481** size of the soft heap limit can be determined by invoking 5482** sqlite3_soft_heap_limit64() with a negative argument. 5483** 5484** ^If the argument N is zero then the soft heap limit is disabled. 5485** 5486** ^(The soft heap limit is not enforced in the current implementation 5487** if one or more of following conditions are true: 5488** 5489** <ul> 5490** <li> The soft heap limit is set to zero. 5491** <li> Memory accounting is disabled using a combination of the 5492** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5493** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5494** <li> An alternative page cache implementation is specified using 5495** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5496** <li> The page cache allocates from its own memory pool supplied 5497** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5498** from the heap. 5499** </ul>)^ 5500** 5501** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5502** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5503** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5504** the soft heap limit is enforced on every memory allocation. Without 5505** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5506** when memory is allocated by the page cache. Testing suggests that because 5507** the page cache is the predominate memory user in SQLite, most 5508** applications will achieve adequate soft heap limit enforcement without 5509** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5510** 5511** The circumstances under which SQLite will enforce the soft heap limit may 5512** changes in future releases of SQLite. 5513*/ 5514SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5515 5516/* 5517** CAPI3REF: Deprecated Soft Heap Limit Interface 5518** DEPRECATED 5519** 5520** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5521** interface. This routine is provided for historical compatibility 5522** only. All new applications should use the 5523** [sqlite3_soft_heap_limit64()] interface rather than this one. 5524*/ 5525SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5526 5527 5528/* 5529** CAPI3REF: Extract Metadata About A Column Of A Table 5530** METHOD: sqlite3 5531** 5532** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5533** information about column C of table T in database D 5534** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5535** interface returns SQLITE_OK and fills in the non-NULL pointers in 5536** the final five arguments with appropriate values if the specified 5537** column exists. ^The sqlite3_table_column_metadata() interface returns 5538** SQLITE_ERROR and if the specified column does not exist. 5539** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5540** NULL pointer, then this routine simply checks for the existence of the 5541** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5542** does not. 5543** 5544** ^The column is identified by the second, third and fourth parameters to 5545** this function. ^(The second parameter is either the name of the database 5546** (i.e. "main", "temp", or an attached database) containing the specified 5547** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5548** for the table using the same algorithm used by the database engine to 5549** resolve unqualified table references. 5550** 5551** ^The third and fourth parameters to this function are the table and column 5552** name of the desired column, respectively. 5553** 5554** ^Metadata is returned by writing to the memory locations passed as the 5th 5555** and subsequent parameters to this function. ^Any of these arguments may be 5556** NULL, in which case the corresponding element of metadata is omitted. 5557** 5558** ^(<blockquote> 5559** <table border="1"> 5560** <tr><th> Parameter <th> Output<br>Type <th> Description 5561** 5562** <tr><td> 5th <td> const char* <td> Data type 5563** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5564** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5565** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5566** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5567** </table> 5568** </blockquote>)^ 5569** 5570** ^The memory pointed to by the character pointers returned for the 5571** declaration type and collation sequence is valid until the next 5572** call to any SQLite API function. 5573** 5574** ^If the specified table is actually a view, an [error code] is returned. 5575** 5576** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5577** is not a [WITHOUT ROWID] table and an 5578** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5579** parameters are set for the explicitly declared column. ^(If there is no 5580** [INTEGER PRIMARY KEY] column, then the outputs 5581** for the [rowid] are set as follows: 5582** 5583** <pre> 5584** data type: "INTEGER" 5585** collation sequence: "BINARY" 5586** not null: 0 5587** primary key: 1 5588** auto increment: 0 5589** </pre>)^ 5590** 5591** ^This function causes all database schemas to be read from disk and 5592** parsed, if that has not already been done, and returns an error if 5593** any errors are encountered while loading the schema. 5594*/ 5595SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5596 sqlite3 *db, /* Connection handle */ 5597 const char *zDbName, /* Database name or NULL */ 5598 const char *zTableName, /* Table name */ 5599 const char *zColumnName, /* Column name */ 5600 char const **pzDataType, /* OUTPUT: Declared data type */ 5601 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5602 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5603 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5604 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5605); 5606 5607/* 5608** CAPI3REF: Load An Extension 5609** METHOD: sqlite3 5610** 5611** ^This interface loads an SQLite extension library from the named file. 5612** 5613** ^The sqlite3_load_extension() interface attempts to load an 5614** [SQLite extension] library contained in the file zFile. If 5615** the file cannot be loaded directly, attempts are made to load 5616** with various operating-system specific extensions added. 5617** So for example, if "samplelib" cannot be loaded, then names like 5618** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5619** be tried also. 5620** 5621** ^The entry point is zProc. 5622** ^(zProc may be 0, in which case SQLite will try to come up with an 5623** entry point name on its own. It first tries "sqlite3_extension_init". 5624** If that does not work, it constructs a name "sqlite3_X_init" where the 5625** X is consists of the lower-case equivalent of all ASCII alphabetic 5626** characters in the filename from the last "/" to the first following 5627** "." and omitting any initial "lib".)^ 5628** ^The sqlite3_load_extension() interface returns 5629** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5630** ^If an error occurs and pzErrMsg is not 0, then the 5631** [sqlite3_load_extension()] interface shall attempt to 5632** fill *pzErrMsg with error message text stored in memory 5633** obtained from [sqlite3_malloc()]. The calling function 5634** should free this memory by calling [sqlite3_free()]. 5635** 5636** ^Extension loading must be enabled using 5637** [sqlite3_enable_load_extension()] or 5638** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5639** prior to calling this API, 5640** otherwise an error will be returned. 5641** 5642** <b>Security warning:</b> It is recommended that the 5643** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5644** interface. The use of the [sqlite3_enable_load_extension()] interface 5645** should be avoided. This will keep the SQL function [load_extension()] 5646** disabled and prevent SQL injections from giving attackers 5647** access to extension loading capabilities. 5648** 5649** See also the [load_extension() SQL function]. 5650*/ 5651SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5652 sqlite3 *db, /* Load the extension into this database connection */ 5653 const char *zFile, /* Name of the shared library containing extension */ 5654 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5655 char **pzErrMsg /* Put error message here if not 0 */ 5656); 5657 5658/* 5659** CAPI3REF: Enable Or Disable Extension Loading 5660** METHOD: sqlite3 5661** 5662** ^So as not to open security holes in older applications that are 5663** unprepared to deal with [extension loading], and as a means of disabling 5664** [extension loading] while evaluating user-entered SQL, the following API 5665** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5666** 5667** ^Extension loading is off by default. 5668** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5669** to turn extension loading on and call it with onoff==0 to turn 5670** it back off again. 5671** 5672** ^This interface enables or disables both the C-API 5673** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5674** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5675** to enable or disable only the C-API.)^ 5676** 5677** <b>Security warning:</b> It is recommended that extension loading 5678** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5679** rather than this interface, so the [load_extension()] SQL function 5680** remains disabled. This will prevent SQL injections from giving attackers 5681** access to extension loading capabilities. 5682*/ 5683SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5684 5685/* 5686** CAPI3REF: Automatically Load Statically Linked Extensions 5687** 5688** ^This interface causes the xEntryPoint() function to be invoked for 5689** each new [database connection] that is created. The idea here is that 5690** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5691** that is to be automatically loaded into all new database connections. 5692** 5693** ^(Even though the function prototype shows that xEntryPoint() takes 5694** no arguments and returns void, SQLite invokes xEntryPoint() with three 5695** arguments and expects an integer result as if the signature of the 5696** entry point where as follows: 5697** 5698** <blockquote><pre> 5699** int xEntryPoint( 5700** sqlite3 *db, 5701** const char **pzErrMsg, 5702** const struct sqlite3_api_routines *pThunk 5703** ); 5704** </pre></blockquote>)^ 5705** 5706** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5707** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5708** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5709** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5710** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5711** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5712** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5713** 5714** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5715** on the list of automatic extensions is a harmless no-op. ^No entry point 5716** will be called more than once for each database connection that is opened. 5717** 5718** See also: [sqlite3_reset_auto_extension()] 5719** and [sqlite3_cancel_auto_extension()] 5720*/ 5721SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void(*xEntryPoint)(void)); 5722 5723/* 5724** CAPI3REF: Cancel Automatic Extension Loading 5725** 5726** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5727** initialization routine X that was registered using a prior call to 5728** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5729** routine returns 1 if initialization routine X was successfully 5730** unregistered and it returns 0 if X was not on the list of initialization 5731** routines. 5732*/ 5733SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5734 5735/* 5736** CAPI3REF: Reset Automatic Extension Loading 5737** 5738** ^This interface disables all automatic extensions previously 5739** registered using [sqlite3_auto_extension()]. 5740*/ 5741SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5742 5743/* 5744** The interface to the virtual-table mechanism is currently considered 5745** to be experimental. The interface might change in incompatible ways. 5746** If this is a problem for you, do not use the interface at this time. 5747** 5748** When the virtual-table mechanism stabilizes, we will declare the 5749** interface fixed, support it indefinitely, and remove this comment. 5750*/ 5751 5752/* 5753** Structures used by the virtual table interface 5754*/ 5755typedef struct sqlite3_vtab sqlite3_vtab; 5756typedef struct sqlite3_index_info sqlite3_index_info; 5757typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5758typedef struct sqlite3_module sqlite3_module; 5759 5760/* 5761** CAPI3REF: Virtual Table Object 5762** KEYWORDS: sqlite3_module {virtual table module} 5763** 5764** This structure, sometimes called a "virtual table module", 5765** defines the implementation of a [virtual tables]. 5766** This structure consists mostly of methods for the module. 5767** 5768** ^A virtual table module is created by filling in a persistent 5769** instance of this structure and passing a pointer to that instance 5770** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5771** ^The registration remains valid until it is replaced by a different 5772** module or until the [database connection] closes. The content 5773** of this structure must not change while it is registered with 5774** any database connection. 5775*/ 5776struct sqlite3_module { 5777 int iVersion; 5778 int (*xCreate)(sqlite3*, void *pAux, 5779 int argc, const char *const*argv, 5780 sqlite3_vtab **ppVTab, char**); 5781 int (*xConnect)(sqlite3*, void *pAux, 5782 int argc, const char *const*argv, 5783 sqlite3_vtab **ppVTab, char**); 5784 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5785 int (*xDisconnect)(sqlite3_vtab *pVTab); 5786 int (*xDestroy)(sqlite3_vtab *pVTab); 5787 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5788 int (*xClose)(sqlite3_vtab_cursor*); 5789 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5790 int argc, sqlite3_value **argv); 5791 int (*xNext)(sqlite3_vtab_cursor*); 5792 int (*xEof)(sqlite3_vtab_cursor*); 5793 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5794 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5795 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5796 int (*xBegin)(sqlite3_vtab *pVTab); 5797 int (*xSync)(sqlite3_vtab *pVTab); 5798 int (*xCommit)(sqlite3_vtab *pVTab); 5799 int (*xRollback)(sqlite3_vtab *pVTab); 5800 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5801 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5802 void **ppArg); 5803 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5804 /* The methods above are in version 1 of the sqlite_module object. Those 5805 ** below are for version 2 and greater. */ 5806 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5807 int (*xRelease)(sqlite3_vtab *pVTab, int); 5808 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5809}; 5810 5811/* 5812** CAPI3REF: Virtual Table Indexing Information 5813** KEYWORDS: sqlite3_index_info 5814** 5815** The sqlite3_index_info structure and its substructures is used as part 5816** of the [virtual table] interface to 5817** pass information into and receive the reply from the [xBestIndex] 5818** method of a [virtual table module]. The fields under **Inputs** are the 5819** inputs to xBestIndex and are read-only. xBestIndex inserts its 5820** results into the **Outputs** fields. 5821** 5822** ^(The aConstraint[] array records WHERE clause constraints of the form: 5823** 5824** <blockquote>column OP expr</blockquote> 5825** 5826** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5827** stored in aConstraint[].op using one of the 5828** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5829** ^(The index of the column is stored in 5830** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5831** expr on the right-hand side can be evaluated (and thus the constraint 5832** is usable) and false if it cannot.)^ 5833** 5834** ^The optimizer automatically inverts terms of the form "expr OP column" 5835** and makes other simplifications to the WHERE clause in an attempt to 5836** get as many WHERE clause terms into the form shown above as possible. 5837** ^The aConstraint[] array only reports WHERE clause terms that are 5838** relevant to the particular virtual table being queried. 5839** 5840** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5841** ^Each term of aOrderBy records a column of the ORDER BY clause. 5842** 5843** The colUsed field indicates which columns of the virtual table may be 5844** required by the current scan. Virtual table columns are numbered from 5845** zero in the order in which they appear within the CREATE TABLE statement 5846** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5847** the corresponding bit is set within the colUsed mask if the column may be 5848** required by SQLite. If the table has at least 64 columns and any column 5849** to the right of the first 63 is required, then bit 63 of colUsed is also 5850** set. In other words, column iCol may be required if the expression 5851** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5852** non-zero. 5853** 5854** The [xBestIndex] method must fill aConstraintUsage[] with information 5855** about what parameters to pass to xFilter. ^If argvIndex>0 then 5856** the right-hand side of the corresponding aConstraint[] is evaluated 5857** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5858** is true, then the constraint is assumed to be fully handled by the 5859** virtual table and is not checked again by SQLite.)^ 5860** 5861** ^The idxNum and idxPtr values are recorded and passed into the 5862** [xFilter] method. 5863** ^[sqlite3_free()] is used to free idxPtr if and only if 5864** needToFreeIdxPtr is true. 5865** 5866** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5867** the correct order to satisfy the ORDER BY clause so that no separate 5868** sorting step is required. 5869** 5870** ^The estimatedCost value is an estimate of the cost of a particular 5871** strategy. A cost of N indicates that the cost of the strategy is similar 5872** to a linear scan of an SQLite table with N rows. A cost of log(N) 5873** indicates that the expense of the operation is similar to that of a 5874** binary search on a unique indexed field of an SQLite table with N rows. 5875** 5876** ^The estimatedRows value is an estimate of the number of rows that 5877** will be returned by the strategy. 5878** 5879** The xBestIndex method may optionally populate the idxFlags field with a 5880** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5881** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5882** assumes that the strategy may visit at most one row. 5883** 5884** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5885** SQLite also assumes that if a call to the xUpdate() method is made as 5886** part of the same statement to delete or update a virtual table row and the 5887** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5888** any database changes. In other words, if the xUpdate() returns 5889** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5890** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5891** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5892** the xUpdate method are automatically rolled back by SQLite. 5893** 5894** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5895** structure for SQLite version 3.8.2. If a virtual table extension is 5896** used with an SQLite version earlier than 3.8.2, the results of attempting 5897** to read or write the estimatedRows field are undefined (but are likely 5898** to included crashing the application). The estimatedRows field should 5899** therefore only be used if [sqlite3_libversion_number()] returns a 5900** value greater than or equal to 3008002. Similarly, the idxFlags field 5901** was added for version 3.9.0. It may therefore only be used if 5902** sqlite3_libversion_number() returns a value greater than or equal to 5903** 3009000. 5904*/ 5905struct sqlite3_index_info { 5906 /* Inputs */ 5907 int nConstraint; /* Number of entries in aConstraint */ 5908 struct sqlite3_index_constraint { 5909 int iColumn; /* Column constrained. -1 for ROWID */ 5910 unsigned char op; /* Constraint operator */ 5911 unsigned char usable; /* True if this constraint is usable */ 5912 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5913 } *aConstraint; /* Table of WHERE clause constraints */ 5914 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5915 struct sqlite3_index_orderby { 5916 int iColumn; /* Column number */ 5917 unsigned char desc; /* True for DESC. False for ASC. */ 5918 } *aOrderBy; /* The ORDER BY clause */ 5919 /* Outputs */ 5920 struct sqlite3_index_constraint_usage { 5921 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5922 unsigned char omit; /* Do not code a test for this constraint */ 5923 } *aConstraintUsage; 5924 int idxNum; /* Number used to identify the index */ 5925 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5926 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5927 int orderByConsumed; /* True if output is already ordered */ 5928 double estimatedCost; /* Estimated cost of using this index */ 5929 /* Fields below are only available in SQLite 3.8.2 and later */ 5930 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5931 /* Fields below are only available in SQLite 3.9.0 and later */ 5932 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5933 /* Fields below are only available in SQLite 3.10.0 and later */ 5934 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5935}; 5936 5937/* 5938** CAPI3REF: Virtual Table Scan Flags 5939*/ 5940#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5941 5942/* 5943** CAPI3REF: Virtual Table Constraint Operator Codes 5944** 5945** These macros defined the allowed values for the 5946** [sqlite3_index_info].aConstraint[].op field. Each value represents 5947** an operator that is part of a constraint term in the wHERE clause of 5948** a query that uses a [virtual table]. 5949*/ 5950#define SQLITE_INDEX_CONSTRAINT_EQ 2 5951#define SQLITE_INDEX_CONSTRAINT_GT 4 5952#define SQLITE_INDEX_CONSTRAINT_LE 8 5953#define SQLITE_INDEX_CONSTRAINT_LT 16 5954#define SQLITE_INDEX_CONSTRAINT_GE 32 5955#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5956#define SQLITE_INDEX_CONSTRAINT_LIKE 65 5957#define SQLITE_INDEX_CONSTRAINT_GLOB 66 5958#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5959 5960/* 5961** CAPI3REF: Register A Virtual Table Implementation 5962** METHOD: sqlite3 5963** 5964** ^These routines are used to register a new [virtual table module] name. 5965** ^Module names must be registered before 5966** creating a new [virtual table] using the module and before using a 5967** preexisting [virtual table] for the module. 5968** 5969** ^The module name is registered on the [database connection] specified 5970** by the first parameter. ^The name of the module is given by the 5971** second parameter. ^The third parameter is a pointer to 5972** the implementation of the [virtual table module]. ^The fourth 5973** parameter is an arbitrary client data pointer that is passed through 5974** into the [xCreate] and [xConnect] methods of the virtual table module 5975** when a new virtual table is be being created or reinitialized. 5976** 5977** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5978** is a pointer to a destructor for the pClientData. ^SQLite will 5979** invoke the destructor function (if it is not NULL) when SQLite 5980** no longer needs the pClientData pointer. ^The destructor will also 5981** be invoked if the call to sqlite3_create_module_v2() fails. 5982** ^The sqlite3_create_module() 5983** interface is equivalent to sqlite3_create_module_v2() with a NULL 5984** destructor. 5985*/ 5986SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5987 sqlite3 *db, /* SQLite connection to register module with */ 5988 const char *zName, /* Name of the module */ 5989 const sqlite3_module *p, /* Methods for the module */ 5990 void *pClientData /* Client data for xCreate/xConnect */ 5991); 5992SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5993 sqlite3 *db, /* SQLite connection to register module with */ 5994 const char *zName, /* Name of the module */ 5995 const sqlite3_module *p, /* Methods for the module */ 5996 void *pClientData, /* Client data for xCreate/xConnect */ 5997 void(*xDestroy)(void*) /* Module destructor function */ 5998); 5999 6000/* 6001** CAPI3REF: Virtual Table Instance Object 6002** KEYWORDS: sqlite3_vtab 6003** 6004** Every [virtual table module] implementation uses a subclass 6005** of this object to describe a particular instance 6006** of the [virtual table]. Each subclass will 6007** be tailored to the specific needs of the module implementation. 6008** The purpose of this superclass is to define certain fields that are 6009** common to all module implementations. 6010** 6011** ^Virtual tables methods can set an error message by assigning a 6012** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6013** take care that any prior string is freed by a call to [sqlite3_free()] 6014** prior to assigning a new string to zErrMsg. ^After the error message 6015** is delivered up to the client application, the string will be automatically 6016** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6017*/ 6018struct sqlite3_vtab { 6019 const sqlite3_module *pModule; /* The module for this virtual table */ 6020 int nRef; /* Number of open cursors */ 6021 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6022 /* Virtual table implementations will typically add additional fields */ 6023}; 6024 6025/* 6026** CAPI3REF: Virtual Table Cursor Object 6027** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6028** 6029** Every [virtual table module] implementation uses a subclass of the 6030** following structure to describe cursors that point into the 6031** [virtual table] and are used 6032** to loop through the virtual table. Cursors are created using the 6033** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6034** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6035** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6036** of the module. Each module implementation will define 6037** the content of a cursor structure to suit its own needs. 6038** 6039** This superclass exists in order to define fields of the cursor that 6040** are common to all implementations. 6041*/ 6042struct sqlite3_vtab_cursor { 6043 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6044 /* Virtual table implementations will typically add additional fields */ 6045}; 6046 6047/* 6048** CAPI3REF: Declare The Schema Of A Virtual Table 6049** 6050** ^The [xCreate] and [xConnect] methods of a 6051** [virtual table module] call this interface 6052** to declare the format (the names and datatypes of the columns) of 6053** the virtual tables they implement. 6054*/ 6055SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6056 6057/* 6058** CAPI3REF: Overload A Function For A Virtual Table 6059** METHOD: sqlite3 6060** 6061** ^(Virtual tables can provide alternative implementations of functions 6062** using the [xFindFunction] method of the [virtual table module]. 6063** But global versions of those functions 6064** must exist in order to be overloaded.)^ 6065** 6066** ^(This API makes sure a global version of a function with a particular 6067** name and number of parameters exists. If no such function exists 6068** before this API is called, a new function is created.)^ ^The implementation 6069** of the new function always causes an exception to be thrown. So 6070** the new function is not good for anything by itself. Its only 6071** purpose is to be a placeholder function that can be overloaded 6072** by a [virtual table]. 6073*/ 6074SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6075 6076/* 6077** The interface to the virtual-table mechanism defined above (back up 6078** to a comment remarkably similar to this one) is currently considered 6079** to be experimental. The interface might change in incompatible ways. 6080** If this is a problem for you, do not use the interface at this time. 6081** 6082** When the virtual-table mechanism stabilizes, we will declare the 6083** interface fixed, support it indefinitely, and remove this comment. 6084*/ 6085 6086/* 6087** CAPI3REF: A Handle To An Open BLOB 6088** KEYWORDS: {BLOB handle} {BLOB handles} 6089** 6090** An instance of this object represents an open BLOB on which 6091** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6092** ^Objects of this type are created by [sqlite3_blob_open()] 6093** and destroyed by [sqlite3_blob_close()]. 6094** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6095** can be used to read or write small subsections of the BLOB. 6096** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6097*/ 6098typedef struct sqlite3_blob sqlite3_blob; 6099 6100/* 6101** CAPI3REF: Open A BLOB For Incremental I/O 6102** METHOD: sqlite3 6103** CONSTRUCTOR: sqlite3_blob 6104** 6105** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6106** in row iRow, column zColumn, table zTable in database zDb; 6107** in other words, the same BLOB that would be selected by: 6108** 6109** <pre> 6110** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6111** </pre>)^ 6112** 6113** ^(Parameter zDb is not the filename that contains the database, but 6114** rather the symbolic name of the database. For attached databases, this is 6115** the name that appears after the AS keyword in the [ATTACH] statement. 6116** For the main database file, the database name is "main". For TEMP 6117** tables, the database name is "temp".)^ 6118** 6119** ^If the flags parameter is non-zero, then the BLOB is opened for read 6120** and write access. ^If the flags parameter is zero, the BLOB is opened for 6121** read-only access. 6122** 6123** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6124** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6125** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6126** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6127** on *ppBlob after this function it returns. 6128** 6129** This function fails with SQLITE_ERROR if any of the following are true: 6130** <ul> 6131** <li> ^(Database zDb does not exist)^, 6132** <li> ^(Table zTable does not exist within database zDb)^, 6133** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6134** <li> ^(Column zColumn does not exist)^, 6135** <li> ^(Row iRow is not present in the table)^, 6136** <li> ^(The specified column of row iRow contains a value that is not 6137** a TEXT or BLOB value)^, 6138** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6139** constraint and the blob is being opened for read/write access)^, 6140** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6141** column zColumn is part of a [child key] definition and the blob is 6142** being opened for read/write access)^. 6143** </ul> 6144** 6145** ^Unless it returns SQLITE_MISUSE, this function sets the 6146** [database connection] error code and message accessible via 6147** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6148** 6149** 6150** ^(If the row that a BLOB handle points to is modified by an 6151** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6152** then the BLOB handle is marked as "expired". 6153** This is true if any column of the row is changed, even a column 6154** other than the one the BLOB handle is open on.)^ 6155** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6156** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6157** ^(Changes written into a BLOB prior to the BLOB expiring are not 6158** rolled back by the expiration of the BLOB. Such changes will eventually 6159** commit if the transaction continues to completion.)^ 6160** 6161** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6162** the opened blob. ^The size of a blob may not be changed by this 6163** interface. Use the [UPDATE] SQL command to change the size of a 6164** blob. 6165** 6166** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6167** and the built-in [zeroblob] SQL function may be used to create a 6168** zero-filled blob to read or write using the incremental-blob interface. 6169** 6170** To avoid a resource leak, every open [BLOB handle] should eventually 6171** be released by a call to [sqlite3_blob_close()]. 6172*/ 6173SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 6174 sqlite3*, 6175 const char *zDb, 6176 const char *zTable, 6177 const char *zColumn, 6178 sqlite3_int64 iRow, 6179 int flags, 6180 sqlite3_blob **ppBlob 6181); 6182 6183/* 6184** CAPI3REF: Move a BLOB Handle to a New Row 6185** METHOD: sqlite3_blob 6186** 6187** ^This function is used to move an existing blob handle so that it points 6188** to a different row of the same database table. ^The new row is identified 6189** by the rowid value passed as the second argument. Only the row can be 6190** changed. ^The database, table and column on which the blob handle is open 6191** remain the same. Moving an existing blob handle to a new row can be 6192** faster than closing the existing handle and opening a new one. 6193** 6194** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6195** it must exist and there must be either a blob or text value stored in 6196** the nominated column.)^ ^If the new row is not present in the table, or if 6197** it does not contain a blob or text value, or if another error occurs, an 6198** SQLite error code is returned and the blob handle is considered aborted. 6199** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6200** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6201** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6202** always returns zero. 6203** 6204** ^This function sets the database handle error code and message. 6205*/ 6206SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6207 6208/* 6209** CAPI3REF: Close A BLOB Handle 6210** DESTRUCTOR: sqlite3_blob 6211** 6212** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6213** unconditionally. Even if this routine returns an error code, the 6214** handle is still closed.)^ 6215** 6216** ^If the blob handle being closed was opened for read-write access, and if 6217** the database is in auto-commit mode and there are no other open read-write 6218** blob handles or active write statements, the current transaction is 6219** committed. ^If an error occurs while committing the transaction, an error 6220** code is returned and the transaction rolled back. 6221** 6222** Calling this function with an argument that is not a NULL pointer or an 6223** open blob handle results in undefined behaviour. ^Calling this routine 6224** with a null pointer (such as would be returned by a failed call to 6225** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6226** is passed a valid open blob handle, the values returned by the 6227** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6228*/ 6229SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 6230 6231/* 6232** CAPI3REF: Return The Size Of An Open BLOB 6233** METHOD: sqlite3_blob 6234** 6235** ^Returns the size in bytes of the BLOB accessible via the 6236** successfully opened [BLOB handle] in its only argument. ^The 6237** incremental blob I/O routines can only read or overwriting existing 6238** blob content; they cannot change the size of a blob. 6239** 6240** This routine only works on a [BLOB handle] which has been created 6241** by a prior successful call to [sqlite3_blob_open()] and which has not 6242** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6243** to this routine results in undefined and probably undesirable behavior. 6244*/ 6245SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 6246 6247/* 6248** CAPI3REF: Read Data From A BLOB Incrementally 6249** METHOD: sqlite3_blob 6250** 6251** ^(This function is used to read data from an open [BLOB handle] into a 6252** caller-supplied buffer. N bytes of data are copied into buffer Z 6253** from the open BLOB, starting at offset iOffset.)^ 6254** 6255** ^If offset iOffset is less than N bytes from the end of the BLOB, 6256** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6257** less than zero, [SQLITE_ERROR] is returned and no data is read. 6258** ^The size of the blob (and hence the maximum value of N+iOffset) 6259** can be determined using the [sqlite3_blob_bytes()] interface. 6260** 6261** ^An attempt to read from an expired [BLOB handle] fails with an 6262** error code of [SQLITE_ABORT]. 6263** 6264** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6265** Otherwise, an [error code] or an [extended error code] is returned.)^ 6266** 6267** This routine only works on a [BLOB handle] which has been created 6268** by a prior successful call to [sqlite3_blob_open()] and which has not 6269** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6270** to this routine results in undefined and probably undesirable behavior. 6271** 6272** See also: [sqlite3_blob_write()]. 6273*/ 6274SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6275 6276/* 6277** CAPI3REF: Write Data Into A BLOB Incrementally 6278** METHOD: sqlite3_blob 6279** 6280** ^(This function is used to write data into an open [BLOB handle] from a 6281** caller-supplied buffer. N bytes of data are copied from the buffer Z 6282** into the open BLOB, starting at offset iOffset.)^ 6283** 6284** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6285** Otherwise, an [error code] or an [extended error code] is returned.)^ 6286** ^Unless SQLITE_MISUSE is returned, this function sets the 6287** [database connection] error code and message accessible via 6288** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6289** 6290** ^If the [BLOB handle] passed as the first argument was not opened for 6291** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6292** this function returns [SQLITE_READONLY]. 6293** 6294** This function may only modify the contents of the BLOB; it is 6295** not possible to increase the size of a BLOB using this API. 6296** ^If offset iOffset is less than N bytes from the end of the BLOB, 6297** [SQLITE_ERROR] is returned and no data is written. The size of the 6298** BLOB (and hence the maximum value of N+iOffset) can be determined 6299** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6300** than zero [SQLITE_ERROR] is returned and no data is written. 6301** 6302** ^An attempt to write to an expired [BLOB handle] fails with an 6303** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6304** before the [BLOB handle] expired are not rolled back by the 6305** expiration of the handle, though of course those changes might 6306** have been overwritten by the statement that expired the BLOB handle 6307** or by other independent statements. 6308** 6309** This routine only works on a [BLOB handle] which has been created 6310** by a prior successful call to [sqlite3_blob_open()] and which has not 6311** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6312** to this routine results in undefined and probably undesirable behavior. 6313** 6314** See also: [sqlite3_blob_read()]. 6315*/ 6316SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6317 6318/* 6319** CAPI3REF: Virtual File System Objects 6320** 6321** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6322** that SQLite uses to interact 6323** with the underlying operating system. Most SQLite builds come with a 6324** single default VFS that is appropriate for the host computer. 6325** New VFSes can be registered and existing VFSes can be unregistered. 6326** The following interfaces are provided. 6327** 6328** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6329** ^Names are case sensitive. 6330** ^Names are zero-terminated UTF-8 strings. 6331** ^If there is no match, a NULL pointer is returned. 6332** ^If zVfsName is NULL then the default VFS is returned. 6333** 6334** ^New VFSes are registered with sqlite3_vfs_register(). 6335** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6336** ^The same VFS can be registered multiple times without injury. 6337** ^To make an existing VFS into the default VFS, register it again 6338** with the makeDflt flag set. If two different VFSes with the 6339** same name are registered, the behavior is undefined. If a 6340** VFS is registered with a name that is NULL or an empty string, 6341** then the behavior is undefined. 6342** 6343** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6344** ^(If the default VFS is unregistered, another VFS is chosen as 6345** the default. The choice for the new VFS is arbitrary.)^ 6346*/ 6347SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6348SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6349SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6350 6351/* 6352** CAPI3REF: Mutexes 6353** 6354** The SQLite core uses these routines for thread 6355** synchronization. Though they are intended for internal 6356** use by SQLite, code that links against SQLite is 6357** permitted to use any of these routines. 6358** 6359** The SQLite source code contains multiple implementations 6360** of these mutex routines. An appropriate implementation 6361** is selected automatically at compile-time. The following 6362** implementations are available in the SQLite core: 6363** 6364** <ul> 6365** <li> SQLITE_MUTEX_PTHREADS 6366** <li> SQLITE_MUTEX_W32 6367** <li> SQLITE_MUTEX_NOOP 6368** </ul> 6369** 6370** The SQLITE_MUTEX_NOOP implementation is a set of routines 6371** that does no real locking and is appropriate for use in 6372** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6373** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6374** and Windows. 6375** 6376** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6377** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6378** implementation is included with the library. In this case the 6379** application must supply a custom mutex implementation using the 6380** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6381** before calling sqlite3_initialize() or any other public sqlite3_ 6382** function that calls sqlite3_initialize(). 6383** 6384** ^The sqlite3_mutex_alloc() routine allocates a new 6385** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6386** routine returns NULL if it is unable to allocate the requested 6387** mutex. The argument to sqlite3_mutex_alloc() must one of these 6388** integer constants: 6389** 6390** <ul> 6391** <li> SQLITE_MUTEX_FAST 6392** <li> SQLITE_MUTEX_RECURSIVE 6393** <li> SQLITE_MUTEX_STATIC_MASTER 6394** <li> SQLITE_MUTEX_STATIC_MEM 6395** <li> SQLITE_MUTEX_STATIC_OPEN 6396** <li> SQLITE_MUTEX_STATIC_PRNG 6397** <li> SQLITE_MUTEX_STATIC_LRU 6398** <li> SQLITE_MUTEX_STATIC_PMEM 6399** <li> SQLITE_MUTEX_STATIC_APP1 6400** <li> SQLITE_MUTEX_STATIC_APP2 6401** <li> SQLITE_MUTEX_STATIC_APP3 6402** <li> SQLITE_MUTEX_STATIC_VFS1 6403** <li> SQLITE_MUTEX_STATIC_VFS2 6404** <li> SQLITE_MUTEX_STATIC_VFS3 6405** </ul> 6406** 6407** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6408** cause sqlite3_mutex_alloc() to create 6409** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6410** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6411** The mutex implementation does not need to make a distinction 6412** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6413** not want to. SQLite will only request a recursive mutex in 6414** cases where it really needs one. If a faster non-recursive mutex 6415** implementation is available on the host platform, the mutex subsystem 6416** might return such a mutex in response to SQLITE_MUTEX_FAST. 6417** 6418** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6419** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6420** a pointer to a static preexisting mutex. ^Nine static mutexes are 6421** used by the current version of SQLite. Future versions of SQLite 6422** may add additional static mutexes. Static mutexes are for internal 6423** use by SQLite only. Applications that use SQLite mutexes should 6424** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6425** SQLITE_MUTEX_RECURSIVE. 6426** 6427** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6428** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6429** returns a different mutex on every call. ^For the static 6430** mutex types, the same mutex is returned on every call that has 6431** the same type number. 6432** 6433** ^The sqlite3_mutex_free() routine deallocates a previously 6434** allocated dynamic mutex. Attempting to deallocate a static 6435** mutex results in undefined behavior. 6436** 6437** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6438** to enter a mutex. ^If another thread is already within the mutex, 6439** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6440** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6441** upon successful entry. ^(Mutexes created using 6442** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6443** In such cases, the 6444** mutex must be exited an equal number of times before another thread 6445** can enter.)^ If the same thread tries to enter any mutex other 6446** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6447** 6448** ^(Some systems (for example, Windows 95) do not support the operation 6449** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6450** will always return SQLITE_BUSY. The SQLite core only ever uses 6451** sqlite3_mutex_try() as an optimization so this is acceptable 6452** behavior.)^ 6453** 6454** ^The sqlite3_mutex_leave() routine exits a mutex that was 6455** previously entered by the same thread. The behavior 6456** is undefined if the mutex is not currently entered by the 6457** calling thread or is not currently allocated. 6458** 6459** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6460** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6461** behave as no-ops. 6462** 6463** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6464*/ 6465SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6466SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6467SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6468SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6469SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6470 6471/* 6472** CAPI3REF: Mutex Methods Object 6473** 6474** An instance of this structure defines the low-level routines 6475** used to allocate and use mutexes. 6476** 6477** Usually, the default mutex implementations provided by SQLite are 6478** sufficient, however the application has the option of substituting a custom 6479** implementation for specialized deployments or systems for which SQLite 6480** does not provide a suitable implementation. In this case, the application 6481** creates and populates an instance of this structure to pass 6482** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6483** Additionally, an instance of this structure can be used as an 6484** output variable when querying the system for the current mutex 6485** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6486** 6487** ^The xMutexInit method defined by this structure is invoked as 6488** part of system initialization by the sqlite3_initialize() function. 6489** ^The xMutexInit routine is called by SQLite exactly once for each 6490** effective call to [sqlite3_initialize()]. 6491** 6492** ^The xMutexEnd method defined by this structure is invoked as 6493** part of system shutdown by the sqlite3_shutdown() function. The 6494** implementation of this method is expected to release all outstanding 6495** resources obtained by the mutex methods implementation, especially 6496** those obtained by the xMutexInit method. ^The xMutexEnd() 6497** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6498** 6499** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6500** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6501** xMutexNotheld) implement the following interfaces (respectively): 6502** 6503** <ul> 6504** <li> [sqlite3_mutex_alloc()] </li> 6505** <li> [sqlite3_mutex_free()] </li> 6506** <li> [sqlite3_mutex_enter()] </li> 6507** <li> [sqlite3_mutex_try()] </li> 6508** <li> [sqlite3_mutex_leave()] </li> 6509** <li> [sqlite3_mutex_held()] </li> 6510** <li> [sqlite3_mutex_notheld()] </li> 6511** </ul>)^ 6512** 6513** The only difference is that the public sqlite3_XXX functions enumerated 6514** above silently ignore any invocations that pass a NULL pointer instead 6515** of a valid mutex handle. The implementations of the methods defined 6516** by this structure are not required to handle this case, the results 6517** of passing a NULL pointer instead of a valid mutex handle are undefined 6518** (i.e. it is acceptable to provide an implementation that segfaults if 6519** it is passed a NULL pointer). 6520** 6521** The xMutexInit() method must be threadsafe. It must be harmless to 6522** invoke xMutexInit() multiple times within the same process and without 6523** intervening calls to xMutexEnd(). Second and subsequent calls to 6524** xMutexInit() must be no-ops. 6525** 6526** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6527** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6528** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6529** memory allocation for a fast or recursive mutex. 6530** 6531** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6532** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6533** If xMutexInit fails in any way, it is expected to clean up after itself 6534** prior to returning. 6535*/ 6536typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6537struct sqlite3_mutex_methods { 6538 int (*xMutexInit)(void); 6539 int (*xMutexEnd)(void); 6540 sqlite3_mutex *(*xMutexAlloc)(int); 6541 void (*xMutexFree)(sqlite3_mutex *); 6542 void (*xMutexEnter)(sqlite3_mutex *); 6543 int (*xMutexTry)(sqlite3_mutex *); 6544 void (*xMutexLeave)(sqlite3_mutex *); 6545 int (*xMutexHeld)(sqlite3_mutex *); 6546 int (*xMutexNotheld)(sqlite3_mutex *); 6547}; 6548 6549/* 6550** CAPI3REF: Mutex Verification Routines 6551** 6552** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6553** are intended for use inside assert() statements. The SQLite core 6554** never uses these routines except inside an assert() and applications 6555** are advised to follow the lead of the core. The SQLite core only 6556** provides implementations for these routines when it is compiled 6557** with the SQLITE_DEBUG flag. External mutex implementations 6558** are only required to provide these routines if SQLITE_DEBUG is 6559** defined and if NDEBUG is not defined. 6560** 6561** These routines should return true if the mutex in their argument 6562** is held or not held, respectively, by the calling thread. 6563** 6564** The implementation is not required to provide versions of these 6565** routines that actually work. If the implementation does not provide working 6566** versions of these routines, it should at least provide stubs that always 6567** return true so that one does not get spurious assertion failures. 6568** 6569** If the argument to sqlite3_mutex_held() is a NULL pointer then 6570** the routine should return 1. This seems counter-intuitive since 6571** clearly the mutex cannot be held if it does not exist. But 6572** the reason the mutex does not exist is because the build is not 6573** using mutexes. And we do not want the assert() containing the 6574** call to sqlite3_mutex_held() to fail, so a non-zero return is 6575** the appropriate thing to do. The sqlite3_mutex_notheld() 6576** interface should also return 1 when given a NULL pointer. 6577*/ 6578#ifndef NDEBUG 6579SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6580SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6581#endif 6582 6583/* 6584** CAPI3REF: Mutex Types 6585** 6586** The [sqlite3_mutex_alloc()] interface takes a single argument 6587** which is one of these integer constants. 6588** 6589** The set of static mutexes may change from one SQLite release to the 6590** next. Applications that override the built-in mutex logic must be 6591** prepared to accommodate additional static mutexes. 6592*/ 6593#define SQLITE_MUTEX_FAST 0 6594#define SQLITE_MUTEX_RECURSIVE 1 6595#define SQLITE_MUTEX_STATIC_MASTER 2 6596#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6597#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6598#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6599#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6600#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6601#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6602#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6603#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6604#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6605#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6606#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6607#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6608#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6609 6610/* 6611** CAPI3REF: Retrieve the mutex for a database connection 6612** METHOD: sqlite3 6613** 6614** ^This interface returns a pointer the [sqlite3_mutex] object that 6615** serializes access to the [database connection] given in the argument 6616** when the [threading mode] is Serialized. 6617** ^If the [threading mode] is Single-thread or Multi-thread then this 6618** routine returns a NULL pointer. 6619*/ 6620SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6621 6622/* 6623** CAPI3REF: Low-Level Control Of Database Files 6624** METHOD: sqlite3 6625** 6626** ^The [sqlite3_file_control()] interface makes a direct call to the 6627** xFileControl method for the [sqlite3_io_methods] object associated 6628** with a particular database identified by the second argument. ^The 6629** name of the database is "main" for the main database or "temp" for the 6630** TEMP database, or the name that appears after the AS keyword for 6631** databases that are added using the [ATTACH] SQL command. 6632** ^A NULL pointer can be used in place of "main" to refer to the 6633** main database file. 6634** ^The third and fourth parameters to this routine 6635** are passed directly through to the second and third parameters of 6636** the xFileControl method. ^The return value of the xFileControl 6637** method becomes the return value of this routine. 6638** 6639** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6640** a pointer to the underlying [sqlite3_file] object to be written into 6641** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6642** case is a short-circuit path which does not actually invoke the 6643** underlying sqlite3_io_methods.xFileControl method. 6644** 6645** ^If the second parameter (zDbName) does not match the name of any 6646** open database file, then SQLITE_ERROR is returned. ^This error 6647** code is not remembered and will not be recalled by [sqlite3_errcode()] 6648** or [sqlite3_errmsg()]. The underlying xFileControl method might 6649** also return SQLITE_ERROR. There is no way to distinguish between 6650** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6651** xFileControl method. 6652** 6653** See also: [SQLITE_FCNTL_LOCKSTATE] 6654*/ 6655SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6656 6657/* 6658** CAPI3REF: Testing Interface 6659** 6660** ^The sqlite3_test_control() interface is used to read out internal 6661** state of SQLite and to inject faults into SQLite for testing 6662** purposes. ^The first parameter is an operation code that determines 6663** the number, meaning, and operation of all subsequent parameters. 6664** 6665** This interface is not for use by applications. It exists solely 6666** for verifying the correct operation of the SQLite library. Depending 6667** on how the SQLite library is compiled, this interface might not exist. 6668** 6669** The details of the operation codes, their meanings, the parameters 6670** they take, and what they do are all subject to change without notice. 6671** Unlike most of the SQLite API, this function is not guaranteed to 6672** operate consistently from one release to the next. 6673*/ 6674SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6675 6676/* 6677** CAPI3REF: Testing Interface Operation Codes 6678** 6679** These constants are the valid operation code parameters used 6680** as the first argument to [sqlite3_test_control()]. 6681** 6682** These parameters and their meanings are subject to change 6683** without notice. These values are for testing purposes only. 6684** Applications should not use any of these parameters or the 6685** [sqlite3_test_control()] interface. 6686*/ 6687#define SQLITE_TESTCTRL_FIRST 5 6688#define SQLITE_TESTCTRL_PRNG_SAVE 5 6689#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6690#define SQLITE_TESTCTRL_PRNG_RESET 7 6691#define SQLITE_TESTCTRL_BITVEC_TEST 8 6692#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6693#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6694#define SQLITE_TESTCTRL_PENDING_BYTE 11 6695#define SQLITE_TESTCTRL_ASSERT 12 6696#define SQLITE_TESTCTRL_ALWAYS 13 6697#define SQLITE_TESTCTRL_RESERVE 14 6698#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6699#define SQLITE_TESTCTRL_ISKEYWORD 16 6700#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6701#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6702#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6703#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6704#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6705#define SQLITE_TESTCTRL_BYTEORDER 22 6706#define SQLITE_TESTCTRL_ISINIT 23 6707#define SQLITE_TESTCTRL_SORTER_MMAP 24 6708#define SQLITE_TESTCTRL_IMPOSTER 25 6709#define SQLITE_TESTCTRL_LAST 25 6710 6711/* 6712** CAPI3REF: SQLite Runtime Status 6713** 6714** ^These interfaces are used to retrieve runtime status information 6715** about the performance of SQLite, and optionally to reset various 6716** highwater marks. ^The first argument is an integer code for 6717** the specific parameter to measure. ^(Recognized integer codes 6718** are of the form [status parameters | SQLITE_STATUS_...].)^ 6719** ^The current value of the parameter is returned into *pCurrent. 6720** ^The highest recorded value is returned in *pHighwater. ^If the 6721** resetFlag is true, then the highest record value is reset after 6722** *pHighwater is written. ^(Some parameters do not record the highest 6723** value. For those parameters 6724** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6725** ^(Other parameters record only the highwater mark and not the current 6726** value. For these latter parameters nothing is written into *pCurrent.)^ 6727** 6728** ^The sqlite3_status() and sqlite3_status64() routines return 6729** SQLITE_OK on success and a non-zero [error code] on failure. 6730** 6731** If either the current value or the highwater mark is too large to 6732** be represented by a 32-bit integer, then the values returned by 6733** sqlite3_status() are undefined. 6734** 6735** See also: [sqlite3_db_status()] 6736*/ 6737SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6738SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6739 int op, 6740 sqlite3_int64 *pCurrent, 6741 sqlite3_int64 *pHighwater, 6742 int resetFlag 6743); 6744 6745 6746/* 6747** CAPI3REF: Status Parameters 6748** KEYWORDS: {status parameters} 6749** 6750** These integer constants designate various run-time status parameters 6751** that can be returned by [sqlite3_status()]. 6752** 6753** <dl> 6754** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6755** <dd>This parameter is the current amount of memory checked out 6756** using [sqlite3_malloc()], either directly or indirectly. The 6757** figure includes calls made to [sqlite3_malloc()] by the application 6758** and internal memory usage by the SQLite library. Scratch memory 6759** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6760** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6761** this parameter. The amount returned is the sum of the allocation 6762** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6763** 6764** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6765** <dd>This parameter records the largest memory allocation request 6766** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6767** internal equivalents). Only the value returned in the 6768** *pHighwater parameter to [sqlite3_status()] is of interest. 6769** The value written into the *pCurrent parameter is undefined.</dd>)^ 6770** 6771** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6772** <dd>This parameter records the number of separate memory allocations 6773** currently checked out.</dd>)^ 6774** 6775** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6776** <dd>This parameter returns the number of pages used out of the 6777** [pagecache memory allocator] that was configured using 6778** [SQLITE_CONFIG_PAGECACHE]. The 6779** value returned is in pages, not in bytes.</dd>)^ 6780** 6781** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6782** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6783** <dd>This parameter returns the number of bytes of page cache 6784** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6785** buffer and where forced to overflow to [sqlite3_malloc()]. The 6786** returned value includes allocations that overflowed because they 6787** where too large (they were larger than the "sz" parameter to 6788** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6789** no space was left in the page cache.</dd>)^ 6790** 6791** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6792** <dd>This parameter records the largest memory allocation request 6793** handed to [pagecache memory allocator]. Only the value returned in the 6794** *pHighwater parameter to [sqlite3_status()] is of interest. 6795** The value written into the *pCurrent parameter is undefined.</dd>)^ 6796** 6797** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6798** <dd>This parameter returns the number of allocations used out of the 6799** [scratch memory allocator] configured using 6800** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6801** in bytes. Since a single thread may only have one scratch allocation 6802** outstanding at time, this parameter also reports the number of threads 6803** using scratch memory at the same time.</dd>)^ 6804** 6805** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6806** <dd>This parameter returns the number of bytes of scratch memory 6807** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6808** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6809** returned include overflows because the requested allocation was too 6810** larger (that is, because the requested allocation was larger than the 6811** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6812** slots were available. 6813** </dd>)^ 6814** 6815** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6816** <dd>This parameter records the largest memory allocation request 6817** handed to [scratch memory allocator]. Only the value returned in the 6818** *pHighwater parameter to [sqlite3_status()] is of interest. 6819** The value written into the *pCurrent parameter is undefined.</dd>)^ 6820** 6821** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6822** <dd>The *pHighwater parameter records the deepest parser stack. 6823** The *pCurrent value is undefined. The *pHighwater value is only 6824** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6825** </dl> 6826** 6827** New status parameters may be added from time to time. 6828*/ 6829#define SQLITE_STATUS_MEMORY_USED 0 6830#define SQLITE_STATUS_PAGECACHE_USED 1 6831#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6832#define SQLITE_STATUS_SCRATCH_USED 3 6833#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6834#define SQLITE_STATUS_MALLOC_SIZE 5 6835#define SQLITE_STATUS_PARSER_STACK 6 6836#define SQLITE_STATUS_PAGECACHE_SIZE 7 6837#define SQLITE_STATUS_SCRATCH_SIZE 8 6838#define SQLITE_STATUS_MALLOC_COUNT 9 6839 6840/* 6841** CAPI3REF: Database Connection Status 6842** METHOD: sqlite3 6843** 6844** ^This interface is used to retrieve runtime status information 6845** about a single [database connection]. ^The first argument is the 6846** database connection object to be interrogated. ^The second argument 6847** is an integer constant, taken from the set of 6848** [SQLITE_DBSTATUS options], that 6849** determines the parameter to interrogate. The set of 6850** [SQLITE_DBSTATUS options] is likely 6851** to grow in future releases of SQLite. 6852** 6853** ^The current value of the requested parameter is written into *pCur 6854** and the highest instantaneous value is written into *pHiwtr. ^If 6855** the resetFlg is true, then the highest instantaneous value is 6856** reset back down to the current value. 6857** 6858** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6859** non-zero [error code] on failure. 6860** 6861** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6862*/ 6863SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6864 6865/* 6866** CAPI3REF: Status Parameters for database connections 6867** KEYWORDS: {SQLITE_DBSTATUS options} 6868** 6869** These constants are the available integer "verbs" that can be passed as 6870** the second argument to the [sqlite3_db_status()] interface. 6871** 6872** New verbs may be added in future releases of SQLite. Existing verbs 6873** might be discontinued. Applications should check the return code from 6874** [sqlite3_db_status()] to make sure that the call worked. 6875** The [sqlite3_db_status()] interface will return a non-zero error code 6876** if a discontinued or unsupported verb is invoked. 6877** 6878** <dl> 6879** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6880** <dd>This parameter returns the number of lookaside memory slots currently 6881** checked out.</dd>)^ 6882** 6883** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6884** <dd>This parameter returns the number malloc attempts that were 6885** satisfied using lookaside memory. Only the high-water value is meaningful; 6886** the current value is always zero.)^ 6887** 6888** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6889** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6890** <dd>This parameter returns the number malloc attempts that might have 6891** been satisfied using lookaside memory but failed due to the amount of 6892** memory requested being larger than the lookaside slot size. 6893** Only the high-water value is meaningful; 6894** the current value is always zero.)^ 6895** 6896** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6897** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6898** <dd>This parameter returns the number malloc attempts that might have 6899** been satisfied using lookaside memory but failed due to all lookaside 6900** memory already being in use. 6901** Only the high-water value is meaningful; 6902** the current value is always zero.)^ 6903** 6904** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6905** <dd>This parameter returns the approximate number of bytes of heap 6906** memory used by all pager caches associated with the database connection.)^ 6907** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6908** 6909** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6910** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6911** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6912** pager cache is shared between two or more connections the bytes of heap 6913** memory used by that pager cache is divided evenly between the attached 6914** connections.)^ In other words, if none of the pager caches associated 6915** with the database connection are shared, this request returns the same 6916** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6917** shared, the value returned by this call will be smaller than that returned 6918** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6919** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6920** 6921** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6922** <dd>This parameter returns the approximate number of bytes of heap 6923** memory used to store the schema for all databases associated 6924** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6925** ^The full amount of memory used by the schemas is reported, even if the 6926** schema memory is shared with other database connections due to 6927** [shared cache mode] being enabled. 6928** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6929** 6930** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6931** <dd>This parameter returns the approximate number of bytes of heap 6932** and lookaside memory used by all prepared statements associated with 6933** the database connection.)^ 6934** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6935** </dd> 6936** 6937** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6938** <dd>This parameter returns the number of pager cache hits that have 6939** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6940** is always 0. 6941** </dd> 6942** 6943** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6944** <dd>This parameter returns the number of pager cache misses that have 6945** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6946** is always 0. 6947** </dd> 6948** 6949** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6950** <dd>This parameter returns the number of dirty cache entries that have 6951** been written to disk. Specifically, the number of pages written to the 6952** wal file in wal mode databases, or the number of pages written to the 6953** database file in rollback mode databases. Any pages written as part of 6954** transaction rollback or database recovery operations are not included. 6955** If an IO or other error occurs while writing a page to disk, the effect 6956** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6957** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6958** </dd> 6959** 6960** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6961** <dd>This parameter returns zero for the current value if and only if 6962** all foreign key constraints (deferred or immediate) have been 6963** resolved.)^ ^The highwater mark is always 0. 6964** </dd> 6965** </dl> 6966*/ 6967#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6968#define SQLITE_DBSTATUS_CACHE_USED 1 6969#define SQLITE_DBSTATUS_SCHEMA_USED 2 6970#define SQLITE_DBSTATUS_STMT_USED 3 6971#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6972#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6973#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6974#define SQLITE_DBSTATUS_CACHE_HIT 7 6975#define SQLITE_DBSTATUS_CACHE_MISS 8 6976#define SQLITE_DBSTATUS_CACHE_WRITE 9 6977#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6978#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 6979#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 6980 6981 6982/* 6983** CAPI3REF: Prepared Statement Status 6984** METHOD: sqlite3_stmt 6985** 6986** ^(Each prepared statement maintains various 6987** [SQLITE_STMTSTATUS counters] that measure the number 6988** of times it has performed specific operations.)^ These counters can 6989** be used to monitor the performance characteristics of the prepared 6990** statements. For example, if the number of table steps greatly exceeds 6991** the number of table searches or result rows, that would tend to indicate 6992** that the prepared statement is using a full table scan rather than 6993** an index. 6994** 6995** ^(This interface is used to retrieve and reset counter values from 6996** a [prepared statement]. The first argument is the prepared statement 6997** object to be interrogated. The second argument 6998** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6999** to be interrogated.)^ 7000** ^The current value of the requested counter is returned. 7001** ^If the resetFlg is true, then the counter is reset to zero after this 7002** interface call returns. 7003** 7004** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7005*/ 7006SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7007 7008/* 7009** CAPI3REF: Status Parameters for prepared statements 7010** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7011** 7012** These preprocessor macros define integer codes that name counter 7013** values associated with the [sqlite3_stmt_status()] interface. 7014** The meanings of the various counters are as follows: 7015** 7016** <dl> 7017** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7018** <dd>^This is the number of times that SQLite has stepped forward in 7019** a table as part of a full table scan. Large numbers for this counter 7020** may indicate opportunities for performance improvement through 7021** careful use of indices.</dd> 7022** 7023** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7024** <dd>^This is the number of sort operations that have occurred. 7025** A non-zero value in this counter may indicate an opportunity to 7026** improvement performance through careful use of indices.</dd> 7027** 7028** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7029** <dd>^This is the number of rows inserted into transient indices that 7030** were created automatically in order to help joins run faster. 7031** A non-zero value in this counter may indicate an opportunity to 7032** improvement performance by adding permanent indices that do not 7033** need to be reinitialized each time the statement is run.</dd> 7034** 7035** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7036** <dd>^This is the number of virtual machine operations executed 7037** by the prepared statement if that number is less than or equal 7038** to 2147483647. The number of virtual machine operations can be 7039** used as a proxy for the total work done by the prepared statement. 7040** If the number of virtual machine operations exceeds 2147483647 7041** then the value returned by this statement status code is undefined. 7042** </dd> 7043** </dl> 7044*/ 7045#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7046#define SQLITE_STMTSTATUS_SORT 2 7047#define SQLITE_STMTSTATUS_AUTOINDEX 3 7048#define SQLITE_STMTSTATUS_VM_STEP 4 7049 7050/* 7051** CAPI3REF: Custom Page Cache Object 7052** 7053** The sqlite3_pcache type is opaque. It is implemented by 7054** the pluggable module. The SQLite core has no knowledge of 7055** its size or internal structure and never deals with the 7056** sqlite3_pcache object except by holding and passing pointers 7057** to the object. 7058** 7059** See [sqlite3_pcache_methods2] for additional information. 7060*/ 7061typedef struct sqlite3_pcache sqlite3_pcache; 7062 7063/* 7064** CAPI3REF: Custom Page Cache Object 7065** 7066** The sqlite3_pcache_page object represents a single page in the 7067** page cache. The page cache will allocate instances of this 7068** object. Various methods of the page cache use pointers to instances 7069** of this object as parameters or as their return value. 7070** 7071** See [sqlite3_pcache_methods2] for additional information. 7072*/ 7073typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7074struct sqlite3_pcache_page { 7075 void *pBuf; /* The content of the page */ 7076 void *pExtra; /* Extra information associated with the page */ 7077}; 7078 7079/* 7080** CAPI3REF: Application Defined Page Cache. 7081** KEYWORDS: {page cache} 7082** 7083** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7084** register an alternative page cache implementation by passing in an 7085** instance of the sqlite3_pcache_methods2 structure.)^ 7086** In many applications, most of the heap memory allocated by 7087** SQLite is used for the page cache. 7088** By implementing a 7089** custom page cache using this API, an application can better control 7090** the amount of memory consumed by SQLite, the way in which 7091** that memory is allocated and released, and the policies used to 7092** determine exactly which parts of a database file are cached and for 7093** how long. 7094** 7095** The alternative page cache mechanism is an 7096** extreme measure that is only needed by the most demanding applications. 7097** The built-in page cache is recommended for most uses. 7098** 7099** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7100** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7101** the application may discard the parameter after the call to 7102** [sqlite3_config()] returns.)^ 7103** 7104** [[the xInit() page cache method]] 7105** ^(The xInit() method is called once for each effective 7106** call to [sqlite3_initialize()])^ 7107** (usually only once during the lifetime of the process). ^(The xInit() 7108** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7109** The intent of the xInit() method is to set up global data structures 7110** required by the custom page cache implementation. 7111** ^(If the xInit() method is NULL, then the 7112** built-in default page cache is used instead of the application defined 7113** page cache.)^ 7114** 7115** [[the xShutdown() page cache method]] 7116** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7117** It can be used to clean up 7118** any outstanding resources before process shutdown, if required. 7119** ^The xShutdown() method may be NULL. 7120** 7121** ^SQLite automatically serializes calls to the xInit method, 7122** so the xInit method need not be threadsafe. ^The 7123** xShutdown method is only called from [sqlite3_shutdown()] so it does 7124** not need to be threadsafe either. All other methods must be threadsafe 7125** in multithreaded applications. 7126** 7127** ^SQLite will never invoke xInit() more than once without an intervening 7128** call to xShutdown(). 7129** 7130** [[the xCreate() page cache methods]] 7131** ^SQLite invokes the xCreate() method to construct a new cache instance. 7132** SQLite will typically create one cache instance for each open database file, 7133** though this is not guaranteed. ^The 7134** first parameter, szPage, is the size in bytes of the pages that must 7135** be allocated by the cache. ^szPage will always a power of two. ^The 7136** second parameter szExtra is a number of bytes of extra storage 7137** associated with each page cache entry. ^The szExtra parameter will 7138** a number less than 250. SQLite will use the 7139** extra szExtra bytes on each page to store metadata about the underlying 7140** database page on disk. The value passed into szExtra depends 7141** on the SQLite version, the target platform, and how SQLite was compiled. 7142** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7143** created will be used to cache database pages of a file stored on disk, or 7144** false if it is used for an in-memory database. The cache implementation 7145** does not have to do anything special based with the value of bPurgeable; 7146** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7147** never invoke xUnpin() except to deliberately delete a page. 7148** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7149** false will always have the "discard" flag set to true. 7150** ^Hence, a cache created with bPurgeable false will 7151** never contain any unpinned pages. 7152** 7153** [[the xCachesize() page cache method]] 7154** ^(The xCachesize() method may be called at any time by SQLite to set the 7155** suggested maximum cache-size (number of pages stored by) the cache 7156** instance passed as the first argument. This is the value configured using 7157** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7158** parameter, the implementation is not required to do anything with this 7159** value; it is advisory only. 7160** 7161** [[the xPagecount() page cache methods]] 7162** The xPagecount() method must return the number of pages currently 7163** stored in the cache, both pinned and unpinned. 7164** 7165** [[the xFetch() page cache methods]] 7166** The xFetch() method locates a page in the cache and returns a pointer to 7167** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7168** The pBuf element of the returned sqlite3_pcache_page object will be a 7169** pointer to a buffer of szPage bytes used to store the content of a 7170** single database page. The pExtra element of sqlite3_pcache_page will be 7171** a pointer to the szExtra bytes of extra storage that SQLite has requested 7172** for each entry in the page cache. 7173** 7174** The page to be fetched is determined by the key. ^The minimum key value 7175** is 1. After it has been retrieved using xFetch, the page is considered 7176** to be "pinned". 7177** 7178** If the requested page is already in the page cache, then the page cache 7179** implementation must return a pointer to the page buffer with its content 7180** intact. If the requested page is not already in the cache, then the 7181** cache implementation should use the value of the createFlag 7182** parameter to help it determined what action to take: 7183** 7184** <table border=1 width=85% align=center> 7185** <tr><th> createFlag <th> Behavior when page is not already in cache 7186** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7187** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7188** Otherwise return NULL. 7189** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7190** NULL if allocating a new page is effectively impossible. 7191** </table> 7192** 7193** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7194** will only use a createFlag of 2 after a prior call with a createFlag of 1 7195** failed.)^ In between the to xFetch() calls, SQLite may 7196** attempt to unpin one or more cache pages by spilling the content of 7197** pinned pages to disk and synching the operating system disk cache. 7198** 7199** [[the xUnpin() page cache method]] 7200** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7201** as its second argument. If the third parameter, discard, is non-zero, 7202** then the page must be evicted from the cache. 7203** ^If the discard parameter is 7204** zero, then the page may be discarded or retained at the discretion of 7205** page cache implementation. ^The page cache implementation 7206** may choose to evict unpinned pages at any time. 7207** 7208** The cache must not perform any reference counting. A single 7209** call to xUnpin() unpins the page regardless of the number of prior calls 7210** to xFetch(). 7211** 7212** [[the xRekey() page cache methods]] 7213** The xRekey() method is used to change the key value associated with the 7214** page passed as the second argument. If the cache 7215** previously contains an entry associated with newKey, it must be 7216** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7217** to be pinned. 7218** 7219** When SQLite calls the xTruncate() method, the cache must discard all 7220** existing cache entries with page numbers (keys) greater than or equal 7221** to the value of the iLimit parameter passed to xTruncate(). If any 7222** of these pages are pinned, they are implicitly unpinned, meaning that 7223** they can be safely discarded. 7224** 7225** [[the xDestroy() page cache method]] 7226** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7227** All resources associated with the specified cache should be freed. ^After 7228** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7229** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7230** functions. 7231** 7232** [[the xShrink() page cache method]] 7233** ^SQLite invokes the xShrink() method when it wants the page cache to 7234** free up as much of heap memory as possible. The page cache implementation 7235** is not obligated to free any memory, but well-behaved implementations should 7236** do their best. 7237*/ 7238typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7239struct sqlite3_pcache_methods2 { 7240 int iVersion; 7241 void *pArg; 7242 int (*xInit)(void*); 7243 void (*xShutdown)(void*); 7244 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7245 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7246 int (*xPagecount)(sqlite3_pcache*); 7247 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7248 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7249 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7250 unsigned oldKey, unsigned newKey); 7251 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7252 void (*xDestroy)(sqlite3_pcache*); 7253 void (*xShrink)(sqlite3_pcache*); 7254}; 7255 7256/* 7257** This is the obsolete pcache_methods object that has now been replaced 7258** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7259** retained in the header file for backwards compatibility only. 7260*/ 7261typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7262struct sqlite3_pcache_methods { 7263 void *pArg; 7264 int (*xInit)(void*); 7265 void (*xShutdown)(void*); 7266 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7267 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7268 int (*xPagecount)(sqlite3_pcache*); 7269 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7270 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7271 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7272 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7273 void (*xDestroy)(sqlite3_pcache*); 7274}; 7275 7276 7277/* 7278** CAPI3REF: Online Backup Object 7279** 7280** The sqlite3_backup object records state information about an ongoing 7281** online backup operation. ^The sqlite3_backup object is created by 7282** a call to [sqlite3_backup_init()] and is destroyed by a call to 7283** [sqlite3_backup_finish()]. 7284** 7285** See Also: [Using the SQLite Online Backup API] 7286*/ 7287typedef struct sqlite3_backup sqlite3_backup; 7288 7289/* 7290** CAPI3REF: Online Backup API. 7291** 7292** The backup API copies the content of one database into another. 7293** It is useful either for creating backups of databases or 7294** for copying in-memory databases to or from persistent files. 7295** 7296** See Also: [Using the SQLite Online Backup API] 7297** 7298** ^SQLite holds a write transaction open on the destination database file 7299** for the duration of the backup operation. 7300** ^The source database is read-locked only while it is being read; 7301** it is not locked continuously for the entire backup operation. 7302** ^Thus, the backup may be performed on a live source database without 7303** preventing other database connections from 7304** reading or writing to the source database while the backup is underway. 7305** 7306** ^(To perform a backup operation: 7307** <ol> 7308** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7309** backup, 7310** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7311** the data between the two databases, and finally 7312** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7313** associated with the backup operation. 7314** </ol>)^ 7315** There should be exactly one call to sqlite3_backup_finish() for each 7316** successful call to sqlite3_backup_init(). 7317** 7318** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7319** 7320** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7321** [database connection] associated with the destination database 7322** and the database name, respectively. 7323** ^The database name is "main" for the main database, "temp" for the 7324** temporary database, or the name specified after the AS keyword in 7325** an [ATTACH] statement for an attached database. 7326** ^The S and M arguments passed to 7327** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7328** and database name of the source database, respectively. 7329** ^The source and destination [database connections] (parameters S and D) 7330** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7331** an error. 7332** 7333** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7334** there is already a read or read-write transaction open on the 7335** destination database. 7336** 7337** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7338** returned and an error code and error message are stored in the 7339** destination [database connection] D. 7340** ^The error code and message for the failed call to sqlite3_backup_init() 7341** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7342** [sqlite3_errmsg16()] functions. 7343** ^A successful call to sqlite3_backup_init() returns a pointer to an 7344** [sqlite3_backup] object. 7345** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7346** sqlite3_backup_finish() functions to perform the specified backup 7347** operation. 7348** 7349** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7350** 7351** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7352** the source and destination databases specified by [sqlite3_backup] object B. 7353** ^If N is negative, all remaining source pages are copied. 7354** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7355** are still more pages to be copied, then the function returns [SQLITE_OK]. 7356** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7357** from source to destination, then it returns [SQLITE_DONE]. 7358** ^If an error occurs while running sqlite3_backup_step(B,N), 7359** then an [error code] is returned. ^As well as [SQLITE_OK] and 7360** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7361** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7362** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7363** 7364** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7365** <ol> 7366** <li> the destination database was opened read-only, or 7367** <li> the destination database is using write-ahead-log journaling 7368** and the destination and source page sizes differ, or 7369** <li> the destination database is an in-memory database and the 7370** destination and source page sizes differ. 7371** </ol>)^ 7372** 7373** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7374** the [sqlite3_busy_handler | busy-handler function] 7375** is invoked (if one is specified). ^If the 7376** busy-handler returns non-zero before the lock is available, then 7377** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7378** sqlite3_backup_step() can be retried later. ^If the source 7379** [database connection] 7380** is being used to write to the source database when sqlite3_backup_step() 7381** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7382** case the call to sqlite3_backup_step() can be retried later on. ^(If 7383** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7384** [SQLITE_READONLY] is returned, then 7385** there is no point in retrying the call to sqlite3_backup_step(). These 7386** errors are considered fatal.)^ The application must accept 7387** that the backup operation has failed and pass the backup operation handle 7388** to the sqlite3_backup_finish() to release associated resources. 7389** 7390** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7391** on the destination file. ^The exclusive lock is not released until either 7392** sqlite3_backup_finish() is called or the backup operation is complete 7393** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7394** sqlite3_backup_step() obtains a [shared lock] on the source database that 7395** lasts for the duration of the sqlite3_backup_step() call. 7396** ^Because the source database is not locked between calls to 7397** sqlite3_backup_step(), the source database may be modified mid-way 7398** through the backup process. ^If the source database is modified by an 7399** external process or via a database connection other than the one being 7400** used by the backup operation, then the backup will be automatically 7401** restarted by the next call to sqlite3_backup_step(). ^If the source 7402** database is modified by the using the same database connection as is used 7403** by the backup operation, then the backup database is automatically 7404** updated at the same time. 7405** 7406** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7407** 7408** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7409** application wishes to abandon the backup operation, the application 7410** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7411** ^The sqlite3_backup_finish() interfaces releases all 7412** resources associated with the [sqlite3_backup] object. 7413** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7414** active write-transaction on the destination database is rolled back. 7415** The [sqlite3_backup] object is invalid 7416** and may not be used following a call to sqlite3_backup_finish(). 7417** 7418** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7419** sqlite3_backup_step() errors occurred, regardless or whether or not 7420** sqlite3_backup_step() completed. 7421** ^If an out-of-memory condition or IO error occurred during any prior 7422** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7423** sqlite3_backup_finish() returns the corresponding [error code]. 7424** 7425** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7426** is not a permanent error and does not affect the return value of 7427** sqlite3_backup_finish(). 7428** 7429** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7430** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7431** 7432** ^The sqlite3_backup_remaining() routine returns the number of pages still 7433** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7434** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7435** in the source database at the conclusion of the most recent 7436** sqlite3_backup_step(). 7437** ^(The values returned by these functions are only updated by 7438** sqlite3_backup_step(). If the source database is modified in a way that 7439** changes the size of the source database or the number of pages remaining, 7440** those changes are not reflected in the output of sqlite3_backup_pagecount() 7441** and sqlite3_backup_remaining() until after the next 7442** sqlite3_backup_step().)^ 7443** 7444** <b>Concurrent Usage of Database Handles</b> 7445** 7446** ^The source [database connection] may be used by the application for other 7447** purposes while a backup operation is underway or being initialized. 7448** ^If SQLite is compiled and configured to support threadsafe database 7449** connections, then the source database connection may be used concurrently 7450** from within other threads. 7451** 7452** However, the application must guarantee that the destination 7453** [database connection] is not passed to any other API (by any thread) after 7454** sqlite3_backup_init() is called and before the corresponding call to 7455** sqlite3_backup_finish(). SQLite does not currently check to see 7456** if the application incorrectly accesses the destination [database connection] 7457** and so no error code is reported, but the operations may malfunction 7458** nevertheless. Use of the destination database connection while a 7459** backup is in progress might also also cause a mutex deadlock. 7460** 7461** If running in [shared cache mode], the application must 7462** guarantee that the shared cache used by the destination database 7463** is not accessed while the backup is running. In practice this means 7464** that the application must guarantee that the disk file being 7465** backed up to is not accessed by any connection within the process, 7466** not just the specific connection that was passed to sqlite3_backup_init(). 7467** 7468** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7469** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7470** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7471** APIs are not strictly speaking threadsafe. If they are invoked at the 7472** same time as another thread is invoking sqlite3_backup_step() it is 7473** possible that they return invalid values. 7474*/ 7475SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7476 sqlite3 *pDest, /* Destination database handle */ 7477 const char *zDestName, /* Destination database name */ 7478 sqlite3 *pSource, /* Source database handle */ 7479 const char *zSourceName /* Source database name */ 7480); 7481SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7482SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7483SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7484SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7485 7486/* 7487** CAPI3REF: Unlock Notification 7488** METHOD: sqlite3 7489** 7490** ^When running in shared-cache mode, a database operation may fail with 7491** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7492** individual tables within the shared-cache cannot be obtained. See 7493** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7494** ^This API may be used to register a callback that SQLite will invoke 7495** when the connection currently holding the required lock relinquishes it. 7496** ^This API is only available if the library was compiled with the 7497** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7498** 7499** See Also: [Using the SQLite Unlock Notification Feature]. 7500** 7501** ^Shared-cache locks are released when a database connection concludes 7502** its current transaction, either by committing it or rolling it back. 7503** 7504** ^When a connection (known as the blocked connection) fails to obtain a 7505** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7506** identity of the database connection (the blocking connection) that 7507** has locked the required resource is stored internally. ^After an 7508** application receives an SQLITE_LOCKED error, it may call the 7509** sqlite3_unlock_notify() method with the blocked connection handle as 7510** the first argument to register for a callback that will be invoked 7511** when the blocking connections current transaction is concluded. ^The 7512** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7513** call that concludes the blocking connections transaction. 7514** 7515** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7516** there is a chance that the blocking connection will have already 7517** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7518** If this happens, then the specified callback is invoked immediately, 7519** from within the call to sqlite3_unlock_notify().)^ 7520** 7521** ^If the blocked connection is attempting to obtain a write-lock on a 7522** shared-cache table, and more than one other connection currently holds 7523** a read-lock on the same table, then SQLite arbitrarily selects one of 7524** the other connections to use as the blocking connection. 7525** 7526** ^(There may be at most one unlock-notify callback registered by a 7527** blocked connection. If sqlite3_unlock_notify() is called when the 7528** blocked connection already has a registered unlock-notify callback, 7529** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7530** called with a NULL pointer as its second argument, then any existing 7531** unlock-notify callback is canceled. ^The blocked connections 7532** unlock-notify callback may also be canceled by closing the blocked 7533** connection using [sqlite3_close()]. 7534** 7535** The unlock-notify callback is not reentrant. If an application invokes 7536** any sqlite3_xxx API functions from within an unlock-notify callback, a 7537** crash or deadlock may be the result. 7538** 7539** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7540** returns SQLITE_OK. 7541** 7542** <b>Callback Invocation Details</b> 7543** 7544** When an unlock-notify callback is registered, the application provides a 7545** single void* pointer that is passed to the callback when it is invoked. 7546** However, the signature of the callback function allows SQLite to pass 7547** it an array of void* context pointers. The first argument passed to 7548** an unlock-notify callback is a pointer to an array of void* pointers, 7549** and the second is the number of entries in the array. 7550** 7551** When a blocking connections transaction is concluded, there may be 7552** more than one blocked connection that has registered for an unlock-notify 7553** callback. ^If two or more such blocked connections have specified the 7554** same callback function, then instead of invoking the callback function 7555** multiple times, it is invoked once with the set of void* context pointers 7556** specified by the blocked connections bundled together into an array. 7557** This gives the application an opportunity to prioritize any actions 7558** related to the set of unblocked database connections. 7559** 7560** <b>Deadlock Detection</b> 7561** 7562** Assuming that after registering for an unlock-notify callback a 7563** database waits for the callback to be issued before taking any further 7564** action (a reasonable assumption), then using this API may cause the 7565** application to deadlock. For example, if connection X is waiting for 7566** connection Y's transaction to be concluded, and similarly connection 7567** Y is waiting on connection X's transaction, then neither connection 7568** will proceed and the system may remain deadlocked indefinitely. 7569** 7570** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7571** detection. ^If a given call to sqlite3_unlock_notify() would put the 7572** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7573** unlock-notify callback is registered. The system is said to be in 7574** a deadlocked state if connection A has registered for an unlock-notify 7575** callback on the conclusion of connection B's transaction, and connection 7576** B has itself registered for an unlock-notify callback when connection 7577** A's transaction is concluded. ^Indirect deadlock is also detected, so 7578** the system is also considered to be deadlocked if connection B has 7579** registered for an unlock-notify callback on the conclusion of connection 7580** C's transaction, where connection C is waiting on connection A. ^Any 7581** number of levels of indirection are allowed. 7582** 7583** <b>The "DROP TABLE" Exception</b> 7584** 7585** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7586** always appropriate to call sqlite3_unlock_notify(). There is however, 7587** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7588** SQLite checks if there are any currently executing SELECT statements 7589** that belong to the same connection. If there are, SQLITE_LOCKED is 7590** returned. In this case there is no "blocking connection", so invoking 7591** sqlite3_unlock_notify() results in the unlock-notify callback being 7592** invoked immediately. If the application then re-attempts the "DROP TABLE" 7593** or "DROP INDEX" query, an infinite loop might be the result. 7594** 7595** One way around this problem is to check the extended error code returned 7596** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7597** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7598** the special "DROP TABLE/INDEX" case, the extended error code is just 7599** SQLITE_LOCKED.)^ 7600*/ 7601SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7602 sqlite3 *pBlocked, /* Waiting connection */ 7603 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7604 void *pNotifyArg /* Argument to pass to xNotify */ 7605); 7606 7607 7608/* 7609** CAPI3REF: String Comparison 7610** 7611** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7612** and extensions to compare the contents of two buffers containing UTF-8 7613** strings in a case-independent fashion, using the same definition of "case 7614** independence" that SQLite uses internally when comparing identifiers. 7615*/ 7616SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7617SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7618 7619/* 7620** CAPI3REF: String Globbing 7621* 7622** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7623** string X matches the [GLOB] pattern P. 7624** ^The definition of [GLOB] pattern matching used in 7625** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7626** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7627** is case sensitive. 7628** 7629** Note that this routine returns zero on a match and non-zero if the strings 7630** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7631** 7632** See also: [sqlite3_strlike()]. 7633*/ 7634SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7635 7636/* 7637** CAPI3REF: String LIKE Matching 7638* 7639** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7640** string X matches the [LIKE] pattern P with escape character E. 7641** ^The definition of [LIKE] pattern matching used in 7642** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7643** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7644** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7645** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7646** insensitive - equivalent upper and lower case ASCII characters match 7647** one another. 7648** 7649** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7650** only ASCII characters are case folded. 7651** 7652** Note that this routine returns zero on a match and non-zero if the strings 7653** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7654** 7655** See also: [sqlite3_strglob()]. 7656*/ 7657SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7658 7659/* 7660** CAPI3REF: Error Logging Interface 7661** 7662** ^The [sqlite3_log()] interface writes a message into the [error log] 7663** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7664** ^If logging is enabled, the zFormat string and subsequent arguments are 7665** used with [sqlite3_snprintf()] to generate the final output string. 7666** 7667** The sqlite3_log() interface is intended for use by extensions such as 7668** virtual tables, collating functions, and SQL functions. While there is 7669** nothing to prevent an application from calling sqlite3_log(), doing so 7670** is considered bad form. 7671** 7672** The zFormat string must not be NULL. 7673** 7674** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7675** will not use dynamically allocated memory. The log message is stored in 7676** a fixed-length buffer on the stack. If the log message is longer than 7677** a few hundred characters, it will be truncated to the length of the 7678** buffer. 7679*/ 7680SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7681 7682/* 7683** CAPI3REF: Write-Ahead Log Commit Hook 7684** METHOD: sqlite3 7685** 7686** ^The [sqlite3_wal_hook()] function is used to register a callback that 7687** is invoked each time data is committed to a database in wal mode. 7688** 7689** ^(The callback is invoked by SQLite after the commit has taken place and 7690** the associated write-lock on the database released)^, so the implementation 7691** may read, write or [checkpoint] the database as required. 7692** 7693** ^The first parameter passed to the callback function when it is invoked 7694** is a copy of the third parameter passed to sqlite3_wal_hook() when 7695** registering the callback. ^The second is a copy of the database handle. 7696** ^The third parameter is the name of the database that was written to - 7697** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7698** is the number of pages currently in the write-ahead log file, 7699** including those that were just committed. 7700** 7701** The callback function should normally return [SQLITE_OK]. ^If an error 7702** code is returned, that error will propagate back up through the 7703** SQLite code base to cause the statement that provoked the callback 7704** to report an error, though the commit will have still occurred. If the 7705** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7706** that does not correspond to any valid SQLite error code, the results 7707** are undefined. 7708** 7709** A single database handle may have at most a single write-ahead log callback 7710** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7711** previously registered write-ahead log callback. ^Note that the 7712** [sqlite3_wal_autocheckpoint()] interface and the 7713** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7714** overwrite any prior [sqlite3_wal_hook()] settings. 7715*/ 7716SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7717 sqlite3*, 7718 int(*)(void *,sqlite3*,const char*,int), 7719 void* 7720); 7721 7722/* 7723** CAPI3REF: Configure an auto-checkpoint 7724** METHOD: sqlite3 7725** 7726** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7727** [sqlite3_wal_hook()] that causes any database on [database connection] D 7728** to automatically [checkpoint] 7729** after committing a transaction if there are N or 7730** more frames in the [write-ahead log] file. ^Passing zero or 7731** a negative value as the nFrame parameter disables automatic 7732** checkpoints entirely. 7733** 7734** ^The callback registered by this function replaces any existing callback 7735** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7736** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7737** configured by this function. 7738** 7739** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7740** from SQL. 7741** 7742** ^Checkpoints initiated by this mechanism are 7743** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7744** 7745** ^Every new [database connection] defaults to having the auto-checkpoint 7746** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7747** pages. The use of this interface 7748** is only necessary if the default setting is found to be suboptimal 7749** for a particular application. 7750*/ 7751SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7752 7753/* 7754** CAPI3REF: Checkpoint a database 7755** METHOD: sqlite3 7756** 7757** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7758** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7759** 7760** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7761** [write-ahead log] for database X on [database connection] D to be 7762** transferred into the database file and for the write-ahead log to 7763** be reset. See the [checkpointing] documentation for addition 7764** information. 7765** 7766** This interface used to be the only way to cause a checkpoint to 7767** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7768** interface was added. This interface is retained for backwards 7769** compatibility and as a convenience for applications that need to manually 7770** start a callback but which do not need the full power (and corresponding 7771** complication) of [sqlite3_wal_checkpoint_v2()]. 7772*/ 7773SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7774 7775/* 7776** CAPI3REF: Checkpoint a database 7777** METHOD: sqlite3 7778** 7779** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7780** operation on database X of [database connection] D in mode M. Status 7781** information is written back into integers pointed to by L and C.)^ 7782** ^(The M parameter must be a valid [checkpoint mode]:)^ 7783** 7784** <dl> 7785** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7786** ^Checkpoint as many frames as possible without waiting for any database 7787** readers or writers to finish, then sync the database file if all frames 7788** in the log were checkpointed. ^The [busy-handler callback] 7789** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7790** ^On the other hand, passive mode might leave the checkpoint unfinished 7791** if there are concurrent readers or writers. 7792** 7793** <dt>SQLITE_CHECKPOINT_FULL<dd> 7794** ^This mode blocks (it invokes the 7795** [sqlite3_busy_handler|busy-handler callback]) until there is no 7796** database writer and all readers are reading from the most recent database 7797** snapshot. ^It then checkpoints all frames in the log file and syncs the 7798** database file. ^This mode blocks new database writers while it is pending, 7799** but new database readers are allowed to continue unimpeded. 7800** 7801** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7802** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7803** that after checkpointing the log file it blocks (calls the 7804** [busy-handler callback]) 7805** until all readers are reading from the database file only. ^This ensures 7806** that the next writer will restart the log file from the beginning. 7807** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7808** database writer attempts while it is pending, but does not impede readers. 7809** 7810** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7811** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7812** addition that it also truncates the log file to zero bytes just prior 7813** to a successful return. 7814** </dl> 7815** 7816** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7817** the log file or to -1 if the checkpoint could not run because 7818** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7819** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7820** log file (including any that were already checkpointed before the function 7821** was called) or to -1 if the checkpoint could not run due to an error or 7822** because the database is not in WAL mode. ^Note that upon successful 7823** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7824** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7825** 7826** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7827** any other process is running a checkpoint operation at the same time, the 7828** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7829** busy-handler configured, it will not be invoked in this case. 7830** 7831** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7832** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7833** obtained immediately, and a busy-handler is configured, it is invoked and 7834** the writer lock retried until either the busy-handler returns 0 or the lock 7835** is successfully obtained. ^The busy-handler is also invoked while waiting for 7836** database readers as described above. ^If the busy-handler returns 0 before 7837** the writer lock is obtained or while waiting for database readers, the 7838** checkpoint operation proceeds from that point in the same way as 7839** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7840** without blocking any further. ^SQLITE_BUSY is returned in this case. 7841** 7842** ^If parameter zDb is NULL or points to a zero length string, then the 7843** specified operation is attempted on all WAL databases [attached] to 7844** [database connection] db. In this case the 7845** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7846** an SQLITE_BUSY error is encountered when processing one or more of the 7847** attached WAL databases, the operation is still attempted on any remaining 7848** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7849** error occurs while processing an attached database, processing is abandoned 7850** and the error code is returned to the caller immediately. ^If no error 7851** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7852** databases, SQLITE_OK is returned. 7853** 7854** ^If database zDb is the name of an attached database that is not in WAL 7855** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7856** zDb is not NULL (or a zero length string) and is not the name of any 7857** attached database, SQLITE_ERROR is returned to the caller. 7858** 7859** ^Unless it returns SQLITE_MISUSE, 7860** the sqlite3_wal_checkpoint_v2() interface 7861** sets the error information that is queried by 7862** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7863** 7864** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7865** from SQL. 7866*/ 7867SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7868 sqlite3 *db, /* Database handle */ 7869 const char *zDb, /* Name of attached database (or NULL) */ 7870 int eMode, /* SQLITE_CHECKPOINT_* value */ 7871 int *pnLog, /* OUT: Size of WAL log in frames */ 7872 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7873); 7874 7875/* 7876** CAPI3REF: Checkpoint Mode Values 7877** KEYWORDS: {checkpoint mode} 7878** 7879** These constants define all valid values for the "checkpoint mode" passed 7880** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7881** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7882** meaning of each of these checkpoint modes. 7883*/ 7884#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7885#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7886#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7887#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7888 7889/* 7890** CAPI3REF: Virtual Table Interface Configuration 7891** 7892** This function may be called by either the [xConnect] or [xCreate] method 7893** of a [virtual table] implementation to configure 7894** various facets of the virtual table interface. 7895** 7896** If this interface is invoked outside the context of an xConnect or 7897** xCreate virtual table method then the behavior is undefined. 7898** 7899** At present, there is only one option that may be configured using 7900** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7901** may be added in the future. 7902*/ 7903SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7904 7905/* 7906** CAPI3REF: Virtual Table Configuration Options 7907** 7908** These macros define the various options to the 7909** [sqlite3_vtab_config()] interface that [virtual table] implementations 7910** can use to customize and optimize their behavior. 7911** 7912** <dl> 7913** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7914** <dd>Calls of the form 7915** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7916** where X is an integer. If X is zero, then the [virtual table] whose 7917** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7918** support constraints. In this configuration (which is the default) if 7919** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7920** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7921** specified as part of the users SQL statement, regardless of the actual 7922** ON CONFLICT mode specified. 7923** 7924** If X is non-zero, then the virtual table implementation guarantees 7925** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7926** any modifications to internal or persistent data structures have been made. 7927** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7928** is able to roll back a statement or database transaction, and abandon 7929** or continue processing the current SQL statement as appropriate. 7930** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7931** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7932** had been ABORT. 7933** 7934** Virtual table implementations that are required to handle OR REPLACE 7935** must do so within the [xUpdate] method. If a call to the 7936** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7937** CONFLICT policy is REPLACE, the virtual table implementation should 7938** silently replace the appropriate rows within the xUpdate callback and 7939** return SQLITE_OK. Or, if this is not possible, it may return 7940** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7941** constraint handling. 7942** </dl> 7943*/ 7944#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7945 7946/* 7947** CAPI3REF: Determine The Virtual Table Conflict Policy 7948** 7949** This function may only be called from within a call to the [xUpdate] method 7950** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7951** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7952** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7953** of the SQL statement that triggered the call to the [xUpdate] method of the 7954** [virtual table]. 7955*/ 7956SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7957 7958/* 7959** CAPI3REF: Conflict resolution modes 7960** KEYWORDS: {conflict resolution mode} 7961** 7962** These constants are returned by [sqlite3_vtab_on_conflict()] to 7963** inform a [virtual table] implementation what the [ON CONFLICT] mode 7964** is for the SQL statement being evaluated. 7965** 7966** Note that the [SQLITE_IGNORE] constant is also used as a potential 7967** return value from the [sqlite3_set_authorizer()] callback and that 7968** [SQLITE_ABORT] is also a [result code]. 7969*/ 7970#define SQLITE_ROLLBACK 1 7971/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7972#define SQLITE_FAIL 3 7973/* #define SQLITE_ABORT 4 // Also an error code */ 7974#define SQLITE_REPLACE 5 7975 7976/* 7977** CAPI3REF: Prepared Statement Scan Status Opcodes 7978** KEYWORDS: {scanstatus options} 7979** 7980** The following constants can be used for the T parameter to the 7981** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7982** different metric for sqlite3_stmt_scanstatus() to return. 7983** 7984** When the value returned to V is a string, space to hold that string is 7985** managed by the prepared statement S and will be automatically freed when 7986** S is finalized. 7987** 7988** <dl> 7989** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7990** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7991** set to the total number of times that the X-th loop has run.</dd> 7992** 7993** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7994** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7995** to the total number of rows examined by all iterations of the X-th loop.</dd> 7996** 7997** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7998** <dd>^The "double" variable pointed to by the T parameter will be set to the 7999** query planner's estimate for the average number of rows output from each 8000** iteration of the X-th loop. If the query planner's estimates was accurate, 8001** then this value will approximate the quotient NVISIT/NLOOP and the 8002** product of this value for all prior loops with the same SELECTID will 8003** be the NLOOP value for the current loop. 8004** 8005** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8006** <dd>^The "const char *" variable pointed to by the T parameter will be set 8007** to a zero-terminated UTF-8 string containing the name of the index or table 8008** used for the X-th loop. 8009** 8010** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8011** <dd>^The "const char *" variable pointed to by the T parameter will be set 8012** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8013** description for the X-th loop. 8014** 8015** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8016** <dd>^The "int" variable pointed to by the T parameter will be set to the 8017** "select-id" for the X-th loop. The select-id identifies which query or 8018** subquery the loop is part of. The main query has a select-id of zero. 8019** The select-id is the same value as is output in the first column 8020** of an [EXPLAIN QUERY PLAN] query. 8021** </dl> 8022*/ 8023#define SQLITE_SCANSTAT_NLOOP 0 8024#define SQLITE_SCANSTAT_NVISIT 1 8025#define SQLITE_SCANSTAT_EST 2 8026#define SQLITE_SCANSTAT_NAME 3 8027#define SQLITE_SCANSTAT_EXPLAIN 4 8028#define SQLITE_SCANSTAT_SELECTID 5 8029 8030/* 8031** CAPI3REF: Prepared Statement Scan Status 8032** METHOD: sqlite3_stmt 8033** 8034** This interface returns information about the predicted and measured 8035** performance for pStmt. Advanced applications can use this 8036** interface to compare the predicted and the measured performance and 8037** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8038** 8039** Since this interface is expected to be rarely used, it is only 8040** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8041** compile-time option. 8042** 8043** The "iScanStatusOp" parameter determines which status information to return. 8044** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8045** of this interface is undefined. 8046** ^The requested measurement is written into a variable pointed to by 8047** the "pOut" parameter. 8048** Parameter "idx" identifies the specific loop to retrieve statistics for. 8049** Loops are numbered starting from zero. ^If idx is out of range - less than 8050** zero or greater than or equal to the total number of loops used to implement 8051** the statement - a non-zero value is returned and the variable that pOut 8052** points to is unchanged. 8053** 8054** ^Statistics might not be available for all loops in all statements. ^In cases 8055** where there exist loops with no available statistics, this function behaves 8056** as if the loop did not exist - it returns non-zero and leave the variable 8057** that pOut points to unchanged. 8058** 8059** See also: [sqlite3_stmt_scanstatus_reset()] 8060*/ 8061SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( 8062 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8063 int idx, /* Index of loop to report on */ 8064 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8065 void *pOut /* Result written here */ 8066); 8067 8068/* 8069** CAPI3REF: Zero Scan-Status Counters 8070** METHOD: sqlite3_stmt 8071** 8072** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8073** 8074** This API is only available if the library is built with pre-processor 8075** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8076*/ 8077SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8078 8079/* 8080** CAPI3REF: Flush caches to disk mid-transaction 8081** 8082** ^If a write-transaction is open on [database connection] D when the 8083** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8084** pages in the pager-cache that are not currently in use are written out 8085** to disk. A dirty page may be in use if a database cursor created by an 8086** active SQL statement is reading from it, or if it is page 1 of a database 8087** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8088** interface flushes caches for all schemas - "main", "temp", and 8089** any [attached] databases. 8090** 8091** ^If this function needs to obtain extra database locks before dirty pages 8092** can be flushed to disk, it does so. ^If those locks cannot be obtained 8093** immediately and there is a busy-handler callback configured, it is invoked 8094** in the usual manner. ^If the required lock still cannot be obtained, then 8095** the database is skipped and an attempt made to flush any dirty pages 8096** belonging to the next (if any) database. ^If any databases are skipped 8097** because locks cannot be obtained, but no other error occurs, this 8098** function returns SQLITE_BUSY. 8099** 8100** ^If any other error occurs while flushing dirty pages to disk (for 8101** example an IO error or out-of-memory condition), then processing is 8102** abandoned and an SQLite [error code] is returned to the caller immediately. 8103** 8104** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8105** 8106** ^This function does not set the database handle error code or message 8107** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8108*/ 8109SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); 8110 8111/* 8112** CAPI3REF: The pre-update hook. 8113** 8114** ^These interfaces are only available if SQLite is compiled using the 8115** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8116** 8117** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8118** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8119** on a [rowid table]. 8120** ^At most one preupdate hook may be registered at a time on a single 8121** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8122** the previous setting. 8123** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8124** with a NULL pointer as the second parameter. 8125** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8126** the first parameter to callbacks. 8127** 8128** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8129** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8130** tables. 8131** 8132** ^The second parameter to the preupdate callback is a pointer to 8133** the [database connection] that registered the preupdate hook. 8134** ^The third parameter to the preupdate callback is one of the constants 8135** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8136** kind of update operation that is about to occur. 8137** ^(The fourth parameter to the preupdate callback is the name of the 8138** database within the database connection that is being modified. This 8139** will be "main" for the main database or "temp" for TEMP tables or 8140** the name given after the AS keyword in the [ATTACH] statement for attached 8141** databases.)^ 8142** ^The fifth parameter to the preupdate callback is the name of the 8143** table that is being modified. 8144** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8145** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8146** undefined for SQLITE_INSERT changes. 8147** ^The seventh parameter to the preupdate callback is the final [rowid] of 8148** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8149** undefined for SQLITE_DELETE changes. 8150** 8151** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8152** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8153** provide additional information about a preupdate event. These routines 8154** may only be called from within a preupdate callback. Invoking any of 8155** these routines from outside of a preupdate callback or with a 8156** [database connection] pointer that is different from the one supplied 8157** to the preupdate callback results in undefined and probably undesirable 8158** behavior. 8159** 8160** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8161** in the row that is being inserted, updated, or deleted. 8162** 8163** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8164** a [protected sqlite3_value] that contains the value of the Nth column of 8165** the table row before it is updated. The N parameter must be between 0 8166** and one less than the number of columns or the behavior will be 8167** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8168** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8169** behavior is undefined. The [sqlite3_value] that P points to 8170** will be destroyed when the preupdate callback returns. 8171** 8172** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8173** a [protected sqlite3_value] that contains the value of the Nth column of 8174** the table row after it is updated. The N parameter must be between 0 8175** and one less than the number of columns or the behavior will be 8176** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8177** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8178** behavior is undefined. The [sqlite3_value] that P points to 8179** will be destroyed when the preupdate callback returns. 8180** 8181** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8182** callback was invoked as a result of a direct insert, update, or delete 8183** operation; or 1 for inserts, updates, or deletes invoked by top-level 8184** triggers; or 2 for changes resulting from triggers called by top-level 8185** triggers; and so forth. 8186** 8187** See also: [sqlite3_update_hook()] 8188*/ 8189SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_preupdate_hook( 8190 sqlite3 *db, 8191 void(*xPreUpdate)( 8192 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8193 sqlite3 *db, /* Database handle */ 8194 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8195 char const *zDb, /* Database name */ 8196 char const *zName, /* Table name */ 8197 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8198 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8199 ), 8200 void* 8201); 8202SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8203SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_count(sqlite3 *); 8204SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_depth(sqlite3 *); 8205SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8206 8207/* 8208** CAPI3REF: Low-level system error code 8209** 8210** ^Attempt to return the underlying operating system error code or error 8211** number that caused the most recent I/O error or failure to open a file. 8212** The return value is OS-dependent. For example, on unix systems, after 8213** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8214** called to get back the underlying "errno" that caused the problem, such 8215** as ENOSPC, EAUTH, EISDIR, and so forth. 8216*/ 8217SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*); 8218 8219/* 8220** CAPI3REF: Database Snapshot 8221** KEYWORDS: {snapshot} 8222** EXPERIMENTAL 8223** 8224** An instance of the snapshot object records the state of a [WAL mode] 8225** database for some specific point in history. 8226** 8227** In [WAL mode], multiple [database connections] that are open on the 8228** same database file can each be reading a different historical version 8229** of the database file. When a [database connection] begins a read 8230** transaction, that connection sees an unchanging copy of the database 8231** as it existed for the point in time when the transaction first started. 8232** Subsequent changes to the database from other connections are not seen 8233** by the reader until a new read transaction is started. 8234** 8235** The sqlite3_snapshot object records state information about an historical 8236** version of the database file so that it is possible to later open a new read 8237** transaction that sees that historical version of the database rather than 8238** the most recent version. 8239** 8240** The constructor for this object is [sqlite3_snapshot_get()]. The 8241** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8242** to an historical snapshot (if possible). The destructor for 8243** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8244*/ 8245typedef struct sqlite3_snapshot sqlite3_snapshot; 8246 8247/* 8248** CAPI3REF: Record A Database Snapshot 8249** EXPERIMENTAL 8250** 8251** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8252** new [sqlite3_snapshot] object that records the current state of 8253** schema S in database connection D. ^On success, the 8254** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8255** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8256** ^If schema S of [database connection] D is not a [WAL mode] database 8257** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 8258** leaves the *P value unchanged and returns an appropriate [error code]. 8259** 8260** The [sqlite3_snapshot] object returned from a successful call to 8261** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8262** to avoid a memory leak. 8263** 8264** The [sqlite3_snapshot_get()] interface is only available when the 8265** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8266*/ 8267SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( 8268 sqlite3 *db, 8269 const char *zSchema, 8270 sqlite3_snapshot **ppSnapshot 8271); 8272 8273/* 8274** CAPI3REF: Start a read transaction on an historical snapshot 8275** EXPERIMENTAL 8276** 8277** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8278** read transaction for schema S of 8279** [database connection] D such that the read transaction 8280** refers to historical [snapshot] P, rather than the most 8281** recent change to the database. 8282** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8283** or an appropriate [error code] if it fails. 8284** 8285** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8286** the first operation following the [BEGIN] that takes the schema S 8287** out of [autocommit mode]. 8288** ^In other words, schema S must not currently be in 8289** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8290** database connection D must be out of [autocommit mode]. 8291** ^A [snapshot] will fail to open if it has been overwritten by a 8292** [checkpoint]. 8293** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8294** database connection D does not know that the database file for 8295** schema S is in [WAL mode]. A database connection might not know 8296** that the database file is in [WAL mode] if there has been no prior 8297** I/O on that database connection, or if the database entered [WAL mode] 8298** after the most recent I/O on the database connection.)^ 8299** (Hint: Run "[PRAGMA application_id]" against a newly opened 8300** database connection in order to make it ready to use snapshots.) 8301** 8302** The [sqlite3_snapshot_open()] interface is only available when the 8303** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8304*/ 8305SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( 8306 sqlite3 *db, 8307 const char *zSchema, 8308 sqlite3_snapshot *pSnapshot 8309); 8310 8311/* 8312** CAPI3REF: Destroy a snapshot 8313** EXPERIMENTAL 8314** 8315** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8316** The application must eventually free every [sqlite3_snapshot] object 8317** using this routine to avoid a memory leak. 8318** 8319** The [sqlite3_snapshot_free()] interface is only available when the 8320** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8321*/ 8322SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); 8323 8324/* 8325** CAPI3REF: Compare the ages of two snapshot handles. 8326** EXPERIMENTAL 8327** 8328** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8329** of two valid snapshot handles. 8330** 8331** If the two snapshot handles are not associated with the same database 8332** file, the result of the comparison is undefined. 8333** 8334** Additionally, the result of the comparison is only valid if both of the 8335** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8336** last time the wal file was deleted. The wal file is deleted when the 8337** database is changed back to rollback mode or when the number of database 8338** clients drops to zero. If either snapshot handle was obtained before the 8339** wal file was last deleted, the value returned by this function 8340** is undefined. 8341** 8342** Otherwise, this API returns a negative value if P1 refers to an older 8343** snapshot than P2, zero if the two handles refer to the same database 8344** snapshot, and a positive value if P1 is a newer snapshot than P2. 8345*/ 8346SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_cmp( 8347 sqlite3_snapshot *p1, 8348 sqlite3_snapshot *p2 8349); 8350 8351/* 8352** Undo the hack that converts floating point types to integer for 8353** builds on processors without floating point support. 8354*/ 8355#ifdef SQLITE_OMIT_FLOATING_POINT 8356# undef double 8357#endif 8358 8359#ifdef __cplusplus 8360} /* End of the 'extern "C"' block */ 8361#endif 8362#endif /* SQLITE3_H */ 8363 8364/******** Begin file sqlite3rtree.h *********/ 8365/* 8366** 2010 August 30 8367** 8368** The author disclaims copyright to this source code. In place of 8369** a legal notice, here is a blessing: 8370** 8371** May you do good and not evil. 8372** May you find forgiveness for yourself and forgive others. 8373** May you share freely, never taking more than you give. 8374** 8375************************************************************************* 8376*/ 8377 8378#ifndef _SQLITE3RTREE_H_ 8379#define _SQLITE3RTREE_H_ 8380 8381 8382#ifdef __cplusplus 8383extern "C" { 8384#endif 8385 8386typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8387typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8388 8389/* The double-precision datatype used by RTree depends on the 8390** SQLITE_RTREE_INT_ONLY compile-time option. 8391*/ 8392#ifdef SQLITE_RTREE_INT_ONLY 8393 typedef sqlite3_int64 sqlite3_rtree_dbl; 8394#else 8395 typedef double sqlite3_rtree_dbl; 8396#endif 8397 8398/* 8399** Register a geometry callback named zGeom that can be used as part of an 8400** R-Tree geometry query as follows: 8401** 8402** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8403*/ 8404SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 8405 sqlite3 *db, 8406 const char *zGeom, 8407 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8408 void *pContext 8409); 8410 8411 8412/* 8413** A pointer to a structure of the following type is passed as the first 8414** argument to callbacks registered using rtree_geometry_callback(). 8415*/ 8416struct sqlite3_rtree_geometry { 8417 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8418 int nParam; /* Size of array aParam[] */ 8419 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8420 void *pUser; /* Callback implementation user data */ 8421 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8422}; 8423 8424/* 8425** Register a 2nd-generation geometry callback named zScore that can be 8426** used as part of an R-Tree geometry query as follows: 8427** 8428** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8429*/ 8430SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 8431 sqlite3 *db, 8432 const char *zQueryFunc, 8433 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8434 void *pContext, 8435 void (*xDestructor)(void*) 8436); 8437 8438 8439/* 8440** A pointer to a structure of the following type is passed as the 8441** argument to scored geometry callback registered using 8442** sqlite3_rtree_query_callback(). 8443** 8444** Note that the first 5 fields of this structure are identical to 8445** sqlite3_rtree_geometry. This structure is a subclass of 8446** sqlite3_rtree_geometry. 8447*/ 8448struct sqlite3_rtree_query_info { 8449 void *pContext; /* pContext from when function registered */ 8450 int nParam; /* Number of function parameters */ 8451 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8452 void *pUser; /* callback can use this, if desired */ 8453 void (*xDelUser)(void*); /* function to free pUser */ 8454 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8455 unsigned int *anQueue; /* Number of pending entries in the queue */ 8456 int nCoord; /* Number of coordinates */ 8457 int iLevel; /* Level of current node or entry */ 8458 int mxLevel; /* The largest iLevel value in the tree */ 8459 sqlite3_int64 iRowid; /* Rowid for current entry */ 8460 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8461 int eParentWithin; /* Visibility of parent node */ 8462 int eWithin; /* OUT: Visiblity */ 8463 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8464 /* The following fields are only available in 3.8.11 and later */ 8465 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8466}; 8467 8468/* 8469** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8470*/ 8471#define NOT_WITHIN 0 /* Object completely outside of query region */ 8472#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8473#define FULLY_WITHIN 2 /* Object fully contained within query region */ 8474 8475 8476#ifdef __cplusplus 8477} /* end of the 'extern "C"' block */ 8478#endif 8479 8480#endif /* ifndef _SQLITE3RTREE_H_ */ 8481 8482/******** End of sqlite3rtree.h *********/ 8483/******** Begin file sqlite3session.h *********/ 8484 8485#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8486#define __SQLITESESSION_H_ 1 8487 8488/* 8489** Make sure we can call this stuff from C++. 8490*/ 8491#ifdef __cplusplus 8492extern "C" { 8493#endif 8494 8495 8496/* 8497** CAPI3REF: Session Object Handle 8498*/ 8499typedef struct sqlite3_session sqlite3_session; 8500 8501/* 8502** CAPI3REF: Changeset Iterator Handle 8503*/ 8504typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8505 8506/* 8507** CAPI3REF: Create A New Session Object 8508** 8509** Create a new session object attached to database handle db. If successful, 8510** a pointer to the new object is written to *ppSession and SQLITE_OK is 8511** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8512** error code (e.g. SQLITE_NOMEM) is returned. 8513** 8514** It is possible to create multiple session objects attached to a single 8515** database handle. 8516** 8517** Session objects created using this function should be deleted using the 8518** [sqlite3session_delete()] function before the database handle that they 8519** are attached to is itself closed. If the database handle is closed before 8520** the session object is deleted, then the results of calling any session 8521** module function, including [sqlite3session_delete()] on the session object 8522** are undefined. 8523** 8524** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8525** is not possible for an application to register a pre-update hook on a 8526** database handle that has one or more session objects attached. Nor is 8527** it possible to create a session object attached to a database handle for 8528** which a pre-update hook is already defined. The results of attempting 8529** either of these things are undefined. 8530** 8531** The session object will be used to create changesets for tables in 8532** database zDb, where zDb is either "main", or "temp", or the name of an 8533** attached database. It is not an error if database zDb is not attached 8534** to the database when the session object is created. 8535*/ 8536int sqlite3session_create( 8537 sqlite3 *db, /* Database handle */ 8538 const char *zDb, /* Name of db (e.g. "main") */ 8539 sqlite3_session **ppSession /* OUT: New session object */ 8540); 8541 8542/* 8543** CAPI3REF: Delete A Session Object 8544** 8545** Delete a session object previously allocated using 8546** [sqlite3session_create()]. Once a session object has been deleted, the 8547** results of attempting to use pSession with any other session module 8548** function are undefined. 8549** 8550** Session objects must be deleted before the database handle to which they 8551** are attached is closed. Refer to the documentation for 8552** [sqlite3session_create()] for details. 8553*/ 8554void sqlite3session_delete(sqlite3_session *pSession); 8555 8556 8557/* 8558** CAPI3REF: Enable Or Disable A Session Object 8559** 8560** Enable or disable the recording of changes by a session object. When 8561** enabled, a session object records changes made to the database. When 8562** disabled - it does not. A newly created session object is enabled. 8563** Refer to the documentation for [sqlite3session_changeset()] for further 8564** details regarding how enabling and disabling a session object affects 8565** the eventual changesets. 8566** 8567** Passing zero to this function disables the session. Passing a value 8568** greater than zero enables it. Passing a value less than zero is a 8569** no-op, and may be used to query the current state of the session. 8570** 8571** The return value indicates the final state of the session object: 0 if 8572** the session is disabled, or 1 if it is enabled. 8573*/ 8574int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8575 8576/* 8577** CAPI3REF: Set Or Clear the Indirect Change Flag 8578** 8579** Each change recorded by a session object is marked as either direct or 8580** indirect. A change is marked as indirect if either: 8581** 8582** <ul> 8583** <li> The session object "indirect" flag is set when the change is 8584** made, or 8585** <li> The change is made by an SQL trigger or foreign key action 8586** instead of directly as a result of a users SQL statement. 8587** </ul> 8588** 8589** If a single row is affected by more than one operation within a session, 8590** then the change is considered indirect if all operations meet the criteria 8591** for an indirect change above, or direct otherwise. 8592** 8593** This function is used to set, clear or query the session object indirect 8594** flag. If the second argument passed to this function is zero, then the 8595** indirect flag is cleared. If it is greater than zero, the indirect flag 8596** is set. Passing a value less than zero does not modify the current value 8597** of the indirect flag, and may be used to query the current state of the 8598** indirect flag for the specified session object. 8599** 8600** The return value indicates the final state of the indirect flag: 0 if 8601** it is clear, or 1 if it is set. 8602*/ 8603int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8604 8605/* 8606** CAPI3REF: Attach A Table To A Session Object 8607** 8608** If argument zTab is not NULL, then it is the name of a table to attach 8609** to the session object passed as the first argument. All subsequent changes 8610** made to the table while the session object is enabled will be recorded. See 8611** documentation for [sqlite3session_changeset()] for further details. 8612** 8613** Or, if argument zTab is NULL, then changes are recorded for all tables 8614** in the database. If additional tables are added to the database (by 8615** executing "CREATE TABLE" statements) after this call is made, changes for 8616** the new tables are also recorded. 8617** 8618** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8619** defined as part of their CREATE TABLE statement. It does not matter if the 8620** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8621** KEY may consist of a single column, or may be a composite key. 8622** 8623** It is not an error if the named table does not exist in the database. Nor 8624** is it an error if the named table does not have a PRIMARY KEY. However, 8625** no changes will be recorded in either of these scenarios. 8626** 8627** Changes are not recorded for individual rows that have NULL values stored 8628** in one or more of their PRIMARY KEY columns. 8629** 8630** SQLITE_OK is returned if the call completes without error. Or, if an error 8631** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8632*/ 8633int sqlite3session_attach( 8634 sqlite3_session *pSession, /* Session object */ 8635 const char *zTab /* Table name */ 8636); 8637 8638/* 8639** CAPI3REF: Set a table filter on a Session Object. 8640** 8641** The second argument (xFilter) is the "filter callback". For changes to rows 8642** in tables that are not attached to the Session oject, the filter is called 8643** to determine whether changes to the table's rows should be tracked or not. 8644** If xFilter returns 0, changes is not tracked. Note that once a table is 8645** attached, xFilter will not be called again. 8646*/ 8647void sqlite3session_table_filter( 8648 sqlite3_session *pSession, /* Session object */ 8649 int(*xFilter)( 8650 void *pCtx, /* Copy of third arg to _filter_table() */ 8651 const char *zTab /* Table name */ 8652 ), 8653 void *pCtx /* First argument passed to xFilter */ 8654); 8655 8656/* 8657** CAPI3REF: Generate A Changeset From A Session Object 8658** 8659** Obtain a changeset containing changes to the tables attached to the 8660** session object passed as the first argument. If successful, 8661** set *ppChangeset to point to a buffer containing the changeset 8662** and *pnChangeset to the size of the changeset in bytes before returning 8663** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8664** zero and return an SQLite error code. 8665** 8666** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8667** each representing a change to a single row of an attached table. An INSERT 8668** change contains the values of each field of a new database row. A DELETE 8669** contains the original values of each field of a deleted database row. An 8670** UPDATE change contains the original values of each field of an updated 8671** database row along with the updated values for each updated non-primary-key 8672** column. It is not possible for an UPDATE change to represent a change that 8673** modifies the values of primary key columns. If such a change is made, it 8674** is represented in a changeset as a DELETE followed by an INSERT. 8675** 8676** Changes are not recorded for rows that have NULL values stored in one or 8677** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8678** no corresponding change is present in the changesets returned by this 8679** function. If an existing row with one or more NULL values stored in 8680** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8681** only an INSERT is appears in the changeset. Similarly, if an existing row 8682** with non-NULL PRIMARY KEY values is updated so that one or more of its 8683** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8684** DELETE change only. 8685** 8686** The contents of a changeset may be traversed using an iterator created 8687** using the [sqlite3changeset_start()] API. A changeset may be applied to 8688** a database with a compatible schema using the [sqlite3changeset_apply()] 8689** API. 8690** 8691** Within a changeset generated by this function, all changes related to a 8692** single table are grouped together. In other words, when iterating through 8693** a changeset or when applying a changeset to a database, all changes related 8694** to a single table are processed before moving on to the next table. Tables 8695** are sorted in the same order in which they were attached (or auto-attached) 8696** to the sqlite3_session object. The order in which the changes related to 8697** a single table are stored is undefined. 8698** 8699** Following a successful call to this function, it is the responsibility of 8700** the caller to eventually free the buffer that *ppChangeset points to using 8701** [sqlite3_free()]. 8702** 8703** <h3>Changeset Generation</h3> 8704** 8705** Once a table has been attached to a session object, the session object 8706** records the primary key values of all new rows inserted into the table. 8707** It also records the original primary key and other column values of any 8708** deleted or updated rows. For each unique primary key value, data is only 8709** recorded once - the first time a row with said primary key is inserted, 8710** updated or deleted in the lifetime of the session. 8711** 8712** There is one exception to the previous paragraph: when a row is inserted, 8713** updated or deleted, if one or more of its primary key columns contain a 8714** NULL value, no record of the change is made. 8715** 8716** The session object therefore accumulates two types of records - those 8717** that consist of primary key values only (created when the user inserts 8718** a new record) and those that consist of the primary key values and the 8719** original values of other table columns (created when the users deletes 8720** or updates a record). 8721** 8722** When this function is called, the requested changeset is created using 8723** both the accumulated records and the current contents of the database 8724** file. Specifically: 8725** 8726** <ul> 8727** <li> For each record generated by an insert, the database is queried 8728** for a row with a matching primary key. If one is found, an INSERT 8729** change is added to the changeset. If no such row is found, no change 8730** is added to the changeset. 8731** 8732** <li> For each record generated by an update or delete, the database is 8733** queried for a row with a matching primary key. If such a row is 8734** found and one or more of the non-primary key fields have been 8735** modified from their original values, an UPDATE change is added to 8736** the changeset. Or, if no such row is found in the table, a DELETE 8737** change is added to the changeset. If there is a row with a matching 8738** primary key in the database, but all fields contain their original 8739** values, no change is added to the changeset. 8740** </ul> 8741** 8742** This means, amongst other things, that if a row is inserted and then later 8743** deleted while a session object is active, neither the insert nor the delete 8744** will be present in the changeset. Or if a row is deleted and then later a 8745** row with the same primary key values inserted while a session object is 8746** active, the resulting changeset will contain an UPDATE change instead of 8747** a DELETE and an INSERT. 8748** 8749** When a session object is disabled (see the [sqlite3session_enable()] API), 8750** it does not accumulate records when rows are inserted, updated or deleted. 8751** This may appear to have some counter-intuitive effects if a single row 8752** is written to more than once during a session. For example, if a row 8753** is inserted while a session object is enabled, then later deleted while 8754** the same session object is disabled, no INSERT record will appear in the 8755** changeset, even though the delete took place while the session was disabled. 8756** Or, if one field of a row is updated while a session is disabled, and 8757** another field of the same row is updated while the session is enabled, the 8758** resulting changeset will contain an UPDATE change that updates both fields. 8759*/ 8760int sqlite3session_changeset( 8761 sqlite3_session *pSession, /* Session object */ 8762 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8763 void **ppChangeset /* OUT: Buffer containing changeset */ 8764); 8765 8766/* 8767** CAPI3REF: Load The Difference Between Tables Into A Session 8768** 8769** If it is not already attached to the session object passed as the first 8770** argument, this function attaches table zTbl in the same manner as the 8771** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8772** does not have a primary key, this function is a no-op (but does not return 8773** an error). 8774** 8775** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8776** attached to the same database handle as the session object that contains 8777** a table compatible with the table attached to the session by this function. 8778** A table is considered compatible if it: 8779** 8780** <ul> 8781** <li> Has the same name, 8782** <li> Has the same set of columns declared in the same order, and 8783** <li> Has the same PRIMARY KEY definition. 8784** </ul> 8785** 8786** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8787** are compatible but do not have any PRIMARY KEY columns, it is not an error 8788** but no changes are added to the session object. As with other session 8789** APIs, tables without PRIMARY KEYs are simply ignored. 8790** 8791** This function adds a set of changes to the session object that could be 8792** used to update the table in database zFrom (call this the "from-table") 8793** so that its content is the same as the table attached to the session 8794** object (call this the "to-table"). Specifically: 8795** 8796** <ul> 8797** <li> For each row (primary key) that exists in the to-table but not in 8798** the from-table, an INSERT record is added to the session object. 8799** 8800** <li> For each row (primary key) that exists in the to-table but not in 8801** the from-table, a DELETE record is added to the session object. 8802** 8803** <li> For each row (primary key) that exists in both tables, but features 8804** different in each, an UPDATE record is added to the session. 8805** </ul> 8806** 8807** To clarify, if this function is called and then a changeset constructed 8808** using [sqlite3session_changeset()], then after applying that changeset to 8809** database zFrom the contents of the two compatible tables would be 8810** identical. 8811** 8812** It an error if database zFrom does not exist or does not contain the 8813** required compatible table. 8814** 8815** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8816** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8817** may be set to point to a buffer containing an English language error 8818** message. It is the responsibility of the caller to free this buffer using 8819** sqlite3_free(). 8820*/ 8821int sqlite3session_diff( 8822 sqlite3_session *pSession, 8823 const char *zFromDb, 8824 const char *zTbl, 8825 char **pzErrMsg 8826); 8827 8828 8829/* 8830** CAPI3REF: Generate A Patchset From A Session Object 8831** 8832** The differences between a patchset and a changeset are that: 8833** 8834** <ul> 8835** <li> DELETE records consist of the primary key fields only. The 8836** original values of other fields are omitted. 8837** <li> The original values of any modified fields are omitted from 8838** UPDATE records. 8839** </ul> 8840** 8841** A patchset blob may be used with up to date versions of all 8842** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8843** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8844** attempting to use a patchset blob with old versions of the 8845** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8846** 8847** Because the non-primary key "old.*" fields are omitted, no 8848** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8849** is passed to the sqlite3changeset_apply() API. Other conflict types work 8850** in the same way as for changesets. 8851** 8852** Changes within a patchset are ordered in the same way as for changesets 8853** generated by the sqlite3session_changeset() function (i.e. all changes for 8854** a single table are grouped together, tables appear in the order in which 8855** they were attached to the session object). 8856*/ 8857int sqlite3session_patchset( 8858 sqlite3_session *pSession, /* Session object */ 8859 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8860 void **ppPatchset /* OUT: Buffer containing changeset */ 8861); 8862 8863/* 8864** CAPI3REF: Test if a changeset has recorded any changes. 8865** 8866** Return non-zero if no changes to attached tables have been recorded by 8867** the session object passed as the first argument. Otherwise, if one or 8868** more changes have been recorded, return zero. 8869** 8870** Even if this function returns zero, it is possible that calling 8871** [sqlite3session_changeset()] on the session handle may still return a 8872** changeset that contains no changes. This can happen when a row in 8873** an attached table is modified and then later on the original values 8874** are restored. However, if this function returns non-zero, then it is 8875** guaranteed that a call to sqlite3session_changeset() will return a 8876** changeset containing zero changes. 8877*/ 8878int sqlite3session_isempty(sqlite3_session *pSession); 8879 8880/* 8881** CAPI3REF: Create An Iterator To Traverse A Changeset 8882** 8883** Create an iterator used to iterate through the contents of a changeset. 8884** If successful, *pp is set to point to the iterator handle and SQLITE_OK 8885** is returned. Otherwise, if an error occurs, *pp is set to zero and an 8886** SQLite error code is returned. 8887** 8888** The following functions can be used to advance and query a changeset 8889** iterator created by this function: 8890** 8891** <ul> 8892** <li> [sqlite3changeset_next()] 8893** <li> [sqlite3changeset_op()] 8894** <li> [sqlite3changeset_new()] 8895** <li> [sqlite3changeset_old()] 8896** </ul> 8897** 8898** It is the responsibility of the caller to eventually destroy the iterator 8899** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 8900** changeset (pChangeset) must remain valid until after the iterator is 8901** destroyed. 8902** 8903** Assuming the changeset blob was created by one of the 8904** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 8905** [sqlite3changeset_invert()] functions, all changes within the changeset 8906** that apply to a single table are grouped together. This means that when 8907** an application iterates through a changeset using an iterator created by 8908** this function, all changes that relate to a single table are visted 8909** consecutively. There is no chance that the iterator will visit a change 8910** the applies to table X, then one for table Y, and then later on visit 8911** another change for table X. 8912*/ 8913int sqlite3changeset_start( 8914 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 8915 int nChangeset, /* Size of changeset blob in bytes */ 8916 void *pChangeset /* Pointer to blob containing changeset */ 8917); 8918 8919 8920/* 8921** CAPI3REF: Advance A Changeset Iterator 8922** 8923** This function may only be used with iterators created by function 8924** [sqlite3changeset_start()]. If it is called on an iterator passed to 8925** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 8926** is returned and the call has no effect. 8927** 8928** Immediately after an iterator is created by sqlite3changeset_start(), it 8929** does not point to any change in the changeset. Assuming the changeset 8930** is not empty, the first call to this function advances the iterator to 8931** point to the first change in the changeset. Each subsequent call advances 8932** the iterator to point to the next change in the changeset (if any). If 8933** no error occurs and the iterator points to a valid change after a call 8934** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 8935** Otherwise, if all changes in the changeset have already been visited, 8936** SQLITE_DONE is returned. 8937** 8938** If an error occurs, an SQLite error code is returned. Possible error 8939** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 8940** SQLITE_NOMEM. 8941*/ 8942int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 8943 8944/* 8945** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 8946** 8947** The pIter argument passed to this function may either be an iterator 8948** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 8949** created by [sqlite3changeset_start()]. In the latter case, the most recent 8950** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 8951** is not the case, this function returns [SQLITE_MISUSE]. 8952** 8953** If argument pzTab is not NULL, then *pzTab is set to point to a 8954** nul-terminated utf-8 encoded string containing the name of the table 8955** affected by the current change. The buffer remains valid until either 8956** sqlite3changeset_next() is called on the iterator or until the 8957** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 8958** set to the number of columns in the table affected by the change. If 8959** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 8960** is an indirect change, or false (0) otherwise. See the documentation for 8961** [sqlite3session_indirect()] for a description of direct and indirect 8962** changes. Finally, if pOp is not NULL, then *pOp is set to one of 8963** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 8964** type of change that the iterator currently points to. 8965** 8966** If no error occurs, SQLITE_OK is returned. If an error does occur, an 8967** SQLite error code is returned. The values of the output variables may not 8968** be trusted in this case. 8969*/ 8970int sqlite3changeset_op( 8971 sqlite3_changeset_iter *pIter, /* Iterator object */ 8972 const char **pzTab, /* OUT: Pointer to table name */ 8973 int *pnCol, /* OUT: Number of columns in table */ 8974 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 8975 int *pbIndirect /* OUT: True for an 'indirect' change */ 8976); 8977 8978/* 8979** CAPI3REF: Obtain The Primary Key Definition Of A Table 8980** 8981** For each modified table, a changeset includes the following: 8982** 8983** <ul> 8984** <li> The number of columns in the table, and 8985** <li> Which of those columns make up the tables PRIMARY KEY. 8986** </ul> 8987** 8988** This function is used to find which columns comprise the PRIMARY KEY of 8989** the table modified by the change that iterator pIter currently points to. 8990** If successful, *pabPK is set to point to an array of nCol entries, where 8991** nCol is the number of columns in the table. Elements of *pabPK are set to 8992** 0x01 if the corresponding column is part of the tables primary key, or 8993** 0x00 if it is not. 8994** 8995** If argumet pnCol is not NULL, then *pnCol is set to the number of columns 8996** in the table. 8997** 8998** If this function is called when the iterator does not point to a valid 8999** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9000** SQLITE_OK is returned and the output variables populated as described 9001** above. 9002*/ 9003int sqlite3changeset_pk( 9004 sqlite3_changeset_iter *pIter, /* Iterator object */ 9005 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9006 int *pnCol /* OUT: Number of entries in output array */ 9007); 9008 9009/* 9010** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9011** 9012** The pIter argument passed to this function may either be an iterator 9013** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9014** created by [sqlite3changeset_start()]. In the latter case, the most recent 9015** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9016** Furthermore, it may only be called if the type of change that the iterator 9017** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9018** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9019** 9020** Argument iVal must be greater than or equal to 0, and less than the number 9021** of columns in the table affected by the current change. Otherwise, 9022** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9023** 9024** If successful, this function sets *ppValue to point to a protected 9025** sqlite3_value object containing the iVal'th value from the vector of 9026** original row values stored as part of the UPDATE or DELETE change and 9027** returns SQLITE_OK. The name of the function comes from the fact that this 9028** is similar to the "old.*" columns available to update or delete triggers. 9029** 9030** If some other error occurs (e.g. an OOM condition), an SQLite error code 9031** is returned and *ppValue is set to NULL. 9032*/ 9033int sqlite3changeset_old( 9034 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9035 int iVal, /* Column number */ 9036 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9037); 9038 9039/* 9040** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9041** 9042** The pIter argument passed to this function may either be an iterator 9043** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9044** created by [sqlite3changeset_start()]. In the latter case, the most recent 9045** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9046** Furthermore, it may only be called if the type of change that the iterator 9047** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9048** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9049** 9050** Argument iVal must be greater than or equal to 0, and less than the number 9051** of columns in the table affected by the current change. Otherwise, 9052** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9053** 9054** If successful, this function sets *ppValue to point to a protected 9055** sqlite3_value object containing the iVal'th value from the vector of 9056** new row values stored as part of the UPDATE or INSERT change and 9057** returns SQLITE_OK. If the change is an UPDATE and does not include 9058** a new value for the requested column, *ppValue is set to NULL and 9059** SQLITE_OK returned. The name of the function comes from the fact that 9060** this is similar to the "new.*" columns available to update or delete 9061** triggers. 9062** 9063** If some other error occurs (e.g. an OOM condition), an SQLite error code 9064** is returned and *ppValue is set to NULL. 9065*/ 9066int sqlite3changeset_new( 9067 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9068 int iVal, /* Column number */ 9069 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9070); 9071 9072/* 9073** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9074** 9075** This function should only be used with iterator objects passed to a 9076** conflict-handler callback by [sqlite3changeset_apply()] with either 9077** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9078** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9079** is set to NULL. 9080** 9081** Argument iVal must be greater than or equal to 0, and less than the number 9082** of columns in the table affected by the current change. Otherwise, 9083** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9084** 9085** If successful, this function sets *ppValue to point to a protected 9086** sqlite3_value object containing the iVal'th value from the 9087** "conflicting row" associated with the current conflict-handler callback 9088** and returns SQLITE_OK. 9089** 9090** If some other error occurs (e.g. an OOM condition), an SQLite error code 9091** is returned and *ppValue is set to NULL. 9092*/ 9093int sqlite3changeset_conflict( 9094 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9095 int iVal, /* Column number */ 9096 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9097); 9098 9099/* 9100** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9101** 9102** This function may only be called with an iterator passed to an 9103** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9104** it sets the output variable to the total number of known foreign key 9105** violations in the destination database and returns SQLITE_OK. 9106** 9107** In all other cases this function returns SQLITE_MISUSE. 9108*/ 9109int sqlite3changeset_fk_conflicts( 9110 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9111 int *pnOut /* OUT: Number of FK violations */ 9112); 9113 9114 9115/* 9116** CAPI3REF: Finalize A Changeset Iterator 9117** 9118** This function is used to finalize an iterator allocated with 9119** [sqlite3changeset_start()]. 9120** 9121** This function should only be called on iterators created using the 9122** [sqlite3changeset_start()] function. If an application calls this 9123** function with an iterator passed to a conflict-handler by 9124** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9125** call has no effect. 9126** 9127** If an error was encountered within a call to an sqlite3changeset_xxx() 9128** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9129** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9130** to that error is returned by this function. Otherwise, SQLITE_OK is 9131** returned. This is to allow the following pattern (pseudo-code): 9132** 9133** sqlite3changeset_start(); 9134** while( SQLITE_ROW==sqlite3changeset_next() ){ 9135** // Do something with change. 9136** } 9137** rc = sqlite3changeset_finalize(); 9138** if( rc!=SQLITE_OK ){ 9139** // An error has occurred 9140** } 9141*/ 9142int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9143 9144/* 9145** CAPI3REF: Invert A Changeset 9146** 9147** This function is used to "invert" a changeset object. Applying an inverted 9148** changeset to a database reverses the effects of applying the uninverted 9149** changeset. Specifically: 9150** 9151** <ul> 9152** <li> Each DELETE change is changed to an INSERT, and 9153** <li> Each INSERT change is changed to a DELETE, and 9154** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9155** </ul> 9156** 9157** This function does not change the order in which changes appear within 9158** the changeset. It merely reverses the sense of each individual change. 9159** 9160** If successful, a pointer to a buffer containing the inverted changeset 9161** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9162** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9163** zeroed and an SQLite error code returned. 9164** 9165** It is the responsibility of the caller to eventually call sqlite3_free() 9166** on the *ppOut pointer to free the buffer allocation following a successful 9167** call to this function. 9168** 9169** WARNING/TODO: This function currently assumes that the input is a valid 9170** changeset. If it is not, the results are undefined. 9171*/ 9172int sqlite3changeset_invert( 9173 int nIn, const void *pIn, /* Input changeset */ 9174 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9175); 9176 9177/* 9178** CAPI3REF: Concatenate Two Changeset Objects 9179** 9180** This function is used to concatenate two changesets, A and B, into a 9181** single changeset. The result is a changeset equivalent to applying 9182** changeset A followed by changeset B. 9183** 9184** This function combines the two input changesets using an 9185** sqlite3_changegroup object. Calling it produces similar results as the 9186** following code fragment: 9187** 9188** sqlite3_changegroup *pGrp; 9189** rc = sqlite3_changegroup_new(&pGrp); 9190** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9191** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9192** if( rc==SQLITE_OK ){ 9193** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9194** }else{ 9195** *ppOut = 0; 9196** *pnOut = 0; 9197** } 9198** 9199** Refer to the sqlite3_changegroup documentation below for details. 9200*/ 9201int sqlite3changeset_concat( 9202 int nA, /* Number of bytes in buffer pA */ 9203 void *pA, /* Pointer to buffer containing changeset A */ 9204 int nB, /* Number of bytes in buffer pB */ 9205 void *pB, /* Pointer to buffer containing changeset B */ 9206 int *pnOut, /* OUT: Number of bytes in output changeset */ 9207 void **ppOut /* OUT: Buffer containing output changeset */ 9208); 9209 9210 9211/* 9212** Changegroup handle. 9213*/ 9214typedef struct sqlite3_changegroup sqlite3_changegroup; 9215 9216/* 9217** CAPI3REF: Combine two or more changesets into a single changeset. 9218** 9219** An sqlite3_changegroup object is used to combine two or more changesets 9220** (or patchsets) into a single changeset (or patchset). A single changegroup 9221** object may combine changesets or patchsets, but not both. The output is 9222** always in the same format as the input. 9223** 9224** If successful, this function returns SQLITE_OK and populates (*pp) with 9225** a pointer to a new sqlite3_changegroup object before returning. The caller 9226** should eventually free the returned object using a call to 9227** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9228** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9229** 9230** The usual usage pattern for an sqlite3_changegroup object is as follows: 9231** 9232** <ul> 9233** <li> It is created using a call to sqlite3changegroup_new(). 9234** 9235** <li> Zero or more changesets (or patchsets) are added to the object 9236** by calling sqlite3changegroup_add(). 9237** 9238** <li> The result of combining all input changesets together is obtained 9239** by the application via a call to sqlite3changegroup_output(). 9240** 9241** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9242** </ul> 9243** 9244** Any number of calls to add() and output() may be made between the calls to 9245** new() and delete(), and in any order. 9246** 9247** As well as the regular sqlite3changegroup_add() and 9248** sqlite3changegroup_output() functions, also available are the streaming 9249** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9250*/ 9251int sqlite3changegroup_new(sqlite3_changegroup **pp); 9252 9253/* 9254** Add all changes within the changeset (or patchset) in buffer pData (size 9255** nData bytes) to the changegroup. 9256** 9257** If the buffer contains a patchset, then all prior calls to this function 9258** on the same changegroup object must also have specified patchsets. Or, if 9259** the buffer contains a changeset, so must have the earlier calls to this 9260** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9261** to the changegroup. 9262** 9263** Rows within the changeset and changegroup are identified by the values in 9264** their PRIMARY KEY columns. A change in the changeset is considered to 9265** apply to the same row as a change already present in the changegroup if 9266** the two rows have the same primary key. 9267** 9268** Changes to rows that that do not already appear in the changegroup are 9269** simply copied into it. Or, if both the new changeset and the changegroup 9270** contain changes that apply to a single row, the final contents of the 9271** changegroup depends on the type of each change, as follows: 9272** 9273** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9274** <tr><th style="white-space:pre">Existing Change </th> 9275** <th style="white-space:pre">New Change </th> 9276** <th>Output Change 9277** <tr><td>INSERT <td>INSERT <td> 9278** The new change is ignored. This case does not occur if the new 9279** changeset was recorded immediately after the changesets already 9280** added to the changegroup. 9281** <tr><td>INSERT <td>UPDATE <td> 9282** The INSERT change remains in the changegroup. The values in the 9283** INSERT change are modified as if the row was inserted by the 9284** existing change and then updated according to the new change. 9285** <tr><td>INSERT <td>DELETE <td> 9286** The existing INSERT is removed from the changegroup. The DELETE is 9287** not added. 9288** <tr><td>UPDATE <td>INSERT <td> 9289** The new change is ignored. This case does not occur if the new 9290** changeset was recorded immediately after the changesets already 9291** added to the changegroup. 9292** <tr><td>UPDATE <td>UPDATE <td> 9293** The existing UPDATE remains within the changegroup. It is amended 9294** so that the accompanying values are as if the row was updated once 9295** by the existing change and then again by the new change. 9296** <tr><td>UPDATE <td>DELETE <td> 9297** The existing UPDATE is replaced by the new DELETE within the 9298** changegroup. 9299** <tr><td>DELETE <td>INSERT <td> 9300** If one or more of the column values in the row inserted by the 9301** new change differ from those in the row deleted by the existing 9302** change, the existing DELETE is replaced by an UPDATE within the 9303** changegroup. Otherwise, if the inserted row is exactly the same 9304** as the deleted row, the existing DELETE is simply discarded. 9305** <tr><td>DELETE <td>UPDATE <td> 9306** The new change is ignored. This case does not occur if the new 9307** changeset was recorded immediately after the changesets already 9308** added to the changegroup. 9309** <tr><td>DELETE <td>DELETE <td> 9310** The new change is ignored. This case does not occur if the new 9311** changeset was recorded immediately after the changesets already 9312** added to the changegroup. 9313** </table> 9314** 9315** If the new changeset contains changes to a table that is already present 9316** in the changegroup, then the number of columns and the position of the 9317** primary key columns for the table must be consistent. If this is not the 9318** case, this function fails with SQLITE_SCHEMA. If the input changeset 9319** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9320** returned. Or, if an out-of-memory condition occurs during processing, this 9321** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9322** final contents of the changegroup is undefined. 9323** 9324** If no error occurs, SQLITE_OK is returned. 9325*/ 9326int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9327 9328/* 9329** Obtain a buffer containing a changeset (or patchset) representing the 9330** current contents of the changegroup. If the inputs to the changegroup 9331** were themselves changesets, the output is a changeset. Or, if the 9332** inputs were patchsets, the output is also a patchset. 9333** 9334** As with the output of the sqlite3session_changeset() and 9335** sqlite3session_patchset() functions, all changes related to a single 9336** table are grouped together in the output of this function. Tables appear 9337** in the same order as for the very first changeset added to the changegroup. 9338** If the second or subsequent changesets added to the changegroup contain 9339** changes for tables that do not appear in the first changeset, they are 9340** appended onto the end of the output changeset, again in the order in 9341** which they are first encountered. 9342** 9343** If an error occurs, an SQLite error code is returned and the output 9344** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9345** is returned and the output variables are set to the size of and a 9346** pointer to the output buffer, respectively. In this case it is the 9347** responsibility of the caller to eventually free the buffer using a 9348** call to sqlite3_free(). 9349*/ 9350int sqlite3changegroup_output( 9351 sqlite3_changegroup*, 9352 int *pnData, /* OUT: Size of output buffer in bytes */ 9353 void **ppData /* OUT: Pointer to output buffer */ 9354); 9355 9356/* 9357** Delete a changegroup object. 9358*/ 9359void sqlite3changegroup_delete(sqlite3_changegroup*); 9360 9361/* 9362** CAPI3REF: Apply A Changeset To A Database 9363** 9364** Apply a changeset to a database. This function attempts to update the 9365** "main" database attached to handle db with the changes found in the 9366** changeset passed via the second and third arguments. 9367** 9368** The fourth argument (xFilter) passed to this function is the "filter 9369** callback". If it is not NULL, then for each table affected by at least one 9370** change in the changeset, the filter callback is invoked with 9371** the table name as the second argument, and a copy of the context pointer 9372** passed as the sixth argument to this function as the first. If the "filter 9373** callback" returns zero, then no attempt is made to apply any changes to 9374** the table. Otherwise, if the return value is non-zero or the xFilter 9375** argument to this function is NULL, all changes related to the table are 9376** attempted. 9377** 9378** For each table that is not excluded by the filter callback, this function 9379** tests that the target database contains a compatible table. A table is 9380** considered compatible if all of the following are true: 9381** 9382** <ul> 9383** <li> The table has the same name as the name recorded in the 9384** changeset, and 9385** <li> The table has the same number of columns as recorded in the 9386** changeset, and 9387** <li> The table has primary key columns in the same position as 9388** recorded in the changeset. 9389** </ul> 9390** 9391** If there is no compatible table, it is not an error, but none of the 9392** changes associated with the table are applied. A warning message is issued 9393** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9394** one such warning is issued for each table in the changeset. 9395** 9396** For each change for which there is a compatible table, an attempt is made 9397** to modify the table contents according to the UPDATE, INSERT or DELETE 9398** change. If a change cannot be applied cleanly, the conflict handler 9399** function passed as the fifth argument to sqlite3changeset_apply() may be 9400** invoked. A description of exactly when the conflict handler is invoked for 9401** each type of change is below. 9402** 9403** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9404** of passing anything other than a valid function pointer as the xConflict 9405** argument are undefined. 9406** 9407** Each time the conflict handler function is invoked, it must return one 9408** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9409** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9410** if the second argument passed to the conflict handler is either 9411** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9412** returns an illegal value, any changes already made are rolled back and 9413** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9414** actions are taken by sqlite3changeset_apply() depending on the value 9415** returned by each invocation of the conflict-handler function. Refer to 9416** the documentation for the three 9417** [SQLITE_CHANGESET_OMIT|available return values] for details. 9418** 9419** <dl> 9420** <dt>DELETE Changes<dd> 9421** For each DELETE change, this function checks if the target database 9422** contains a row with the same primary key value (or values) as the 9423** original row values stored in the changeset. If it does, and the values 9424** stored in all non-primary key columns also match the values stored in 9425** the changeset the row is deleted from the target database. 9426** 9427** If a row with matching primary key values is found, but one or more of 9428** the non-primary key fields contains a value different from the original 9429** row value stored in the changeset, the conflict-handler function is 9430** invoked with [SQLITE_CHANGESET_DATA] as the second argument. 9431** 9432** If no row with matching primary key values is found in the database, 9433** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9434** passed as the second argument. 9435** 9436** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9437** (which can only happen if a foreign key constraint is violated), the 9438** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9439** passed as the second argument. This includes the case where the DELETE 9440** operation is attempted because an earlier call to the conflict handler 9441** function returned [SQLITE_CHANGESET_REPLACE]. 9442** 9443** <dt>INSERT Changes<dd> 9444** For each INSERT change, an attempt is made to insert the new row into 9445** the database. 9446** 9447** If the attempt to insert the row fails because the database already 9448** contains a row with the same primary key values, the conflict handler 9449** function is invoked with the second argument set to 9450** [SQLITE_CHANGESET_CONFLICT]. 9451** 9452** If the attempt to insert the row fails because of some other constraint 9453** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9454** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9455** This includes the case where the INSERT operation is re-attempted because 9456** an earlier call to the conflict handler function returned 9457** [SQLITE_CHANGESET_REPLACE]. 9458** 9459** <dt>UPDATE Changes<dd> 9460** For each UPDATE change, this function checks if the target database 9461** contains a row with the same primary key value (or values) as the 9462** original row values stored in the changeset. If it does, and the values 9463** stored in all non-primary key columns also match the values stored in 9464** the changeset the row is updated within the target database. 9465** 9466** If a row with matching primary key values is found, but one or more of 9467** the non-primary key fields contains a value different from an original 9468** row value stored in the changeset, the conflict-handler function is 9469** invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9470** UPDATE changes only contain values for non-primary key fields that are 9471** to be modified, only those fields need to match the original values to 9472** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9473** 9474** If no row with matching primary key values is found in the database, 9475** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9476** passed as the second argument. 9477** 9478** If the UPDATE operation is attempted, but SQLite returns 9479** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9480** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9481** This includes the case where the UPDATE operation is attempted after 9482** an earlier call to the conflict handler function returned 9483** [SQLITE_CHANGESET_REPLACE]. 9484** </dl> 9485** 9486** It is safe to execute SQL statements, including those that write to the 9487** table that the callback related to, from within the xConflict callback. 9488** This can be used to further customize the applications conflict 9489** resolution strategy. 9490** 9491** All changes made by this function are enclosed in a savepoint transaction. 9492** If any other error (aside from a constraint failure when attempting to 9493** write to the target database) occurs, then the savepoint transaction is 9494** rolled back, restoring the target database to its original state, and an 9495** SQLite error code returned. 9496*/ 9497int sqlite3changeset_apply( 9498 sqlite3 *db, /* Apply change to "main" db of this handle */ 9499 int nChangeset, /* Size of changeset in bytes */ 9500 void *pChangeset, /* Changeset blob */ 9501 int(*xFilter)( 9502 void *pCtx, /* Copy of sixth arg to _apply() */ 9503 const char *zTab /* Table name */ 9504 ), 9505 int(*xConflict)( 9506 void *pCtx, /* Copy of sixth arg to _apply() */ 9507 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9508 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9509 ), 9510 void *pCtx /* First argument passed to xConflict */ 9511); 9512 9513/* 9514** CAPI3REF: Constants Passed To The Conflict Handler 9515** 9516** Values that may be passed as the second argument to a conflict-handler. 9517** 9518** <dl> 9519** <dt>SQLITE_CHANGESET_DATA<dd> 9520** The conflict handler is invoked with CHANGESET_DATA as the second argument 9521** when processing a DELETE or UPDATE change if a row with the required 9522** PRIMARY KEY fields is present in the database, but one or more other 9523** (non primary-key) fields modified by the update do not contain the 9524** expected "before" values. 9525** 9526** The conflicting row, in this case, is the database row with the matching 9527** primary key. 9528** 9529** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9530** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9531** argument when processing a DELETE or UPDATE change if a row with the 9532** required PRIMARY KEY fields is not present in the database. 9533** 9534** There is no conflicting row in this case. The results of invoking the 9535** sqlite3changeset_conflict() API are undefined. 9536** 9537** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9538** CHANGESET_CONFLICT is passed as the second argument to the conflict 9539** handler while processing an INSERT change if the operation would result 9540** in duplicate primary key values. 9541** 9542** The conflicting row in this case is the database row with the matching 9543** primary key. 9544** 9545** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9546** If foreign key handling is enabled, and applying a changeset leaves the 9547** database in a state containing foreign key violations, the conflict 9548** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9549** exactly once before the changeset is committed. If the conflict handler 9550** returns CHANGESET_OMIT, the changes, including those that caused the 9551** foreign key constraint violation, are committed. Or, if it returns 9552** CHANGESET_ABORT, the changeset is rolled back. 9553** 9554** No current or conflicting row information is provided. The only function 9555** it is possible to call on the supplied sqlite3_changeset_iter handle 9556** is sqlite3changeset_fk_conflicts(). 9557** 9558** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9559** If any other constraint violation occurs while applying a change (i.e. 9560** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9561** invoked with CHANGESET_CONSTRAINT as the second argument. 9562** 9563** There is no conflicting row in this case. The results of invoking the 9564** sqlite3changeset_conflict() API are undefined. 9565** 9566** </dl> 9567*/ 9568#define SQLITE_CHANGESET_DATA 1 9569#define SQLITE_CHANGESET_NOTFOUND 2 9570#define SQLITE_CHANGESET_CONFLICT 3 9571#define SQLITE_CHANGESET_CONSTRAINT 4 9572#define SQLITE_CHANGESET_FOREIGN_KEY 5 9573 9574/* 9575** CAPI3REF: Constants Returned By The Conflict Handler 9576** 9577** A conflict handler callback must return one of the following three values. 9578** 9579** <dl> 9580** <dt>SQLITE_CHANGESET_OMIT<dd> 9581** If a conflict handler returns this value no special action is taken. The 9582** change that caused the conflict is not applied. The session module 9583** continues to the next change in the changeset. 9584** 9585** <dt>SQLITE_CHANGESET_REPLACE<dd> 9586** This value may only be returned if the second argument to the conflict 9587** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9588** is not the case, any changes applied so far are rolled back and the 9589** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9590** 9591** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9592** handler, then the conflicting row is either updated or deleted, depending 9593** on the type of change. 9594** 9595** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9596** handler, then the conflicting row is removed from the database and a 9597** second attempt to apply the change is made. If this second attempt fails, 9598** the original row is restored to the database before continuing. 9599** 9600** <dt>SQLITE_CHANGESET_ABORT<dd> 9601** If this value is returned, any changes applied so far are rolled back 9602** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9603** </dl> 9604*/ 9605#define SQLITE_CHANGESET_OMIT 0 9606#define SQLITE_CHANGESET_REPLACE 1 9607#define SQLITE_CHANGESET_ABORT 2 9608 9609/* 9610** CAPI3REF: Streaming Versions of API functions. 9611** 9612** The six streaming API xxx_strm() functions serve similar purposes to the 9613** corresponding non-streaming API functions: 9614** 9615** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9616** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9617** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9618** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9619** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9620** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9621** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9622** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9623** </table> 9624** 9625** Non-streaming functions that accept changesets (or patchsets) as input 9626** require that the entire changeset be stored in a single buffer in memory. 9627** Similarly, those that return a changeset or patchset do so by returning 9628** a pointer to a single large buffer allocated using sqlite3_malloc(). 9629** Normally this is convenient. However, if an application running in a 9630** low-memory environment is required to handle very large changesets, the 9631** large contiguous memory allocations required can become onerous. 9632** 9633** In order to avoid this problem, instead of a single large buffer, input 9634** is passed to a streaming API functions by way of a callback function that 9635** the sessions module invokes to incrementally request input data as it is 9636** required. In all cases, a pair of API function parameters such as 9637** 9638** <pre> 9639** int nChangeset, 9640** void *pChangeset, 9641** </pre> 9642** 9643** Is replaced by: 9644** 9645** <pre> 9646** int (*xInput)(void *pIn, void *pData, int *pnData), 9647** void *pIn, 9648** </pre> 9649** 9650** Each time the xInput callback is invoked by the sessions module, the first 9651** argument passed is a copy of the supplied pIn context pointer. The second 9652** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9653** error occurs the xInput method should copy up to (*pnData) bytes of data 9654** into the buffer and set (*pnData) to the actual number of bytes copied 9655** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9656** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9657** error code should be returned. In all cases, if an xInput callback returns 9658** an error, all processing is abandoned and the streaming API function 9659** returns a copy of the error code to the caller. 9660** 9661** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9662** invoked by the sessions module at any point during the lifetime of the 9663** iterator. If such an xInput callback returns an error, the iterator enters 9664** an error state, whereby all subsequent calls to iterator functions 9665** immediately fail with the same error code as returned by xInput. 9666** 9667** Similarly, streaming API functions that return changesets (or patchsets) 9668** return them in chunks by way of a callback function instead of via a 9669** pointer to a single large buffer. In this case, a pair of parameters such 9670** as: 9671** 9672** <pre> 9673** int *pnChangeset, 9674** void **ppChangeset, 9675** </pre> 9676** 9677** Is replaced by: 9678** 9679** <pre> 9680** int (*xOutput)(void *pOut, const void *pData, int nData), 9681** void *pOut 9682** </pre> 9683** 9684** The xOutput callback is invoked zero or more times to return data to 9685** the application. The first parameter passed to each call is a copy of the 9686** pOut pointer supplied by the application. The second parameter, pData, 9687** points to a buffer nData bytes in size containing the chunk of output 9688** data being returned. If the xOutput callback successfully processes the 9689** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9690** it should return some other SQLite error code. In this case processing 9691** is immediately abandoned and the streaming API function returns a copy 9692** of the xOutput error code to the application. 9693** 9694** The sessions module never invokes an xOutput callback with the third 9695** parameter set to a value less than or equal to zero. Other than this, 9696** no guarantees are made as to the size of the chunks of data returned. 9697*/ 9698int sqlite3changeset_apply_strm( 9699 sqlite3 *db, /* Apply change to "main" db of this handle */ 9700 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9701 void *pIn, /* First arg for xInput */ 9702 int(*xFilter)( 9703 void *pCtx, /* Copy of sixth arg to _apply() */ 9704 const char *zTab /* Table name */ 9705 ), 9706 int(*xConflict)( 9707 void *pCtx, /* Copy of sixth arg to _apply() */ 9708 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9709 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9710 ), 9711 void *pCtx /* First argument passed to xConflict */ 9712); 9713int sqlite3changeset_concat_strm( 9714 int (*xInputA)(void *pIn, void *pData, int *pnData), 9715 void *pInA, 9716 int (*xInputB)(void *pIn, void *pData, int *pnData), 9717 void *pInB, 9718 int (*xOutput)(void *pOut, const void *pData, int nData), 9719 void *pOut 9720); 9721int sqlite3changeset_invert_strm( 9722 int (*xInput)(void *pIn, void *pData, int *pnData), 9723 void *pIn, 9724 int (*xOutput)(void *pOut, const void *pData, int nData), 9725 void *pOut 9726); 9727int sqlite3changeset_start_strm( 9728 sqlite3_changeset_iter **pp, 9729 int (*xInput)(void *pIn, void *pData, int *pnData), 9730 void *pIn 9731); 9732int sqlite3session_changeset_strm( 9733 sqlite3_session *pSession, 9734 int (*xOutput)(void *pOut, const void *pData, int nData), 9735 void *pOut 9736); 9737int sqlite3session_patchset_strm( 9738 sqlite3_session *pSession, 9739 int (*xOutput)(void *pOut, const void *pData, int nData), 9740 void *pOut 9741); 9742int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9743 int (*xInput)(void *pIn, void *pData, int *pnData), 9744 void *pIn 9745); 9746int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9747 int (*xOutput)(void *pOut, const void *pData, int nData), 9748 void *pOut 9749); 9750 9751 9752/* 9753** Make sure we can call this stuff from C++. 9754*/ 9755#ifdef __cplusplus 9756} 9757#endif 9758 9759#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9760 9761/******** End of sqlite3session.h *********/ 9762/******** Begin file fts5.h *********/ 9763/* 9764** 2014 May 31 9765** 9766** The author disclaims copyright to this source code. In place of 9767** a legal notice, here is a blessing: 9768** 9769** May you do good and not evil. 9770** May you find forgiveness for yourself and forgive others. 9771** May you share freely, never taking more than you give. 9772** 9773****************************************************************************** 9774** 9775** Interfaces to extend FTS5. Using the interfaces defined in this file, 9776** FTS5 may be extended with: 9777** 9778** * custom tokenizers, and 9779** * custom auxiliary functions. 9780*/ 9781 9782 9783#ifndef _FTS5_H 9784#define _FTS5_H 9785 9786 9787#ifdef __cplusplus 9788extern "C" { 9789#endif 9790 9791/************************************************************************* 9792** CUSTOM AUXILIARY FUNCTIONS 9793** 9794** Virtual table implementations may overload SQL functions by implementing 9795** the sqlite3_module.xFindFunction() method. 9796*/ 9797 9798typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9799typedef struct Fts5Context Fts5Context; 9800typedef struct Fts5PhraseIter Fts5PhraseIter; 9801 9802typedef void (*fts5_extension_function)( 9803 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9804 Fts5Context *pFts, /* First arg to pass to pApi functions */ 9805 sqlite3_context *pCtx, /* Context for returning result/error */ 9806 int nVal, /* Number of values in apVal[] array */ 9807 sqlite3_value **apVal /* Array of trailing arguments */ 9808); 9809 9810struct Fts5PhraseIter { 9811 const unsigned char *a; 9812 const unsigned char *b; 9813}; 9814 9815/* 9816** EXTENSION API FUNCTIONS 9817** 9818** xUserData(pFts): 9819** Return a copy of the context pointer the extension function was 9820** registered with. 9821** 9822** xColumnTotalSize(pFts, iCol, pnToken): 9823** If parameter iCol is less than zero, set output variable *pnToken 9824** to the total number of tokens in the FTS5 table. Or, if iCol is 9825** non-negative but less than the number of columns in the table, return 9826** the total number of tokens in column iCol, considering all rows in 9827** the FTS5 table. 9828** 9829** If parameter iCol is greater than or equal to the number of columns 9830** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9831** an OOM condition or IO error), an appropriate SQLite error code is 9832** returned. 9833** 9834** xColumnCount(pFts): 9835** Return the number of columns in the table. 9836** 9837** xColumnSize(pFts, iCol, pnToken): 9838** If parameter iCol is less than zero, set output variable *pnToken 9839** to the total number of tokens in the current row. Or, if iCol is 9840** non-negative but less than the number of columns in the table, set 9841** *pnToken to the number of tokens in column iCol of the current row. 9842** 9843** If parameter iCol is greater than or equal to the number of columns 9844** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9845** an OOM condition or IO error), an appropriate SQLite error code is 9846** returned. 9847** 9848** This function may be quite inefficient if used with an FTS5 table 9849** created with the "columnsize=0" option. 9850** 9851** xColumnText: 9852** This function attempts to retrieve the text of column iCol of the 9853** current document. If successful, (*pz) is set to point to a buffer 9854** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 9855** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 9856** if an error occurs, an SQLite error code is returned and the final values 9857** of (*pz) and (*pn) are undefined. 9858** 9859** xPhraseCount: 9860** Returns the number of phrases in the current query expression. 9861** 9862** xPhraseSize: 9863** Returns the number of tokens in phrase iPhrase of the query. Phrases 9864** are numbered starting from zero. 9865** 9866** xInstCount: 9867** Set *pnInst to the total number of occurrences of all phrases within 9868** the query within the current row. Return SQLITE_OK if successful, or 9869** an error code (i.e. SQLITE_NOMEM) if an error occurs. 9870** 9871** This API can be quite slow if used with an FTS5 table created with the 9872** "detail=none" or "detail=column" option. If the FTS5 table is created 9873** with either "detail=none" or "detail=column" and "content=" option 9874** (i.e. if it is a contentless table), then this API always returns 0. 9875** 9876** xInst: 9877** Query for the details of phrase match iIdx within the current row. 9878** Phrase matches are numbered starting from zero, so the iIdx argument 9879** should be greater than or equal to zero and smaller than the value 9880** output by xInstCount(). 9881** 9882** Usually, output parameter *piPhrase is set to the phrase number, *piCol 9883** to the column in which it occurs and *piOff the token offset of the 9884** first token of the phrase. The exception is if the table was created 9885** with the offsets=0 option specified. In this case *piOff is always 9886** set to -1. 9887** 9888** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 9889** if an error occurs. 9890** 9891** This API can be quite slow if used with an FTS5 table created with the 9892** "detail=none" or "detail=column" option. 9893** 9894** xRowid: 9895** Returns the rowid of the current row. 9896** 9897** xTokenize: 9898** Tokenize text using the tokenizer belonging to the FTS5 table. 9899** 9900** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 9901** This API function is used to query the FTS table for phrase iPhrase 9902** of the current query. Specifically, a query equivalent to: 9903** 9904** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 9905** 9906** with $p set to a phrase equivalent to the phrase iPhrase of the 9907** current query is executed. Any column filter that applies to 9908** phrase iPhrase of the current query is included in $p. For each 9909** row visited, the callback function passed as the fourth argument 9910** is invoked. The context and API objects passed to the callback 9911** function may be used to access the properties of each matched row. 9912** Invoking Api.xUserData() returns a copy of the pointer passed as 9913** the third argument to pUserData. 9914** 9915** If the callback function returns any value other than SQLITE_OK, the 9916** query is abandoned and the xQueryPhrase function returns immediately. 9917** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 9918** Otherwise, the error code is propagated upwards. 9919** 9920** If the query runs to completion without incident, SQLITE_OK is returned. 9921** Or, if some error occurs before the query completes or is aborted by 9922** the callback, an SQLite error code is returned. 9923** 9924** 9925** xSetAuxdata(pFts5, pAux, xDelete) 9926** 9927** Save the pointer passed as the second argument as the extension functions 9928** "auxiliary data". The pointer may then be retrieved by the current or any 9929** future invocation of the same fts5 extension function made as part of 9930** of the same MATCH query using the xGetAuxdata() API. 9931** 9932** Each extension function is allocated a single auxiliary data slot for 9933** each FTS query (MATCH expression). If the extension function is invoked 9934** more than once for a single FTS query, then all invocations share a 9935** single auxiliary data context. 9936** 9937** If there is already an auxiliary data pointer when this function is 9938** invoked, then it is replaced by the new pointer. If an xDelete callback 9939** was specified along with the original pointer, it is invoked at this 9940** point. 9941** 9942** The xDelete callback, if one is specified, is also invoked on the 9943** auxiliary data pointer after the FTS5 query has finished. 9944** 9945** If an error (e.g. an OOM condition) occurs within this function, an 9946** the auxiliary data is set to NULL and an error code returned. If the 9947** xDelete parameter was not NULL, it is invoked on the auxiliary data 9948** pointer before returning. 9949** 9950** 9951** xGetAuxdata(pFts5, bClear) 9952** 9953** Returns the current auxiliary data pointer for the fts5 extension 9954** function. See the xSetAuxdata() method for details. 9955** 9956** If the bClear argument is non-zero, then the auxiliary data is cleared 9957** (set to NULL) before this function returns. In this case the xDelete, 9958** if any, is not invoked. 9959** 9960** 9961** xRowCount(pFts5, pnRow) 9962** 9963** This function is used to retrieve the total number of rows in the table. 9964** In other words, the same value that would be returned by: 9965** 9966** SELECT count(*) FROM ftstable; 9967** 9968** xPhraseFirst() 9969** This function is used, along with type Fts5PhraseIter and the xPhraseNext 9970** method, to iterate through all instances of a single query phrase within 9971** the current row. This is the same information as is accessible via the 9972** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 9973** to use, this API may be faster under some circumstances. To iterate 9974** through instances of phrase iPhrase, use the following code: 9975** 9976** Fts5PhraseIter iter; 9977** int iCol, iOff; 9978** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 9979** iCol>=0; 9980** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 9981** ){ 9982** // An instance of phrase iPhrase at offset iOff of column iCol 9983** } 9984** 9985** The Fts5PhraseIter structure is defined above. Applications should not 9986** modify this structure directly - it should only be used as shown above 9987** with the xPhraseFirst() and xPhraseNext() API methods (and by 9988** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 9989** 9990** This API can be quite slow if used with an FTS5 table created with the 9991** "detail=none" or "detail=column" option. If the FTS5 table is created 9992** with either "detail=none" or "detail=column" and "content=" option 9993** (i.e. if it is a contentless table), then this API always iterates 9994** through an empty set (all calls to xPhraseFirst() set iCol to -1). 9995** 9996** xPhraseNext() 9997** See xPhraseFirst above. 9998** 9999** xPhraseFirstColumn() 10000** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10001** and xPhraseNext() APIs described above. The difference is that instead 10002** of iterating through all instances of a phrase in the current row, these 10003** APIs are used to iterate through the set of columns in the current row 10004** that contain one or more instances of a specified phrase. For example: 10005** 10006** Fts5PhraseIter iter; 10007** int iCol; 10008** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10009** iCol>=0; 10010** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10011** ){ 10012** // Column iCol contains at least one instance of phrase iPhrase 10013** } 10014** 10015** This API can be quite slow if used with an FTS5 table created with the 10016** "detail=none" option. If the FTS5 table is created with either 10017** "detail=none" "content=" option (i.e. if it is a contentless table), 10018** then this API always iterates through an empty set (all calls to 10019** xPhraseFirstColumn() set iCol to -1). 10020** 10021** The information accessed using this API and its companion 10022** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10023** (or xInst/xInstCount). The chief advantage of this API is that it is 10024** significantly more efficient than those alternatives when used with 10025** "detail=column" tables. 10026** 10027** xPhraseNextColumn() 10028** See xPhraseFirstColumn above. 10029*/ 10030struct Fts5ExtensionApi { 10031 int iVersion; /* Currently always set to 3 */ 10032 10033 void *(*xUserData)(Fts5Context*); 10034 10035 int (*xColumnCount)(Fts5Context*); 10036 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10037 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10038 10039 int (*xTokenize)(Fts5Context*, 10040 const char *pText, int nText, /* Text to tokenize */ 10041 void *pCtx, /* Context passed to xToken() */ 10042 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10043 ); 10044 10045 int (*xPhraseCount)(Fts5Context*); 10046 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10047 10048 int (*xInstCount)(Fts5Context*, int *pnInst); 10049 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10050 10051 sqlite3_int64 (*xRowid)(Fts5Context*); 10052 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10053 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10054 10055 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10056 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10057 ); 10058 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10059 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10060 10061 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10062 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10063 10064 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10065 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10066}; 10067 10068/* 10069** CUSTOM AUXILIARY FUNCTIONS 10070*************************************************************************/ 10071 10072/************************************************************************* 10073** CUSTOM TOKENIZERS 10074** 10075** Applications may also register custom tokenizer types. A tokenizer 10076** is registered by providing fts5 with a populated instance of the 10077** following structure. All structure methods must be defined, setting 10078** any member of the fts5_tokenizer struct to NULL leads to undefined 10079** behaviour. The structure methods are expected to function as follows: 10080** 10081** xCreate: 10082** This function is used to allocate and initialize a tokenizer instance. 10083** A tokenizer instance is required to actually tokenize text. 10084** 10085** The first argument passed to this function is a copy of the (void*) 10086** pointer provided by the application when the fts5_tokenizer object 10087** was registered with FTS5 (the third argument to xCreateTokenizer()). 10088** The second and third arguments are an array of nul-terminated strings 10089** containing the tokenizer arguments, if any, specified following the 10090** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10091** to create the FTS5 table. 10092** 10093** The final argument is an output variable. If successful, (*ppOut) 10094** should be set to point to the new tokenizer handle and SQLITE_OK 10095** returned. If an error occurs, some value other than SQLITE_OK should 10096** be returned. In this case, fts5 assumes that the final value of *ppOut 10097** is undefined. 10098** 10099** xDelete: 10100** This function is invoked to delete a tokenizer handle previously 10101** allocated using xCreate(). Fts5 guarantees that this function will 10102** be invoked exactly once for each successful call to xCreate(). 10103** 10104** xTokenize: 10105** This function is expected to tokenize the nText byte string indicated 10106** by argument pText. pText may or may not be nul-terminated. The first 10107** argument passed to this function is a pointer to an Fts5Tokenizer object 10108** returned by an earlier call to xCreate(). 10109** 10110** The second argument indicates the reason that FTS5 is requesting 10111** tokenization of the supplied text. This is always one of the following 10112** four values: 10113** 10114** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10115** or removed from the FTS table. The tokenizer is being invoked to 10116** determine the set of tokens to add to (or delete from) the 10117** FTS index. 10118** 10119** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10120** against the FTS index. The tokenizer is being called to tokenize 10121** a bareword or quoted string specified as part of the query. 10122** 10123** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10124** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10125** followed by a "*" character, indicating that the last token 10126** returned by the tokenizer will be treated as a token prefix. 10127** 10128** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10129** satisfy an fts5_api.xTokenize() request made by an auxiliary 10130** function. Or an fts5_api.xColumnSize() request made by the same 10131** on a columnsize=0 database. 10132** </ul> 10133** 10134** For each token in the input string, the supplied callback xToken() must 10135** be invoked. The first argument to it should be a copy of the pointer 10136** passed as the second argument to xTokenize(). The third and fourth 10137** arguments are a pointer to a buffer containing the token text, and the 10138** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10139** of the first byte of and first byte immediately following the text from 10140** which the token is derived within the input. 10141** 10142** The second argument passed to the xToken() callback ("tflags") should 10143** normally be set to 0. The exception is if the tokenizer supports 10144** synonyms. In this case see the discussion below for details. 10145** 10146** FTS5 assumes the xToken() callback is invoked for each token in the 10147** order that they occur within the input text. 10148** 10149** If an xToken() callback returns any value other than SQLITE_OK, then 10150** the tokenization should be abandoned and the xTokenize() method should 10151** immediately return a copy of the xToken() return value. Or, if the 10152** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10153** if an error occurs with the xTokenize() implementation itself, it 10154** may abandon the tokenization and return any error code other than 10155** SQLITE_OK or SQLITE_DONE. 10156** 10157** SYNONYM SUPPORT 10158** 10159** Custom tokenizers may also support synonyms. Consider a case in which a 10160** user wishes to query for a phrase such as "first place". Using the 10161** built-in tokenizers, the FTS5 query 'first + place' will match instances 10162** of "first place" within the document set, but not alternative forms 10163** such as "1st place". In some applications, it would be better to match 10164** all instances of "first place" or "1st place" regardless of which form 10165** the user specified in the MATCH query text. 10166** 10167** There are several ways to approach this in FTS5: 10168** 10169** <ol><li> By mapping all synonyms to a single token. In this case, the 10170** In the above example, this means that the tokenizer returns the 10171** same token for inputs "first" and "1st". Say that token is in 10172** fact "first", so that when the user inserts the document "I won 10173** 1st place" entries are added to the index for tokens "i", "won", 10174** "first" and "place". If the user then queries for '1st + place', 10175** the tokenizer substitutes "first" for "1st" and the query works 10176** as expected. 10177** 10178** <li> By adding multiple synonyms for a single term to the FTS index. 10179** In this case, when tokenizing query text, the tokenizer may 10180** provide multiple synonyms for a single term within the document. 10181** FTS5 then queries the index for each synonym individually. For 10182** example, faced with the query: 10183** 10184** <codeblock> 10185** ... MATCH 'first place'</codeblock> 10186** 10187** the tokenizer offers both "1st" and "first" as synonyms for the 10188** first token in the MATCH query and FTS5 effectively runs a query 10189** similar to: 10190** 10191** <codeblock> 10192** ... MATCH '(first OR 1st) place'</codeblock> 10193** 10194** except that, for the purposes of auxiliary functions, the query 10195** still appears to contain just two phrases - "(first OR 1st)" 10196** being treated as a single phrase. 10197** 10198** <li> By adding multiple synonyms for a single term to the FTS index. 10199** Using this method, when tokenizing document text, the tokenizer 10200** provides multiple synonyms for each token. So that when a 10201** document such as "I won first place" is tokenized, entries are 10202** added to the FTS index for "i", "won", "first", "1st" and 10203** "place". 10204** 10205** This way, even if the tokenizer does not provide synonyms 10206** when tokenizing query text (it should not - to do would be 10207** inefficient), it doesn't matter if the user queries for 10208** 'first + place' or '1st + place', as there are entires in the 10209** FTS index corresponding to both forms of the first token. 10210** </ol> 10211** 10212** Whether it is parsing document or query text, any call to xToken that 10213** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10214** is considered to supply a synonym for the previous token. For example, 10215** when parsing the document "I won first place", a tokenizer that supports 10216** synonyms would call xToken() 5 times, as follows: 10217** 10218** <codeblock> 10219** xToken(pCtx, 0, "i", 1, 0, 1); 10220** xToken(pCtx, 0, "won", 3, 2, 5); 10221** xToken(pCtx, 0, "first", 5, 6, 11); 10222** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10223** xToken(pCtx, 0, "place", 5, 12, 17); 10224**</codeblock> 10225** 10226** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10227** xToken() is called. Multiple synonyms may be specified for a single token 10228** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10229** There is no limit to the number of synonyms that may be provided for a 10230** single token. 10231** 10232** In many cases, method (1) above is the best approach. It does not add 10233** extra data to the FTS index or require FTS5 to query for multiple terms, 10234** so it is efficient in terms of disk space and query speed. However, it 10235** does not support prefix queries very well. If, as suggested above, the 10236** token "first" is subsituted for "1st" by the tokenizer, then the query: 10237** 10238** <codeblock> 10239** ... MATCH '1s*'</codeblock> 10240** 10241** will not match documents that contain the token "1st" (as the tokenizer 10242** will probably not map "1s" to any prefix of "first"). 10243** 10244** For full prefix support, method (3) may be preferred. In this case, 10245** because the index contains entries for both "first" and "1st", prefix 10246** queries such as 'fi*' or '1s*' will match correctly. However, because 10247** extra entries are added to the FTS index, this method uses more space 10248** within the database. 10249** 10250** Method (2) offers a midpoint between (1) and (3). Using this method, 10251** a query such as '1s*' will match documents that contain the literal 10252** token "1st", but not "first" (assuming the tokenizer is not able to 10253** provide synonyms for prefixes). However, a non-prefix query like '1st' 10254** will match against "1st" and "first". This method does not require 10255** extra disk space, as no extra entries are added to the FTS index. 10256** On the other hand, it may require more CPU cycles to run MATCH queries, 10257** as separate queries of the FTS index are required for each synonym. 10258** 10259** When using methods (2) or (3), it is important that the tokenizer only 10260** provide synonyms when tokenizing document text (method (2)) or query 10261** text (method (3)), not both. Doing so will not cause any errors, but is 10262** inefficient. 10263*/ 10264typedef struct Fts5Tokenizer Fts5Tokenizer; 10265typedef struct fts5_tokenizer fts5_tokenizer; 10266struct fts5_tokenizer { 10267 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10268 void (*xDelete)(Fts5Tokenizer*); 10269 int (*xTokenize)(Fts5Tokenizer*, 10270 void *pCtx, 10271 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10272 const char *pText, int nText, 10273 int (*xToken)( 10274 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10275 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10276 const char *pToken, /* Pointer to buffer containing token */ 10277 int nToken, /* Size of token in bytes */ 10278 int iStart, /* Byte offset of token within input text */ 10279 int iEnd /* Byte offset of end of token within input text */ 10280 ) 10281 ); 10282}; 10283 10284/* Flags that may be passed as the third argument to xTokenize() */ 10285#define FTS5_TOKENIZE_QUERY 0x0001 10286#define FTS5_TOKENIZE_PREFIX 0x0002 10287#define FTS5_TOKENIZE_DOCUMENT 0x0004 10288#define FTS5_TOKENIZE_AUX 0x0008 10289 10290/* Flags that may be passed by the tokenizer implementation back to FTS5 10291** as the third argument to the supplied xToken callback. */ 10292#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10293 10294/* 10295** END OF CUSTOM TOKENIZERS 10296*************************************************************************/ 10297 10298/************************************************************************* 10299** FTS5 EXTENSION REGISTRATION API 10300*/ 10301typedef struct fts5_api fts5_api; 10302struct fts5_api { 10303 int iVersion; /* Currently always set to 2 */ 10304 10305 /* Create a new tokenizer */ 10306 int (*xCreateTokenizer)( 10307 fts5_api *pApi, 10308 const char *zName, 10309 void *pContext, 10310 fts5_tokenizer *pTokenizer, 10311 void (*xDestroy)(void*) 10312 ); 10313 10314 /* Find an existing tokenizer */ 10315 int (*xFindTokenizer)( 10316 fts5_api *pApi, 10317 const char *zName, 10318 void **ppContext, 10319 fts5_tokenizer *pTokenizer 10320 ); 10321 10322 /* Create a new auxiliary function */ 10323 int (*xCreateFunction)( 10324 fts5_api *pApi, 10325 const char *zName, 10326 void *pContext, 10327 fts5_extension_function xFunction, 10328 void (*xDestroy)(void*) 10329 ); 10330}; 10331 10332/* 10333** END OF REGISTRATION API 10334*************************************************************************/ 10335 10336#ifdef __cplusplus 10337} /* end of the 'extern "C"' block */ 10338#endif 10339 10340#endif /* _FTS5_H */ 10341 10342/******** End of fts5.h *********/ 10343