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 suppose 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** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52#ifndef SQLITE_API 53# define SQLITE_API 54#endif 55 56 57/* 58** These no-op macros are used in front of interfaces to mark those 59** interfaces as either deprecated or experimental. New applications 60** should not use deprecated interfaces - they are support for backwards 61** compatibility only. Application writers should be aware that 62** experimental interfaces are subject to change in point releases. 63** 64** These macros used to resolve to various kinds of compiler magic that 65** would generate warning messages when they were used. But that 66** compiler magic ended up generating such a flurry of bug reports 67** that we have taken it all out and gone back to using simple 68** noop macros. 69*/ 70#define SQLITE_DEPRECATED 71#define SQLITE_EXPERIMENTAL 72 73/* 74** Ensure these symbols were not defined by some previous header file. 75*/ 76#ifdef SQLITE_VERSION 77# undef SQLITE_VERSION 78#endif 79#ifdef SQLITE_VERSION_NUMBER 80# undef SQLITE_VERSION_NUMBER 81#endif 82 83/* 84** CAPI3REF: Compile-Time Library Version Numbers 85** 86** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87** evaluates to a string literal that is the SQLite version in the 88** format "X.Y.Z" where X is the major version number (always 3 for 89** SQLite3) and Y is the minor version number and Z is the release number.)^ 90** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92** numbers used in [SQLITE_VERSION].)^ 93** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94** be larger than the release from which it is derived. Either Y will 95** be held constant and Z will be incremented or else Y will be incremented 96** and Z will be reset to zero. 97** 98** Since version 3.6.18, SQLite source code has been stored in the 99** <a href="http://www.fossil-scm.org/">Fossil configuration management 100** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101** a string which identifies a particular check-in of SQLite 102** within its configuration management system. ^The SQLITE_SOURCE_ID 103** string contains the date and time of the check-in (UTC) and an SHA1 104** hash of the entire source tree. 105** 106** See also: [sqlite3_libversion()], 107** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108** [sqlite_version()] and [sqlite_source_id()]. 109*/ 110#define SQLITE_VERSION "3.7.17" 111#define SQLITE_VERSION_NUMBER 3007017 112#define SQLITE_SOURCE_ID "2013-05-20 00:56:22 118a3b35693b134d56ebd780123b7fd6f1497668" 113 114/* 115** CAPI3REF: Run-Time Library Version Numbers 116** KEYWORDS: sqlite3_version, sqlite3_sourceid 117** 118** These interfaces provide the same information as the [SQLITE_VERSION], 119** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120** but are associated with the library instead of the header file. ^(Cautious 121** programmers might include assert() statements in their application to 122** verify that values returned by these interfaces match the macros in 123** the header, and thus insure that the application is 124** compiled with matching library and header files. 125** 126** <blockquote><pre> 127** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130** </pre></blockquote>)^ 131** 132** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133** macro. ^The sqlite3_libversion() function returns a pointer to the 134** to the sqlite3_version[] string constant. The sqlite3_libversion() 135** function is provided for use in DLLs since DLL users usually do not have 136** direct access to string constants within the DLL. ^The 137** sqlite3_libversion_number() function returns an integer equal to 138** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139** a pointer to a string constant whose value is the same as the 140** [SQLITE_SOURCE_ID] C preprocessor macro. 141** 142** See also: [sqlite_version()] and [sqlite_source_id()]. 143*/ 144SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145SQLITE_API const char *sqlite3_libversion(void); 146SQLITE_API const char *sqlite3_sourceid(void); 147SQLITE_API int sqlite3_libversion_number(void); 148 149/* 150** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151** 152** ^The sqlite3_compileoption_used() function returns 0 or 1 153** indicating whether the specified option was defined at 154** compile time. ^The SQLITE_ prefix may be omitted from the 155** option name passed to sqlite3_compileoption_used(). 156** 157** ^The sqlite3_compileoption_get() function allows iterating 158** over the list of options that were defined at compile time by 159** returning the N-th compile time option string. ^If N is out of range, 160** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161** prefix is omitted from any strings returned by 162** sqlite3_compileoption_get(). 163** 164** ^Support for the diagnostic functions sqlite3_compileoption_used() 165** and sqlite3_compileoption_get() may be omitted by specifying the 166** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167** 168** See also: SQL functions [sqlite_compileoption_used()] and 169** [sqlite_compileoption_get()] and the [compile_options pragma]. 170*/ 171#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173SQLITE_API const char *sqlite3_compileoption_get(int N); 174#endif 175 176/* 177** CAPI3REF: Test To See If The Library Is Threadsafe 178** 179** ^The sqlite3_threadsafe() function returns zero if and only if 180** SQLite was compiled with mutexing code omitted due to the 181** [SQLITE_THREADSAFE] compile-time option being set to 0. 182** 183** SQLite can be compiled with or without mutexes. When 184** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185** are enabled and SQLite is threadsafe. When the 186** [SQLITE_THREADSAFE] macro is 0, 187** the mutexes are omitted. Without the mutexes, it is not safe 188** to use SQLite concurrently from more than one thread. 189** 190** Enabling mutexes incurs a measurable performance penalty. 191** So if speed is of utmost importance, it makes sense to disable 192** the mutexes. But for maximum safety, mutexes should be enabled. 193** ^The default behavior is for mutexes to be enabled. 194** 195** This interface can be used by an application to make sure that the 196** version of SQLite that it is linking against was compiled with 197** the desired setting of the [SQLITE_THREADSAFE] macro. 198** 199** This interface only reports on the compile-time mutex setting 200** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202** can be fully or partially disabled using a call to [sqlite3_config()] 203** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205** sqlite3_threadsafe() function shows only the compile-time setting of 206** thread safety, not any run-time changes to that setting made by 207** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208** is unchanged by calls to sqlite3_config().)^ 209** 210** See the [threading mode] documentation for additional information. 211*/ 212SQLITE_API int sqlite3_threadsafe(void); 213 214/* 215** CAPI3REF: Database Connection Handle 216** KEYWORDS: {database connection} {database connections} 217** 218** Each open SQLite database is represented by a pointer to an instance of 219** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 222** and [sqlite3_close_v2()] are its destructors. There are many other 223** interfaces (such as 224** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 225** [sqlite3_busy_timeout()] to name but three) that are methods on an 226** sqlite3 object. 227*/ 228typedef struct sqlite3 sqlite3; 229 230/* 231** CAPI3REF: 64-Bit Integer Types 232** KEYWORDS: sqlite_int64 sqlite_uint64 233** 234** Because there is no cross-platform way to specify 64-bit integer types 235** SQLite includes typedefs for 64-bit signed and unsigned integers. 236** 237** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 238** The sqlite_int64 and sqlite_uint64 types are supported for backwards 239** compatibility only. 240** 241** ^The sqlite3_int64 and sqlite_int64 types can store integer values 242** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 243** sqlite3_uint64 and sqlite_uint64 types can store integer values 244** between 0 and +18446744073709551615 inclusive. 245*/ 246#ifdef SQLITE_INT64_TYPE 247 typedef SQLITE_INT64_TYPE sqlite_int64; 248 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 249#elif defined(_MSC_VER) || defined(__BORLANDC__) 250 typedef __int64 sqlite_int64; 251 typedef unsigned __int64 sqlite_uint64; 252#else 253 typedef long long int sqlite_int64; 254 typedef unsigned long long int sqlite_uint64; 255#endif 256typedef sqlite_int64 sqlite3_int64; 257typedef sqlite_uint64 sqlite3_uint64; 258 259/* 260** If compiling for a processor that lacks floating point support, 261** substitute integer for floating-point. 262*/ 263#ifdef SQLITE_OMIT_FLOATING_POINT 264# define double sqlite3_int64 265#endif 266 267/* 268** CAPI3REF: Closing A Database Connection 269** 270** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 271** for the [sqlite3] object. 272** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if 273** the [sqlite3] object is successfully destroyed and all associated 274** resources are deallocated. 275** 276** ^If the database connection is associated with unfinalized prepared 277** statements or unfinished sqlite3_backup objects then sqlite3_close() 278** will leave the database connection open and return [SQLITE_BUSY]. 279** ^If sqlite3_close_v2() is called with unfinalized prepared statements 280** and unfinished sqlite3_backups, then the database connection becomes 281** an unusable "zombie" which will automatically be deallocated when the 282** last prepared statement is finalized or the last sqlite3_backup is 283** finished. The sqlite3_close_v2() interface is intended for use with 284** host languages that are garbage collected, and where the order in which 285** destructors are called is arbitrary. 286** 287** Applications should [sqlite3_finalize | finalize] all [prepared statements], 288** [sqlite3_blob_close | close] all [BLOB handles], and 289** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 290** with the [sqlite3] object prior to attempting to close the object. ^If 291** sqlite3_close_v2() is called on a [database connection] that still has 292** outstanding [prepared statements], [BLOB handles], and/or 293** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation 294** of resources is deferred until all [prepared statements], [BLOB handles], 295** and [sqlite3_backup] objects are also destroyed. 296** 297** ^If an [sqlite3] object is destroyed while a transaction is open, 298** the transaction is automatically rolled back. 299** 300** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 301** must be either a NULL 302** pointer or an [sqlite3] object pointer obtained 303** from [sqlite3_open()], [sqlite3_open16()], or 304** [sqlite3_open_v2()], and not previously closed. 305** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 306** argument is a harmless no-op. 307*/ 308SQLITE_API int sqlite3_close(sqlite3*); 309SQLITE_API int sqlite3_close_v2(sqlite3*); 310 311/* 312** The type for a callback function. 313** This is legacy and deprecated. It is included for historical 314** compatibility and is not documented. 315*/ 316typedef int (*sqlite3_callback)(void*,int,char**, char**); 317 318/* 319** CAPI3REF: One-Step Query Execution Interface 320** 321** The sqlite3_exec() interface is a convenience wrapper around 322** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 323** that allows an application to run multiple statements of SQL 324** without having to use a lot of C code. 325** 326** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 327** semicolon-separate SQL statements passed into its 2nd argument, 328** in the context of the [database connection] passed in as its 1st 329** argument. ^If the callback function of the 3rd argument to 330** sqlite3_exec() is not NULL, then it is invoked for each result row 331** coming out of the evaluated SQL statements. ^The 4th argument to 332** sqlite3_exec() is relayed through to the 1st argument of each 333** callback invocation. ^If the callback pointer to sqlite3_exec() 334** is NULL, then no callback is ever invoked and result rows are 335** ignored. 336** 337** ^If an error occurs while evaluating the SQL statements passed into 338** sqlite3_exec(), then execution of the current statement stops and 339** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 340** is not NULL then any error message is written into memory obtained 341** from [sqlite3_malloc()] and passed back through the 5th parameter. 342** To avoid memory leaks, the application should invoke [sqlite3_free()] 343** on error message strings returned through the 5th parameter of 344** of sqlite3_exec() after the error message string is no longer needed. 345** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 346** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 347** NULL before returning. 348** 349** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 350** routine returns SQLITE_ABORT without invoking the callback again and 351** without running any subsequent SQL statements. 352** 353** ^The 2nd argument to the sqlite3_exec() callback function is the 354** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 355** callback is an array of pointers to strings obtained as if from 356** [sqlite3_column_text()], one for each column. ^If an element of a 357** result row is NULL then the corresponding string pointer for the 358** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 359** sqlite3_exec() callback is an array of pointers to strings where each 360** entry represents the name of corresponding result column as obtained 361** from [sqlite3_column_name()]. 362** 363** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 364** to an empty string, or a pointer that contains only whitespace and/or 365** SQL comments, then no SQL statements are evaluated and the database 366** is not changed. 367** 368** Restrictions: 369** 370** <ul> 371** <li> The application must insure that the 1st parameter to sqlite3_exec() 372** is a valid and open [database connection]. 373** <li> The application must not close [database connection] specified by 374** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 375** <li> The application must not modify the SQL statement text passed into 376** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 377** </ul> 378*/ 379SQLITE_API int sqlite3_exec( 380 sqlite3*, /* An open database */ 381 const char *sql, /* SQL to be evaluated */ 382 int (*callback)(void*,int,char**,char**), /* Callback function */ 383 void *, /* 1st argument to callback */ 384 char **errmsg /* Error msg written here */ 385); 386 387/* 388** CAPI3REF: Result Codes 389** KEYWORDS: SQLITE_OK {error code} {error codes} 390** KEYWORDS: {result code} {result codes} 391** 392** Many SQLite functions return an integer result code from the set shown 393** here in order to indicate success or failure. 394** 395** New error codes may be added in future versions of SQLite. 396** 397** See also: [SQLITE_IOERR_READ | extended result codes], 398** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 399*/ 400#define SQLITE_OK 0 /* Successful result */ 401/* beginning-of-error-codes */ 402#define SQLITE_ERROR 1 /* SQL error or missing database */ 403#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 404#define SQLITE_PERM 3 /* Access permission denied */ 405#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 406#define SQLITE_BUSY 5 /* The database file is locked */ 407#define SQLITE_LOCKED 6 /* A table in the database is locked */ 408#define SQLITE_NOMEM 7 /* A malloc() failed */ 409#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 410#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 411#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 412#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 413#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 414#define SQLITE_FULL 13 /* Insertion failed because database is full */ 415#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 416#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 417#define SQLITE_EMPTY 16 /* Database is empty */ 418#define SQLITE_SCHEMA 17 /* The database schema changed */ 419#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 420#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 421#define SQLITE_MISMATCH 20 /* Data type mismatch */ 422#define SQLITE_MISUSE 21 /* Library used incorrectly */ 423#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 424#define SQLITE_AUTH 23 /* Authorization denied */ 425#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 426#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 427#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 428#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 429#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 430#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 431#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 432/* end-of-error-codes */ 433 434/* 435** CAPI3REF: Extended Result Codes 436** KEYWORDS: {extended error code} {extended error codes} 437** KEYWORDS: {extended result code} {extended result codes} 438** 439** In its default configuration, SQLite API routines return one of 26 integer 440** [SQLITE_OK | result codes]. However, experience has shown that many of 441** these result codes are too coarse-grained. They do not provide as 442** much information about problems as programmers might like. In an effort to 443** address this, newer versions of SQLite (version 3.3.8 and later) include 444** support for additional result codes that provide more detailed information 445** about errors. The extended result codes are enabled or disabled 446** on a per database connection basis using the 447** [sqlite3_extended_result_codes()] API. 448** 449** Some of the available extended result codes are listed here. 450** One may expect the number of extended result codes will be expand 451** over time. Software that uses extended result codes should expect 452** to see new result codes in future releases of SQLite. 453** 454** The SQLITE_OK result code will never be extended. It will always 455** be exactly zero. 456*/ 457#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 458#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 459#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 460#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 461#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 462#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 463#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 464#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 465#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 466#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 467#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 468#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 469#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 470#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 471#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 472#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 473#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 474#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 475#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 476#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 477#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 478#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 479#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 480#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 481#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 482#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 483#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 484#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 485#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 486#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 487#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 488#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 489#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 490#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 491#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 492#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 493#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 494#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 495#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 496#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 497#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 498#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 499#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 500#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 501#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 502 503/* 504** CAPI3REF: Flags For File Open Operations 505** 506** These bit values are intended for use in the 507** 3rd parameter to the [sqlite3_open_v2()] interface and 508** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 509*/ 510#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 511#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 512#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 513#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 514#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 515#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 516#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 517#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 518#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 519#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 520#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 521#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 522#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 523#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 524#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 525#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 526#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 527#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 528#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 529#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 530 531/* Reserved: 0x00F00000 */ 532 533/* 534** CAPI3REF: Device Characteristics 535** 536** The xDeviceCharacteristics method of the [sqlite3_io_methods] 537** object returns an integer which is a vector of these 538** bit values expressing I/O characteristics of the mass storage 539** device that holds the file that the [sqlite3_io_methods] 540** refers to. 541** 542** The SQLITE_IOCAP_ATOMIC property means that all writes of 543** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 544** mean that writes of blocks that are nnn bytes in size and 545** are aligned to an address which is an integer multiple of 546** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 547** that when data is appended to a file, the data is appended 548** first then the size of the file is extended, never the other 549** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 550** information is written to disk in the same order as calls 551** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 552** after reboot following a crash or power loss, the only bytes in a 553** file that were written at the application level might have changed 554** and that adjacent bytes, even bytes within the same sector are 555** guaranteed to be unchanged. 556*/ 557#define SQLITE_IOCAP_ATOMIC 0x00000001 558#define SQLITE_IOCAP_ATOMIC512 0x00000002 559#define SQLITE_IOCAP_ATOMIC1K 0x00000004 560#define SQLITE_IOCAP_ATOMIC2K 0x00000008 561#define SQLITE_IOCAP_ATOMIC4K 0x00000010 562#define SQLITE_IOCAP_ATOMIC8K 0x00000020 563#define SQLITE_IOCAP_ATOMIC16K 0x00000040 564#define SQLITE_IOCAP_ATOMIC32K 0x00000080 565#define SQLITE_IOCAP_ATOMIC64K 0x00000100 566#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 567#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 568#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 569#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 570 571/* 572** CAPI3REF: File Locking Levels 573** 574** SQLite uses one of these integer values as the second 575** argument to calls it makes to the xLock() and xUnlock() methods 576** of an [sqlite3_io_methods] object. 577*/ 578#define SQLITE_LOCK_NONE 0 579#define SQLITE_LOCK_SHARED 1 580#define SQLITE_LOCK_RESERVED 2 581#define SQLITE_LOCK_PENDING 3 582#define SQLITE_LOCK_EXCLUSIVE 4 583 584/* 585** CAPI3REF: Synchronization Type Flags 586** 587** When SQLite invokes the xSync() method of an 588** [sqlite3_io_methods] object it uses a combination of 589** these integer values as the second argument. 590** 591** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 592** sync operation only needs to flush data to mass storage. Inode 593** information need not be flushed. If the lower four bits of the flag 594** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 595** If the lower four bits equal SQLITE_SYNC_FULL, that means 596** to use Mac OS X style fullsync instead of fsync(). 597** 598** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 599** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 600** settings. The [synchronous pragma] determines when calls to the 601** xSync VFS method occur and applies uniformly across all platforms. 602** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 603** energetic or rigorous or forceful the sync operations are and 604** only make a difference on Mac OSX for the default SQLite code. 605** (Third-party VFS implementations might also make the distinction 606** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 607** operating systems natively supported by SQLite, only Mac OSX 608** cares about the difference.) 609*/ 610#define SQLITE_SYNC_NORMAL 0x00002 611#define SQLITE_SYNC_FULL 0x00003 612#define SQLITE_SYNC_DATAONLY 0x00010 613 614/* 615** CAPI3REF: OS Interface Open File Handle 616** 617** An [sqlite3_file] object represents an open file in the 618** [sqlite3_vfs | OS interface layer]. Individual OS interface 619** implementations will 620** want to subclass this object by appending additional fields 621** for their own use. The pMethods entry is a pointer to an 622** [sqlite3_io_methods] object that defines methods for performing 623** I/O operations on the open file. 624*/ 625typedef struct sqlite3_file sqlite3_file; 626struct sqlite3_file { 627 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 628}; 629 630/* 631** CAPI3REF: OS Interface File Virtual Methods Object 632** 633** Every file opened by the [sqlite3_vfs.xOpen] method populates an 634** [sqlite3_file] object (or, more commonly, a subclass of the 635** [sqlite3_file] object) with a pointer to an instance of this object. 636** This object defines the methods used to perform various operations 637** against the open file represented by the [sqlite3_file] object. 638** 639** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 640** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 641** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 642** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 643** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 644** to NULL. 645** 646** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 647** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 648** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 649** flag may be ORed in to indicate that only the data of the file 650** and not its inode needs to be synced. 651** 652** The integer values to xLock() and xUnlock() are one of 653** <ul> 654** <li> [SQLITE_LOCK_NONE], 655** <li> [SQLITE_LOCK_SHARED], 656** <li> [SQLITE_LOCK_RESERVED], 657** <li> [SQLITE_LOCK_PENDING], or 658** <li> [SQLITE_LOCK_EXCLUSIVE]. 659** </ul> 660** xLock() increases the lock. xUnlock() decreases the lock. 661** The xCheckReservedLock() method checks whether any database connection, 662** either in this process or in some other process, is holding a RESERVED, 663** PENDING, or EXCLUSIVE lock on the file. It returns true 664** if such a lock exists and false otherwise. 665** 666** The xFileControl() method is a generic interface that allows custom 667** VFS implementations to directly control an open file using the 668** [sqlite3_file_control()] interface. The second "op" argument is an 669** integer opcode. The third argument is a generic pointer intended to 670** point to a structure that may contain arguments or space in which to 671** write return values. Potential uses for xFileControl() might be 672** functions to enable blocking locks with timeouts, to change the 673** locking strategy (for example to use dot-file locks), to inquire 674** about the status of a lock, or to break stale locks. The SQLite 675** core reserves all opcodes less than 100 for its own use. 676** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 677** Applications that define a custom xFileControl method should use opcodes 678** greater than 100 to avoid conflicts. VFS implementations should 679** return [SQLITE_NOTFOUND] for file control opcodes that they do not 680** recognize. 681** 682** The xSectorSize() method returns the sector size of the 683** device that underlies the file. The sector size is the 684** minimum write that can be performed without disturbing 685** other bytes in the file. The xDeviceCharacteristics() 686** method returns a bit vector describing behaviors of the 687** underlying device: 688** 689** <ul> 690** <li> [SQLITE_IOCAP_ATOMIC] 691** <li> [SQLITE_IOCAP_ATOMIC512] 692** <li> [SQLITE_IOCAP_ATOMIC1K] 693** <li> [SQLITE_IOCAP_ATOMIC2K] 694** <li> [SQLITE_IOCAP_ATOMIC4K] 695** <li> [SQLITE_IOCAP_ATOMIC8K] 696** <li> [SQLITE_IOCAP_ATOMIC16K] 697** <li> [SQLITE_IOCAP_ATOMIC32K] 698** <li> [SQLITE_IOCAP_ATOMIC64K] 699** <li> [SQLITE_IOCAP_SAFE_APPEND] 700** <li> [SQLITE_IOCAP_SEQUENTIAL] 701** </ul> 702** 703** The SQLITE_IOCAP_ATOMIC property means that all writes of 704** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 705** mean that writes of blocks that are nnn bytes in size and 706** are aligned to an address which is an integer multiple of 707** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 708** that when data is appended to a file, the data is appended 709** first then the size of the file is extended, never the other 710** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 711** information is written to disk in the same order as calls 712** to xWrite(). 713** 714** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 715** in the unread portions of the buffer with zeros. A VFS that 716** fails to zero-fill short reads might seem to work. However, 717** failure to zero-fill short reads will eventually lead to 718** database corruption. 719*/ 720typedef struct sqlite3_io_methods sqlite3_io_methods; 721struct sqlite3_io_methods { 722 int iVersion; 723 int (*xClose)(sqlite3_file*); 724 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 725 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 726 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 727 int (*xSync)(sqlite3_file*, int flags); 728 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 729 int (*xLock)(sqlite3_file*, int); 730 int (*xUnlock)(sqlite3_file*, int); 731 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 732 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 733 int (*xSectorSize)(sqlite3_file*); 734 int (*xDeviceCharacteristics)(sqlite3_file*); 735 /* Methods above are valid for version 1 */ 736 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 737 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 738 void (*xShmBarrier)(sqlite3_file*); 739 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 740 /* Methods above are valid for version 2 */ 741 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 742 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 743 /* Methods above are valid for version 3 */ 744 /* Additional methods may be added in future releases */ 745}; 746 747/* 748** CAPI3REF: Standard File Control Opcodes 749** 750** These integer constants are opcodes for the xFileControl method 751** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 752** interface. 753** 754** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 755** opcode causes the xFileControl method to write the current state of 756** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 757** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 758** into an integer that the pArg argument points to. This capability 759** is used during testing and only needs to be supported when SQLITE_TEST 760** is defined. 761** <ul> 762** <li>[[SQLITE_FCNTL_SIZE_HINT]] 763** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 764** layer a hint of how large the database file will grow to be during the 765** current transaction. This hint is not guaranteed to be accurate but it 766** is often close. The underlying VFS might choose to preallocate database 767** file space based on this hint in order to help writes to the database 768** file run faster. 769** 770** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 771** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 772** extends and truncates the database file in chunks of a size specified 773** by the user. The fourth argument to [sqlite3_file_control()] should 774** point to an integer (type int) containing the new chunk-size to use 775** for the nominated database. Allocating database file space in large 776** chunks (say 1MB at a time), may reduce file-system fragmentation and 777** improve performance on some systems. 778** 779** <li>[[SQLITE_FCNTL_FILE_POINTER]] 780** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 781** to the [sqlite3_file] object associated with a particular database 782** connection. See the [sqlite3_file_control()] documentation for 783** additional information. 784** 785** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 786** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 787** SQLite and sent to all VFSes in place of a call to the xSync method 788** when the database connection has [PRAGMA synchronous] set to OFF.)^ 789** Some specialized VFSes need this signal in order to operate correctly 790** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 791** VFSes do not need this signal and should silently ignore this opcode. 792** Applications should not call [sqlite3_file_control()] with this 793** opcode as doing so may disrupt the operation of the specialized VFSes 794** that do require it. 795** 796** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 797** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 798** retry counts and intervals for certain disk I/O operations for the 799** windows [VFS] in order to provide robustness in the presence of 800** anti-virus programs. By default, the windows VFS will retry file read, 801** file write, and file delete operations up to 10 times, with a delay 802** of 25 milliseconds before the first retry and with the delay increasing 803** by an additional 25 milliseconds with each subsequent retry. This 804** opcode allows these two values (10 retries and 25 milliseconds of delay) 805** to be adjusted. The values are changed for all database connections 806** within the same process. The argument is a pointer to an array of two 807** integers where the first integer i the new retry count and the second 808** integer is the delay. If either integer is negative, then the setting 809** is not changed but instead the prior value of that setting is written 810** into the array entry, allowing the current retry settings to be 811** interrogated. The zDbName parameter is ignored. 812** 813** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 814** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 815** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 816** write ahead log and shared memory files used for transaction control 817** are automatically deleted when the latest connection to the database 818** closes. Setting persistent WAL mode causes those files to persist after 819** close. Persisting the files is useful when other processes that do not 820** have write permission on the directory containing the database file want 821** to read the database file, as the WAL and shared memory files must exist 822** in order for the database to be readable. The fourth parameter to 823** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 824** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 825** WAL mode. If the integer is -1, then it is overwritten with the current 826** WAL persistence setting. 827** 828** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 829** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 830** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 831** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 832** xDeviceCharacteristics methods. The fourth parameter to 833** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 834** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 835** mode. If the integer is -1, then it is overwritten with the current 836** zero-damage mode setting. 837** 838** <li>[[SQLITE_FCNTL_OVERWRITE]] 839** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 840** a write transaction to indicate that, unless it is rolled back for some 841** reason, the entire database file will be overwritten by the current 842** transaction. This is used by VACUUM operations. 843** 844** <li>[[SQLITE_FCNTL_VFSNAME]] 845** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 846** all [VFSes] in the VFS stack. The names are of all VFS shims and the 847** final bottom-level VFS are written into memory obtained from 848** [sqlite3_malloc()] and the result is stored in the char* variable 849** that the fourth parameter of [sqlite3_file_control()] points to. 850** The caller is responsible for freeing the memory when done. As with 851** all file-control actions, there is no guarantee that this will actually 852** do anything. Callers should initialize the char* variable to a NULL 853** pointer in case this file-control is not implemented. This file-control 854** is intended for diagnostic use only. 855** 856** <li>[[SQLITE_FCNTL_PRAGMA]] 857** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 858** file control is sent to the open [sqlite3_file] object corresponding 859** to the database file to which the pragma statement refers. ^The argument 860** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 861** pointers to strings (char**) in which the second element of the array 862** is the name of the pragma and the third element is the argument to the 863** pragma or NULL if the pragma has no argument. ^The handler for an 864** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 865** of the char** argument point to a string obtained from [sqlite3_mprintf()] 866** or the equivalent and that string will become the result of the pragma or 867** the error message if the pragma fails. ^If the 868** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 869** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 870** file control returns [SQLITE_OK], then the parser assumes that the 871** VFS has handled the PRAGMA itself and the parser generates a no-op 872** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 873** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 874** that the VFS encountered an error while handling the [PRAGMA] and the 875** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 876** file control occurs at the beginning of pragma statement analysis and so 877** it is able to override built-in [PRAGMA] statements. 878** 879** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 880** ^The [SQLITE_FCNTL_BUSYHANDLER] 881** file-control may be invoked by SQLite on the database file handle 882** shortly after it is opened in order to provide a custom VFS with access 883** to the connections busy-handler callback. The argument is of type (void **) 884** - an array of two (void *) values. The first (void *) actually points 885** to a function of type (int (*)(void *)). In order to invoke the connections 886** busy-handler, this function should be invoked with the second (void *) in 887** the array as the only argument. If it returns non-zero, then the operation 888** should be retried. If it returns zero, the custom VFS should abandon the 889** current operation. 890** 891** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 892** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 893** to have SQLite generate a 894** temporary filename using the same algorithm that is followed to generate 895** temporary filenames for TEMP tables and other internal uses. The 896** argument should be a char** which will be filled with the filename 897** written into memory obtained from [sqlite3_malloc()]. The caller should 898** invoke [sqlite3_free()] on the result to avoid a memory leak. 899** 900** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 901** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 902** maximum number of bytes that will be used for memory-mapped I/O. 903** The argument is a pointer to a value of type sqlite3_int64 that 904** is an advisory maximum number of bytes in the file to memory map. The 905** pointer is overwritten with the old value. The limit is not changed if 906** the value originally pointed to is negative, and so the current limit 907** can be queried by passing in a pointer to a negative number. This 908** file-control is used internally to implement [PRAGMA mmap_size]. 909** 910** </ul> 911*/ 912#define SQLITE_FCNTL_LOCKSTATE 1 913#define SQLITE_GET_LOCKPROXYFILE 2 914#define SQLITE_SET_LOCKPROXYFILE 3 915#define SQLITE_LAST_ERRNO 4 916#define SQLITE_FCNTL_SIZE_HINT 5 917#define SQLITE_FCNTL_CHUNK_SIZE 6 918#define SQLITE_FCNTL_FILE_POINTER 7 919#define SQLITE_FCNTL_SYNC_OMITTED 8 920#define SQLITE_FCNTL_WIN32_AV_RETRY 9 921#define SQLITE_FCNTL_PERSIST_WAL 10 922#define SQLITE_FCNTL_OVERWRITE 11 923#define SQLITE_FCNTL_VFSNAME 12 924#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 925#define SQLITE_FCNTL_PRAGMA 14 926#define SQLITE_FCNTL_BUSYHANDLER 15 927#define SQLITE_FCNTL_TEMPFILENAME 16 928#define SQLITE_FCNTL_MMAP_SIZE 18 929 930/* 931** CAPI3REF: Mutex Handle 932** 933** The mutex module within SQLite defines [sqlite3_mutex] to be an 934** abstract type for a mutex object. The SQLite core never looks 935** at the internal representation of an [sqlite3_mutex]. It only 936** deals with pointers to the [sqlite3_mutex] object. 937** 938** Mutexes are created using [sqlite3_mutex_alloc()]. 939*/ 940typedef struct sqlite3_mutex sqlite3_mutex; 941 942/* 943** CAPI3REF: OS Interface Object 944** 945** An instance of the sqlite3_vfs object defines the interface between 946** the SQLite core and the underlying operating system. The "vfs" 947** in the name of the object stands for "virtual file system". See 948** the [VFS | VFS documentation] for further information. 949** 950** The value of the iVersion field is initially 1 but may be larger in 951** future versions of SQLite. Additional fields may be appended to this 952** object when the iVersion value is increased. Note that the structure 953** of the sqlite3_vfs object changes in the transaction between 954** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 955** modified. 956** 957** The szOsFile field is the size of the subclassed [sqlite3_file] 958** structure used by this VFS. mxPathname is the maximum length of 959** a pathname in this VFS. 960** 961** Registered sqlite3_vfs objects are kept on a linked list formed by 962** the pNext pointer. The [sqlite3_vfs_register()] 963** and [sqlite3_vfs_unregister()] interfaces manage this list 964** in a thread-safe way. The [sqlite3_vfs_find()] interface 965** searches the list. Neither the application code nor the VFS 966** implementation should use the pNext pointer. 967** 968** The pNext field is the only field in the sqlite3_vfs 969** structure that SQLite will ever modify. SQLite will only access 970** or modify this field while holding a particular static mutex. 971** The application should never modify anything within the sqlite3_vfs 972** object once the object has been registered. 973** 974** The zName field holds the name of the VFS module. The name must 975** be unique across all VFS modules. 976** 977** [[sqlite3_vfs.xOpen]] 978** ^SQLite guarantees that the zFilename parameter to xOpen 979** is either a NULL pointer or string obtained 980** from xFullPathname() with an optional suffix added. 981** ^If a suffix is added to the zFilename parameter, it will 982** consist of a single "-" character followed by no more than 983** 11 alphanumeric and/or "-" characters. 984** ^SQLite further guarantees that 985** the string will be valid and unchanged until xClose() is 986** called. Because of the previous sentence, 987** the [sqlite3_file] can safely store a pointer to the 988** filename if it needs to remember the filename for some reason. 989** If the zFilename parameter to xOpen is a NULL pointer then xOpen 990** must invent its own temporary name for the file. ^Whenever the 991** xFilename parameter is NULL it will also be the case that the 992** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 993** 994** The flags argument to xOpen() includes all bits set in 995** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 996** or [sqlite3_open16()] is used, then flags includes at least 997** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 998** If xOpen() opens a file read-only then it sets *pOutFlags to 999** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1000** 1001** ^(SQLite will also add one of the following flags to the xOpen() 1002** call, depending on the object being opened: 1003** 1004** <ul> 1005** <li> [SQLITE_OPEN_MAIN_DB] 1006** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1007** <li> [SQLITE_OPEN_TEMP_DB] 1008** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1009** <li> [SQLITE_OPEN_TRANSIENT_DB] 1010** <li> [SQLITE_OPEN_SUBJOURNAL] 1011** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1012** <li> [SQLITE_OPEN_WAL] 1013** </ul>)^ 1014** 1015** The file I/O implementation can use the object type flags to 1016** change the way it deals with files. For example, an application 1017** that does not care about crash recovery or rollback might make 1018** the open of a journal file a no-op. Writes to this journal would 1019** also be no-ops, and any attempt to read the journal would return 1020** SQLITE_IOERR. Or the implementation might recognize that a database 1021** file will be doing page-aligned sector reads and writes in a random 1022** order and set up its I/O subsystem accordingly. 1023** 1024** SQLite might also add one of the following flags to the xOpen method: 1025** 1026** <ul> 1027** <li> [SQLITE_OPEN_DELETEONCLOSE] 1028** <li> [SQLITE_OPEN_EXCLUSIVE] 1029** </ul> 1030** 1031** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1032** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1033** will be set for TEMP databases and their journals, transient 1034** databases, and subjournals. 1035** 1036** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1037** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1038** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1039** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1040** SQLITE_OPEN_CREATE, is used to indicate that file should always 1041** be created, and that it is an error if it already exists. 1042** It is <i>not</i> used to indicate the file should be opened 1043** for exclusive access. 1044** 1045** ^At least szOsFile bytes of memory are allocated by SQLite 1046** to hold the [sqlite3_file] structure passed as the third 1047** argument to xOpen. The xOpen method does not have to 1048** allocate the structure; it should just fill it in. Note that 1049** the xOpen method must set the sqlite3_file.pMethods to either 1050** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1051** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1052** element will be valid after xOpen returns regardless of the success 1053** or failure of the xOpen call. 1054** 1055** [[sqlite3_vfs.xAccess]] 1056** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1057** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1058** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1059** to test whether a file is at least readable. The file can be a 1060** directory. 1061** 1062** ^SQLite will always allocate at least mxPathname+1 bytes for the 1063** output buffer xFullPathname. The exact size of the output buffer 1064** is also passed as a parameter to both methods. If the output buffer 1065** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1066** handled as a fatal error by SQLite, vfs implementations should endeavor 1067** to prevent this by setting mxPathname to a sufficiently large value. 1068** 1069** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1070** interfaces are not strictly a part of the filesystem, but they are 1071** included in the VFS structure for completeness. 1072** The xRandomness() function attempts to return nBytes bytes 1073** of good-quality randomness into zOut. The return value is 1074** the actual number of bytes of randomness obtained. 1075** The xSleep() method causes the calling thread to sleep for at 1076** least the number of microseconds given. ^The xCurrentTime() 1077** method returns a Julian Day Number for the current date and time as 1078** a floating point value. 1079** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1080** Day Number multiplied by 86400000 (the number of milliseconds in 1081** a 24-hour day). 1082** ^SQLite will use the xCurrentTimeInt64() method to get the current 1083** date and time if that method is available (if iVersion is 2 or 1084** greater and the function pointer is not NULL) and will fall back 1085** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1086** 1087** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1088** are not used by the SQLite core. These optional interfaces are provided 1089** by some VFSes to facilitate testing of the VFS code. By overriding 1090** system calls with functions under its control, a test program can 1091** simulate faults and error conditions that would otherwise be difficult 1092** or impossible to induce. The set of system calls that can be overridden 1093** varies from one VFS to another, and from one version of the same VFS to the 1094** next. Applications that use these interfaces must be prepared for any 1095** or all of these interfaces to be NULL or for their behavior to change 1096** from one release to the next. Applications must not attempt to access 1097** any of these methods if the iVersion of the VFS is less than 3. 1098*/ 1099typedef struct sqlite3_vfs sqlite3_vfs; 1100typedef void (*sqlite3_syscall_ptr)(void); 1101struct sqlite3_vfs { 1102 int iVersion; /* Structure version number (currently 3) */ 1103 int szOsFile; /* Size of subclassed sqlite3_file */ 1104 int mxPathname; /* Maximum file pathname length */ 1105 sqlite3_vfs *pNext; /* Next registered VFS */ 1106 const char *zName; /* Name of this virtual file system */ 1107 void *pAppData; /* Pointer to application-specific data */ 1108 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1109 int flags, int *pOutFlags); 1110 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1111 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1112 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1113 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1114 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1115 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1116 void (*xDlClose)(sqlite3_vfs*, void*); 1117 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1118 int (*xSleep)(sqlite3_vfs*, int microseconds); 1119 int (*xCurrentTime)(sqlite3_vfs*, double*); 1120 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1121 /* 1122 ** The methods above are in version 1 of the sqlite_vfs object 1123 ** definition. Those that follow are added in version 2 or later 1124 */ 1125 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1126 /* 1127 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1128 ** Those below are for version 3 and greater. 1129 */ 1130 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1131 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1132 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1133 /* 1134 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1135 ** New fields may be appended in figure versions. The iVersion 1136 ** value will increment whenever this happens. 1137 */ 1138}; 1139 1140/* 1141** CAPI3REF: Flags for the xAccess VFS method 1142** 1143** These integer constants can be used as the third parameter to 1144** the xAccess method of an [sqlite3_vfs] object. They determine 1145** what kind of permissions the xAccess method is looking for. 1146** With SQLITE_ACCESS_EXISTS, the xAccess method 1147** simply checks whether the file exists. 1148** With SQLITE_ACCESS_READWRITE, the xAccess method 1149** checks whether the named directory is both readable and writable 1150** (in other words, if files can be added, removed, and renamed within 1151** the directory). 1152** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1153** [temp_store_directory pragma], though this could change in a future 1154** release of SQLite. 1155** With SQLITE_ACCESS_READ, the xAccess method 1156** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1157** currently unused, though it might be used in a future release of 1158** SQLite. 1159*/ 1160#define SQLITE_ACCESS_EXISTS 0 1161#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1162#define SQLITE_ACCESS_READ 2 /* Unused */ 1163 1164/* 1165** CAPI3REF: Flags for the xShmLock VFS method 1166** 1167** These integer constants define the various locking operations 1168** allowed by the xShmLock method of [sqlite3_io_methods]. The 1169** following are the only legal combinations of flags to the 1170** xShmLock method: 1171** 1172** <ul> 1173** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1174** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1175** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1176** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1177** </ul> 1178** 1179** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1180** was given no the corresponding lock. 1181** 1182** The xShmLock method can transition between unlocked and SHARED or 1183** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1184** and EXCLUSIVE. 1185*/ 1186#define SQLITE_SHM_UNLOCK 1 1187#define SQLITE_SHM_LOCK 2 1188#define SQLITE_SHM_SHARED 4 1189#define SQLITE_SHM_EXCLUSIVE 8 1190 1191/* 1192** CAPI3REF: Maximum xShmLock index 1193** 1194** The xShmLock method on [sqlite3_io_methods] may use values 1195** between 0 and this upper bound as its "offset" argument. 1196** The SQLite core will never attempt to acquire or release a 1197** lock outside of this range 1198*/ 1199#define SQLITE_SHM_NLOCK 8 1200 1201 1202/* 1203** CAPI3REF: Initialize The SQLite Library 1204** 1205** ^The sqlite3_initialize() routine initializes the 1206** SQLite library. ^The sqlite3_shutdown() routine 1207** deallocates any resources that were allocated by sqlite3_initialize(). 1208** These routines are designed to aid in process initialization and 1209** shutdown on embedded systems. Workstation applications using 1210** SQLite normally do not need to invoke either of these routines. 1211** 1212** A call to sqlite3_initialize() is an "effective" call if it is 1213** the first time sqlite3_initialize() is invoked during the lifetime of 1214** the process, or if it is the first time sqlite3_initialize() is invoked 1215** following a call to sqlite3_shutdown(). ^(Only an effective call 1216** of sqlite3_initialize() does any initialization. All other calls 1217** are harmless no-ops.)^ 1218** 1219** A call to sqlite3_shutdown() is an "effective" call if it is the first 1220** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1221** an effective call to sqlite3_shutdown() does any deinitialization. 1222** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1223** 1224** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1225** is not. The sqlite3_shutdown() interface must only be called from a 1226** single thread. All open [database connections] must be closed and all 1227** other SQLite resources must be deallocated prior to invoking 1228** sqlite3_shutdown(). 1229** 1230** Among other things, ^sqlite3_initialize() will invoke 1231** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1232** will invoke sqlite3_os_end(). 1233** 1234** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1235** ^If for some reason, sqlite3_initialize() is unable to initialize 1236** the library (perhaps it is unable to allocate a needed resource such 1237** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1238** 1239** ^The sqlite3_initialize() routine is called internally by many other 1240** SQLite interfaces so that an application usually does not need to 1241** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1242** calls sqlite3_initialize() so the SQLite library will be automatically 1243** initialized when [sqlite3_open()] is called if it has not be initialized 1244** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1245** compile-time option, then the automatic calls to sqlite3_initialize() 1246** are omitted and the application must call sqlite3_initialize() directly 1247** prior to using any other SQLite interface. For maximum portability, 1248** it is recommended that applications always invoke sqlite3_initialize() 1249** directly prior to using any other SQLite interface. Future releases 1250** of SQLite may require this. In other words, the behavior exhibited 1251** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1252** default behavior in some future release of SQLite. 1253** 1254** The sqlite3_os_init() routine does operating-system specific 1255** initialization of the SQLite library. The sqlite3_os_end() 1256** routine undoes the effect of sqlite3_os_init(). Typical tasks 1257** performed by these routines include allocation or deallocation 1258** of static resources, initialization of global variables, 1259** setting up a default [sqlite3_vfs] module, or setting up 1260** a default configuration using [sqlite3_config()]. 1261** 1262** The application should never invoke either sqlite3_os_init() 1263** or sqlite3_os_end() directly. The application should only invoke 1264** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1265** interface is called automatically by sqlite3_initialize() and 1266** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1267** implementations for sqlite3_os_init() and sqlite3_os_end() 1268** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1269** When [custom builds | built for other platforms] 1270** (using the [SQLITE_OS_OTHER=1] compile-time 1271** option) the application must supply a suitable implementation for 1272** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1273** implementation of sqlite3_os_init() or sqlite3_os_end() 1274** must return [SQLITE_OK] on success and some other [error code] upon 1275** failure. 1276*/ 1277SQLITE_API int sqlite3_initialize(void); 1278SQLITE_API int sqlite3_shutdown(void); 1279SQLITE_API int sqlite3_os_init(void); 1280SQLITE_API int sqlite3_os_end(void); 1281 1282/* 1283** CAPI3REF: Configuring The SQLite Library 1284** 1285** The sqlite3_config() interface is used to make global configuration 1286** changes to SQLite in order to tune SQLite to the specific needs of 1287** the application. The default configuration is recommended for most 1288** applications and so this routine is usually not necessary. It is 1289** provided to support rare applications with unusual needs. 1290** 1291** The sqlite3_config() interface is not threadsafe. The application 1292** must insure that no other SQLite interfaces are invoked by other 1293** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1294** may only be invoked prior to library initialization using 1295** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1296** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1297** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1298** Note, however, that ^sqlite3_config() can be called as part of the 1299** implementation of an application-defined [sqlite3_os_init()]. 1300** 1301** The first argument to sqlite3_config() is an integer 1302** [configuration option] that determines 1303** what property of SQLite is to be configured. Subsequent arguments 1304** vary depending on the [configuration option] 1305** in the first argument. 1306** 1307** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1308** ^If the option is unknown or SQLite is unable to set the option 1309** then this routine returns a non-zero [error code]. 1310*/ 1311SQLITE_API int sqlite3_config(int, ...); 1312 1313/* 1314** CAPI3REF: Configure database connections 1315** 1316** The sqlite3_db_config() interface is used to make configuration 1317** changes to a [database connection]. The interface is similar to 1318** [sqlite3_config()] except that the changes apply to a single 1319** [database connection] (specified in the first argument). 1320** 1321** The second argument to sqlite3_db_config(D,V,...) is the 1322** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1323** that indicates what aspect of the [database connection] is being configured. 1324** Subsequent arguments vary depending on the configuration verb. 1325** 1326** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1327** the call is considered successful. 1328*/ 1329SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1330 1331/* 1332** CAPI3REF: Memory Allocation Routines 1333** 1334** An instance of this object defines the interface between SQLite 1335** and low-level memory allocation routines. 1336** 1337** This object is used in only one place in the SQLite interface. 1338** A pointer to an instance of this object is the argument to 1339** [sqlite3_config()] when the configuration option is 1340** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1341** By creating an instance of this object 1342** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1343** during configuration, an application can specify an alternative 1344** memory allocation subsystem for SQLite to use for all of its 1345** dynamic memory needs. 1346** 1347** Note that SQLite comes with several [built-in memory allocators] 1348** that are perfectly adequate for the overwhelming majority of applications 1349** and that this object is only useful to a tiny minority of applications 1350** with specialized memory allocation requirements. This object is 1351** also used during testing of SQLite in order to specify an alternative 1352** memory allocator that simulates memory out-of-memory conditions in 1353** order to verify that SQLite recovers gracefully from such 1354** conditions. 1355** 1356** The xMalloc, xRealloc, and xFree methods must work like the 1357** malloc(), realloc() and free() functions from the standard C library. 1358** ^SQLite guarantees that the second argument to 1359** xRealloc is always a value returned by a prior call to xRoundup. 1360** 1361** xSize should return the allocated size of a memory allocation 1362** previously obtained from xMalloc or xRealloc. The allocated size 1363** is always at least as big as the requested size but may be larger. 1364** 1365** The xRoundup method returns what would be the allocated size of 1366** a memory allocation given a particular requested size. Most memory 1367** allocators round up memory allocations at least to the next multiple 1368** of 8. Some allocators round up to a larger multiple or to a power of 2. 1369** Every memory allocation request coming in through [sqlite3_malloc()] 1370** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1371** that causes the corresponding memory allocation to fail. 1372** 1373** The xInit method initializes the memory allocator. (For example, 1374** it might allocate any require mutexes or initialize internal data 1375** structures. The xShutdown method is invoked (indirectly) by 1376** [sqlite3_shutdown()] and should deallocate any resources acquired 1377** by xInit. The pAppData pointer is used as the only parameter to 1378** xInit and xShutdown. 1379** 1380** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1381** the xInit method, so the xInit method need not be threadsafe. The 1382** xShutdown method is only called from [sqlite3_shutdown()] so it does 1383** not need to be threadsafe either. For all other methods, SQLite 1384** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1385** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1386** it is by default) and so the methods are automatically serialized. 1387** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1388** methods must be threadsafe or else make their own arrangements for 1389** serialization. 1390** 1391** SQLite will never invoke xInit() more than once without an intervening 1392** call to xShutdown(). 1393*/ 1394typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1395struct sqlite3_mem_methods { 1396 void *(*xMalloc)(int); /* Memory allocation function */ 1397 void (*xFree)(void*); /* Free a prior allocation */ 1398 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1399 int (*xSize)(void*); /* Return the size of an allocation */ 1400 int (*xRoundup)(int); /* Round up request size to allocation size */ 1401 int (*xInit)(void*); /* Initialize the memory allocator */ 1402 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1403 void *pAppData; /* Argument to xInit() and xShutdown() */ 1404}; 1405 1406/* 1407** CAPI3REF: Configuration Options 1408** KEYWORDS: {configuration option} 1409** 1410** These constants are the available integer configuration options that 1411** can be passed as the first argument to the [sqlite3_config()] interface. 1412** 1413** New configuration options may be added in future releases of SQLite. 1414** Existing configuration options might be discontinued. Applications 1415** should check the return code from [sqlite3_config()] to make sure that 1416** the call worked. The [sqlite3_config()] interface will return a 1417** non-zero [error code] if a discontinued or unsupported configuration option 1418** is invoked. 1419** 1420** <dl> 1421** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1422** <dd>There are no arguments to this option. ^This option sets the 1423** [threading mode] to Single-thread. In other words, it disables 1424** all mutexing and puts SQLite into a mode where it can only be used 1425** by a single thread. ^If SQLite is compiled with 1426** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1427** it is not possible to change the [threading mode] from its default 1428** value of Single-thread and so [sqlite3_config()] will return 1429** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1430** configuration option.</dd> 1431** 1432** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1433** <dd>There are no arguments to this option. ^This option sets the 1434** [threading mode] to Multi-thread. In other words, it disables 1435** mutexing on [database connection] and [prepared statement] objects. 1436** The application is responsible for serializing access to 1437** [database connections] and [prepared statements]. But other mutexes 1438** are enabled so that SQLite will be safe to use in a multi-threaded 1439** environment as long as no two threads attempt to use the same 1440** [database connection] at the same time. ^If SQLite is compiled with 1441** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1442** it is not possible to set the Multi-thread [threading mode] and 1443** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1444** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1445** 1446** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1447** <dd>There are no arguments to this option. ^This option sets the 1448** [threading mode] to Serialized. In other words, this option enables 1449** all mutexes including the recursive 1450** mutexes on [database connection] and [prepared statement] objects. 1451** In this mode (which is the default when SQLite is compiled with 1452** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1453** to [database connections] and [prepared statements] so that the 1454** application is free to use the same [database connection] or the 1455** same [prepared statement] in different threads at the same time. 1456** ^If SQLite is compiled with 1457** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1458** it is not possible to set the Serialized [threading mode] and 1459** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1460** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1461** 1462** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1463** <dd> ^(This option takes a single argument which is a pointer to an 1464** instance of the [sqlite3_mem_methods] structure. The argument specifies 1465** alternative low-level memory allocation routines to be used in place of 1466** the memory allocation routines built into SQLite.)^ ^SQLite makes 1467** its own private copy of the content of the [sqlite3_mem_methods] structure 1468** before the [sqlite3_config()] call returns.</dd> 1469** 1470** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1471** <dd> ^(This option takes a single argument which is a pointer to an 1472** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1473** structure is filled with the currently defined memory allocation routines.)^ 1474** This option can be used to overload the default memory allocation 1475** routines with a wrapper that simulations memory allocation failure or 1476** tracks memory usage, for example. </dd> 1477** 1478** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1479** <dd> ^This option takes single argument of type int, interpreted as a 1480** boolean, which enables or disables the collection of memory allocation 1481** statistics. ^(When memory allocation statistics are disabled, the 1482** following SQLite interfaces become non-operational: 1483** <ul> 1484** <li> [sqlite3_memory_used()] 1485** <li> [sqlite3_memory_highwater()] 1486** <li> [sqlite3_soft_heap_limit64()] 1487** <li> [sqlite3_status()] 1488** </ul>)^ 1489** ^Memory allocation statistics are enabled by default unless SQLite is 1490** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1491** allocation statistics are disabled by default. 1492** </dd> 1493** 1494** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1495** <dd> ^This option specifies a static memory buffer that SQLite can use for 1496** scratch memory. There are three arguments: A pointer an 8-byte 1497** aligned memory buffer from which the scratch allocations will be 1498** drawn, the size of each scratch allocation (sz), 1499** and the maximum number of scratch allocations (N). The sz 1500** argument must be a multiple of 16. 1501** The first argument must be a pointer to an 8-byte aligned buffer 1502** of at least sz*N bytes of memory. 1503** ^SQLite will use no more than two scratch buffers per thread. So 1504** N should be set to twice the expected maximum number of threads. 1505** ^SQLite will never require a scratch buffer that is more than 6 1506** times the database page size. ^If SQLite needs needs additional 1507** scratch memory beyond what is provided by this configuration option, then 1508** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1509** 1510** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1511** <dd> ^This option specifies a static memory buffer that SQLite can use for 1512** the database page cache with the default page cache implementation. 1513** This configuration should not be used if an application-define page 1514** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1515** There are three arguments to this option: A pointer to 8-byte aligned 1516** memory, the size of each page buffer (sz), and the number of pages (N). 1517** The sz argument should be the size of the largest database page 1518** (a power of two between 512 and 32768) plus a little extra for each 1519** page header. ^The page header size is 20 to 40 bytes depending on 1520** the host architecture. ^It is harmless, apart from the wasted memory, 1521** to make sz a little too large. The first 1522** argument should point to an allocation of at least sz*N bytes of memory. 1523** ^SQLite will use the memory provided by the first argument to satisfy its 1524** memory needs for the first N pages that it adds to cache. ^If additional 1525** page cache memory is needed beyond what is provided by this option, then 1526** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1527** The pointer in the first argument must 1528** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1529** will be undefined.</dd> 1530** 1531** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1532** <dd> ^This option specifies a static memory buffer that SQLite will use 1533** for all of its dynamic memory allocation needs beyond those provided 1534** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1535** There are three arguments: An 8-byte aligned pointer to the memory, 1536** the number of bytes in the memory buffer, and the minimum allocation size. 1537** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1538** to using its default memory allocator (the system malloc() implementation), 1539** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1540** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1541** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1542** allocator is engaged to handle all of SQLites memory allocation needs. 1543** The first pointer (the memory pointer) must be aligned to an 8-byte 1544** boundary or subsequent behavior of SQLite will be undefined. 1545** The minimum allocation size is capped at 2**12. Reasonable values 1546** for the minimum allocation size are 2**5 through 2**8.</dd> 1547** 1548** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1549** <dd> ^(This option takes a single argument which is a pointer to an 1550** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1551** alternative low-level mutex routines to be used in place 1552** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1553** content of the [sqlite3_mutex_methods] structure before the call to 1554** [sqlite3_config()] returns. ^If SQLite is compiled with 1555** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1556** the entire mutexing subsystem is omitted from the build and hence calls to 1557** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1558** return [SQLITE_ERROR].</dd> 1559** 1560** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1561** <dd> ^(This option takes a single argument which is a pointer to an 1562** instance of the [sqlite3_mutex_methods] structure. The 1563** [sqlite3_mutex_methods] 1564** structure is filled with the currently defined mutex routines.)^ 1565** This option can be used to overload the default mutex allocation 1566** routines with a wrapper used to track mutex usage for performance 1567** profiling or testing, for example. ^If SQLite is compiled with 1568** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1569** the entire mutexing subsystem is omitted from the build and hence calls to 1570** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1571** return [SQLITE_ERROR].</dd> 1572** 1573** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1574** <dd> ^(This option takes two arguments that determine the default 1575** memory allocation for the lookaside memory allocator on each 1576** [database connection]. The first argument is the 1577** size of each lookaside buffer slot and the second is the number of 1578** slots allocated to each database connection.)^ ^(This option sets the 1579** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1580** verb to [sqlite3_db_config()] can be used to change the lookaside 1581** configuration on individual connections.)^ </dd> 1582** 1583** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1584** <dd> ^(This option takes a single argument which is a pointer to 1585** an [sqlite3_pcache_methods2] object. This object specifies the interface 1586** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1587** object and uses it for page cache memory allocations.</dd> 1588** 1589** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1590** <dd> ^(This option takes a single argument which is a pointer to an 1591** [sqlite3_pcache_methods2] object. SQLite copies of the current 1592** page cache implementation into that object.)^ </dd> 1593** 1594** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1595** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1596** global [error log]. 1597** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1598** function with a call signature of void(*)(void*,int,const char*), 1599** and a pointer to void. ^If the function pointer is not NULL, it is 1600** invoked by [sqlite3_log()] to process each logging event. ^If the 1601** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1602** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1603** passed through as the first parameter to the application-defined logger 1604** function whenever that function is invoked. ^The second parameter to 1605** the logger function is a copy of the first parameter to the corresponding 1606** [sqlite3_log()] call and is intended to be a [result code] or an 1607** [extended result code]. ^The third parameter passed to the logger is 1608** log message after formatting via [sqlite3_snprintf()]. 1609** The SQLite logging interface is not reentrant; the logger function 1610** supplied by the application must not invoke any SQLite interface. 1611** In a multi-threaded application, the application-defined logger 1612** function must be threadsafe. </dd> 1613** 1614** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1615** <dd> This option takes a single argument of type int. If non-zero, then 1616** URI handling is globally enabled. If the parameter is zero, then URI handling 1617** is globally disabled. If URI handling is globally enabled, all filenames 1618** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1619** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1620** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1621** connection is opened. If it is globally disabled, filenames are 1622** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1623** database connection is opened. By default, URI handling is globally 1624** disabled. The default value may be changed by compiling with the 1625** [SQLITE_USE_URI] symbol defined. 1626** 1627** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1628** <dd> This option takes a single integer argument which is interpreted as 1629** a boolean in order to enable or disable the use of covering indices for 1630** full table scans in the query optimizer. The default setting is determined 1631** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1632** if that compile-time option is omitted. 1633** The ability to disable the use of covering indices for full table scans 1634** is because some incorrectly coded legacy applications might malfunction 1635** malfunction when the optimization is enabled. Providing the ability to 1636** disable the optimization allows the older, buggy application code to work 1637** without change even with newer versions of SQLite. 1638** 1639** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1640** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1641** <dd> These options are obsolete and should not be used by new code. 1642** They are retained for backwards compatibility but are now no-ops. 1643** </dd> 1644** 1645** [[SQLITE_CONFIG_SQLLOG]] 1646** <dt>SQLITE_CONFIG_SQLLOG 1647** <dd>This option is only available if sqlite is compiled with the 1648** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1649** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1650** The second should be of type (void*). The callback is invoked by the library 1651** in three separate circumstances, identified by the value passed as the 1652** fourth parameter. If the fourth parameter is 0, then the database connection 1653** passed as the second argument has just been opened. The third argument 1654** points to a buffer containing the name of the main database file. If the 1655** fourth parameter is 1, then the SQL statement that the third parameter 1656** points to has just been executed. Or, if the fourth parameter is 2, then 1657** the connection being passed as the second parameter is being closed. The 1658** third parameter is passed NULL In this case. An example of using this 1659** configuration option can be seen in the "test_sqllog.c" source file in 1660** the canonical SQLite source tree.</dd> 1661** 1662** [[SQLITE_CONFIG_MMAP_SIZE]] 1663** <dt>SQLITE_CONFIG_MMAP_SIZE 1664** <dd>SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1665** that are the default mmap size limit (the default setting for 1666** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1667** The default setting can be overridden by each database connection using 1668** either the [PRAGMA mmap_size] command, or by using the 1669** [SQLITE_FCNTL_MMAP_SIZE] file control. The maximum allowed mmap size 1670** cannot be changed at run-time. Nor may the maximum allowed mmap size 1671** exceed the compile-time maximum mmap size set by the 1672** [SQLITE_MAX_MMAP_SIZE] compile-time option. 1673** If either argument to this option is negative, then that argument is 1674** changed to its compile-time default. 1675** </dl> 1676*/ 1677#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1678#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1679#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1680#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1681#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1682#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1683#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1684#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1685#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1686#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1687#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1688/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1689#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1690#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1691#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1692#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1693#define SQLITE_CONFIG_URI 17 /* int */ 1694#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1695#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1696#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1697#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1698#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1699 1700/* 1701** CAPI3REF: Database Connection Configuration Options 1702** 1703** These constants are the available integer configuration options that 1704** can be passed as the second argument to the [sqlite3_db_config()] interface. 1705** 1706** New configuration options may be added in future releases of SQLite. 1707** Existing configuration options might be discontinued. Applications 1708** should check the return code from [sqlite3_db_config()] to make sure that 1709** the call worked. ^The [sqlite3_db_config()] interface will return a 1710** non-zero [error code] if a discontinued or unsupported configuration option 1711** is invoked. 1712** 1713** <dl> 1714** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1715** <dd> ^This option takes three additional arguments that determine the 1716** [lookaside memory allocator] configuration for the [database connection]. 1717** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1718** pointer to a memory buffer to use for lookaside memory. 1719** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1720** may be NULL in which case SQLite will allocate the 1721** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1722** size of each lookaside buffer slot. ^The third argument is the number of 1723** slots. The size of the buffer in the first argument must be greater than 1724** or equal to the product of the second and third arguments. The buffer 1725** must be aligned to an 8-byte boundary. ^If the second argument to 1726** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1727** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1728** configuration for a database connection can only be changed when that 1729** connection is not currently using lookaside memory, or in other words 1730** when the "current value" returned by 1731** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1732** Any attempt to change the lookaside memory configuration when lookaside 1733** memory is in use leaves the configuration unchanged and returns 1734** [SQLITE_BUSY].)^</dd> 1735** 1736** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1737** <dd> ^This option is used to enable or disable the enforcement of 1738** [foreign key constraints]. There should be two additional arguments. 1739** The first argument is an integer which is 0 to disable FK enforcement, 1740** positive to enable FK enforcement or negative to leave FK enforcement 1741** unchanged. The second parameter is a pointer to an integer into which 1742** is written 0 or 1 to indicate whether FK enforcement is off or on 1743** following this call. The second parameter may be a NULL pointer, in 1744** which case the FK enforcement setting is not reported back. </dd> 1745** 1746** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1747** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1748** There should be two additional arguments. 1749** The first argument is an integer which is 0 to disable triggers, 1750** positive to enable triggers or negative to leave the setting unchanged. 1751** The second parameter is a pointer to an integer into which 1752** is written 0 or 1 to indicate whether triggers are disabled or enabled 1753** following this call. The second parameter may be a NULL pointer, in 1754** which case the trigger setting is not reported back. </dd> 1755** 1756** </dl> 1757*/ 1758#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1759#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1760#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1761 1762 1763/* 1764** CAPI3REF: Enable Or Disable Extended Result Codes 1765** 1766** ^The sqlite3_extended_result_codes() routine enables or disables the 1767** [extended result codes] feature of SQLite. ^The extended result 1768** codes are disabled by default for historical compatibility. 1769*/ 1770SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1771 1772/* 1773** CAPI3REF: Last Insert Rowid 1774** 1775** ^Each entry in an SQLite table has a unique 64-bit signed 1776** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1777** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1778** names are not also used by explicitly declared columns. ^If 1779** the table has a column of type [INTEGER PRIMARY KEY] then that column 1780** is another alias for the rowid. 1781** 1782** ^This routine returns the [rowid] of the most recent 1783** successful [INSERT] into the database from the [database connection] 1784** in the first argument. ^As of SQLite version 3.7.7, this routines 1785** records the last insert rowid of both ordinary tables and [virtual tables]. 1786** ^If no successful [INSERT]s 1787** have ever occurred on that database connection, zero is returned. 1788** 1789** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1790** method, then this routine will return the [rowid] of the inserted 1791** row as long as the trigger or virtual table method is running. 1792** But once the trigger or virtual table method ends, the value returned 1793** by this routine reverts to what it was before the trigger or virtual 1794** table method began.)^ 1795** 1796** ^An [INSERT] that fails due to a constraint violation is not a 1797** successful [INSERT] and does not change the value returned by this 1798** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1799** and INSERT OR ABORT make no changes to the return value of this 1800** routine when their insertion fails. ^(When INSERT OR REPLACE 1801** encounters a constraint violation, it does not fail. The 1802** INSERT continues to completion after deleting rows that caused 1803** the constraint problem so INSERT OR REPLACE will always change 1804** the return value of this interface.)^ 1805** 1806** ^For the purposes of this routine, an [INSERT] is considered to 1807** be successful even if it is subsequently rolled back. 1808** 1809** This function is accessible to SQL statements via the 1810** [last_insert_rowid() SQL function]. 1811** 1812** If a separate thread performs a new [INSERT] on the same 1813** database connection while the [sqlite3_last_insert_rowid()] 1814** function is running and thus changes the last insert [rowid], 1815** then the value returned by [sqlite3_last_insert_rowid()] is 1816** unpredictable and might not equal either the old or the new 1817** last insert [rowid]. 1818*/ 1819SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1820 1821/* 1822** CAPI3REF: Count The Number Of Rows Modified 1823** 1824** ^This function returns the number of database rows that were changed 1825** or inserted or deleted by the most recently completed SQL statement 1826** on the [database connection] specified by the first parameter. 1827** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1828** or [DELETE] statement are counted. Auxiliary changes caused by 1829** triggers or [foreign key actions] are not counted.)^ Use the 1830** [sqlite3_total_changes()] function to find the total number of changes 1831** including changes caused by triggers and foreign key actions. 1832** 1833** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1834** are not counted. Only real table changes are counted. 1835** 1836** ^(A "row change" is a change to a single row of a single table 1837** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1838** are changed as side effects of [REPLACE] constraint resolution, 1839** rollback, ABORT processing, [DROP TABLE], or by any other 1840** mechanisms do not count as direct row changes.)^ 1841** 1842** A "trigger context" is a scope of execution that begins and 1843** ends with the script of a [CREATE TRIGGER | trigger]. 1844** Most SQL statements are 1845** evaluated outside of any trigger. This is the "top level" 1846** trigger context. If a trigger fires from the top level, a 1847** new trigger context is entered for the duration of that one 1848** trigger. Subtriggers create subcontexts for their duration. 1849** 1850** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1851** not create a new trigger context. 1852** 1853** ^This function returns the number of direct row changes in the 1854** most recent INSERT, UPDATE, or DELETE statement within the same 1855** trigger context. 1856** 1857** ^Thus, when called from the top level, this function returns the 1858** number of changes in the most recent INSERT, UPDATE, or DELETE 1859** that also occurred at the top level. ^(Within the body of a trigger, 1860** the sqlite3_changes() interface can be called to find the number of 1861** changes in the most recently completed INSERT, UPDATE, or DELETE 1862** statement within the body of the same trigger. 1863** However, the number returned does not include changes 1864** caused by subtriggers since those have their own context.)^ 1865** 1866** See also the [sqlite3_total_changes()] interface, the 1867** [count_changes pragma], and the [changes() SQL function]. 1868** 1869** If a separate thread makes changes on the same database connection 1870** while [sqlite3_changes()] is running then the value returned 1871** is unpredictable and not meaningful. 1872*/ 1873SQLITE_API int sqlite3_changes(sqlite3*); 1874 1875/* 1876** CAPI3REF: Total Number Of Rows Modified 1877** 1878** ^This function returns the number of row changes caused by [INSERT], 1879** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1880** ^(The count returned by sqlite3_total_changes() includes all changes 1881** from all [CREATE TRIGGER | trigger] contexts and changes made by 1882** [foreign key actions]. However, 1883** the count does not include changes used to implement [REPLACE] constraints, 1884** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1885** count does not include rows of views that fire an [INSTEAD OF trigger], 1886** though if the INSTEAD OF trigger makes changes of its own, those changes 1887** are counted.)^ 1888** ^The sqlite3_total_changes() function counts the changes as soon as 1889** the statement that makes them is completed (when the statement handle 1890** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1891** 1892** See also the [sqlite3_changes()] interface, the 1893** [count_changes pragma], and the [total_changes() SQL function]. 1894** 1895** If a separate thread makes changes on the same database connection 1896** while [sqlite3_total_changes()] is running then the value 1897** returned is unpredictable and not meaningful. 1898*/ 1899SQLITE_API int sqlite3_total_changes(sqlite3*); 1900 1901/* 1902** CAPI3REF: Interrupt A Long-Running Query 1903** 1904** ^This function causes any pending database operation to abort and 1905** return at its earliest opportunity. This routine is typically 1906** called in response to a user action such as pressing "Cancel" 1907** or Ctrl-C where the user wants a long query operation to halt 1908** immediately. 1909** 1910** ^It is safe to call this routine from a thread different from the 1911** thread that is currently running the database operation. But it 1912** is not safe to call this routine with a [database connection] that 1913** is closed or might close before sqlite3_interrupt() returns. 1914** 1915** ^If an SQL operation is very nearly finished at the time when 1916** sqlite3_interrupt() is called, then it might not have an opportunity 1917** to be interrupted and might continue to completion. 1918** 1919** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1920** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1921** that is inside an explicit transaction, then the entire transaction 1922** will be rolled back automatically. 1923** 1924** ^The sqlite3_interrupt(D) call is in effect until all currently running 1925** SQL statements on [database connection] D complete. ^Any new SQL statements 1926** that are started after the sqlite3_interrupt() call and before the 1927** running statements reaches zero are interrupted as if they had been 1928** running prior to the sqlite3_interrupt() call. ^New SQL statements 1929** that are started after the running statement count reaches zero are 1930** not effected by the sqlite3_interrupt(). 1931** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1932** SQL statements is a no-op and has no effect on SQL statements 1933** that are started after the sqlite3_interrupt() call returns. 1934** 1935** If the database connection closes while [sqlite3_interrupt()] 1936** is running then bad things will likely happen. 1937*/ 1938SQLITE_API void sqlite3_interrupt(sqlite3*); 1939 1940/* 1941** CAPI3REF: Determine If An SQL Statement Is Complete 1942** 1943** These routines are useful during command-line input to determine if the 1944** currently entered text seems to form a complete SQL statement or 1945** if additional input is needed before sending the text into 1946** SQLite for parsing. ^These routines return 1 if the input string 1947** appears to be a complete SQL statement. ^A statement is judged to be 1948** complete if it ends with a semicolon token and is not a prefix of a 1949** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1950** string literals or quoted identifier names or comments are not 1951** independent tokens (they are part of the token in which they are 1952** embedded) and thus do not count as a statement terminator. ^Whitespace 1953** and comments that follow the final semicolon are ignored. 1954** 1955** ^These routines return 0 if the statement is incomplete. ^If a 1956** memory allocation fails, then SQLITE_NOMEM is returned. 1957** 1958** ^These routines do not parse the SQL statements thus 1959** will not detect syntactically incorrect SQL. 1960** 1961** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1962** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1963** automatically by sqlite3_complete16(). If that initialization fails, 1964** then the return value from sqlite3_complete16() will be non-zero 1965** regardless of whether or not the input SQL is complete.)^ 1966** 1967** The input to [sqlite3_complete()] must be a zero-terminated 1968** UTF-8 string. 1969** 1970** The input to [sqlite3_complete16()] must be a zero-terminated 1971** UTF-16 string in native byte order. 1972*/ 1973SQLITE_API int sqlite3_complete(const char *sql); 1974SQLITE_API int sqlite3_complete16(const void *sql); 1975 1976/* 1977** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1978** 1979** ^This routine sets a callback function that might be invoked whenever 1980** an attempt is made to open a database table that another thread 1981** or process has locked. 1982** 1983** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1984** is returned immediately upon encountering the lock. ^If the busy callback 1985** is not NULL, then the callback might be invoked with two arguments. 1986** 1987** ^The first argument to the busy handler is a copy of the void* pointer which 1988** is the third argument to sqlite3_busy_handler(). ^The second argument to 1989** the busy handler callback is the number of times that the busy handler has 1990** been invoked for this locking event. ^If the 1991** busy callback returns 0, then no additional attempts are made to 1992** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1993** ^If the callback returns non-zero, then another attempt 1994** is made to open the database for reading and the cycle repeats. 1995** 1996** The presence of a busy handler does not guarantee that it will be invoked 1997** when there is lock contention. ^If SQLite determines that invoking the busy 1998** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1999** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 2000** Consider a scenario where one process is holding a read lock that 2001** it is trying to promote to a reserved lock and 2002** a second process is holding a reserved lock that it is trying 2003** to promote to an exclusive lock. The first process cannot proceed 2004** because it is blocked by the second and the second process cannot 2005** proceed because it is blocked by the first. If both processes 2006** invoke the busy handlers, neither will make any progress. Therefore, 2007** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2008** will induce the first process to release its read lock and allow 2009** the second process to proceed. 2010** 2011** ^The default busy callback is NULL. 2012** 2013** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 2014** when SQLite is in the middle of a large transaction where all the 2015** changes will not fit into the in-memory cache. SQLite will 2016** already hold a RESERVED lock on the database file, but it needs 2017** to promote this lock to EXCLUSIVE so that it can spill cache 2018** pages into the database file without harm to concurrent 2019** readers. ^If it is unable to promote the lock, then the in-memory 2020** cache will be left in an inconsistent state and so the error 2021** code is promoted from the relatively benign [SQLITE_BUSY] to 2022** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 2023** forces an automatic rollback of the changes. See the 2024** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 2025** CorruptionFollowingBusyError</a> wiki page for a discussion of why 2026** this is important. 2027** 2028** ^(There can only be a single busy handler defined for each 2029** [database connection]. Setting a new busy handler clears any 2030** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2031** will also set or clear the busy handler. 2032** 2033** The busy callback should not take any actions which modify the 2034** database connection that invoked the busy handler. Any such actions 2035** result in undefined behavior. 2036** 2037** A busy handler must not close the database connection 2038** or [prepared statement] that invoked the busy handler. 2039*/ 2040SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2041 2042/* 2043** CAPI3REF: Set A Busy Timeout 2044** 2045** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2046** for a specified amount of time when a table is locked. ^The handler 2047** will sleep multiple times until at least "ms" milliseconds of sleeping 2048** have accumulated. ^After at least "ms" milliseconds of sleeping, 2049** the handler returns 0 which causes [sqlite3_step()] to return 2050** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 2051** 2052** ^Calling this routine with an argument less than or equal to zero 2053** turns off all busy handlers. 2054** 2055** ^(There can only be a single busy handler for a particular 2056** [database connection] any any given moment. If another busy handler 2057** was defined (using [sqlite3_busy_handler()]) prior to calling 2058** this routine, that other busy handler is cleared.)^ 2059*/ 2060SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2061 2062/* 2063** CAPI3REF: Convenience Routines For Running Queries 2064** 2065** This is a legacy interface that is preserved for backwards compatibility. 2066** Use of this interface is not recommended. 2067** 2068** Definition: A <b>result table</b> is memory data structure created by the 2069** [sqlite3_get_table()] interface. A result table records the 2070** complete query results from one or more queries. 2071** 2072** The table conceptually has a number of rows and columns. But 2073** these numbers are not part of the result table itself. These 2074** numbers are obtained separately. Let N be the number of rows 2075** and M be the number of columns. 2076** 2077** A result table is an array of pointers to zero-terminated UTF-8 strings. 2078** There are (N+1)*M elements in the array. The first M pointers point 2079** to zero-terminated strings that contain the names of the columns. 2080** The remaining entries all point to query results. NULL values result 2081** in NULL pointers. All other values are in their UTF-8 zero-terminated 2082** string representation as returned by [sqlite3_column_text()]. 2083** 2084** A result table might consist of one or more memory allocations. 2085** It is not safe to pass a result table directly to [sqlite3_free()]. 2086** A result table should be deallocated using [sqlite3_free_table()]. 2087** 2088** ^(As an example of the result table format, suppose a query result 2089** is as follows: 2090** 2091** <blockquote><pre> 2092** Name | Age 2093** ----------------------- 2094** Alice | 43 2095** Bob | 28 2096** Cindy | 21 2097** </pre></blockquote> 2098** 2099** There are two column (M==2) and three rows (N==3). Thus the 2100** result table has 8 entries. Suppose the result table is stored 2101** in an array names azResult. Then azResult holds this content: 2102** 2103** <blockquote><pre> 2104** azResult[0] = "Name"; 2105** azResult[1] = "Age"; 2106** azResult[2] = "Alice"; 2107** azResult[3] = "43"; 2108** azResult[4] = "Bob"; 2109** azResult[5] = "28"; 2110** azResult[6] = "Cindy"; 2111** azResult[7] = "21"; 2112** </pre></blockquote>)^ 2113** 2114** ^The sqlite3_get_table() function evaluates one or more 2115** semicolon-separated SQL statements in the zero-terminated UTF-8 2116** string of its 2nd parameter and returns a result table to the 2117** pointer given in its 3rd parameter. 2118** 2119** After the application has finished with the result from sqlite3_get_table(), 2120** it must pass the result table pointer to sqlite3_free_table() in order to 2121** release the memory that was malloced. Because of the way the 2122** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2123** function must not try to call [sqlite3_free()] directly. Only 2124** [sqlite3_free_table()] is able to release the memory properly and safely. 2125** 2126** The sqlite3_get_table() interface is implemented as a wrapper around 2127** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2128** to any internal data structures of SQLite. It uses only the public 2129** interface defined here. As a consequence, errors that occur in the 2130** wrapper layer outside of the internal [sqlite3_exec()] call are not 2131** reflected in subsequent calls to [sqlite3_errcode()] or 2132** [sqlite3_errmsg()]. 2133*/ 2134SQLITE_API int sqlite3_get_table( 2135 sqlite3 *db, /* An open database */ 2136 const char *zSql, /* SQL to be evaluated */ 2137 char ***pazResult, /* Results of the query */ 2138 int *pnRow, /* Number of result rows written here */ 2139 int *pnColumn, /* Number of result columns written here */ 2140 char **pzErrmsg /* Error msg written here */ 2141); 2142SQLITE_API void sqlite3_free_table(char **result); 2143 2144/* 2145** CAPI3REF: Formatted String Printing Functions 2146** 2147** These routines are work-alikes of the "printf()" family of functions 2148** from the standard C library. 2149** 2150** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2151** results into memory obtained from [sqlite3_malloc()]. 2152** The strings returned by these two routines should be 2153** released by [sqlite3_free()]. ^Both routines return a 2154** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2155** memory to hold the resulting string. 2156** 2157** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2158** the standard C library. The result is written into the 2159** buffer supplied as the second parameter whose size is given by 2160** the first parameter. Note that the order of the 2161** first two parameters is reversed from snprintf().)^ This is an 2162** historical accident that cannot be fixed without breaking 2163** backwards compatibility. ^(Note also that sqlite3_snprintf() 2164** returns a pointer to its buffer instead of the number of 2165** characters actually written into the buffer.)^ We admit that 2166** the number of characters written would be a more useful return 2167** value but we cannot change the implementation of sqlite3_snprintf() 2168** now without breaking compatibility. 2169** 2170** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2171** guarantees that the buffer is always zero-terminated. ^The first 2172** parameter "n" is the total size of the buffer, including space for 2173** the zero terminator. So the longest string that can be completely 2174** written will be n-1 characters. 2175** 2176** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2177** 2178** These routines all implement some additional formatting 2179** options that are useful for constructing SQL statements. 2180** All of the usual printf() formatting options apply. In addition, there 2181** is are "%q", "%Q", and "%z" options. 2182** 2183** ^(The %q option works like %s in that it substitutes a nul-terminated 2184** string from the argument list. But %q also doubles every '\'' character. 2185** %q is designed for use inside a string literal.)^ By doubling each '\'' 2186** character it escapes that character and allows it to be inserted into 2187** the string. 2188** 2189** For example, assume the string variable zText contains text as follows: 2190** 2191** <blockquote><pre> 2192** char *zText = "It's a happy day!"; 2193** </pre></blockquote> 2194** 2195** One can use this text in an SQL statement as follows: 2196** 2197** <blockquote><pre> 2198** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2199** sqlite3_exec(db, zSQL, 0, 0, 0); 2200** sqlite3_free(zSQL); 2201** </pre></blockquote> 2202** 2203** Because the %q format string is used, the '\'' character in zText 2204** is escaped and the SQL generated is as follows: 2205** 2206** <blockquote><pre> 2207** INSERT INTO table1 VALUES('It''s a happy day!') 2208** </pre></blockquote> 2209** 2210** This is correct. Had we used %s instead of %q, the generated SQL 2211** would have looked like this: 2212** 2213** <blockquote><pre> 2214** INSERT INTO table1 VALUES('It's a happy day!'); 2215** </pre></blockquote> 2216** 2217** This second example is an SQL syntax error. As a general rule you should 2218** always use %q instead of %s when inserting text into a string literal. 2219** 2220** ^(The %Q option works like %q except it also adds single quotes around 2221** the outside of the total string. Additionally, if the parameter in the 2222** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2223** single quotes).)^ So, for example, one could say: 2224** 2225** <blockquote><pre> 2226** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2227** sqlite3_exec(db, zSQL, 0, 0, 0); 2228** sqlite3_free(zSQL); 2229** </pre></blockquote> 2230** 2231** The code above will render a correct SQL statement in the zSQL 2232** variable even if the zText variable is a NULL pointer. 2233** 2234** ^(The "%z" formatting option works like "%s" but with the 2235** addition that after the string has been read and copied into 2236** the result, [sqlite3_free()] is called on the input string.)^ 2237*/ 2238SQLITE_API char *sqlite3_mprintf(const char*,...); 2239SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2240SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2241SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2242 2243/* 2244** CAPI3REF: Memory Allocation Subsystem 2245** 2246** The SQLite core uses these three routines for all of its own 2247** internal memory allocation needs. "Core" in the previous sentence 2248** does not include operating-system specific VFS implementation. The 2249** Windows VFS uses native malloc() and free() for some operations. 2250** 2251** ^The sqlite3_malloc() routine returns a pointer to a block 2252** of memory at least N bytes in length, where N is the parameter. 2253** ^If sqlite3_malloc() is unable to obtain sufficient free 2254** memory, it returns a NULL pointer. ^If the parameter N to 2255** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2256** a NULL pointer. 2257** 2258** ^Calling sqlite3_free() with a pointer previously returned 2259** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2260** that it might be reused. ^The sqlite3_free() routine is 2261** a no-op if is called with a NULL pointer. Passing a NULL pointer 2262** to sqlite3_free() is harmless. After being freed, memory 2263** should neither be read nor written. Even reading previously freed 2264** memory might result in a segmentation fault or other severe error. 2265** Memory corruption, a segmentation fault, or other severe error 2266** might result if sqlite3_free() is called with a non-NULL pointer that 2267** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2268** 2269** ^(The sqlite3_realloc() interface attempts to resize a 2270** prior memory allocation to be at least N bytes, where N is the 2271** second parameter. The memory allocation to be resized is the first 2272** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2273** is a NULL pointer then its behavior is identical to calling 2274** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2275** ^If the second parameter to sqlite3_realloc() is zero or 2276** negative then the behavior is exactly the same as calling 2277** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2278** ^sqlite3_realloc() returns a pointer to a memory allocation 2279** of at least N bytes in size or NULL if sufficient memory is unavailable. 2280** ^If M is the size of the prior allocation, then min(N,M) bytes 2281** of the prior allocation are copied into the beginning of buffer returned 2282** by sqlite3_realloc() and the prior allocation is freed. 2283** ^If sqlite3_realloc() returns NULL, then the prior allocation 2284** is not freed. 2285** 2286** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2287** is always aligned to at least an 8 byte boundary, or to a 2288** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2289** option is used. 2290** 2291** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2292** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2293** implementation of these routines to be omitted. That capability 2294** is no longer provided. Only built-in memory allocators can be used. 2295** 2296** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2297** the system malloc() and free() directly when converting 2298** filenames between the UTF-8 encoding used by SQLite 2299** and whatever filename encoding is used by the particular Windows 2300** installation. Memory allocation errors were detected, but 2301** they were reported back as [SQLITE_CANTOPEN] or 2302** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2303** 2304** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2305** must be either NULL or else pointers obtained from a prior 2306** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2307** not yet been released. 2308** 2309** The application must not read or write any part of 2310** a block of memory after it has been released using 2311** [sqlite3_free()] or [sqlite3_realloc()]. 2312*/ 2313SQLITE_API void *sqlite3_malloc(int); 2314SQLITE_API void *sqlite3_realloc(void*, int); 2315SQLITE_API void sqlite3_free(void*); 2316 2317/* 2318** CAPI3REF: Memory Allocator Statistics 2319** 2320** SQLite provides these two interfaces for reporting on the status 2321** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2322** routines, which form the built-in memory allocation subsystem. 2323** 2324** ^The [sqlite3_memory_used()] routine returns the number of bytes 2325** of memory currently outstanding (malloced but not freed). 2326** ^The [sqlite3_memory_highwater()] routine returns the maximum 2327** value of [sqlite3_memory_used()] since the high-water mark 2328** was last reset. ^The values returned by [sqlite3_memory_used()] and 2329** [sqlite3_memory_highwater()] include any overhead 2330** added by SQLite in its implementation of [sqlite3_malloc()], 2331** but not overhead added by the any underlying system library 2332** routines that [sqlite3_malloc()] may call. 2333** 2334** ^The memory high-water mark is reset to the current value of 2335** [sqlite3_memory_used()] if and only if the parameter to 2336** [sqlite3_memory_highwater()] is true. ^The value returned 2337** by [sqlite3_memory_highwater(1)] is the high-water mark 2338** prior to the reset. 2339*/ 2340SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2341SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2342 2343/* 2344** CAPI3REF: Pseudo-Random Number Generator 2345** 2346** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2347** select random [ROWID | ROWIDs] when inserting new records into a table that 2348** already uses the largest possible [ROWID]. The PRNG is also used for 2349** the build-in random() and randomblob() SQL functions. This interface allows 2350** applications to access the same PRNG for other purposes. 2351** 2352** ^A call to this routine stores N bytes of randomness into buffer P. 2353** 2354** ^The first time this routine is invoked (either internally or by 2355** the application) the PRNG is seeded using randomness obtained 2356** from the xRandomness method of the default [sqlite3_vfs] object. 2357** ^On all subsequent invocations, the pseudo-randomness is generated 2358** internally and without recourse to the [sqlite3_vfs] xRandomness 2359** method. 2360*/ 2361SQLITE_API void sqlite3_randomness(int N, void *P); 2362 2363/* 2364** CAPI3REF: Compile-Time Authorization Callbacks 2365** 2366** ^This routine registers an authorizer callback with a particular 2367** [database connection], supplied in the first argument. 2368** ^The authorizer callback is invoked as SQL statements are being compiled 2369** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2370** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2371** points during the compilation process, as logic is being created 2372** to perform various actions, the authorizer callback is invoked to 2373** see if those actions are allowed. ^The authorizer callback should 2374** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2375** specific action but allow the SQL statement to continue to be 2376** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2377** rejected with an error. ^If the authorizer callback returns 2378** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2379** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2380** the authorizer will fail with an error message. 2381** 2382** When the callback returns [SQLITE_OK], that means the operation 2383** requested is ok. ^When the callback returns [SQLITE_DENY], the 2384** [sqlite3_prepare_v2()] or equivalent call that triggered the 2385** authorizer will fail with an error message explaining that 2386** access is denied. 2387** 2388** ^The first parameter to the authorizer callback is a copy of the third 2389** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2390** to the callback is an integer [SQLITE_COPY | action code] that specifies 2391** the particular action to be authorized. ^The third through sixth parameters 2392** to the callback are zero-terminated strings that contain additional 2393** details about the action to be authorized. 2394** 2395** ^If the action code is [SQLITE_READ] 2396** and the callback returns [SQLITE_IGNORE] then the 2397** [prepared statement] statement is constructed to substitute 2398** a NULL value in place of the table column that would have 2399** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2400** return can be used to deny an untrusted user access to individual 2401** columns of a table. 2402** ^If the action code is [SQLITE_DELETE] and the callback returns 2403** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2404** [truncate optimization] is disabled and all rows are deleted individually. 2405** 2406** An authorizer is used when [sqlite3_prepare | preparing] 2407** SQL statements from an untrusted source, to ensure that the SQL statements 2408** do not try to access data they are not allowed to see, or that they do not 2409** try to execute malicious statements that damage the database. For 2410** example, an application may allow a user to enter arbitrary 2411** SQL queries for evaluation by a database. But the application does 2412** not want the user to be able to make arbitrary changes to the 2413** database. An authorizer could then be put in place while the 2414** user-entered SQL is being [sqlite3_prepare | prepared] that 2415** disallows everything except [SELECT] statements. 2416** 2417** Applications that need to process SQL from untrusted sources 2418** might also consider lowering resource limits using [sqlite3_limit()] 2419** and limiting database size using the [max_page_count] [PRAGMA] 2420** in addition to using an authorizer. 2421** 2422** ^(Only a single authorizer can be in place on a database connection 2423** at a time. Each call to sqlite3_set_authorizer overrides the 2424** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2425** The authorizer is disabled by default. 2426** 2427** The authorizer callback must not do anything that will modify 2428** the database connection that invoked the authorizer callback. 2429** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2430** database connections for the meaning of "modify" in this paragraph. 2431** 2432** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2433** statement might be re-prepared during [sqlite3_step()] due to a 2434** schema change. Hence, the application should ensure that the 2435** correct authorizer callback remains in place during the [sqlite3_step()]. 2436** 2437** ^Note that the authorizer callback is invoked only during 2438** [sqlite3_prepare()] or its variants. Authorization is not 2439** performed during statement evaluation in [sqlite3_step()], unless 2440** as stated in the previous paragraph, sqlite3_step() invokes 2441** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2442*/ 2443SQLITE_API int sqlite3_set_authorizer( 2444 sqlite3*, 2445 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2446 void *pUserData 2447); 2448 2449/* 2450** CAPI3REF: Authorizer Return Codes 2451** 2452** The [sqlite3_set_authorizer | authorizer callback function] must 2453** return either [SQLITE_OK] or one of these two constants in order 2454** to signal SQLite whether or not the action is permitted. See the 2455** [sqlite3_set_authorizer | authorizer documentation] for additional 2456** information. 2457** 2458** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2459** from the [sqlite3_vtab_on_conflict()] interface. 2460*/ 2461#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2462#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2463 2464/* 2465** CAPI3REF: Authorizer Action Codes 2466** 2467** The [sqlite3_set_authorizer()] interface registers a callback function 2468** that is invoked to authorize certain SQL statement actions. The 2469** second parameter to the callback is an integer code that specifies 2470** what action is being authorized. These are the integer action codes that 2471** the authorizer callback may be passed. 2472** 2473** These action code values signify what kind of operation is to be 2474** authorized. The 3rd and 4th parameters to the authorization 2475** callback function will be parameters or NULL depending on which of these 2476** codes is used as the second parameter. ^(The 5th parameter to the 2477** authorizer callback is the name of the database ("main", "temp", 2478** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2479** is the name of the inner-most trigger or view that is responsible for 2480** the access attempt or NULL if this access attempt is directly from 2481** top-level SQL code. 2482*/ 2483/******************************************* 3rd ************ 4th ***********/ 2484#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2485#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2486#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2487#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2488#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2489#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2490#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2491#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2492#define SQLITE_DELETE 9 /* Table Name NULL */ 2493#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2494#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2495#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2496#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2497#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2498#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2499#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2500#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2501#define SQLITE_INSERT 18 /* Table Name NULL */ 2502#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2503#define SQLITE_READ 20 /* Table Name Column Name */ 2504#define SQLITE_SELECT 21 /* NULL NULL */ 2505#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2506#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2507#define SQLITE_ATTACH 24 /* Filename NULL */ 2508#define SQLITE_DETACH 25 /* Database Name NULL */ 2509#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2510#define SQLITE_REINDEX 27 /* Index Name NULL */ 2511#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2512#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2513#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2514#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2515#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2516#define SQLITE_COPY 0 /* No longer used */ 2517 2518/* 2519** CAPI3REF: Tracing And Profiling Functions 2520** 2521** These routines register callback functions that can be used for 2522** tracing and profiling the execution of SQL statements. 2523** 2524** ^The callback function registered by sqlite3_trace() is invoked at 2525** various times when an SQL statement is being run by [sqlite3_step()]. 2526** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2527** SQL statement text as the statement first begins executing. 2528** ^(Additional sqlite3_trace() callbacks might occur 2529** as each triggered subprogram is entered. The callbacks for triggers 2530** contain a UTF-8 SQL comment that identifies the trigger.)^ 2531** 2532** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2533** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2534** 2535** ^The callback function registered by sqlite3_profile() is invoked 2536** as each SQL statement finishes. ^The profile callback contains 2537** the original statement text and an estimate of wall-clock time 2538** of how long that statement took to run. ^The profile callback 2539** time is in units of nanoseconds, however the current implementation 2540** is only capable of millisecond resolution so the six least significant 2541** digits in the time are meaningless. Future versions of SQLite 2542** might provide greater resolution on the profiler callback. The 2543** sqlite3_profile() function is considered experimental and is 2544** subject to change in future versions of SQLite. 2545*/ 2546SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2547SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2548 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2549 2550/* 2551** CAPI3REF: Query Progress Callbacks 2552** 2553** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2554** function X to be invoked periodically during long running calls to 2555** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2556** database connection D. An example use for this 2557** interface is to keep a GUI updated during a large query. 2558** 2559** ^The parameter P is passed through as the only parameter to the 2560** callback function X. ^The parameter N is the number of 2561** [virtual machine instructions] that are evaluated between successive 2562** invocations of the callback X. 2563** 2564** ^Only a single progress handler may be defined at one time per 2565** [database connection]; setting a new progress handler cancels the 2566** old one. ^Setting parameter X to NULL disables the progress handler. 2567** ^The progress handler is also disabled by setting N to a value less 2568** than 1. 2569** 2570** ^If the progress callback returns non-zero, the operation is 2571** interrupted. This feature can be used to implement a 2572** "Cancel" button on a GUI progress dialog box. 2573** 2574** The progress handler callback must not do anything that will modify 2575** the database connection that invoked the progress handler. 2576** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2577** database connections for the meaning of "modify" in this paragraph. 2578** 2579*/ 2580SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2581 2582/* 2583** CAPI3REF: Opening A New Database Connection 2584** 2585** ^These routines open an SQLite database file as specified by the 2586** filename argument. ^The filename argument is interpreted as UTF-8 for 2587** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2588** order for sqlite3_open16(). ^(A [database connection] handle is usually 2589** returned in *ppDb, even if an error occurs. The only exception is that 2590** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2591** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2592** object.)^ ^(If the database is opened (and/or created) successfully, then 2593** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2594** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2595** an English language description of the error following a failure of any 2596** of the sqlite3_open() routines. 2597** 2598** ^The default encoding for the database will be UTF-8 if 2599** sqlite3_open() or sqlite3_open_v2() is called and 2600** UTF-16 in the native byte order if sqlite3_open16() is used. 2601** 2602** Whether or not an error occurs when it is opened, resources 2603** associated with the [database connection] handle should be released by 2604** passing it to [sqlite3_close()] when it is no longer required. 2605** 2606** The sqlite3_open_v2() interface works like sqlite3_open() 2607** except that it accepts two additional parameters for additional control 2608** over the new database connection. ^(The flags parameter to 2609** sqlite3_open_v2() can take one of 2610** the following three values, optionally combined with the 2611** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2612** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2613** 2614** <dl> 2615** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2616** <dd>The database is opened in read-only mode. If the database does not 2617** already exist, an error is returned.</dd>)^ 2618** 2619** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2620** <dd>The database is opened for reading and writing if possible, or reading 2621** only if the file is write protected by the operating system. In either 2622** case the database must already exist, otherwise an error is returned.</dd>)^ 2623** 2624** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2625** <dd>The database is opened for reading and writing, and is created if 2626** it does not already exist. This is the behavior that is always used for 2627** sqlite3_open() and sqlite3_open16().</dd>)^ 2628** </dl> 2629** 2630** If the 3rd parameter to sqlite3_open_v2() is not one of the 2631** combinations shown above optionally combined with other 2632** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2633** then the behavior is undefined. 2634** 2635** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2636** opens in the multi-thread [threading mode] as long as the single-thread 2637** mode has not been set at compile-time or start-time. ^If the 2638** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2639** in the serialized [threading mode] unless single-thread was 2640** previously selected at compile-time or start-time. 2641** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2642** eligible to use [shared cache mode], regardless of whether or not shared 2643** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2644** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2645** participate in [shared cache mode] even if it is enabled. 2646** 2647** ^The fourth parameter to sqlite3_open_v2() is the name of the 2648** [sqlite3_vfs] object that defines the operating system interface that 2649** the new database connection should use. ^If the fourth parameter is 2650** a NULL pointer then the default [sqlite3_vfs] object is used. 2651** 2652** ^If the filename is ":memory:", then a private, temporary in-memory database 2653** is created for the connection. ^This in-memory database will vanish when 2654** the database connection is closed. Future versions of SQLite might 2655** make use of additional special filenames that begin with the ":" character. 2656** It is recommended that when a database filename actually does begin with 2657** a ":" character you should prefix the filename with a pathname such as 2658** "./" to avoid ambiguity. 2659** 2660** ^If the filename is an empty string, then a private, temporary 2661** on-disk database will be created. ^This private database will be 2662** automatically deleted as soon as the database connection is closed. 2663** 2664** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2665** 2666** ^If [URI filename] interpretation is enabled, and the filename argument 2667** begins with "file:", then the filename is interpreted as a URI. ^URI 2668** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2669** set in the fourth argument to sqlite3_open_v2(), or if it has 2670** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2671** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2672** As of SQLite version 3.7.7, URI filename interpretation is turned off 2673** by default, but future releases of SQLite might enable URI filename 2674** interpretation by default. See "[URI filenames]" for additional 2675** information. 2676** 2677** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2678** authority, then it must be either an empty string or the string 2679** "localhost". ^If the authority is not an empty string or "localhost", an 2680** error is returned to the caller. ^The fragment component of a URI, if 2681** present, is ignored. 2682** 2683** ^SQLite uses the path component of the URI as the name of the disk file 2684** which contains the database. ^If the path begins with a '/' character, 2685** then it is interpreted as an absolute path. ^If the path does not begin 2686** with a '/' (meaning that the authority section is omitted from the URI) 2687** then the path is interpreted as a relative path. 2688** ^On windows, the first component of an absolute path 2689** is a drive specification (e.g. "C:"). 2690** 2691** [[core URI query parameters]] 2692** The query component of a URI may contain parameters that are interpreted 2693** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2694** SQLite interprets the following three query parameters: 2695** 2696** <ul> 2697** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2698** a VFS object that provides the operating system interface that should 2699** be used to access the database file on disk. ^If this option is set to 2700** an empty string the default VFS object is used. ^Specifying an unknown 2701** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2702** present, then the VFS specified by the option takes precedence over 2703** the value passed as the fourth parameter to sqlite3_open_v2(). 2704** 2705** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2706** "rwc", or "memory". Attempting to set it to any other value is 2707** an error)^. 2708** ^If "ro" is specified, then the database is opened for read-only 2709** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2710** third argument to sqlite3_open_v2(). ^If the mode option is set to 2711** "rw", then the database is opened for read-write (but not create) 2712** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2713** been set. ^Value "rwc" is equivalent to setting both 2714** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2715** set to "memory" then a pure [in-memory database] that never reads 2716** or writes from disk is used. ^It is an error to specify a value for 2717** the mode parameter that is less restrictive than that specified by 2718** the flags passed in the third parameter to sqlite3_open_v2(). 2719** 2720** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2721** "private". ^Setting it to "shared" is equivalent to setting the 2722** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2723** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2724** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2725** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2726** a URI filename, its value overrides any behavior requested by setting 2727** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2728** </ul> 2729** 2730** ^Specifying an unknown parameter in the query component of a URI is not an 2731** error. Future versions of SQLite might understand additional query 2732** parameters. See "[query parameters with special meaning to SQLite]" for 2733** additional information. 2734** 2735** [[URI filename examples]] <h3>URI filename examples</h3> 2736** 2737** <table border="1" align=center cellpadding=5> 2738** <tr><th> URI filenames <th> Results 2739** <tr><td> file:data.db <td> 2740** Open the file "data.db" in the current directory. 2741** <tr><td> file:/home/fred/data.db<br> 2742** file:///home/fred/data.db <br> 2743** file://localhost/home/fred/data.db <br> <td> 2744** Open the database file "/home/fred/data.db". 2745** <tr><td> file://darkstar/home/fred/data.db <td> 2746** An error. "darkstar" is not a recognized authority. 2747** <tr><td style="white-space:nowrap"> 2748** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2749** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2750** C:. Note that the %20 escaping in this example is not strictly 2751** necessary - space characters can be used literally 2752** in URI filenames. 2753** <tr><td> file:data.db?mode=ro&cache=private <td> 2754** Open file "data.db" in the current directory for read-only access. 2755** Regardless of whether or not shared-cache mode is enabled by 2756** default, use a private cache. 2757** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2758** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2759** <tr><td> file:data.db?mode=readonly <td> 2760** An error. "readonly" is not a valid option for the "mode" parameter. 2761** </table> 2762** 2763** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2764** query components of a URI. A hexadecimal escape sequence consists of a 2765** percent sign - "%" - followed by exactly two hexadecimal digits 2766** specifying an octet value. ^Before the path or query components of a 2767** URI filename are interpreted, they are encoded using UTF-8 and all 2768** hexadecimal escape sequences replaced by a single byte containing the 2769** corresponding octet. If this process generates an invalid UTF-8 encoding, 2770** the results are undefined. 2771** 2772** <b>Note to Windows users:</b> The encoding used for the filename argument 2773** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2774** codepage is currently defined. Filenames containing international 2775** characters must be converted to UTF-8 prior to passing them into 2776** sqlite3_open() or sqlite3_open_v2(). 2777** 2778** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2779** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2780** features that require the use of temporary files may fail. 2781** 2782** See also: [sqlite3_temp_directory] 2783*/ 2784SQLITE_API int sqlite3_open( 2785 const char *filename, /* Database filename (UTF-8) */ 2786 sqlite3 **ppDb /* OUT: SQLite db handle */ 2787); 2788SQLITE_API int sqlite3_open16( 2789 const void *filename, /* Database filename (UTF-16) */ 2790 sqlite3 **ppDb /* OUT: SQLite db handle */ 2791); 2792SQLITE_API int sqlite3_open_v2( 2793 const char *filename, /* Database filename (UTF-8) */ 2794 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2795 int flags, /* Flags */ 2796 const char *zVfs /* Name of VFS module to use */ 2797); 2798 2799/* 2800** CAPI3REF: Obtain Values For URI Parameters 2801** 2802** These are utility routines, useful to VFS implementations, that check 2803** to see if a database file was a URI that contained a specific query 2804** parameter, and if so obtains the value of that query parameter. 2805** 2806** If F is the database filename pointer passed into the xOpen() method of 2807** a VFS implementation when the flags parameter to xOpen() has one or 2808** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2809** P is the name of the query parameter, then 2810** sqlite3_uri_parameter(F,P) returns the value of the P 2811** parameter if it exists or a NULL pointer if P does not appear as a 2812** query parameter on F. If P is a query parameter of F 2813** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2814** a pointer to an empty string. 2815** 2816** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2817** parameter and returns true (1) or false (0) according to the value 2818** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2819** value of query parameter P is one of "yes", "true", or "on" in any 2820** case or if the value begins with a non-zero number. The 2821** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2822** query parameter P is one of "no", "false", or "off" in any case or 2823** if the value begins with a numeric zero. If P is not a query 2824** parameter on F or if the value of P is does not match any of the 2825** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2826** 2827** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2828** 64-bit signed integer and returns that integer, or D if P does not 2829** exist. If the value of P is something other than an integer, then 2830** zero is returned. 2831** 2832** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2833** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2834** is not a database file pathname pointer that SQLite passed into the xOpen 2835** VFS method, then the behavior of this routine is undefined and probably 2836** undesirable. 2837*/ 2838SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2839SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2840SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2841 2842 2843/* 2844** CAPI3REF: Error Codes And Messages 2845** 2846** ^The sqlite3_errcode() interface returns the numeric [result code] or 2847** [extended result code] for the most recent failed sqlite3_* API call 2848** associated with a [database connection]. If a prior API call failed 2849** but the most recent API call succeeded, the return value from 2850** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2851** interface is the same except that it always returns the 2852** [extended result code] even when extended result codes are 2853** disabled. 2854** 2855** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2856** text that describes the error, as either UTF-8 or UTF-16 respectively. 2857** ^(Memory to hold the error message string is managed internally. 2858** The application does not need to worry about freeing the result. 2859** However, the error string might be overwritten or deallocated by 2860** subsequent calls to other SQLite interface functions.)^ 2861** 2862** ^The sqlite3_errstr() interface returns the English-language text 2863** that describes the [result code], as UTF-8. 2864** ^(Memory to hold the error message string is managed internally 2865** and must not be freed by the application)^. 2866** 2867** When the serialized [threading mode] is in use, it might be the 2868** case that a second error occurs on a separate thread in between 2869** the time of the first error and the call to these interfaces. 2870** When that happens, the second error will be reported since these 2871** interfaces always report the most recent result. To avoid 2872** this, each thread can obtain exclusive use of the [database connection] D 2873** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2874** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2875** all calls to the interfaces listed here are completed. 2876** 2877** If an interface fails with SQLITE_MISUSE, that means the interface 2878** was invoked incorrectly by the application. In that case, the 2879** error code and message may or may not be set. 2880*/ 2881SQLITE_API int sqlite3_errcode(sqlite3 *db); 2882SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2883SQLITE_API const char *sqlite3_errmsg(sqlite3*); 2884SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 2885SQLITE_API const char *sqlite3_errstr(int); 2886 2887/* 2888** CAPI3REF: SQL Statement Object 2889** KEYWORDS: {prepared statement} {prepared statements} 2890** 2891** An instance of this object represents a single SQL statement. 2892** This object is variously known as a "prepared statement" or a 2893** "compiled SQL statement" or simply as a "statement". 2894** 2895** The life of a statement object goes something like this: 2896** 2897** <ol> 2898** <li> Create the object using [sqlite3_prepare_v2()] or a related 2899** function. 2900** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2901** interfaces. 2902** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2903** <li> Reset the statement using [sqlite3_reset()] then go back 2904** to step 2. Do this zero or more times. 2905** <li> Destroy the object using [sqlite3_finalize()]. 2906** </ol> 2907** 2908** Refer to documentation on individual methods above for additional 2909** information. 2910*/ 2911typedef struct sqlite3_stmt sqlite3_stmt; 2912 2913/* 2914** CAPI3REF: Run-time Limits 2915** 2916** ^(This interface allows the size of various constructs to be limited 2917** on a connection by connection basis. The first parameter is the 2918** [database connection] whose limit is to be set or queried. The 2919** second parameter is one of the [limit categories] that define a 2920** class of constructs to be size limited. The third parameter is the 2921** new limit for that construct.)^ 2922** 2923** ^If the new limit is a negative number, the limit is unchanged. 2924** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2925** [limits | hard upper bound] 2926** set at compile-time by a C preprocessor macro called 2927** [limits | SQLITE_MAX_<i>NAME</i>]. 2928** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2929** ^Attempts to increase a limit above its hard upper bound are 2930** silently truncated to the hard upper bound. 2931** 2932** ^Regardless of whether or not the limit was changed, the 2933** [sqlite3_limit()] interface returns the prior value of the limit. 2934** ^Hence, to find the current value of a limit without changing it, 2935** simply invoke this interface with the third parameter set to -1. 2936** 2937** Run-time limits are intended for use in applications that manage 2938** both their own internal database and also databases that are controlled 2939** by untrusted external sources. An example application might be a 2940** web browser that has its own databases for storing history and 2941** separate databases controlled by JavaScript applications downloaded 2942** off the Internet. The internal databases can be given the 2943** large, default limits. Databases managed by external sources can 2944** be given much smaller limits designed to prevent a denial of service 2945** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2946** interface to further control untrusted SQL. The size of the database 2947** created by an untrusted script can be contained using the 2948** [max_page_count] [PRAGMA]. 2949** 2950** New run-time limit categories may be added in future releases. 2951*/ 2952SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 2953 2954/* 2955** CAPI3REF: Run-Time Limit Categories 2956** KEYWORDS: {limit category} {*limit categories} 2957** 2958** These constants define various performance limits 2959** that can be lowered at run-time using [sqlite3_limit()]. 2960** The synopsis of the meanings of the various limits is shown below. 2961** Additional information is available at [limits | Limits in SQLite]. 2962** 2963** <dl> 2964** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2965** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2966** 2967** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2968** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2969** 2970** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2971** <dd>The maximum number of columns in a table definition or in the 2972** result set of a [SELECT] or the maximum number of columns in an index 2973** or in an ORDER BY or GROUP BY clause.</dd>)^ 2974** 2975** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2976** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2977** 2978** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2979** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2980** 2981** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2982** <dd>The maximum number of instructions in a virtual machine program 2983** used to implement an SQL statement. This limit is not currently 2984** enforced, though that might be added in some future release of 2985** SQLite.</dd>)^ 2986** 2987** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2988** <dd>The maximum number of arguments on a function.</dd>)^ 2989** 2990** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2991** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2992** 2993** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2994** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2995** <dd>The maximum length of the pattern argument to the [LIKE] or 2996** [GLOB] operators.</dd>)^ 2997** 2998** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2999** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3000** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3001** 3002** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3003** <dd>The maximum depth of recursion for triggers.</dd>)^ 3004** </dl> 3005*/ 3006#define SQLITE_LIMIT_LENGTH 0 3007#define SQLITE_LIMIT_SQL_LENGTH 1 3008#define SQLITE_LIMIT_COLUMN 2 3009#define SQLITE_LIMIT_EXPR_DEPTH 3 3010#define SQLITE_LIMIT_COMPOUND_SELECT 4 3011#define SQLITE_LIMIT_VDBE_OP 5 3012#define SQLITE_LIMIT_FUNCTION_ARG 6 3013#define SQLITE_LIMIT_ATTACHED 7 3014#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3015#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3016#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3017 3018/* 3019** CAPI3REF: Compiling An SQL Statement 3020** KEYWORDS: {SQL statement compiler} 3021** 3022** To execute an SQL query, it must first be compiled into a byte-code 3023** program using one of these routines. 3024** 3025** The first argument, "db", is a [database connection] obtained from a 3026** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3027** [sqlite3_open16()]. The database connection must not have been closed. 3028** 3029** The second argument, "zSql", is the statement to be compiled, encoded 3030** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3031** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3032** use UTF-16. 3033** 3034** ^If the nByte argument is less than zero, then zSql is read up to the 3035** first zero terminator. ^If nByte is non-negative, then it is the maximum 3036** number of bytes read from zSql. ^When nByte is non-negative, the 3037** zSql string ends at either the first '\000' or '\u0000' character or 3038** the nByte-th byte, whichever comes first. If the caller knows 3039** that the supplied string is nul-terminated, then there is a small 3040** performance advantage to be gained by passing an nByte parameter that 3041** is equal to the number of bytes in the input string <i>including</i> 3042** the nul-terminator bytes as this saves SQLite from having to 3043** make a copy of the input string. 3044** 3045** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3046** past the end of the first SQL statement in zSql. These routines only 3047** compile the first statement in zSql, so *pzTail is left pointing to 3048** what remains uncompiled. 3049** 3050** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3051** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3052** to NULL. ^If the input text contains no SQL (if the input is an empty 3053** string or a comment) then *ppStmt is set to NULL. 3054** The calling procedure is responsible for deleting the compiled 3055** SQL statement using [sqlite3_finalize()] after it has finished with it. 3056** ppStmt may not be NULL. 3057** 3058** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3059** otherwise an [error code] is returned. 3060** 3061** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3062** recommended for all new programs. The two older interfaces are retained 3063** for backwards compatibility, but their use is discouraged. 3064** ^In the "v2" interfaces, the prepared statement 3065** that is returned (the [sqlite3_stmt] object) contains a copy of the 3066** original SQL text. This causes the [sqlite3_step()] interface to 3067** behave differently in three ways: 3068** 3069** <ol> 3070** <li> 3071** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3072** always used to do, [sqlite3_step()] will automatically recompile the SQL 3073** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3074** retries will occur before sqlite3_step() gives up and returns an error. 3075** </li> 3076** 3077** <li> 3078** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3079** [error codes] or [extended error codes]. ^The legacy behavior was that 3080** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3081** and the application would have to make a second call to [sqlite3_reset()] 3082** in order to find the underlying cause of the problem. With the "v2" prepare 3083** interfaces, the underlying reason for the error is returned immediately. 3084** </li> 3085** 3086** <li> 3087** ^If the specific value bound to [parameter | host parameter] in the 3088** WHERE clause might influence the choice of query plan for a statement, 3089** then the statement will be automatically recompiled, as if there had been 3090** a schema change, on the first [sqlite3_step()] call following any change 3091** to the [sqlite3_bind_text | bindings] of that [parameter]. 3092** ^The specific value of WHERE-clause [parameter] might influence the 3093** choice of query plan if the parameter is the left-hand side of a [LIKE] 3094** or [GLOB] operator or if the parameter is compared to an indexed column 3095** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3096** the 3097** </li> 3098** </ol> 3099*/ 3100SQLITE_API int sqlite3_prepare( 3101 sqlite3 *db, /* Database handle */ 3102 const char *zSql, /* SQL statement, UTF-8 encoded */ 3103 int nByte, /* Maximum length of zSql in bytes. */ 3104 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3105 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3106); 3107SQLITE_API int sqlite3_prepare_v2( 3108 sqlite3 *db, /* Database handle */ 3109 const char *zSql, /* SQL statement, UTF-8 encoded */ 3110 int nByte, /* Maximum length of zSql in bytes. */ 3111 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3112 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3113); 3114SQLITE_API int sqlite3_prepare16( 3115 sqlite3 *db, /* Database handle */ 3116 const void *zSql, /* SQL statement, UTF-16 encoded */ 3117 int nByte, /* Maximum length of zSql in bytes. */ 3118 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3119 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3120); 3121SQLITE_API int sqlite3_prepare16_v2( 3122 sqlite3 *db, /* Database handle */ 3123 const void *zSql, /* SQL statement, UTF-16 encoded */ 3124 int nByte, /* Maximum length of zSql in bytes. */ 3125 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3126 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3127); 3128 3129/* 3130** CAPI3REF: Retrieving Statement SQL 3131** 3132** ^This interface can be used to retrieve a saved copy of the original 3133** SQL text used to create a [prepared statement] if that statement was 3134** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3135*/ 3136SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3137 3138/* 3139** CAPI3REF: Determine If An SQL Statement Writes The Database 3140** 3141** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3142** and only if the [prepared statement] X makes no direct changes to 3143** the content of the database file. 3144** 3145** Note that [application-defined SQL functions] or 3146** [virtual tables] might change the database indirectly as a side effect. 3147** ^(For example, if an application defines a function "eval()" that 3148** calls [sqlite3_exec()], then the following SQL statement would 3149** change the database file through side-effects: 3150** 3151** <blockquote><pre> 3152** SELECT eval('DELETE FROM t1') FROM t2; 3153** </pre></blockquote> 3154** 3155** But because the [SELECT] statement does not change the database file 3156** directly, sqlite3_stmt_readonly() would still return true.)^ 3157** 3158** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3159** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3160** since the statements themselves do not actually modify the database but 3161** rather they control the timing of when other statements modify the 3162** database. ^The [ATTACH] and [DETACH] statements also cause 3163** sqlite3_stmt_readonly() to return true since, while those statements 3164** change the configuration of a database connection, they do not make 3165** changes to the content of the database files on disk. 3166*/ 3167SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3168 3169/* 3170** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3171** 3172** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3173** [prepared statement] S has been stepped at least once using 3174** [sqlite3_step(S)] but has not run to completion and/or has not 3175** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3176** interface returns false if S is a NULL pointer. If S is not a 3177** NULL pointer and is not a pointer to a valid [prepared statement] 3178** object, then the behavior is undefined and probably undesirable. 3179** 3180** This interface can be used in combination [sqlite3_next_stmt()] 3181** to locate all prepared statements associated with a database 3182** connection that are in need of being reset. This can be used, 3183** for example, in diagnostic routines to search for prepared 3184** statements that are holding a transaction open. 3185*/ 3186SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3187 3188/* 3189** CAPI3REF: Dynamically Typed Value Object 3190** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3191** 3192** SQLite uses the sqlite3_value object to represent all values 3193** that can be stored in a database table. SQLite uses dynamic typing 3194** for the values it stores. ^Values stored in sqlite3_value objects 3195** can be integers, floating point values, strings, BLOBs, or NULL. 3196** 3197** An sqlite3_value object may be either "protected" or "unprotected". 3198** Some interfaces require a protected sqlite3_value. Other interfaces 3199** will accept either a protected or an unprotected sqlite3_value. 3200** Every interface that accepts sqlite3_value arguments specifies 3201** whether or not it requires a protected sqlite3_value. 3202** 3203** The terms "protected" and "unprotected" refer to whether or not 3204** a mutex is held. An internal mutex is held for a protected 3205** sqlite3_value object but no mutex is held for an unprotected 3206** sqlite3_value object. If SQLite is compiled to be single-threaded 3207** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3208** or if SQLite is run in one of reduced mutex modes 3209** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3210** then there is no distinction between protected and unprotected 3211** sqlite3_value objects and they can be used interchangeably. However, 3212** for maximum code portability it is recommended that applications 3213** still make the distinction between protected and unprotected 3214** sqlite3_value objects even when not strictly required. 3215** 3216** ^The sqlite3_value objects that are passed as parameters into the 3217** implementation of [application-defined SQL functions] are protected. 3218** ^The sqlite3_value object returned by 3219** [sqlite3_column_value()] is unprotected. 3220** Unprotected sqlite3_value objects may only be used with 3221** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3222** The [sqlite3_value_blob | sqlite3_value_type()] family of 3223** interfaces require protected sqlite3_value objects. 3224*/ 3225typedef struct Mem sqlite3_value; 3226 3227/* 3228** CAPI3REF: SQL Function Context Object 3229** 3230** The context in which an SQL function executes is stored in an 3231** sqlite3_context object. ^A pointer to an sqlite3_context object 3232** is always first parameter to [application-defined SQL functions]. 3233** The application-defined SQL function implementation will pass this 3234** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3235** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3236** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3237** and/or [sqlite3_set_auxdata()]. 3238*/ 3239typedef struct sqlite3_context sqlite3_context; 3240 3241/* 3242** CAPI3REF: Binding Values To Prepared Statements 3243** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3244** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3245** 3246** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3247** literals may be replaced by a [parameter] that matches one of following 3248** templates: 3249** 3250** <ul> 3251** <li> ? 3252** <li> ?NNN 3253** <li> :VVV 3254** <li> @VVV 3255** <li> $VVV 3256** </ul> 3257** 3258** In the templates above, NNN represents an integer literal, 3259** and VVV represents an alphanumeric identifier.)^ ^The values of these 3260** parameters (also called "host parameter names" or "SQL parameters") 3261** can be set using the sqlite3_bind_*() routines defined here. 3262** 3263** ^The first argument to the sqlite3_bind_*() routines is always 3264** a pointer to the [sqlite3_stmt] object returned from 3265** [sqlite3_prepare_v2()] or its variants. 3266** 3267** ^The second argument is the index of the SQL parameter to be set. 3268** ^The leftmost SQL parameter has an index of 1. ^When the same named 3269** SQL parameter is used more than once, second and subsequent 3270** occurrences have the same index as the first occurrence. 3271** ^The index for named parameters can be looked up using the 3272** [sqlite3_bind_parameter_index()] API if desired. ^The index 3273** for "?NNN" parameters is the value of NNN. 3274** ^The NNN value must be between 1 and the [sqlite3_limit()] 3275** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3276** 3277** ^The third argument is the value to bind to the parameter. 3278** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3279** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3280** is ignored and the end result is the same as sqlite3_bind_null(). 3281** 3282** ^(In those routines that have a fourth argument, its value is the 3283** number of bytes in the parameter. To be clear: the value is the 3284** number of <u>bytes</u> in the value, not the number of characters.)^ 3285** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3286** is negative, then the length of the string is 3287** the number of bytes up to the first zero terminator. 3288** If the fourth parameter to sqlite3_bind_blob() is negative, then 3289** the behavior is undefined. 3290** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3291** or sqlite3_bind_text16() then that parameter must be the byte offset 3292** where the NUL terminator would occur assuming the string were NUL 3293** terminated. If any NUL characters occur at byte offsets less than 3294** the value of the fourth parameter then the resulting string value will 3295** contain embedded NULs. The result of expressions involving strings 3296** with embedded NULs is undefined. 3297** 3298** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3299** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3300** string after SQLite has finished with it. ^The destructor is called 3301** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3302** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3303** ^If the fifth argument is 3304** the special value [SQLITE_STATIC], then SQLite assumes that the 3305** information is in static, unmanaged space and does not need to be freed. 3306** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3307** SQLite makes its own private copy of the data immediately, before 3308** the sqlite3_bind_*() routine returns. 3309** 3310** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3311** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3312** (just an integer to hold its size) while it is being processed. 3313** Zeroblobs are intended to serve as placeholders for BLOBs whose 3314** content is later written using 3315** [sqlite3_blob_open | incremental BLOB I/O] routines. 3316** ^A negative value for the zeroblob results in a zero-length BLOB. 3317** 3318** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3319** for the [prepared statement] or with a prepared statement for which 3320** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3321** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3322** routine is passed a [prepared statement] that has been finalized, the 3323** result is undefined and probably harmful. 3324** 3325** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3326** ^Unbound parameters are interpreted as NULL. 3327** 3328** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3329** [error code] if anything goes wrong. 3330** ^[SQLITE_RANGE] is returned if the parameter 3331** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3332** 3333** See also: [sqlite3_bind_parameter_count()], 3334** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3335*/ 3336SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3337SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3338SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3339SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3340SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3341SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3342SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3343SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3344SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3345 3346/* 3347** CAPI3REF: Number Of SQL Parameters 3348** 3349** ^This routine can be used to find the number of [SQL parameters] 3350** in a [prepared statement]. SQL parameters are tokens of the 3351** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3352** placeholders for values that are [sqlite3_bind_blob | bound] 3353** to the parameters at a later time. 3354** 3355** ^(This routine actually returns the index of the largest (rightmost) 3356** parameter. For all forms except ?NNN, this will correspond to the 3357** number of unique parameters. If parameters of the ?NNN form are used, 3358** there may be gaps in the list.)^ 3359** 3360** See also: [sqlite3_bind_blob|sqlite3_bind()], 3361** [sqlite3_bind_parameter_name()], and 3362** [sqlite3_bind_parameter_index()]. 3363*/ 3364SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3365 3366/* 3367** CAPI3REF: Name Of A Host Parameter 3368** 3369** ^The sqlite3_bind_parameter_name(P,N) interface returns 3370** the name of the N-th [SQL parameter] in the [prepared statement] P. 3371** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3372** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3373** respectively. 3374** In other words, the initial ":" or "$" or "@" or "?" 3375** is included as part of the name.)^ 3376** ^Parameters of the form "?" without a following integer have no name 3377** and are referred to as "nameless" or "anonymous parameters". 3378** 3379** ^The first host parameter has an index of 1, not 0. 3380** 3381** ^If the value N is out of range or if the N-th parameter is 3382** nameless, then NULL is returned. ^The returned string is 3383** always in UTF-8 encoding even if the named parameter was 3384** originally specified as UTF-16 in [sqlite3_prepare16()] or 3385** [sqlite3_prepare16_v2()]. 3386** 3387** See also: [sqlite3_bind_blob|sqlite3_bind()], 3388** [sqlite3_bind_parameter_count()], and 3389** [sqlite3_bind_parameter_index()]. 3390*/ 3391SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3392 3393/* 3394** CAPI3REF: Index Of A Parameter With A Given Name 3395** 3396** ^Return the index of an SQL parameter given its name. ^The 3397** index value returned is suitable for use as the second 3398** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3399** is returned if no matching parameter is found. ^The parameter 3400** name must be given in UTF-8 even if the original statement 3401** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3402** 3403** See also: [sqlite3_bind_blob|sqlite3_bind()], 3404** [sqlite3_bind_parameter_count()], and 3405** [sqlite3_bind_parameter_index()]. 3406*/ 3407SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3408 3409/* 3410** CAPI3REF: Reset All Bindings On A Prepared Statement 3411** 3412** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3413** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3414** ^Use this routine to reset all host parameters to NULL. 3415*/ 3416SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3417 3418/* 3419** CAPI3REF: Number Of Columns In A Result Set 3420** 3421** ^Return the number of columns in the result set returned by the 3422** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3423** statement that does not return data (for example an [UPDATE]). 3424** 3425** See also: [sqlite3_data_count()] 3426*/ 3427SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3428 3429/* 3430** CAPI3REF: Column Names In A Result Set 3431** 3432** ^These routines return the name assigned to a particular column 3433** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3434** interface returns a pointer to a zero-terminated UTF-8 string 3435** and sqlite3_column_name16() returns a pointer to a zero-terminated 3436** UTF-16 string. ^The first parameter is the [prepared statement] 3437** that implements the [SELECT] statement. ^The second parameter is the 3438** column number. ^The leftmost column is number 0. 3439** 3440** ^The returned string pointer is valid until either the [prepared statement] 3441** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3442** reprepared by the first call to [sqlite3_step()] for a particular run 3443** or until the next call to 3444** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3445** 3446** ^If sqlite3_malloc() fails during the processing of either routine 3447** (for example during a conversion from UTF-8 to UTF-16) then a 3448** NULL pointer is returned. 3449** 3450** ^The name of a result column is the value of the "AS" clause for 3451** that column, if there is an AS clause. If there is no AS clause 3452** then the name of the column is unspecified and may change from 3453** one release of SQLite to the next. 3454*/ 3455SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3456SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3457 3458/* 3459** CAPI3REF: Source Of Data In A Query Result 3460** 3461** ^These routines provide a means to determine the database, table, and 3462** table column that is the origin of a particular result column in 3463** [SELECT] statement. 3464** ^The name of the database or table or column can be returned as 3465** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3466** the database name, the _table_ routines return the table name, and 3467** the origin_ routines return the column name. 3468** ^The returned string is valid until the [prepared statement] is destroyed 3469** using [sqlite3_finalize()] or until the statement is automatically 3470** reprepared by the first call to [sqlite3_step()] for a particular run 3471** or until the same information is requested 3472** again in a different encoding. 3473** 3474** ^The names returned are the original un-aliased names of the 3475** database, table, and column. 3476** 3477** ^The first argument to these interfaces is a [prepared statement]. 3478** ^These functions return information about the Nth result column returned by 3479** the statement, where N is the second function argument. 3480** ^The left-most column is column 0 for these routines. 3481** 3482** ^If the Nth column returned by the statement is an expression or 3483** subquery and is not a column value, then all of these functions return 3484** NULL. ^These routine might also return NULL if a memory allocation error 3485** occurs. ^Otherwise, they return the name of the attached database, table, 3486** or column that query result column was extracted from. 3487** 3488** ^As with all other SQLite APIs, those whose names end with "16" return 3489** UTF-16 encoded strings and the other functions return UTF-8. 3490** 3491** ^These APIs are only available if the library was compiled with the 3492** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3493** 3494** If two or more threads call one or more of these routines against the same 3495** prepared statement and column at the same time then the results are 3496** undefined. 3497** 3498** If two or more threads call one or more 3499** [sqlite3_column_database_name | column metadata interfaces] 3500** for the same [prepared statement] and result column 3501** at the same time then the results are undefined. 3502*/ 3503SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3504SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3505SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3506SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3507SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3508SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3509 3510/* 3511** CAPI3REF: Declared Datatype Of A Query Result 3512** 3513** ^(The first parameter is a [prepared statement]. 3514** If this statement is a [SELECT] statement and the Nth column of the 3515** returned result set of that [SELECT] is a table column (not an 3516** expression or subquery) then the declared type of the table 3517** column is returned.)^ ^If the Nth column of the result set is an 3518** expression or subquery, then a NULL pointer is returned. 3519** ^The returned string is always UTF-8 encoded. 3520** 3521** ^(For example, given the database schema: 3522** 3523** CREATE TABLE t1(c1 VARIANT); 3524** 3525** and the following statement to be compiled: 3526** 3527** SELECT c1 + 1, c1 FROM t1; 3528** 3529** this routine would return the string "VARIANT" for the second result 3530** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3531** 3532** ^SQLite uses dynamic run-time typing. ^So just because a column 3533** is declared to contain a particular type does not mean that the 3534** data stored in that column is of the declared type. SQLite is 3535** strongly typed, but the typing is dynamic not static. ^Type 3536** is associated with individual values, not with the containers 3537** used to hold those values. 3538*/ 3539SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3540SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3541 3542/* 3543** CAPI3REF: Evaluate An SQL Statement 3544** 3545** After a [prepared statement] has been prepared using either 3546** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3547** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3548** must be called one or more times to evaluate the statement. 3549** 3550** The details of the behavior of the sqlite3_step() interface depend 3551** on whether the statement was prepared using the newer "v2" interface 3552** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3553** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3554** new "v2" interface is recommended for new applications but the legacy 3555** interface will continue to be supported. 3556** 3557** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3558** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3559** ^With the "v2" interface, any of the other [result codes] or 3560** [extended result codes] might be returned as well. 3561** 3562** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3563** database locks it needs to do its job. ^If the statement is a [COMMIT] 3564** or occurs outside of an explicit transaction, then you can retry the 3565** statement. If the statement is not a [COMMIT] and occurs within an 3566** explicit transaction then you should rollback the transaction before 3567** continuing. 3568** 3569** ^[SQLITE_DONE] means that the statement has finished executing 3570** successfully. sqlite3_step() should not be called again on this virtual 3571** machine without first calling [sqlite3_reset()] to reset the virtual 3572** machine back to its initial state. 3573** 3574** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3575** is returned each time a new row of data is ready for processing by the 3576** caller. The values may be accessed using the [column access functions]. 3577** sqlite3_step() is called again to retrieve the next row of data. 3578** 3579** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3580** violation) has occurred. sqlite3_step() should not be called again on 3581** the VM. More information may be found by calling [sqlite3_errmsg()]. 3582** ^With the legacy interface, a more specific error code (for example, 3583** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3584** can be obtained by calling [sqlite3_reset()] on the 3585** [prepared statement]. ^In the "v2" interface, 3586** the more specific error code is returned directly by sqlite3_step(). 3587** 3588** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3589** Perhaps it was called on a [prepared statement] that has 3590** already been [sqlite3_finalize | finalized] or on one that had 3591** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3592** be the case that the same database connection is being used by two or 3593** more threads at the same moment in time. 3594** 3595** For all versions of SQLite up to and including 3.6.23.1, a call to 3596** [sqlite3_reset()] was required after sqlite3_step() returned anything 3597** other than [SQLITE_ROW] before any subsequent invocation of 3598** sqlite3_step(). Failure to reset the prepared statement using 3599** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3600** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3601** calling [sqlite3_reset()] automatically in this circumstance rather 3602** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3603** break because any application that ever receives an SQLITE_MISUSE error 3604** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3605** can be used to restore the legacy behavior. 3606** 3607** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3608** API always returns a generic error code, [SQLITE_ERROR], following any 3609** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3610** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3611** specific [error codes] that better describes the error. 3612** We admit that this is a goofy design. The problem has been fixed 3613** with the "v2" interface. If you prepare all of your SQL statements 3614** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3615** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3616** then the more specific [error codes] are returned directly 3617** by sqlite3_step(). The use of the "v2" interface is recommended. 3618*/ 3619SQLITE_API int sqlite3_step(sqlite3_stmt*); 3620 3621/* 3622** CAPI3REF: Number of columns in a result set 3623** 3624** ^The sqlite3_data_count(P) interface returns the number of columns in the 3625** current row of the result set of [prepared statement] P. 3626** ^If prepared statement P does not have results ready to return 3627** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3628** interfaces) then sqlite3_data_count(P) returns 0. 3629** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3630** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3631** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3632** will return non-zero if previous call to [sqlite3_step](P) returned 3633** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3634** where it always returns zero since each step of that multi-step 3635** pragma returns 0 columns of data. 3636** 3637** See also: [sqlite3_column_count()] 3638*/ 3639SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3640 3641/* 3642** CAPI3REF: Fundamental Datatypes 3643** KEYWORDS: SQLITE_TEXT 3644** 3645** ^(Every value in SQLite has one of five fundamental datatypes: 3646** 3647** <ul> 3648** <li> 64-bit signed integer 3649** <li> 64-bit IEEE floating point number 3650** <li> string 3651** <li> BLOB 3652** <li> NULL 3653** </ul>)^ 3654** 3655** These constants are codes for each of those types. 3656** 3657** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3658** for a completely different meaning. Software that links against both 3659** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3660** SQLITE_TEXT. 3661*/ 3662#define SQLITE_INTEGER 1 3663#define SQLITE_FLOAT 2 3664#define SQLITE_BLOB 4 3665#define SQLITE_NULL 5 3666#ifdef SQLITE_TEXT 3667# undef SQLITE_TEXT 3668#else 3669# define SQLITE_TEXT 3 3670#endif 3671#define SQLITE3_TEXT 3 3672 3673/* 3674** CAPI3REF: Result Values From A Query 3675** KEYWORDS: {column access functions} 3676** 3677** These routines form the "result set" interface. 3678** 3679** ^These routines return information about a single column of the current 3680** result row of a query. ^In every case the first argument is a pointer 3681** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3682** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3683** and the second argument is the index of the column for which information 3684** should be returned. ^The leftmost column of the result set has the index 0. 3685** ^The number of columns in the result can be determined using 3686** [sqlite3_column_count()]. 3687** 3688** If the SQL statement does not currently point to a valid row, or if the 3689** column index is out of range, the result is undefined. 3690** These routines may only be called when the most recent call to 3691** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3692** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3693** If any of these routines are called after [sqlite3_reset()] or 3694** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3695** something other than [SQLITE_ROW], the results are undefined. 3696** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3697** are called from a different thread while any of these routines 3698** are pending, then the results are undefined. 3699** 3700** ^The sqlite3_column_type() routine returns the 3701** [SQLITE_INTEGER | datatype code] for the initial data type 3702** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3703** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3704** returned by sqlite3_column_type() is only meaningful if no type 3705** conversions have occurred as described below. After a type conversion, 3706** the value returned by sqlite3_column_type() is undefined. Future 3707** versions of SQLite may change the behavior of sqlite3_column_type() 3708** following a type conversion. 3709** 3710** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3711** routine returns the number of bytes in that BLOB or string. 3712** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3713** the string to UTF-8 and then returns the number of bytes. 3714** ^If the result is a numeric value then sqlite3_column_bytes() uses 3715** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3716** the number of bytes in that string. 3717** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3718** 3719** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3720** routine returns the number of bytes in that BLOB or string. 3721** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3722** the string to UTF-16 and then returns the number of bytes. 3723** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3724** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3725** the number of bytes in that string. 3726** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3727** 3728** ^The values returned by [sqlite3_column_bytes()] and 3729** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3730** of the string. ^For clarity: the values returned by 3731** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3732** bytes in the string, not the number of characters. 3733** 3734** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3735** even empty strings, are always zero-terminated. ^The return 3736** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3737** 3738** ^The object returned by [sqlite3_column_value()] is an 3739** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3740** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3741** If the [unprotected sqlite3_value] object returned by 3742** [sqlite3_column_value()] is used in any other way, including calls 3743** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3744** or [sqlite3_value_bytes()], then the behavior is undefined. 3745** 3746** These routines attempt to convert the value where appropriate. ^For 3747** example, if the internal representation is FLOAT and a text result 3748** is requested, [sqlite3_snprintf()] is used internally to perform the 3749** conversion automatically. ^(The following table details the conversions 3750** that are applied: 3751** 3752** <blockquote> 3753** <table border="1"> 3754** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3755** 3756** <tr><td> NULL <td> INTEGER <td> Result is 0 3757** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3758** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3759** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3760** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3761** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3762** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3763** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3764** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3765** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3766** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3767** <tr><td> TEXT <td> FLOAT <td> Use atof() 3768** <tr><td> TEXT <td> BLOB <td> No change 3769** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3770** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3771** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3772** </table> 3773** </blockquote>)^ 3774** 3775** The table above makes reference to standard C library functions atoi() 3776** and atof(). SQLite does not really use these functions. It has its 3777** own equivalent internal routines. The atoi() and atof() names are 3778** used in the table for brevity and because they are familiar to most 3779** C programmers. 3780** 3781** Note that when type conversions occur, pointers returned by prior 3782** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3783** sqlite3_column_text16() may be invalidated. 3784** Type conversions and pointer invalidations might occur 3785** in the following cases: 3786** 3787** <ul> 3788** <li> The initial content is a BLOB and sqlite3_column_text() or 3789** sqlite3_column_text16() is called. A zero-terminator might 3790** need to be added to the string.</li> 3791** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3792** sqlite3_column_text16() is called. The content must be converted 3793** to UTF-16.</li> 3794** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3795** sqlite3_column_text() is called. The content must be converted 3796** to UTF-8.</li> 3797** </ul> 3798** 3799** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3800** not invalidate a prior pointer, though of course the content of the buffer 3801** that the prior pointer references will have been modified. Other kinds 3802** of conversion are done in place when it is possible, but sometimes they 3803** are not possible and in those cases prior pointers are invalidated. 3804** 3805** The safest and easiest to remember policy is to invoke these routines 3806** in one of the following ways: 3807** 3808** <ul> 3809** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3810** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3811** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3812** </ul> 3813** 3814** In other words, you should call sqlite3_column_text(), 3815** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3816** into the desired format, then invoke sqlite3_column_bytes() or 3817** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3818** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3819** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3820** with calls to sqlite3_column_bytes(). 3821** 3822** ^The pointers returned are valid until a type conversion occurs as 3823** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3824** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3825** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3826** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3827** [sqlite3_free()]. 3828** 3829** ^(If a memory allocation error occurs during the evaluation of any 3830** of these routines, a default value is returned. The default value 3831** is either the integer 0, the floating point number 0.0, or a NULL 3832** pointer. Subsequent calls to [sqlite3_errcode()] will return 3833** [SQLITE_NOMEM].)^ 3834*/ 3835SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3836SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3837SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3838SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3839SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3840SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3841SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3842SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3843SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3844SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3845 3846/* 3847** CAPI3REF: Destroy A Prepared Statement Object 3848** 3849** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3850** ^If the most recent evaluation of the statement encountered no errors 3851** or if the statement is never been evaluated, then sqlite3_finalize() returns 3852** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3853** sqlite3_finalize(S) returns the appropriate [error code] or 3854** [extended error code]. 3855** 3856** ^The sqlite3_finalize(S) routine can be called at any point during 3857** the life cycle of [prepared statement] S: 3858** before statement S is ever evaluated, after 3859** one or more calls to [sqlite3_reset()], or after any call 3860** to [sqlite3_step()] regardless of whether or not the statement has 3861** completed execution. 3862** 3863** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3864** 3865** The application must finalize every [prepared statement] in order to avoid 3866** resource leaks. It is a grievous error for the application to try to use 3867** a prepared statement after it has been finalized. Any use of a prepared 3868** statement after it has been finalized can result in undefined and 3869** undesirable behavior such as segfaults and heap corruption. 3870*/ 3871SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3872 3873/* 3874** CAPI3REF: Reset A Prepared Statement Object 3875** 3876** The sqlite3_reset() function is called to reset a [prepared statement] 3877** object back to its initial state, ready to be re-executed. 3878** ^Any SQL statement variables that had values bound to them using 3879** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3880** Use [sqlite3_clear_bindings()] to reset the bindings. 3881** 3882** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3883** back to the beginning of its program. 3884** 3885** ^If the most recent call to [sqlite3_step(S)] for the 3886** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3887** or if [sqlite3_step(S)] has never before been called on S, 3888** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3889** 3890** ^If the most recent call to [sqlite3_step(S)] for the 3891** [prepared statement] S indicated an error, then 3892** [sqlite3_reset(S)] returns an appropriate [error code]. 3893** 3894** ^The [sqlite3_reset(S)] interface does not change the values 3895** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3896*/ 3897SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3898 3899/* 3900** CAPI3REF: Create Or Redefine SQL Functions 3901** KEYWORDS: {function creation routines} 3902** KEYWORDS: {application-defined SQL function} 3903** KEYWORDS: {application-defined SQL functions} 3904** 3905** ^These functions (collectively known as "function creation routines") 3906** are used to add SQL functions or aggregates or to redefine the behavior 3907** of existing SQL functions or aggregates. The only differences between 3908** these routines are the text encoding expected for 3909** the second parameter (the name of the function being created) 3910** and the presence or absence of a destructor callback for 3911** the application data pointer. 3912** 3913** ^The first parameter is the [database connection] to which the SQL 3914** function is to be added. ^If an application uses more than one database 3915** connection then application-defined SQL functions must be added 3916** to each database connection separately. 3917** 3918** ^The second parameter is the name of the SQL function to be created or 3919** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3920** representation, exclusive of the zero-terminator. ^Note that the name 3921** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3922** ^Any attempt to create a function with a longer name 3923** will result in [SQLITE_MISUSE] being returned. 3924** 3925** ^The third parameter (nArg) 3926** is the number of arguments that the SQL function or 3927** aggregate takes. ^If this parameter is -1, then the SQL function or 3928** aggregate may take any number of arguments between 0 and the limit 3929** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3930** parameter is less than -1 or greater than 127 then the behavior is 3931** undefined. 3932** 3933** ^The fourth parameter, eTextRep, specifies what 3934** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3935** its parameters. Every SQL function implementation must be able to work 3936** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3937** more efficient with one encoding than another. ^An application may 3938** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3939** times with the same function but with different values of eTextRep. 3940** ^When multiple implementations of the same function are available, SQLite 3941** will pick the one that involves the least amount of data conversion. 3942** If there is only a single implementation which does not care what text 3943** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3944** 3945** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3946** function can gain access to this pointer using [sqlite3_user_data()].)^ 3947** 3948** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3949** pointers to C-language functions that implement the SQL function or 3950** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3951** callback only; NULL pointers must be passed as the xStep and xFinal 3952** parameters. ^An aggregate SQL function requires an implementation of xStep 3953** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3954** SQL function or aggregate, pass NULL pointers for all three function 3955** callbacks. 3956** 3957** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3958** then it is destructor for the application data pointer. 3959** The destructor is invoked when the function is deleted, either by being 3960** overloaded or when the database connection closes.)^ 3961** ^The destructor is also invoked if the call to 3962** sqlite3_create_function_v2() fails. 3963** ^When the destructor callback of the tenth parameter is invoked, it 3964** is passed a single argument which is a copy of the application data 3965** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3966** 3967** ^It is permitted to register multiple implementations of the same 3968** functions with the same name but with either differing numbers of 3969** arguments or differing preferred text encodings. ^SQLite will use 3970** the implementation that most closely matches the way in which the 3971** SQL function is used. ^A function implementation with a non-negative 3972** nArg parameter is a better match than a function implementation with 3973** a negative nArg. ^A function where the preferred text encoding 3974** matches the database encoding is a better 3975** match than a function where the encoding is different. 3976** ^A function where the encoding difference is between UTF16le and UTF16be 3977** is a closer match than a function where the encoding difference is 3978** between UTF8 and UTF16. 3979** 3980** ^Built-in functions may be overloaded by new application-defined functions. 3981** 3982** ^An application-defined function is permitted to call other 3983** SQLite interfaces. However, such calls must not 3984** close the database connection nor finalize or reset the prepared 3985** statement in which the function is running. 3986*/ 3987SQLITE_API int sqlite3_create_function( 3988 sqlite3 *db, 3989 const char *zFunctionName, 3990 int nArg, 3991 int eTextRep, 3992 void *pApp, 3993 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3994 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3995 void (*xFinal)(sqlite3_context*) 3996); 3997SQLITE_API int sqlite3_create_function16( 3998 sqlite3 *db, 3999 const void *zFunctionName, 4000 int nArg, 4001 int eTextRep, 4002 void *pApp, 4003 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4004 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4005 void (*xFinal)(sqlite3_context*) 4006); 4007SQLITE_API int sqlite3_create_function_v2( 4008 sqlite3 *db, 4009 const char *zFunctionName, 4010 int nArg, 4011 int eTextRep, 4012 void *pApp, 4013 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4014 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4015 void (*xFinal)(sqlite3_context*), 4016 void(*xDestroy)(void*) 4017); 4018 4019/* 4020** CAPI3REF: Text Encodings 4021** 4022** These constant define integer codes that represent the various 4023** text encodings supported by SQLite. 4024*/ 4025#define SQLITE_UTF8 1 4026#define SQLITE_UTF16LE 2 4027#define SQLITE_UTF16BE 3 4028#define SQLITE_UTF16 4 /* Use native byte order */ 4029#define SQLITE_ANY 5 /* sqlite3_create_function only */ 4030#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4031 4032/* 4033** CAPI3REF: Deprecated Functions 4034** DEPRECATED 4035** 4036** These functions are [deprecated]. In order to maintain 4037** backwards compatibility with older code, these functions continue 4038** to be supported. However, new applications should avoid 4039** the use of these functions. To help encourage people to avoid 4040** using these functions, we are not going to tell you what they do. 4041*/ 4042#ifndef SQLITE_OMIT_DEPRECATED 4043SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4044SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4045SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4046SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4047SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4048SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4049 void*,sqlite3_int64); 4050#endif 4051 4052/* 4053** CAPI3REF: Obtaining SQL Function Parameter Values 4054** 4055** The C-language implementation of SQL functions and aggregates uses 4056** this set of interface routines to access the parameter values on 4057** the function or aggregate. 4058** 4059** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4060** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4061** define callbacks that implement the SQL functions and aggregates. 4062** The 3rd parameter to these callbacks is an array of pointers to 4063** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4064** each parameter to the SQL function. These routines are used to 4065** extract values from the [sqlite3_value] objects. 4066** 4067** These routines work only with [protected sqlite3_value] objects. 4068** Any attempt to use these routines on an [unprotected sqlite3_value] 4069** object results in undefined behavior. 4070** 4071** ^These routines work just like the corresponding [column access functions] 4072** except that these routines take a single [protected sqlite3_value] object 4073** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4074** 4075** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4076** in the native byte-order of the host machine. ^The 4077** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4078** extract UTF-16 strings as big-endian and little-endian respectively. 4079** 4080** ^(The sqlite3_value_numeric_type() interface attempts to apply 4081** numeric affinity to the value. This means that an attempt is 4082** made to convert the value to an integer or floating point. If 4083** such a conversion is possible without loss of information (in other 4084** words, if the value is a string that looks like a number) 4085** then the conversion is performed. Otherwise no conversion occurs. 4086** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4087** 4088** Please pay particular attention to the fact that the pointer returned 4089** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4090** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4091** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4092** or [sqlite3_value_text16()]. 4093** 4094** These routines must be called from the same thread as 4095** the SQL function that supplied the [sqlite3_value*] parameters. 4096*/ 4097SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4098SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4099SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4100SQLITE_API double sqlite3_value_double(sqlite3_value*); 4101SQLITE_API int sqlite3_value_int(sqlite3_value*); 4102SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4103SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4104SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4105SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4106SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4107SQLITE_API int sqlite3_value_type(sqlite3_value*); 4108SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4109 4110/* 4111** CAPI3REF: Obtain Aggregate Function Context 4112** 4113** Implementations of aggregate SQL functions use this 4114** routine to allocate memory for storing their state. 4115** 4116** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4117** for a particular aggregate function, SQLite 4118** allocates N of memory, zeroes out that memory, and returns a pointer 4119** to the new memory. ^On second and subsequent calls to 4120** sqlite3_aggregate_context() for the same aggregate function instance, 4121** the same buffer is returned. Sqlite3_aggregate_context() is normally 4122** called once for each invocation of the xStep callback and then one 4123** last time when the xFinal callback is invoked. ^(When no rows match 4124** an aggregate query, the xStep() callback of the aggregate function 4125** implementation is never called and xFinal() is called exactly once. 4126** In those cases, sqlite3_aggregate_context() might be called for the 4127** first time from within xFinal().)^ 4128** 4129** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4130** when first called if N is less than or equal to zero or if a memory 4131** allocate error occurs. 4132** 4133** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4134** determined by the N parameter on first successful call. Changing the 4135** value of N in subsequent call to sqlite3_aggregate_context() within 4136** the same aggregate function instance will not resize the memory 4137** allocation.)^ Within the xFinal callback, it is customary to set 4138** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4139** pointless memory allocations occur. 4140** 4141** ^SQLite automatically frees the memory allocated by 4142** sqlite3_aggregate_context() when the aggregate query concludes. 4143** 4144** The first parameter must be a copy of the 4145** [sqlite3_context | SQL function context] that is the first parameter 4146** to the xStep or xFinal callback routine that implements the aggregate 4147** function. 4148** 4149** This routine must be called from the same thread in which 4150** the aggregate SQL function is running. 4151*/ 4152SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4153 4154/* 4155** CAPI3REF: User Data For Functions 4156** 4157** ^The sqlite3_user_data() interface returns a copy of 4158** the pointer that was the pUserData parameter (the 5th parameter) 4159** of the [sqlite3_create_function()] 4160** and [sqlite3_create_function16()] routines that originally 4161** registered the application defined function. 4162** 4163** This routine must be called from the same thread in which 4164** the application-defined function is running. 4165*/ 4166SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4167 4168/* 4169** CAPI3REF: Database Connection For Functions 4170** 4171** ^The sqlite3_context_db_handle() interface returns a copy of 4172** the pointer to the [database connection] (the 1st parameter) 4173** of the [sqlite3_create_function()] 4174** and [sqlite3_create_function16()] routines that originally 4175** registered the application defined function. 4176*/ 4177SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4178 4179/* 4180** CAPI3REF: Function Auxiliary Data 4181** 4182** The following two functions may be used by scalar SQL functions to 4183** associate metadata with argument values. If the same value is passed to 4184** multiple invocations of the same SQL function during query execution, under 4185** some circumstances the associated metadata may be preserved. This may 4186** be used, for example, to add a regular-expression matching scalar 4187** function. The compiled version of the regular expression is stored as 4188** metadata associated with the SQL value passed as the regular expression 4189** pattern. The compiled regular expression can be reused on multiple 4190** invocations of the same function so that the original pattern string 4191** does not need to be recompiled on each invocation. 4192** 4193** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4194** associated by the sqlite3_set_auxdata() function with the Nth argument 4195** value to the application-defined function. ^If no metadata has been ever 4196** been set for the Nth argument of the function, or if the corresponding 4197** function parameter has changed since the meta-data was set, 4198** then sqlite3_get_auxdata() returns a NULL pointer. 4199** 4200** ^The sqlite3_set_auxdata() interface saves the metadata 4201** pointed to by its 3rd parameter as the metadata for the N-th 4202** argument of the application-defined function. Subsequent 4203** calls to sqlite3_get_auxdata() might return this data, if it has 4204** not been destroyed. 4205** ^If it is not NULL, SQLite will invoke the destructor 4206** function given by the 4th parameter to sqlite3_set_auxdata() on 4207** the metadata when the corresponding function parameter changes 4208** or when the SQL statement completes, whichever comes first. 4209** 4210** SQLite is free to call the destructor and drop metadata on any 4211** parameter of any function at any time. ^The only guarantee is that 4212** the destructor will be called before the metadata is dropped. 4213** 4214** ^(In practice, metadata is preserved between function calls for 4215** expressions that are constant at compile time. This includes literal 4216** values and [parameters].)^ 4217** 4218** These routines must be called from the same thread in which 4219** the SQL function is running. 4220*/ 4221SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4222SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4223 4224 4225/* 4226** CAPI3REF: Constants Defining Special Destructor Behavior 4227** 4228** These are special values for the destructor that is passed in as the 4229** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4230** argument is SQLITE_STATIC, it means that the content pointer is constant 4231** and will never change. It does not need to be destroyed. ^The 4232** SQLITE_TRANSIENT value means that the content will likely change in 4233** the near future and that SQLite should make its own private copy of 4234** the content before returning. 4235** 4236** The typedef is necessary to work around problems in certain 4237** C++ compilers. 4238*/ 4239typedef void (*sqlite3_destructor_type)(void*); 4240#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4241#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4242 4243/* 4244** CAPI3REF: Setting The Result Of An SQL Function 4245** 4246** These routines are used by the xFunc or xFinal callbacks that 4247** implement SQL functions and aggregates. See 4248** [sqlite3_create_function()] and [sqlite3_create_function16()] 4249** for additional information. 4250** 4251** These functions work very much like the [parameter binding] family of 4252** functions used to bind values to host parameters in prepared statements. 4253** Refer to the [SQL parameter] documentation for additional information. 4254** 4255** ^The sqlite3_result_blob() interface sets the result from 4256** an application-defined function to be the BLOB whose content is pointed 4257** to by the second parameter and which is N bytes long where N is the 4258** third parameter. 4259** 4260** ^The sqlite3_result_zeroblob() interfaces set the result of 4261** the application-defined function to be a BLOB containing all zero 4262** bytes and N bytes in size, where N is the value of the 2nd parameter. 4263** 4264** ^The sqlite3_result_double() interface sets the result from 4265** an application-defined function to be a floating point value specified 4266** by its 2nd argument. 4267** 4268** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4269** cause the implemented SQL function to throw an exception. 4270** ^SQLite uses the string pointed to by the 4271** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4272** as the text of an error message. ^SQLite interprets the error 4273** message string from sqlite3_result_error() as UTF-8. ^SQLite 4274** interprets the string from sqlite3_result_error16() as UTF-16 in native 4275** byte order. ^If the third parameter to sqlite3_result_error() 4276** or sqlite3_result_error16() is negative then SQLite takes as the error 4277** message all text up through the first zero character. 4278** ^If the third parameter to sqlite3_result_error() or 4279** sqlite3_result_error16() is non-negative then SQLite takes that many 4280** bytes (not characters) from the 2nd parameter as the error message. 4281** ^The sqlite3_result_error() and sqlite3_result_error16() 4282** routines make a private copy of the error message text before 4283** they return. Hence, the calling function can deallocate or 4284** modify the text after they return without harm. 4285** ^The sqlite3_result_error_code() function changes the error code 4286** returned by SQLite as a result of an error in a function. ^By default, 4287** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4288** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4289** 4290** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4291** error indicating that a string or BLOB is too long to represent. 4292** 4293** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4294** error indicating that a memory allocation failed. 4295** 4296** ^The sqlite3_result_int() interface sets the return value 4297** of the application-defined function to be the 32-bit signed integer 4298** value given in the 2nd argument. 4299** ^The sqlite3_result_int64() interface sets the return value 4300** of the application-defined function to be the 64-bit signed integer 4301** value given in the 2nd argument. 4302** 4303** ^The sqlite3_result_null() interface sets the return value 4304** of the application-defined function to be NULL. 4305** 4306** ^The sqlite3_result_text(), sqlite3_result_text16(), 4307** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4308** set the return value of the application-defined function to be 4309** a text string which is represented as UTF-8, UTF-16 native byte order, 4310** UTF-16 little endian, or UTF-16 big endian, respectively. 4311** ^SQLite takes the text result from the application from 4312** the 2nd parameter of the sqlite3_result_text* interfaces. 4313** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4314** is negative, then SQLite takes result text from the 2nd parameter 4315** through the first zero character. 4316** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4317** is non-negative, then as many bytes (not characters) of the text 4318** pointed to by the 2nd parameter are taken as the application-defined 4319** function result. If the 3rd parameter is non-negative, then it 4320** must be the byte offset into the string where the NUL terminator would 4321** appear if the string where NUL terminated. If any NUL characters occur 4322** in the string at a byte offset that is less than the value of the 3rd 4323** parameter, then the resulting string will contain embedded NULs and the 4324** result of expressions operating on strings with embedded NULs is undefined. 4325** ^If the 4th parameter to the sqlite3_result_text* interfaces 4326** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4327** function as the destructor on the text or BLOB result when it has 4328** finished using that result. 4329** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4330** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4331** assumes that the text or BLOB result is in constant space and does not 4332** copy the content of the parameter nor call a destructor on the content 4333** when it has finished using that result. 4334** ^If the 4th parameter to the sqlite3_result_text* interfaces 4335** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4336** then SQLite makes a copy of the result into space obtained from 4337** from [sqlite3_malloc()] before it returns. 4338** 4339** ^The sqlite3_result_value() interface sets the result of 4340** the application-defined function to be a copy the 4341** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4342** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4343** so that the [sqlite3_value] specified in the parameter may change or 4344** be deallocated after sqlite3_result_value() returns without harm. 4345** ^A [protected sqlite3_value] object may always be used where an 4346** [unprotected sqlite3_value] object is required, so either 4347** kind of [sqlite3_value] object can be used with this interface. 4348** 4349** If these routines are called from within the different thread 4350** than the one containing the application-defined function that received 4351** the [sqlite3_context] pointer, the results are undefined. 4352*/ 4353SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4354SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4355SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4356SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4357SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4358SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4359SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4360SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4361SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4362SQLITE_API void sqlite3_result_null(sqlite3_context*); 4363SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4364SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4365SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4366SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4367SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4368SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4369 4370/* 4371** CAPI3REF: Define New Collating Sequences 4372** 4373** ^These functions add, remove, or modify a [collation] associated 4374** with the [database connection] specified as the first argument. 4375** 4376** ^The name of the collation is a UTF-8 string 4377** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4378** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4379** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4380** considered to be the same name. 4381** 4382** ^(The third argument (eTextRep) must be one of the constants: 4383** <ul> 4384** <li> [SQLITE_UTF8], 4385** <li> [SQLITE_UTF16LE], 4386** <li> [SQLITE_UTF16BE], 4387** <li> [SQLITE_UTF16], or 4388** <li> [SQLITE_UTF16_ALIGNED]. 4389** </ul>)^ 4390** ^The eTextRep argument determines the encoding of strings passed 4391** to the collating function callback, xCallback. 4392** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4393** force strings to be UTF16 with native byte order. 4394** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4395** on an even byte address. 4396** 4397** ^The fourth argument, pArg, is an application data pointer that is passed 4398** through as the first argument to the collating function callback. 4399** 4400** ^The fifth argument, xCallback, is a pointer to the collating function. 4401** ^Multiple collating functions can be registered using the same name but 4402** with different eTextRep parameters and SQLite will use whichever 4403** function requires the least amount of data transformation. 4404** ^If the xCallback argument is NULL then the collating function is 4405** deleted. ^When all collating functions having the same name are deleted, 4406** that collation is no longer usable. 4407** 4408** ^The collating function callback is invoked with a copy of the pArg 4409** application data pointer and with two strings in the encoding specified 4410** by the eTextRep argument. The collating function must return an 4411** integer that is negative, zero, or positive 4412** if the first string is less than, equal to, or greater than the second, 4413** respectively. A collating function must always return the same answer 4414** given the same inputs. If two or more collating functions are registered 4415** to the same collation name (using different eTextRep values) then all 4416** must give an equivalent answer when invoked with equivalent strings. 4417** The collating function must obey the following properties for all 4418** strings A, B, and C: 4419** 4420** <ol> 4421** <li> If A==B then B==A. 4422** <li> If A==B and B==C then A==C. 4423** <li> If A<B THEN B>A. 4424** <li> If A<B and B<C then A<C. 4425** </ol> 4426** 4427** If a collating function fails any of the above constraints and that 4428** collating function is registered and used, then the behavior of SQLite 4429** is undefined. 4430** 4431** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4432** with the addition that the xDestroy callback is invoked on pArg when 4433** the collating function is deleted. 4434** ^Collating functions are deleted when they are overridden by later 4435** calls to the collation creation functions or when the 4436** [database connection] is closed using [sqlite3_close()]. 4437** 4438** ^The xDestroy callback is <u>not</u> called if the 4439** sqlite3_create_collation_v2() function fails. Applications that invoke 4440** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4441** check the return code and dispose of the application data pointer 4442** themselves rather than expecting SQLite to deal with it for them. 4443** This is different from every other SQLite interface. The inconsistency 4444** is unfortunate but cannot be changed without breaking backwards 4445** compatibility. 4446** 4447** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4448*/ 4449SQLITE_API int sqlite3_create_collation( 4450 sqlite3*, 4451 const char *zName, 4452 int eTextRep, 4453 void *pArg, 4454 int(*xCompare)(void*,int,const void*,int,const void*) 4455); 4456SQLITE_API int sqlite3_create_collation_v2( 4457 sqlite3*, 4458 const char *zName, 4459 int eTextRep, 4460 void *pArg, 4461 int(*xCompare)(void*,int,const void*,int,const void*), 4462 void(*xDestroy)(void*) 4463); 4464SQLITE_API int sqlite3_create_collation16( 4465 sqlite3*, 4466 const void *zName, 4467 int eTextRep, 4468 void *pArg, 4469 int(*xCompare)(void*,int,const void*,int,const void*) 4470); 4471 4472/* 4473** CAPI3REF: Collation Needed Callbacks 4474** 4475** ^To avoid having to register all collation sequences before a database 4476** can be used, a single callback function may be registered with the 4477** [database connection] to be invoked whenever an undefined collation 4478** sequence is required. 4479** 4480** ^If the function is registered using the sqlite3_collation_needed() API, 4481** then it is passed the names of undefined collation sequences as strings 4482** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4483** the names are passed as UTF-16 in machine native byte order. 4484** ^A call to either function replaces the existing collation-needed callback. 4485** 4486** ^(When the callback is invoked, the first argument passed is a copy 4487** of the second argument to sqlite3_collation_needed() or 4488** sqlite3_collation_needed16(). The second argument is the database 4489** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4490** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4491** sequence function required. The fourth parameter is the name of the 4492** required collation sequence.)^ 4493** 4494** The callback function should register the desired collation using 4495** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4496** [sqlite3_create_collation_v2()]. 4497*/ 4498SQLITE_API int sqlite3_collation_needed( 4499 sqlite3*, 4500 void*, 4501 void(*)(void*,sqlite3*,int eTextRep,const char*) 4502); 4503SQLITE_API int sqlite3_collation_needed16( 4504 sqlite3*, 4505 void*, 4506 void(*)(void*,sqlite3*,int eTextRep,const void*) 4507); 4508 4509#ifdef SQLITE_HAS_CODEC 4510/* 4511** Specify the key for an encrypted database. This routine should be 4512** called right after sqlite3_open(). 4513** 4514** The code to implement this API is not available in the public release 4515** of SQLite. 4516*/ 4517SQLITE_API int sqlite3_key( 4518 sqlite3 *db, /* Database to be rekeyed */ 4519 const void *pKey, int nKey /* The key */ 4520); 4521 4522/* 4523** Change the key on an open database. If the current database is not 4524** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4525** database is decrypted. 4526** 4527** The code to implement this API is not available in the public release 4528** of SQLite. 4529*/ 4530SQLITE_API int sqlite3_rekey( 4531 sqlite3 *db, /* Database to be rekeyed */ 4532 const void *pKey, int nKey /* The new key */ 4533); 4534 4535/* 4536** Specify the activation key for a SEE database. Unless 4537** activated, none of the SEE routines will work. 4538*/ 4539SQLITE_API void sqlite3_activate_see( 4540 const char *zPassPhrase /* Activation phrase */ 4541); 4542#endif 4543 4544#ifdef SQLITE_ENABLE_CEROD 4545/* 4546** Specify the activation key for a CEROD database. Unless 4547** activated, none of the CEROD routines will work. 4548*/ 4549SQLITE_API void sqlite3_activate_cerod( 4550 const char *zPassPhrase /* Activation phrase */ 4551); 4552#endif 4553 4554/* 4555** CAPI3REF: Suspend Execution For A Short Time 4556** 4557** The sqlite3_sleep() function causes the current thread to suspend execution 4558** for at least a number of milliseconds specified in its parameter. 4559** 4560** If the operating system does not support sleep requests with 4561** millisecond time resolution, then the time will be rounded up to 4562** the nearest second. The number of milliseconds of sleep actually 4563** requested from the operating system is returned. 4564** 4565** ^SQLite implements this interface by calling the xSleep() 4566** method of the default [sqlite3_vfs] object. If the xSleep() method 4567** of the default VFS is not implemented correctly, or not implemented at 4568** all, then the behavior of sqlite3_sleep() may deviate from the description 4569** in the previous paragraphs. 4570*/ 4571SQLITE_API int sqlite3_sleep(int); 4572 4573/* 4574** CAPI3REF: Name Of The Folder Holding Temporary Files 4575** 4576** ^(If this global variable is made to point to a string which is 4577** the name of a folder (a.k.a. directory), then all temporary files 4578** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4579** will be placed in that directory.)^ ^If this variable 4580** is a NULL pointer, then SQLite performs a search for an appropriate 4581** temporary file directory. 4582** 4583** It is not safe to read or modify this variable in more than one 4584** thread at a time. It is not safe to read or modify this variable 4585** if a [database connection] is being used at the same time in a separate 4586** thread. 4587** It is intended that this variable be set once 4588** as part of process initialization and before any SQLite interface 4589** routines have been called and that this variable remain unchanged 4590** thereafter. 4591** 4592** ^The [temp_store_directory pragma] may modify this variable and cause 4593** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4594** the [temp_store_directory pragma] always assumes that any string 4595** that this variable points to is held in memory obtained from 4596** [sqlite3_malloc] and the pragma may attempt to free that memory 4597** using [sqlite3_free]. 4598** Hence, if this variable is modified directly, either it should be 4599** made NULL or made to point to memory obtained from [sqlite3_malloc] 4600** or else the use of the [temp_store_directory pragma] should be avoided. 4601** 4602** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4603** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4604** features that require the use of temporary files may fail. Here is an 4605** example of how to do this using C++ with the Windows Runtime: 4606** 4607** <blockquote><pre> 4608** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4609** TemporaryFolder->Path->Data(); 4610** char zPathBuf[MAX_PATH + 1]; 4611** memset(zPathBuf, 0, sizeof(zPathBuf)); 4612** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4613** NULL, NULL); 4614** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4615** </pre></blockquote> 4616*/ 4617SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4618 4619/* 4620** CAPI3REF: Name Of The Folder Holding Database Files 4621** 4622** ^(If this global variable is made to point to a string which is 4623** the name of a folder (a.k.a. directory), then all database files 4624** specified with a relative pathname and created or accessed by 4625** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4626** to be relative to that directory.)^ ^If this variable is a NULL 4627** pointer, then SQLite assumes that all database files specified 4628** with a relative pathname are relative to the current directory 4629** for the process. Only the windows VFS makes use of this global 4630** variable; it is ignored by the unix VFS. 4631** 4632** Changing the value of this variable while a database connection is 4633** open can result in a corrupt database. 4634** 4635** It is not safe to read or modify this variable in more than one 4636** thread at a time. It is not safe to read or modify this variable 4637** if a [database connection] is being used at the same time in a separate 4638** thread. 4639** It is intended that this variable be set once 4640** as part of process initialization and before any SQLite interface 4641** routines have been called and that this variable remain unchanged 4642** thereafter. 4643** 4644** ^The [data_store_directory pragma] may modify this variable and cause 4645** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4646** the [data_store_directory pragma] always assumes that any string 4647** that this variable points to is held in memory obtained from 4648** [sqlite3_malloc] and the pragma may attempt to free that memory 4649** using [sqlite3_free]. 4650** Hence, if this variable is modified directly, either it should be 4651** made NULL or made to point to memory obtained from [sqlite3_malloc] 4652** or else the use of the [data_store_directory pragma] should be avoided. 4653*/ 4654SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 4655 4656/* 4657** CAPI3REF: Test For Auto-Commit Mode 4658** KEYWORDS: {autocommit mode} 4659** 4660** ^The sqlite3_get_autocommit() interface returns non-zero or 4661** zero if the given database connection is or is not in autocommit mode, 4662** respectively. ^Autocommit mode is on by default. 4663** ^Autocommit mode is disabled by a [BEGIN] statement. 4664** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4665** 4666** If certain kinds of errors occur on a statement within a multi-statement 4667** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4668** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4669** transaction might be rolled back automatically. The only way to 4670** find out whether SQLite automatically rolled back the transaction after 4671** an error is to use this function. 4672** 4673** If another thread changes the autocommit status of the database 4674** connection while this routine is running, then the return value 4675** is undefined. 4676*/ 4677SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4678 4679/* 4680** CAPI3REF: Find The Database Handle Of A Prepared Statement 4681** 4682** ^The sqlite3_db_handle interface returns the [database connection] handle 4683** to which a [prepared statement] belongs. ^The [database connection] 4684** returned by sqlite3_db_handle is the same [database connection] 4685** that was the first argument 4686** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4687** create the statement in the first place. 4688*/ 4689SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4690 4691/* 4692** CAPI3REF: Return The Filename For A Database Connection 4693** 4694** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4695** associated with database N of connection D. ^The main database file 4696** has the name "main". If there is no attached database N on the database 4697** connection D, or if database N is a temporary or in-memory database, then 4698** a NULL pointer is returned. 4699** 4700** ^The filename returned by this function is the output of the 4701** xFullPathname method of the [VFS]. ^In other words, the filename 4702** will be an absolute pathname, even if the filename used 4703** to open the database originally was a URI or relative pathname. 4704*/ 4705SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4706 4707/* 4708** CAPI3REF: Determine if a database is read-only 4709** 4710** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4711** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4712** the name of a database on connection D. 4713*/ 4714SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4715 4716/* 4717** CAPI3REF: Find the next prepared statement 4718** 4719** ^This interface returns a pointer to the next [prepared statement] after 4720** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4721** then this interface returns a pointer to the first prepared statement 4722** associated with the database connection pDb. ^If no prepared statement 4723** satisfies the conditions of this routine, it returns NULL. 4724** 4725** The [database connection] pointer D in a call to 4726** [sqlite3_next_stmt(D,S)] must refer to an open database 4727** connection and in particular must not be a NULL pointer. 4728*/ 4729SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4730 4731/* 4732** CAPI3REF: Commit And Rollback Notification Callbacks 4733** 4734** ^The sqlite3_commit_hook() interface registers a callback 4735** function to be invoked whenever a transaction is [COMMIT | committed]. 4736** ^Any callback set by a previous call to sqlite3_commit_hook() 4737** for the same database connection is overridden. 4738** ^The sqlite3_rollback_hook() interface registers a callback 4739** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4740** ^Any callback set by a previous call to sqlite3_rollback_hook() 4741** for the same database connection is overridden. 4742** ^The pArg argument is passed through to the callback. 4743** ^If the callback on a commit hook function returns non-zero, 4744** then the commit is converted into a rollback. 4745** 4746** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4747** return the P argument from the previous call of the same function 4748** on the same [database connection] D, or NULL for 4749** the first call for each function on D. 4750** 4751** The commit and rollback hook callbacks are not reentrant. 4752** The callback implementation must not do anything that will modify 4753** the database connection that invoked the callback. Any actions 4754** to modify the database connection must be deferred until after the 4755** completion of the [sqlite3_step()] call that triggered the commit 4756** or rollback hook in the first place. 4757** Note that running any other SQL statements, including SELECT statements, 4758** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4759** the database connections for the meaning of "modify" in this paragraph. 4760** 4761** ^Registering a NULL function disables the callback. 4762** 4763** ^When the commit hook callback routine returns zero, the [COMMIT] 4764** operation is allowed to continue normally. ^If the commit hook 4765** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4766** ^The rollback hook is invoked on a rollback that results from a commit 4767** hook returning non-zero, just as it would be with any other rollback. 4768** 4769** ^For the purposes of this API, a transaction is said to have been 4770** rolled back if an explicit "ROLLBACK" statement is executed, or 4771** an error or constraint causes an implicit rollback to occur. 4772** ^The rollback callback is not invoked if a transaction is 4773** automatically rolled back because the database connection is closed. 4774** 4775** See also the [sqlite3_update_hook()] interface. 4776*/ 4777SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4778SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4779 4780/* 4781** CAPI3REF: Data Change Notification Callbacks 4782** 4783** ^The sqlite3_update_hook() interface registers a callback function 4784** with the [database connection] identified by the first argument 4785** to be invoked whenever a row is updated, inserted or deleted. 4786** ^Any callback set by a previous call to this function 4787** for the same database connection is overridden. 4788** 4789** ^The second argument is a pointer to the function to invoke when a 4790** row is updated, inserted or deleted. 4791** ^The first argument to the callback is a copy of the third argument 4792** to sqlite3_update_hook(). 4793** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4794** or [SQLITE_UPDATE], depending on the operation that caused the callback 4795** to be invoked. 4796** ^The third and fourth arguments to the callback contain pointers to the 4797** database and table name containing the affected row. 4798** ^The final callback parameter is the [rowid] of the row. 4799** ^In the case of an update, this is the [rowid] after the update takes place. 4800** 4801** ^(The update hook is not invoked when internal system tables are 4802** modified (i.e. sqlite_master and sqlite_sequence).)^ 4803** 4804** ^In the current implementation, the update hook 4805** is not invoked when duplication rows are deleted because of an 4806** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4807** invoked when rows are deleted using the [truncate optimization]. 4808** The exceptions defined in this paragraph might change in a future 4809** release of SQLite. 4810** 4811** The update hook implementation must not do anything that will modify 4812** the database connection that invoked the update hook. Any actions 4813** to modify the database connection must be deferred until after the 4814** completion of the [sqlite3_step()] call that triggered the update hook. 4815** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4816** database connections for the meaning of "modify" in this paragraph. 4817** 4818** ^The sqlite3_update_hook(D,C,P) function 4819** returns the P argument from the previous call 4820** on the same [database connection] D, or NULL for 4821** the first call on D. 4822** 4823** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4824** interfaces. 4825*/ 4826SQLITE_API void *sqlite3_update_hook( 4827 sqlite3*, 4828 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4829 void* 4830); 4831 4832/* 4833** CAPI3REF: Enable Or Disable Shared Pager Cache 4834** 4835** ^(This routine enables or disables the sharing of the database cache 4836** and schema data structures between [database connection | connections] 4837** to the same database. Sharing is enabled if the argument is true 4838** and disabled if the argument is false.)^ 4839** 4840** ^Cache sharing is enabled and disabled for an entire process. 4841** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4842** sharing was enabled or disabled for each thread separately. 4843** 4844** ^(The cache sharing mode set by this interface effects all subsequent 4845** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4846** Existing database connections continue use the sharing mode 4847** that was in effect at the time they were opened.)^ 4848** 4849** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4850** successfully. An [error code] is returned otherwise.)^ 4851** 4852** ^Shared cache is disabled by default. But this might change in 4853** future releases of SQLite. Applications that care about shared 4854** cache setting should set it explicitly. 4855** 4856** This interface is threadsafe on processors where writing a 4857** 32-bit integer is atomic. 4858** 4859** See Also: [SQLite Shared-Cache Mode] 4860*/ 4861SQLITE_API int sqlite3_enable_shared_cache(int); 4862 4863/* 4864** CAPI3REF: Attempt To Free Heap Memory 4865** 4866** ^The sqlite3_release_memory() interface attempts to free N bytes 4867** of heap memory by deallocating non-essential memory allocations 4868** held by the database library. Memory used to cache database 4869** pages to improve performance is an example of non-essential memory. 4870** ^sqlite3_release_memory() returns the number of bytes actually freed, 4871** which might be more or less than the amount requested. 4872** ^The sqlite3_release_memory() routine is a no-op returning zero 4873** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4874** 4875** See also: [sqlite3_db_release_memory()] 4876*/ 4877SQLITE_API int sqlite3_release_memory(int); 4878 4879/* 4880** CAPI3REF: Free Memory Used By A Database Connection 4881** 4882** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4883** memory as possible from database connection D. Unlike the 4884** [sqlite3_release_memory()] interface, this interface is effect even 4885** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4886** omitted. 4887** 4888** See also: [sqlite3_release_memory()] 4889*/ 4890SQLITE_API int sqlite3_db_release_memory(sqlite3*); 4891 4892/* 4893** CAPI3REF: Impose A Limit On Heap Size 4894** 4895** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4896** soft limit on the amount of heap memory that may be allocated by SQLite. 4897** ^SQLite strives to keep heap memory utilization below the soft heap 4898** limit by reducing the number of pages held in the page cache 4899** as heap memory usages approaches the limit. 4900** ^The soft heap limit is "soft" because even though SQLite strives to stay 4901** below the limit, it will exceed the limit rather than generate 4902** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4903** is advisory only. 4904** 4905** ^The return value from sqlite3_soft_heap_limit64() is the size of 4906** the soft heap limit prior to the call, or negative in the case of an 4907** error. ^If the argument N is negative 4908** then no change is made to the soft heap limit. Hence, the current 4909** size of the soft heap limit can be determined by invoking 4910** sqlite3_soft_heap_limit64() with a negative argument. 4911** 4912** ^If the argument N is zero then the soft heap limit is disabled. 4913** 4914** ^(The soft heap limit is not enforced in the current implementation 4915** if one or more of following conditions are true: 4916** 4917** <ul> 4918** <li> The soft heap limit is set to zero. 4919** <li> Memory accounting is disabled using a combination of the 4920** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4921** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4922** <li> An alternative page cache implementation is specified using 4923** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 4924** <li> The page cache allocates from its own memory pool supplied 4925** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4926** from the heap. 4927** </ul>)^ 4928** 4929** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4930** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4931** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4932** the soft heap limit is enforced on every memory allocation. Without 4933** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4934** when memory is allocated by the page cache. Testing suggests that because 4935** the page cache is the predominate memory user in SQLite, most 4936** applications will achieve adequate soft heap limit enforcement without 4937** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4938** 4939** The circumstances under which SQLite will enforce the soft heap limit may 4940** changes in future releases of SQLite. 4941*/ 4942SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4943 4944/* 4945** CAPI3REF: Deprecated Soft Heap Limit Interface 4946** DEPRECATED 4947** 4948** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4949** interface. This routine is provided for historical compatibility 4950** only. All new applications should use the 4951** [sqlite3_soft_heap_limit64()] interface rather than this one. 4952*/ 4953SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4954 4955 4956/* 4957** CAPI3REF: Extract Metadata About A Column Of A Table 4958** 4959** ^This routine returns metadata about a specific column of a specific 4960** database table accessible using the [database connection] handle 4961** passed as the first function argument. 4962** 4963** ^The column is identified by the second, third and fourth parameters to 4964** this function. ^The second parameter is either the name of the database 4965** (i.e. "main", "temp", or an attached database) containing the specified 4966** table or NULL. ^If it is NULL, then all attached databases are searched 4967** for the table using the same algorithm used by the database engine to 4968** resolve unqualified table references. 4969** 4970** ^The third and fourth parameters to this function are the table and column 4971** name of the desired column, respectively. Neither of these parameters 4972** may be NULL. 4973** 4974** ^Metadata is returned by writing to the memory locations passed as the 5th 4975** and subsequent parameters to this function. ^Any of these arguments may be 4976** NULL, in which case the corresponding element of metadata is omitted. 4977** 4978** ^(<blockquote> 4979** <table border="1"> 4980** <tr><th> Parameter <th> Output<br>Type <th> Description 4981** 4982** <tr><td> 5th <td> const char* <td> Data type 4983** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4984** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4985** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4986** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4987** </table> 4988** </blockquote>)^ 4989** 4990** ^The memory pointed to by the character pointers returned for the 4991** declaration type and collation sequence is valid only until the next 4992** call to any SQLite API function. 4993** 4994** ^If the specified table is actually a view, an [error code] is returned. 4995** 4996** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4997** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4998** parameters are set for the explicitly declared column. ^(If there is no 4999** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5000** parameters are set as follows: 5001** 5002** <pre> 5003** data type: "INTEGER" 5004** collation sequence: "BINARY" 5005** not null: 0 5006** primary key: 1 5007** auto increment: 0 5008** </pre>)^ 5009** 5010** ^(This function may load one or more schemas from database files. If an 5011** error occurs during this process, or if the requested table or column 5012** cannot be found, an [error code] is returned and an error message left 5013** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5014** 5015** ^This API is only available if the library was compiled with the 5016** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5017*/ 5018SQLITE_API int sqlite3_table_column_metadata( 5019 sqlite3 *db, /* Connection handle */ 5020 const char *zDbName, /* Database name or NULL */ 5021 const char *zTableName, /* Table name */ 5022 const char *zColumnName, /* Column name */ 5023 char const **pzDataType, /* OUTPUT: Declared data type */ 5024 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5025 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5026 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5027 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5028); 5029 5030/* 5031** CAPI3REF: Load An Extension 5032** 5033** ^This interface loads an SQLite extension library from the named file. 5034** 5035** ^The sqlite3_load_extension() interface attempts to load an 5036** [SQLite extension] library contained in the file zFile. If 5037** the file cannot be loaded directly, attempts are made to load 5038** with various operating-system specific extensions added. 5039** So for example, if "samplelib" cannot be loaded, then names like 5040** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5041** be tried also. 5042** 5043** ^The entry point is zProc. 5044** ^(zProc may be 0, in which case SQLite will try to come up with an 5045** entry point name on its own. It first tries "sqlite3_extension_init". 5046** If that does not work, it constructs a name "sqlite3_X_init" where the 5047** X is consists of the lower-case equivalent of all ASCII alphabetic 5048** characters in the filename from the last "/" to the first following 5049** "." and omitting any initial "lib".)^ 5050** ^The sqlite3_load_extension() interface returns 5051** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5052** ^If an error occurs and pzErrMsg is not 0, then the 5053** [sqlite3_load_extension()] interface shall attempt to 5054** fill *pzErrMsg with error message text stored in memory 5055** obtained from [sqlite3_malloc()]. The calling function 5056** should free this memory by calling [sqlite3_free()]. 5057** 5058** ^Extension loading must be enabled using 5059** [sqlite3_enable_load_extension()] prior to calling this API, 5060** otherwise an error will be returned. 5061** 5062** See also the [load_extension() SQL function]. 5063*/ 5064SQLITE_API int sqlite3_load_extension( 5065 sqlite3 *db, /* Load the extension into this database connection */ 5066 const char *zFile, /* Name of the shared library containing extension */ 5067 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5068 char **pzErrMsg /* Put error message here if not 0 */ 5069); 5070 5071/* 5072** CAPI3REF: Enable Or Disable Extension Loading 5073** 5074** ^So as not to open security holes in older applications that are 5075** unprepared to deal with [extension loading], and as a means of disabling 5076** [extension loading] while evaluating user-entered SQL, the following API 5077** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5078** 5079** ^Extension loading is off by default. 5080** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5081** to turn extension loading on and call it with onoff==0 to turn 5082** it back off again. 5083*/ 5084SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5085 5086/* 5087** CAPI3REF: Automatically Load Statically Linked Extensions 5088** 5089** ^This interface causes the xEntryPoint() function to be invoked for 5090** each new [database connection] that is created. The idea here is that 5091** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5092** that is to be automatically loaded into all new database connections. 5093** 5094** ^(Even though the function prototype shows that xEntryPoint() takes 5095** no arguments and returns void, SQLite invokes xEntryPoint() with three 5096** arguments and expects and integer result as if the signature of the 5097** entry point where as follows: 5098** 5099** <blockquote><pre> 5100** int xEntryPoint( 5101** sqlite3 *db, 5102** const char **pzErrMsg, 5103** const struct sqlite3_api_routines *pThunk 5104** ); 5105** </pre></blockquote>)^ 5106** 5107** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5108** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5109** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5110** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5111** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5112** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5113** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5114** 5115** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5116** on the list of automatic extensions is a harmless no-op. ^No entry point 5117** will be called more than once for each database connection that is opened. 5118** 5119** See also: [sqlite3_reset_auto_extension()]. 5120*/ 5121SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5122 5123/* 5124** CAPI3REF: Reset Automatic Extension Loading 5125** 5126** ^This interface disables all automatic extensions previously 5127** registered using [sqlite3_auto_extension()]. 5128*/ 5129SQLITE_API void sqlite3_reset_auto_extension(void); 5130 5131/* 5132** The interface to the virtual-table mechanism is currently considered 5133** to be experimental. The interface might change in incompatible ways. 5134** If this is a problem for you, do not use the interface at this time. 5135** 5136** When the virtual-table mechanism stabilizes, we will declare the 5137** interface fixed, support it indefinitely, and remove this comment. 5138*/ 5139 5140/* 5141** Structures used by the virtual table interface 5142*/ 5143typedef struct sqlite3_vtab sqlite3_vtab; 5144typedef struct sqlite3_index_info sqlite3_index_info; 5145typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5146typedef struct sqlite3_module sqlite3_module; 5147 5148/* 5149** CAPI3REF: Virtual Table Object 5150** KEYWORDS: sqlite3_module {virtual table module} 5151** 5152** This structure, sometimes called a "virtual table module", 5153** defines the implementation of a [virtual tables]. 5154** This structure consists mostly of methods for the module. 5155** 5156** ^A virtual table module is created by filling in a persistent 5157** instance of this structure and passing a pointer to that instance 5158** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5159** ^The registration remains valid until it is replaced by a different 5160** module or until the [database connection] closes. The content 5161** of this structure must not change while it is registered with 5162** any database connection. 5163*/ 5164struct sqlite3_module { 5165 int iVersion; 5166 int (*xCreate)(sqlite3*, void *pAux, 5167 int argc, const char *const*argv, 5168 sqlite3_vtab **ppVTab, char**); 5169 int (*xConnect)(sqlite3*, void *pAux, 5170 int argc, const char *const*argv, 5171 sqlite3_vtab **ppVTab, char**); 5172 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5173 int (*xDisconnect)(sqlite3_vtab *pVTab); 5174 int (*xDestroy)(sqlite3_vtab *pVTab); 5175 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5176 int (*xClose)(sqlite3_vtab_cursor*); 5177 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5178 int argc, sqlite3_value **argv); 5179 int (*xNext)(sqlite3_vtab_cursor*); 5180 int (*xEof)(sqlite3_vtab_cursor*); 5181 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5182 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5183 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5184 int (*xBegin)(sqlite3_vtab *pVTab); 5185 int (*xSync)(sqlite3_vtab *pVTab); 5186 int (*xCommit)(sqlite3_vtab *pVTab); 5187 int (*xRollback)(sqlite3_vtab *pVTab); 5188 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5189 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5190 void **ppArg); 5191 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5192 /* The methods above are in version 1 of the sqlite_module object. Those 5193 ** below are for version 2 and greater. */ 5194 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5195 int (*xRelease)(sqlite3_vtab *pVTab, int); 5196 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5197}; 5198 5199/* 5200** CAPI3REF: Virtual Table Indexing Information 5201** KEYWORDS: sqlite3_index_info 5202** 5203** The sqlite3_index_info structure and its substructures is used as part 5204** of the [virtual table] interface to 5205** pass information into and receive the reply from the [xBestIndex] 5206** method of a [virtual table module]. The fields under **Inputs** are the 5207** inputs to xBestIndex and are read-only. xBestIndex inserts its 5208** results into the **Outputs** fields. 5209** 5210** ^(The aConstraint[] array records WHERE clause constraints of the form: 5211** 5212** <blockquote>column OP expr</blockquote> 5213** 5214** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5215** stored in aConstraint[].op using one of the 5216** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5217** ^(The index of the column is stored in 5218** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5219** expr on the right-hand side can be evaluated (and thus the constraint 5220** is usable) and false if it cannot.)^ 5221** 5222** ^The optimizer automatically inverts terms of the form "expr OP column" 5223** and makes other simplifications to the WHERE clause in an attempt to 5224** get as many WHERE clause terms into the form shown above as possible. 5225** ^The aConstraint[] array only reports WHERE clause terms that are 5226** relevant to the particular virtual table being queried. 5227** 5228** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5229** ^Each term of aOrderBy records a column of the ORDER BY clause. 5230** 5231** The [xBestIndex] method must fill aConstraintUsage[] with information 5232** about what parameters to pass to xFilter. ^If argvIndex>0 then 5233** the right-hand side of the corresponding aConstraint[] is evaluated 5234** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5235** is true, then the constraint is assumed to be fully handled by the 5236** virtual table and is not checked again by SQLite.)^ 5237** 5238** ^The idxNum and idxPtr values are recorded and passed into the 5239** [xFilter] method. 5240** ^[sqlite3_free()] is used to free idxPtr if and only if 5241** needToFreeIdxPtr is true. 5242** 5243** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5244** the correct order to satisfy the ORDER BY clause so that no separate 5245** sorting step is required. 5246** 5247** ^The estimatedCost value is an estimate of the cost of doing the 5248** particular lookup. A full scan of a table with N entries should have 5249** a cost of N. A binary search of a table of N entries should have a 5250** cost of approximately log(N). 5251*/ 5252struct sqlite3_index_info { 5253 /* Inputs */ 5254 int nConstraint; /* Number of entries in aConstraint */ 5255 struct sqlite3_index_constraint { 5256 int iColumn; /* Column on left-hand side of constraint */ 5257 unsigned char op; /* Constraint operator */ 5258 unsigned char usable; /* True if this constraint is usable */ 5259 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5260 } *aConstraint; /* Table of WHERE clause constraints */ 5261 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5262 struct sqlite3_index_orderby { 5263 int iColumn; /* Column number */ 5264 unsigned char desc; /* True for DESC. False for ASC. */ 5265 } *aOrderBy; /* The ORDER BY clause */ 5266 /* Outputs */ 5267 struct sqlite3_index_constraint_usage { 5268 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5269 unsigned char omit; /* Do not code a test for this constraint */ 5270 } *aConstraintUsage; 5271 int idxNum; /* Number used to identify the index */ 5272 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5273 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5274 int orderByConsumed; /* True if output is already ordered */ 5275 double estimatedCost; /* Estimated cost of using this index */ 5276}; 5277 5278/* 5279** CAPI3REF: Virtual Table Constraint Operator Codes 5280** 5281** These macros defined the allowed values for the 5282** [sqlite3_index_info].aConstraint[].op field. Each value represents 5283** an operator that is part of a constraint term in the wHERE clause of 5284** a query that uses a [virtual table]. 5285*/ 5286#define SQLITE_INDEX_CONSTRAINT_EQ 2 5287#define SQLITE_INDEX_CONSTRAINT_GT 4 5288#define SQLITE_INDEX_CONSTRAINT_LE 8 5289#define SQLITE_INDEX_CONSTRAINT_LT 16 5290#define SQLITE_INDEX_CONSTRAINT_GE 32 5291#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5292 5293/* 5294** CAPI3REF: Register A Virtual Table Implementation 5295** 5296** ^These routines are used to register a new [virtual table module] name. 5297** ^Module names must be registered before 5298** creating a new [virtual table] using the module and before using a 5299** preexisting [virtual table] for the module. 5300** 5301** ^The module name is registered on the [database connection] specified 5302** by the first parameter. ^The name of the module is given by the 5303** second parameter. ^The third parameter is a pointer to 5304** the implementation of the [virtual table module]. ^The fourth 5305** parameter is an arbitrary client data pointer that is passed through 5306** into the [xCreate] and [xConnect] methods of the virtual table module 5307** when a new virtual table is be being created or reinitialized. 5308** 5309** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5310** is a pointer to a destructor for the pClientData. ^SQLite will 5311** invoke the destructor function (if it is not NULL) when SQLite 5312** no longer needs the pClientData pointer. ^The destructor will also 5313** be invoked if the call to sqlite3_create_module_v2() fails. 5314** ^The sqlite3_create_module() 5315** interface is equivalent to sqlite3_create_module_v2() with a NULL 5316** destructor. 5317*/ 5318SQLITE_API int sqlite3_create_module( 5319 sqlite3 *db, /* SQLite connection to register module with */ 5320 const char *zName, /* Name of the module */ 5321 const sqlite3_module *p, /* Methods for the module */ 5322 void *pClientData /* Client data for xCreate/xConnect */ 5323); 5324SQLITE_API int sqlite3_create_module_v2( 5325 sqlite3 *db, /* SQLite connection to register module with */ 5326 const char *zName, /* Name of the module */ 5327 const sqlite3_module *p, /* Methods for the module */ 5328 void *pClientData, /* Client data for xCreate/xConnect */ 5329 void(*xDestroy)(void*) /* Module destructor function */ 5330); 5331 5332/* 5333** CAPI3REF: Virtual Table Instance Object 5334** KEYWORDS: sqlite3_vtab 5335** 5336** Every [virtual table module] implementation uses a subclass 5337** of this object to describe a particular instance 5338** of the [virtual table]. Each subclass will 5339** be tailored to the specific needs of the module implementation. 5340** The purpose of this superclass is to define certain fields that are 5341** common to all module implementations. 5342** 5343** ^Virtual tables methods can set an error message by assigning a 5344** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5345** take care that any prior string is freed by a call to [sqlite3_free()] 5346** prior to assigning a new string to zErrMsg. ^After the error message 5347** is delivered up to the client application, the string will be automatically 5348** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5349*/ 5350struct sqlite3_vtab { 5351 const sqlite3_module *pModule; /* The module for this virtual table */ 5352 int nRef; /* NO LONGER USED */ 5353 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5354 /* Virtual table implementations will typically add additional fields */ 5355}; 5356 5357/* 5358** CAPI3REF: Virtual Table Cursor Object 5359** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5360** 5361** Every [virtual table module] implementation uses a subclass of the 5362** following structure to describe cursors that point into the 5363** [virtual table] and are used 5364** to loop through the virtual table. Cursors are created using the 5365** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5366** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5367** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5368** of the module. Each module implementation will define 5369** the content of a cursor structure to suit its own needs. 5370** 5371** This superclass exists in order to define fields of the cursor that 5372** are common to all implementations. 5373*/ 5374struct sqlite3_vtab_cursor { 5375 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5376 /* Virtual table implementations will typically add additional fields */ 5377}; 5378 5379/* 5380** CAPI3REF: Declare The Schema Of A Virtual Table 5381** 5382** ^The [xCreate] and [xConnect] methods of a 5383** [virtual table module] call this interface 5384** to declare the format (the names and datatypes of the columns) of 5385** the virtual tables they implement. 5386*/ 5387SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5388 5389/* 5390** CAPI3REF: Overload A Function For A Virtual Table 5391** 5392** ^(Virtual tables can provide alternative implementations of functions 5393** using the [xFindFunction] method of the [virtual table module]. 5394** But global versions of those functions 5395** must exist in order to be overloaded.)^ 5396** 5397** ^(This API makes sure a global version of a function with a particular 5398** name and number of parameters exists. If no such function exists 5399** before this API is called, a new function is created.)^ ^The implementation 5400** of the new function always causes an exception to be thrown. So 5401** the new function is not good for anything by itself. Its only 5402** purpose is to be a placeholder function that can be overloaded 5403** by a [virtual table]. 5404*/ 5405SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5406 5407/* 5408** The interface to the virtual-table mechanism defined above (back up 5409** to a comment remarkably similar to this one) is currently considered 5410** to be experimental. The interface might change in incompatible ways. 5411** If this is a problem for you, do not use the interface at this time. 5412** 5413** When the virtual-table mechanism stabilizes, we will declare the 5414** interface fixed, support it indefinitely, and remove this comment. 5415*/ 5416 5417/* 5418** CAPI3REF: A Handle To An Open BLOB 5419** KEYWORDS: {BLOB handle} {BLOB handles} 5420** 5421** An instance of this object represents an open BLOB on which 5422** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5423** ^Objects of this type are created by [sqlite3_blob_open()] 5424** and destroyed by [sqlite3_blob_close()]. 5425** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5426** can be used to read or write small subsections of the BLOB. 5427** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5428*/ 5429typedef struct sqlite3_blob sqlite3_blob; 5430 5431/* 5432** CAPI3REF: Open A BLOB For Incremental I/O 5433** 5434** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5435** in row iRow, column zColumn, table zTable in database zDb; 5436** in other words, the same BLOB that would be selected by: 5437** 5438** <pre> 5439** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5440** </pre>)^ 5441** 5442** ^If the flags parameter is non-zero, then the BLOB is opened for read 5443** and write access. ^If it is zero, the BLOB is opened for read access. 5444** ^It is not possible to open a column that is part of an index or primary 5445** key for writing. ^If [foreign key constraints] are enabled, it is 5446** not possible to open a column that is part of a [child key] for writing. 5447** 5448** ^Note that the database name is not the filename that contains 5449** the database but rather the symbolic name of the database that 5450** appears after the AS keyword when the database is connected using [ATTACH]. 5451** ^For the main database file, the database name is "main". 5452** ^For TEMP tables, the database name is "temp". 5453** 5454** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5455** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5456** to be a null pointer.)^ 5457** ^This function sets the [database connection] error code and message 5458** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5459** functions. ^Note that the *ppBlob variable is always initialized in a 5460** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5461** regardless of the success or failure of this routine. 5462** 5463** ^(If the row that a BLOB handle points to is modified by an 5464** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5465** then the BLOB handle is marked as "expired". 5466** This is true if any column of the row is changed, even a column 5467** other than the one the BLOB handle is open on.)^ 5468** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5469** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5470** ^(Changes written into a BLOB prior to the BLOB expiring are not 5471** rolled back by the expiration of the BLOB. Such changes will eventually 5472** commit if the transaction continues to completion.)^ 5473** 5474** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5475** the opened blob. ^The size of a blob may not be changed by this 5476** interface. Use the [UPDATE] SQL command to change the size of a 5477** blob. 5478** 5479** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5480** and the built-in [zeroblob] SQL function can be used, if desired, 5481** to create an empty, zero-filled blob in which to read or write using 5482** this interface. 5483** 5484** To avoid a resource leak, every open [BLOB handle] should eventually 5485** be released by a call to [sqlite3_blob_close()]. 5486*/ 5487SQLITE_API int sqlite3_blob_open( 5488 sqlite3*, 5489 const char *zDb, 5490 const char *zTable, 5491 const char *zColumn, 5492 sqlite3_int64 iRow, 5493 int flags, 5494 sqlite3_blob **ppBlob 5495); 5496 5497/* 5498** CAPI3REF: Move a BLOB Handle to a New Row 5499** 5500** ^This function is used to move an existing blob handle so that it points 5501** to a different row of the same database table. ^The new row is identified 5502** by the rowid value passed as the second argument. Only the row can be 5503** changed. ^The database, table and column on which the blob handle is open 5504** remain the same. Moving an existing blob handle to a new row can be 5505** faster than closing the existing handle and opening a new one. 5506** 5507** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5508** it must exist and there must be either a blob or text value stored in 5509** the nominated column.)^ ^If the new row is not present in the table, or if 5510** it does not contain a blob or text value, or if another error occurs, an 5511** SQLite error code is returned and the blob handle is considered aborted. 5512** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5513** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5514** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5515** always returns zero. 5516** 5517** ^This function sets the database handle error code and message. 5518*/ 5519SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5520 5521/* 5522** CAPI3REF: Close A BLOB Handle 5523** 5524** ^Closes an open [BLOB handle]. 5525** 5526** ^Closing a BLOB shall cause the current transaction to commit 5527** if there are no other BLOBs, no pending prepared statements, and the 5528** database connection is in [autocommit mode]. 5529** ^If any writes were made to the BLOB, they might be held in cache 5530** until the close operation if they will fit. 5531** 5532** ^(Closing the BLOB often forces the changes 5533** out to disk and so if any I/O errors occur, they will likely occur 5534** at the time when the BLOB is closed. Any errors that occur during 5535** closing are reported as a non-zero return value.)^ 5536** 5537** ^(The BLOB is closed unconditionally. Even if this routine returns 5538** an error code, the BLOB is still closed.)^ 5539** 5540** ^Calling this routine with a null pointer (such as would be returned 5541** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5542*/ 5543SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 5544 5545/* 5546** CAPI3REF: Return The Size Of An Open BLOB 5547** 5548** ^Returns the size in bytes of the BLOB accessible via the 5549** successfully opened [BLOB handle] in its only argument. ^The 5550** incremental blob I/O routines can only read or overwriting existing 5551** blob content; they cannot change the size of a blob. 5552** 5553** This routine only works on a [BLOB handle] which has been created 5554** by a prior successful call to [sqlite3_blob_open()] and which has not 5555** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5556** to this routine results in undefined and probably undesirable behavior. 5557*/ 5558SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 5559 5560/* 5561** CAPI3REF: Read Data From A BLOB Incrementally 5562** 5563** ^(This function is used to read data from an open [BLOB handle] into a 5564** caller-supplied buffer. N bytes of data are copied into buffer Z 5565** from the open BLOB, starting at offset iOffset.)^ 5566** 5567** ^If offset iOffset is less than N bytes from the end of the BLOB, 5568** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5569** less than zero, [SQLITE_ERROR] is returned and no data is read. 5570** ^The size of the blob (and hence the maximum value of N+iOffset) 5571** can be determined using the [sqlite3_blob_bytes()] interface. 5572** 5573** ^An attempt to read from an expired [BLOB handle] fails with an 5574** error code of [SQLITE_ABORT]. 5575** 5576** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5577** Otherwise, an [error code] or an [extended error code] is returned.)^ 5578** 5579** This routine only works on a [BLOB handle] which has been created 5580** by a prior successful call to [sqlite3_blob_open()] and which has not 5581** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5582** to this routine results in undefined and probably undesirable behavior. 5583** 5584** See also: [sqlite3_blob_write()]. 5585*/ 5586SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5587 5588/* 5589** CAPI3REF: Write Data Into A BLOB Incrementally 5590** 5591** ^This function is used to write data into an open [BLOB handle] from a 5592** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5593** into the open BLOB, starting at offset iOffset. 5594** 5595** ^If the [BLOB handle] passed as the first argument was not opened for 5596** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5597** this function returns [SQLITE_READONLY]. 5598** 5599** ^This function may only modify the contents of the BLOB; it is 5600** not possible to increase the size of a BLOB using this API. 5601** ^If offset iOffset is less than N bytes from the end of the BLOB, 5602** [SQLITE_ERROR] is returned and no data is written. ^If N is 5603** less than zero [SQLITE_ERROR] is returned and no data is written. 5604** The size of the BLOB (and hence the maximum value of N+iOffset) 5605** can be determined using the [sqlite3_blob_bytes()] interface. 5606** 5607** ^An attempt to write to an expired [BLOB handle] fails with an 5608** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5609** before the [BLOB handle] expired are not rolled back by the 5610** expiration of the handle, though of course those changes might 5611** have been overwritten by the statement that expired the BLOB handle 5612** or by other independent statements. 5613** 5614** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5615** Otherwise, an [error code] or an [extended error code] is returned.)^ 5616** 5617** This routine only works on a [BLOB handle] which has been created 5618** by a prior successful call to [sqlite3_blob_open()] and which has not 5619** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5620** to this routine results in undefined and probably undesirable behavior. 5621** 5622** See also: [sqlite3_blob_read()]. 5623*/ 5624SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5625 5626/* 5627** CAPI3REF: Virtual File System Objects 5628** 5629** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5630** that SQLite uses to interact 5631** with the underlying operating system. Most SQLite builds come with a 5632** single default VFS that is appropriate for the host computer. 5633** New VFSes can be registered and existing VFSes can be unregistered. 5634** The following interfaces are provided. 5635** 5636** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5637** ^Names are case sensitive. 5638** ^Names are zero-terminated UTF-8 strings. 5639** ^If there is no match, a NULL pointer is returned. 5640** ^If zVfsName is NULL then the default VFS is returned. 5641** 5642** ^New VFSes are registered with sqlite3_vfs_register(). 5643** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5644** ^The same VFS can be registered multiple times without injury. 5645** ^To make an existing VFS into the default VFS, register it again 5646** with the makeDflt flag set. If two different VFSes with the 5647** same name are registered, the behavior is undefined. If a 5648** VFS is registered with a name that is NULL or an empty string, 5649** then the behavior is undefined. 5650** 5651** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5652** ^(If the default VFS is unregistered, another VFS is chosen as 5653** the default. The choice for the new VFS is arbitrary.)^ 5654*/ 5655SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5656SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5657SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5658 5659/* 5660** CAPI3REF: Mutexes 5661** 5662** The SQLite core uses these routines for thread 5663** synchronization. Though they are intended for internal 5664** use by SQLite, code that links against SQLite is 5665** permitted to use any of these routines. 5666** 5667** The SQLite source code contains multiple implementations 5668** of these mutex routines. An appropriate implementation 5669** is selected automatically at compile-time. ^(The following 5670** implementations are available in the SQLite core: 5671** 5672** <ul> 5673** <li> SQLITE_MUTEX_PTHREADS 5674** <li> SQLITE_MUTEX_W32 5675** <li> SQLITE_MUTEX_NOOP 5676** </ul>)^ 5677** 5678** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5679** that does no real locking and is appropriate for use in 5680** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5681** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5682** and Windows. 5683** 5684** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5685** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5686** implementation is included with the library. In this case the 5687** application must supply a custom mutex implementation using the 5688** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5689** before calling sqlite3_initialize() or any other public sqlite3_ 5690** function that calls sqlite3_initialize().)^ 5691** 5692** ^The sqlite3_mutex_alloc() routine allocates a new 5693** mutex and returns a pointer to it. ^If it returns NULL 5694** that means that a mutex could not be allocated. ^SQLite 5695** will unwind its stack and return an error. ^(The argument 5696** to sqlite3_mutex_alloc() is one of these integer constants: 5697** 5698** <ul> 5699** <li> SQLITE_MUTEX_FAST 5700** <li> SQLITE_MUTEX_RECURSIVE 5701** <li> SQLITE_MUTEX_STATIC_MASTER 5702** <li> SQLITE_MUTEX_STATIC_MEM 5703** <li> SQLITE_MUTEX_STATIC_MEM2 5704** <li> SQLITE_MUTEX_STATIC_PRNG 5705** <li> SQLITE_MUTEX_STATIC_LRU 5706** <li> SQLITE_MUTEX_STATIC_LRU2 5707** </ul>)^ 5708** 5709** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5710** cause sqlite3_mutex_alloc() to create 5711** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5712** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5713** The mutex implementation does not need to make a distinction 5714** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5715** not want to. ^SQLite will only request a recursive mutex in 5716** cases where it really needs one. ^If a faster non-recursive mutex 5717** implementation is available on the host platform, the mutex subsystem 5718** might return such a mutex in response to SQLITE_MUTEX_FAST. 5719** 5720** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5721** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5722** a pointer to a static preexisting mutex. ^Six static mutexes are 5723** used by the current version of SQLite. Future versions of SQLite 5724** may add additional static mutexes. Static mutexes are for internal 5725** use by SQLite only. Applications that use SQLite mutexes should 5726** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5727** SQLITE_MUTEX_RECURSIVE. 5728** 5729** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5730** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5731** returns a different mutex on every call. ^But for the static 5732** mutex types, the same mutex is returned on every call that has 5733** the same type number. 5734** 5735** ^The sqlite3_mutex_free() routine deallocates a previously 5736** allocated dynamic mutex. ^SQLite is careful to deallocate every 5737** dynamic mutex that it allocates. The dynamic mutexes must not be in 5738** use when they are deallocated. Attempting to deallocate a static 5739** mutex results in undefined behavior. ^SQLite never deallocates 5740** a static mutex. 5741** 5742** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5743** to enter a mutex. ^If another thread is already within the mutex, 5744** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5745** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5746** upon successful entry. ^(Mutexes created using 5747** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5748** In such cases the, 5749** mutex must be exited an equal number of times before another thread 5750** can enter.)^ ^(If the same thread tries to enter any other 5751** kind of mutex more than once, the behavior is undefined. 5752** SQLite will never exhibit 5753** such behavior in its own use of mutexes.)^ 5754** 5755** ^(Some systems (for example, Windows 95) do not support the operation 5756** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5757** will always return SQLITE_BUSY. The SQLite core only ever uses 5758** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5759** 5760** ^The sqlite3_mutex_leave() routine exits a mutex that was 5761** previously entered by the same thread. ^(The behavior 5762** is undefined if the mutex is not currently entered by the 5763** calling thread or is not currently allocated. SQLite will 5764** never do either.)^ 5765** 5766** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5767** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5768** behave as no-ops. 5769** 5770** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5771*/ 5772SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5773SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5774SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5775SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5776SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5777 5778/* 5779** CAPI3REF: Mutex Methods Object 5780** 5781** An instance of this structure defines the low-level routines 5782** used to allocate and use mutexes. 5783** 5784** Usually, the default mutex implementations provided by SQLite are 5785** sufficient, however the user has the option of substituting a custom 5786** implementation for specialized deployments or systems for which SQLite 5787** does not provide a suitable implementation. In this case, the user 5788** creates and populates an instance of this structure to pass 5789** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5790** Additionally, an instance of this structure can be used as an 5791** output variable when querying the system for the current mutex 5792** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5793** 5794** ^The xMutexInit method defined by this structure is invoked as 5795** part of system initialization by the sqlite3_initialize() function. 5796** ^The xMutexInit routine is called by SQLite exactly once for each 5797** effective call to [sqlite3_initialize()]. 5798** 5799** ^The xMutexEnd method defined by this structure is invoked as 5800** part of system shutdown by the sqlite3_shutdown() function. The 5801** implementation of this method is expected to release all outstanding 5802** resources obtained by the mutex methods implementation, especially 5803** those obtained by the xMutexInit method. ^The xMutexEnd() 5804** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5805** 5806** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5807** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5808** xMutexNotheld) implement the following interfaces (respectively): 5809** 5810** <ul> 5811** <li> [sqlite3_mutex_alloc()] </li> 5812** <li> [sqlite3_mutex_free()] </li> 5813** <li> [sqlite3_mutex_enter()] </li> 5814** <li> [sqlite3_mutex_try()] </li> 5815** <li> [sqlite3_mutex_leave()] </li> 5816** <li> [sqlite3_mutex_held()] </li> 5817** <li> [sqlite3_mutex_notheld()] </li> 5818** </ul>)^ 5819** 5820** The only difference is that the public sqlite3_XXX functions enumerated 5821** above silently ignore any invocations that pass a NULL pointer instead 5822** of a valid mutex handle. The implementations of the methods defined 5823** by this structure are not required to handle this case, the results 5824** of passing a NULL pointer instead of a valid mutex handle are undefined 5825** (i.e. it is acceptable to provide an implementation that segfaults if 5826** it is passed a NULL pointer). 5827** 5828** The xMutexInit() method must be threadsafe. ^It must be harmless to 5829** invoke xMutexInit() multiple times within the same process and without 5830** intervening calls to xMutexEnd(). Second and subsequent calls to 5831** xMutexInit() must be no-ops. 5832** 5833** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5834** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5835** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5836** memory allocation for a fast or recursive mutex. 5837** 5838** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5839** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5840** If xMutexInit fails in any way, it is expected to clean up after itself 5841** prior to returning. 5842*/ 5843typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5844struct sqlite3_mutex_methods { 5845 int (*xMutexInit)(void); 5846 int (*xMutexEnd)(void); 5847 sqlite3_mutex *(*xMutexAlloc)(int); 5848 void (*xMutexFree)(sqlite3_mutex *); 5849 void (*xMutexEnter)(sqlite3_mutex *); 5850 int (*xMutexTry)(sqlite3_mutex *); 5851 void (*xMutexLeave)(sqlite3_mutex *); 5852 int (*xMutexHeld)(sqlite3_mutex *); 5853 int (*xMutexNotheld)(sqlite3_mutex *); 5854}; 5855 5856/* 5857** CAPI3REF: Mutex Verification Routines 5858** 5859** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5860** are intended for use inside assert() statements. ^The SQLite core 5861** never uses these routines except inside an assert() and applications 5862** are advised to follow the lead of the core. ^The SQLite core only 5863** provides implementations for these routines when it is compiled 5864** with the SQLITE_DEBUG flag. ^External mutex implementations 5865** are only required to provide these routines if SQLITE_DEBUG is 5866** defined and if NDEBUG is not defined. 5867** 5868** ^These routines should return true if the mutex in their argument 5869** is held or not held, respectively, by the calling thread. 5870** 5871** ^The implementation is not required to provide versions of these 5872** routines that actually work. If the implementation does not provide working 5873** versions of these routines, it should at least provide stubs that always 5874** return true so that one does not get spurious assertion failures. 5875** 5876** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5877** the routine should return 1. This seems counter-intuitive since 5878** clearly the mutex cannot be held if it does not exist. But 5879** the reason the mutex does not exist is because the build is not 5880** using mutexes. And we do not want the assert() containing the 5881** call to sqlite3_mutex_held() to fail, so a non-zero return is 5882** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5883** interface should also return 1 when given a NULL pointer. 5884*/ 5885#ifndef NDEBUG 5886SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 5887SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 5888#endif 5889 5890/* 5891** CAPI3REF: Mutex Types 5892** 5893** The [sqlite3_mutex_alloc()] interface takes a single argument 5894** which is one of these integer constants. 5895** 5896** The set of static mutexes may change from one SQLite release to the 5897** next. Applications that override the built-in mutex logic must be 5898** prepared to accommodate additional static mutexes. 5899*/ 5900#define SQLITE_MUTEX_FAST 0 5901#define SQLITE_MUTEX_RECURSIVE 1 5902#define SQLITE_MUTEX_STATIC_MASTER 2 5903#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5904#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5905#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5906#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5907#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5908#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5909#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5910 5911/* 5912** CAPI3REF: Retrieve the mutex for a database connection 5913** 5914** ^This interface returns a pointer the [sqlite3_mutex] object that 5915** serializes access to the [database connection] given in the argument 5916** when the [threading mode] is Serialized. 5917** ^If the [threading mode] is Single-thread or Multi-thread then this 5918** routine returns a NULL pointer. 5919*/ 5920SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5921 5922/* 5923** CAPI3REF: Low-Level Control Of Database Files 5924** 5925** ^The [sqlite3_file_control()] interface makes a direct call to the 5926** xFileControl method for the [sqlite3_io_methods] object associated 5927** with a particular database identified by the second argument. ^The 5928** name of the database is "main" for the main database or "temp" for the 5929** TEMP database, or the name that appears after the AS keyword for 5930** databases that are added using the [ATTACH] SQL command. 5931** ^A NULL pointer can be used in place of "main" to refer to the 5932** main database file. 5933** ^The third and fourth parameters to this routine 5934** are passed directly through to the second and third parameters of 5935** the xFileControl method. ^The return value of the xFileControl 5936** method becomes the return value of this routine. 5937** 5938** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5939** a pointer to the underlying [sqlite3_file] object to be written into 5940** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5941** case is a short-circuit path which does not actually invoke the 5942** underlying sqlite3_io_methods.xFileControl method. 5943** 5944** ^If the second parameter (zDbName) does not match the name of any 5945** open database file, then SQLITE_ERROR is returned. ^This error 5946** code is not remembered and will not be recalled by [sqlite3_errcode()] 5947** or [sqlite3_errmsg()]. The underlying xFileControl method might 5948** also return SQLITE_ERROR. There is no way to distinguish between 5949** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5950** xFileControl method. 5951** 5952** See also: [SQLITE_FCNTL_LOCKSTATE] 5953*/ 5954SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5955 5956/* 5957** CAPI3REF: Testing Interface 5958** 5959** ^The sqlite3_test_control() interface is used to read out internal 5960** state of SQLite and to inject faults into SQLite for testing 5961** purposes. ^The first parameter is an operation code that determines 5962** the number, meaning, and operation of all subsequent parameters. 5963** 5964** This interface is not for use by applications. It exists solely 5965** for verifying the correct operation of the SQLite library. Depending 5966** on how the SQLite library is compiled, this interface might not exist. 5967** 5968** The details of the operation codes, their meanings, the parameters 5969** they take, and what they do are all subject to change without notice. 5970** Unlike most of the SQLite API, this function is not guaranteed to 5971** operate consistently from one release to the next. 5972*/ 5973SQLITE_API int sqlite3_test_control(int op, ...); 5974 5975/* 5976** CAPI3REF: Testing Interface Operation Codes 5977** 5978** These constants are the valid operation code parameters used 5979** as the first argument to [sqlite3_test_control()]. 5980** 5981** These parameters and their meanings are subject to change 5982** without notice. These values are for testing purposes only. 5983** Applications should not use any of these parameters or the 5984** [sqlite3_test_control()] interface. 5985*/ 5986#define SQLITE_TESTCTRL_FIRST 5 5987#define SQLITE_TESTCTRL_PRNG_SAVE 5 5988#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5989#define SQLITE_TESTCTRL_PRNG_RESET 7 5990#define SQLITE_TESTCTRL_BITVEC_TEST 8 5991#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5992#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5993#define SQLITE_TESTCTRL_PENDING_BYTE 11 5994#define SQLITE_TESTCTRL_ASSERT 12 5995#define SQLITE_TESTCTRL_ALWAYS 13 5996#define SQLITE_TESTCTRL_RESERVE 14 5997#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5998#define SQLITE_TESTCTRL_ISKEYWORD 16 5999#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6000#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6001#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6002#define SQLITE_TESTCTRL_LAST 19 6003 6004/* 6005** CAPI3REF: SQLite Runtime Status 6006** 6007** ^This interface is used to retrieve runtime status information 6008** about the performance of SQLite, and optionally to reset various 6009** highwater marks. ^The first argument is an integer code for 6010** the specific parameter to measure. ^(Recognized integer codes 6011** are of the form [status parameters | SQLITE_STATUS_...].)^ 6012** ^The current value of the parameter is returned into *pCurrent. 6013** ^The highest recorded value is returned in *pHighwater. ^If the 6014** resetFlag is true, then the highest record value is reset after 6015** *pHighwater is written. ^(Some parameters do not record the highest 6016** value. For those parameters 6017** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6018** ^(Other parameters record only the highwater mark and not the current 6019** value. For these latter parameters nothing is written into *pCurrent.)^ 6020** 6021** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6022** non-zero [error code] on failure. 6023** 6024** This routine is threadsafe but is not atomic. This routine can be 6025** called while other threads are running the same or different SQLite 6026** interfaces. However the values returned in *pCurrent and 6027** *pHighwater reflect the status of SQLite at different points in time 6028** and it is possible that another thread might change the parameter 6029** in between the times when *pCurrent and *pHighwater are written. 6030** 6031** See also: [sqlite3_db_status()] 6032*/ 6033SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6034 6035 6036/* 6037** CAPI3REF: Status Parameters 6038** KEYWORDS: {status parameters} 6039** 6040** These integer constants designate various run-time status parameters 6041** that can be returned by [sqlite3_status()]. 6042** 6043** <dl> 6044** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6045** <dd>This parameter is the current amount of memory checked out 6046** using [sqlite3_malloc()], either directly or indirectly. The 6047** figure includes calls made to [sqlite3_malloc()] by the application 6048** and internal memory usage by the SQLite library. Scratch memory 6049** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6050** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6051** this parameter. The amount returned is the sum of the allocation 6052** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6053** 6054** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6055** <dd>This parameter records the largest memory allocation request 6056** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6057** internal equivalents). Only the value returned in the 6058** *pHighwater parameter to [sqlite3_status()] is of interest. 6059** The value written into the *pCurrent parameter is undefined.</dd>)^ 6060** 6061** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6062** <dd>This parameter records the number of separate memory allocations 6063** currently checked out.</dd>)^ 6064** 6065** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6066** <dd>This parameter returns the number of pages used out of the 6067** [pagecache memory allocator] that was configured using 6068** [SQLITE_CONFIG_PAGECACHE]. The 6069** value returned is in pages, not in bytes.</dd>)^ 6070** 6071** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6072** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6073** <dd>This parameter returns the number of bytes of page cache 6074** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6075** buffer and where forced to overflow to [sqlite3_malloc()]. The 6076** returned value includes allocations that overflowed because they 6077** where too large (they were larger than the "sz" parameter to 6078** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6079** no space was left in the page cache.</dd>)^ 6080** 6081** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6082** <dd>This parameter records the largest memory allocation request 6083** handed to [pagecache memory allocator]. Only the value returned in the 6084** *pHighwater parameter to [sqlite3_status()] is of interest. 6085** The value written into the *pCurrent parameter is undefined.</dd>)^ 6086** 6087** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6088** <dd>This parameter returns the number of allocations used out of the 6089** [scratch memory allocator] configured using 6090** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6091** in bytes. Since a single thread may only have one scratch allocation 6092** outstanding at time, this parameter also reports the number of threads 6093** using scratch memory at the same time.</dd>)^ 6094** 6095** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6096** <dd>This parameter returns the number of bytes of scratch memory 6097** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6098** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6099** returned include overflows because the requested allocation was too 6100** larger (that is, because the requested allocation was larger than the 6101** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6102** slots were available. 6103** </dd>)^ 6104** 6105** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6106** <dd>This parameter records the largest memory allocation request 6107** handed to [scratch memory allocator]. Only the value returned in the 6108** *pHighwater parameter to [sqlite3_status()] is of interest. 6109** The value written into the *pCurrent parameter is undefined.</dd>)^ 6110** 6111** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6112** <dd>This parameter records the deepest parser stack. It is only 6113** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6114** </dl> 6115** 6116** New status parameters may be added from time to time. 6117*/ 6118#define SQLITE_STATUS_MEMORY_USED 0 6119#define SQLITE_STATUS_PAGECACHE_USED 1 6120#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6121#define SQLITE_STATUS_SCRATCH_USED 3 6122#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6123#define SQLITE_STATUS_MALLOC_SIZE 5 6124#define SQLITE_STATUS_PARSER_STACK 6 6125#define SQLITE_STATUS_PAGECACHE_SIZE 7 6126#define SQLITE_STATUS_SCRATCH_SIZE 8 6127#define SQLITE_STATUS_MALLOC_COUNT 9 6128 6129/* 6130** CAPI3REF: Database Connection Status 6131** 6132** ^This interface is used to retrieve runtime status information 6133** about a single [database connection]. ^The first argument is the 6134** database connection object to be interrogated. ^The second argument 6135** is an integer constant, taken from the set of 6136** [SQLITE_DBSTATUS options], that 6137** determines the parameter to interrogate. The set of 6138** [SQLITE_DBSTATUS options] is likely 6139** to grow in future releases of SQLite. 6140** 6141** ^The current value of the requested parameter is written into *pCur 6142** and the highest instantaneous value is written into *pHiwtr. ^If 6143** the resetFlg is true, then the highest instantaneous value is 6144** reset back down to the current value. 6145** 6146** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6147** non-zero [error code] on failure. 6148** 6149** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6150*/ 6151SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6152 6153/* 6154** CAPI3REF: Status Parameters for database connections 6155** KEYWORDS: {SQLITE_DBSTATUS options} 6156** 6157** These constants are the available integer "verbs" that can be passed as 6158** the second argument to the [sqlite3_db_status()] interface. 6159** 6160** New verbs may be added in future releases of SQLite. Existing verbs 6161** might be discontinued. Applications should check the return code from 6162** [sqlite3_db_status()] to make sure that the call worked. 6163** The [sqlite3_db_status()] interface will return a non-zero error code 6164** if a discontinued or unsupported verb is invoked. 6165** 6166** <dl> 6167** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6168** <dd>This parameter returns the number of lookaside memory slots currently 6169** checked out.</dd>)^ 6170** 6171** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6172** <dd>This parameter returns the number malloc attempts that were 6173** satisfied using lookaside memory. Only the high-water value is meaningful; 6174** the current value is always zero.)^ 6175** 6176** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6177** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6178** <dd>This parameter returns the number malloc attempts that might have 6179** been satisfied using lookaside memory but failed due to the amount of 6180** memory requested being larger than the lookaside slot size. 6181** Only the high-water value is meaningful; 6182** the current value is always zero.)^ 6183** 6184** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6185** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6186** <dd>This parameter returns the number malloc attempts that might have 6187** been satisfied using lookaside memory but failed due to all lookaside 6188** memory already being in use. 6189** Only the high-water value is meaningful; 6190** the current value is always zero.)^ 6191** 6192** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6193** <dd>This parameter returns the approximate number of of bytes of heap 6194** memory used by all pager caches associated with the database connection.)^ 6195** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6196** 6197** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6198** <dd>This parameter returns the approximate number of of bytes of heap 6199** memory used to store the schema for all databases associated 6200** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6201** ^The full amount of memory used by the schemas is reported, even if the 6202** schema memory is shared with other database connections due to 6203** [shared cache mode] being enabled. 6204** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6205** 6206** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6207** <dd>This parameter returns the approximate number of of bytes of heap 6208** and lookaside memory used by all prepared statements associated with 6209** the database connection.)^ 6210** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6211** </dd> 6212** 6213** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6214** <dd>This parameter returns the number of pager cache hits that have 6215** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6216** is always 0. 6217** </dd> 6218** 6219** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6220** <dd>This parameter returns the number of pager cache misses that have 6221** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6222** is always 0. 6223** </dd> 6224** 6225** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6226** <dd>This parameter returns the number of dirty cache entries that have 6227** been written to disk. Specifically, the number of pages written to the 6228** wal file in wal mode databases, or the number of pages written to the 6229** database file in rollback mode databases. Any pages written as part of 6230** transaction rollback or database recovery operations are not included. 6231** If an IO or other error occurs while writing a page to disk, the effect 6232** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6233** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6234** </dd> 6235** </dl> 6236*/ 6237#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6238#define SQLITE_DBSTATUS_CACHE_USED 1 6239#define SQLITE_DBSTATUS_SCHEMA_USED 2 6240#define SQLITE_DBSTATUS_STMT_USED 3 6241#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6242#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6243#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6244#define SQLITE_DBSTATUS_CACHE_HIT 7 6245#define SQLITE_DBSTATUS_CACHE_MISS 8 6246#define SQLITE_DBSTATUS_CACHE_WRITE 9 6247#define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ 6248 6249 6250/* 6251** CAPI3REF: Prepared Statement Status 6252** 6253** ^(Each prepared statement maintains various 6254** [SQLITE_STMTSTATUS counters] that measure the number 6255** of times it has performed specific operations.)^ These counters can 6256** be used to monitor the performance characteristics of the prepared 6257** statements. For example, if the number of table steps greatly exceeds 6258** the number of table searches or result rows, that would tend to indicate 6259** that the prepared statement is using a full table scan rather than 6260** an index. 6261** 6262** ^(This interface is used to retrieve and reset counter values from 6263** a [prepared statement]. The first argument is the prepared statement 6264** object to be interrogated. The second argument 6265** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6266** to be interrogated.)^ 6267** ^The current value of the requested counter is returned. 6268** ^If the resetFlg is true, then the counter is reset to zero after this 6269** interface call returns. 6270** 6271** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6272*/ 6273SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6274 6275/* 6276** CAPI3REF: Status Parameters for prepared statements 6277** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6278** 6279** These preprocessor macros define integer codes that name counter 6280** values associated with the [sqlite3_stmt_status()] interface. 6281** The meanings of the various counters are as follows: 6282** 6283** <dl> 6284** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6285** <dd>^This is the number of times that SQLite has stepped forward in 6286** a table as part of a full table scan. Large numbers for this counter 6287** may indicate opportunities for performance improvement through 6288** careful use of indices.</dd> 6289** 6290** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6291** <dd>^This is the number of sort operations that have occurred. 6292** A non-zero value in this counter may indicate an opportunity to 6293** improvement performance through careful use of indices.</dd> 6294** 6295** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6296** <dd>^This is the number of rows inserted into transient indices that 6297** were created automatically in order to help joins run faster. 6298** A non-zero value in this counter may indicate an opportunity to 6299** improvement performance by adding permanent indices that do not 6300** need to be reinitialized each time the statement is run.</dd> 6301** </dl> 6302*/ 6303#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6304#define SQLITE_STMTSTATUS_SORT 2 6305#define SQLITE_STMTSTATUS_AUTOINDEX 3 6306 6307/* 6308** CAPI3REF: Custom Page Cache Object 6309** 6310** The sqlite3_pcache type is opaque. It is implemented by 6311** the pluggable module. The SQLite core has no knowledge of 6312** its size or internal structure and never deals with the 6313** sqlite3_pcache object except by holding and passing pointers 6314** to the object. 6315** 6316** See [sqlite3_pcache_methods2] for additional information. 6317*/ 6318typedef struct sqlite3_pcache sqlite3_pcache; 6319 6320/* 6321** CAPI3REF: Custom Page Cache Object 6322** 6323** The sqlite3_pcache_page object represents a single page in the 6324** page cache. The page cache will allocate instances of this 6325** object. Various methods of the page cache use pointers to instances 6326** of this object as parameters or as their return value. 6327** 6328** See [sqlite3_pcache_methods2] for additional information. 6329*/ 6330typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6331struct sqlite3_pcache_page { 6332 void *pBuf; /* The content of the page */ 6333 void *pExtra; /* Extra information associated with the page */ 6334}; 6335 6336/* 6337** CAPI3REF: Application Defined Page Cache. 6338** KEYWORDS: {page cache} 6339** 6340** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6341** register an alternative page cache implementation by passing in an 6342** instance of the sqlite3_pcache_methods2 structure.)^ 6343** In many applications, most of the heap memory allocated by 6344** SQLite is used for the page cache. 6345** By implementing a 6346** custom page cache using this API, an application can better control 6347** the amount of memory consumed by SQLite, the way in which 6348** that memory is allocated and released, and the policies used to 6349** determine exactly which parts of a database file are cached and for 6350** how long. 6351** 6352** The alternative page cache mechanism is an 6353** extreme measure that is only needed by the most demanding applications. 6354** The built-in page cache is recommended for most uses. 6355** 6356** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6357** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6358** the application may discard the parameter after the call to 6359** [sqlite3_config()] returns.)^ 6360** 6361** [[the xInit() page cache method]] 6362** ^(The xInit() method is called once for each effective 6363** call to [sqlite3_initialize()])^ 6364** (usually only once during the lifetime of the process). ^(The xInit() 6365** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6366** The intent of the xInit() method is to set up global data structures 6367** required by the custom page cache implementation. 6368** ^(If the xInit() method is NULL, then the 6369** built-in default page cache is used instead of the application defined 6370** page cache.)^ 6371** 6372** [[the xShutdown() page cache method]] 6373** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6374** It can be used to clean up 6375** any outstanding resources before process shutdown, if required. 6376** ^The xShutdown() method may be NULL. 6377** 6378** ^SQLite automatically serializes calls to the xInit method, 6379** so the xInit method need not be threadsafe. ^The 6380** xShutdown method is only called from [sqlite3_shutdown()] so it does 6381** not need to be threadsafe either. All other methods must be threadsafe 6382** in multithreaded applications. 6383** 6384** ^SQLite will never invoke xInit() more than once without an intervening 6385** call to xShutdown(). 6386** 6387** [[the xCreate() page cache methods]] 6388** ^SQLite invokes the xCreate() method to construct a new cache instance. 6389** SQLite will typically create one cache instance for each open database file, 6390** though this is not guaranteed. ^The 6391** first parameter, szPage, is the size in bytes of the pages that must 6392** be allocated by the cache. ^szPage will always a power of two. ^The 6393** second parameter szExtra is a number of bytes of extra storage 6394** associated with each page cache entry. ^The szExtra parameter will 6395** a number less than 250. SQLite will use the 6396** extra szExtra bytes on each page to store metadata about the underlying 6397** database page on disk. The value passed into szExtra depends 6398** on the SQLite version, the target platform, and how SQLite was compiled. 6399** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6400** created will be used to cache database pages of a file stored on disk, or 6401** false if it is used for an in-memory database. The cache implementation 6402** does not have to do anything special based with the value of bPurgeable; 6403** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6404** never invoke xUnpin() except to deliberately delete a page. 6405** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6406** false will always have the "discard" flag set to true. 6407** ^Hence, a cache created with bPurgeable false will 6408** never contain any unpinned pages. 6409** 6410** [[the xCachesize() page cache method]] 6411** ^(The xCachesize() method may be called at any time by SQLite to set the 6412** suggested maximum cache-size (number of pages stored by) the cache 6413** instance passed as the first argument. This is the value configured using 6414** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6415** parameter, the implementation is not required to do anything with this 6416** value; it is advisory only. 6417** 6418** [[the xPagecount() page cache methods]] 6419** The xPagecount() method must return the number of pages currently 6420** stored in the cache, both pinned and unpinned. 6421** 6422** [[the xFetch() page cache methods]] 6423** The xFetch() method locates a page in the cache and returns a pointer to 6424** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6425** The pBuf element of the returned sqlite3_pcache_page object will be a 6426** pointer to a buffer of szPage bytes used to store the content of a 6427** single database page. The pExtra element of sqlite3_pcache_page will be 6428** a pointer to the szExtra bytes of extra storage that SQLite has requested 6429** for each entry in the page cache. 6430** 6431** The page to be fetched is determined by the key. ^The minimum key value 6432** is 1. After it has been retrieved using xFetch, the page is considered 6433** to be "pinned". 6434** 6435** If the requested page is already in the page cache, then the page cache 6436** implementation must return a pointer to the page buffer with its content 6437** intact. If the requested page is not already in the cache, then the 6438** cache implementation should use the value of the createFlag 6439** parameter to help it determined what action to take: 6440** 6441** <table border=1 width=85% align=center> 6442** <tr><th> createFlag <th> Behavior when page is not already in cache 6443** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6444** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6445** Otherwise return NULL. 6446** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6447** NULL if allocating a new page is effectively impossible. 6448** </table> 6449** 6450** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6451** will only use a createFlag of 2 after a prior call with a createFlag of 1 6452** failed.)^ In between the to xFetch() calls, SQLite may 6453** attempt to unpin one or more cache pages by spilling the content of 6454** pinned pages to disk and synching the operating system disk cache. 6455** 6456** [[the xUnpin() page cache method]] 6457** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6458** as its second argument. If the third parameter, discard, is non-zero, 6459** then the page must be evicted from the cache. 6460** ^If the discard parameter is 6461** zero, then the page may be discarded or retained at the discretion of 6462** page cache implementation. ^The page cache implementation 6463** may choose to evict unpinned pages at any time. 6464** 6465** The cache must not perform any reference counting. A single 6466** call to xUnpin() unpins the page regardless of the number of prior calls 6467** to xFetch(). 6468** 6469** [[the xRekey() page cache methods]] 6470** The xRekey() method is used to change the key value associated with the 6471** page passed as the second argument. If the cache 6472** previously contains an entry associated with newKey, it must be 6473** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6474** to be pinned. 6475** 6476** When SQLite calls the xTruncate() method, the cache must discard all 6477** existing cache entries with page numbers (keys) greater than or equal 6478** to the value of the iLimit parameter passed to xTruncate(). If any 6479** of these pages are pinned, they are implicitly unpinned, meaning that 6480** they can be safely discarded. 6481** 6482** [[the xDestroy() page cache method]] 6483** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6484** All resources associated with the specified cache should be freed. ^After 6485** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6486** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6487** functions. 6488** 6489** [[the xShrink() page cache method]] 6490** ^SQLite invokes the xShrink() method when it wants the page cache to 6491** free up as much of heap memory as possible. The page cache implementation 6492** is not obligated to free any memory, but well-behaved implementations should 6493** do their best. 6494*/ 6495typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6496struct sqlite3_pcache_methods2 { 6497 int iVersion; 6498 void *pArg; 6499 int (*xInit)(void*); 6500 void (*xShutdown)(void*); 6501 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6502 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6503 int (*xPagecount)(sqlite3_pcache*); 6504 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6505 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6506 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6507 unsigned oldKey, unsigned newKey); 6508 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6509 void (*xDestroy)(sqlite3_pcache*); 6510 void (*xShrink)(sqlite3_pcache*); 6511}; 6512 6513/* 6514** This is the obsolete pcache_methods object that has now been replaced 6515** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6516** retained in the header file for backwards compatibility only. 6517*/ 6518typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6519struct sqlite3_pcache_methods { 6520 void *pArg; 6521 int (*xInit)(void*); 6522 void (*xShutdown)(void*); 6523 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6524 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6525 int (*xPagecount)(sqlite3_pcache*); 6526 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6527 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6528 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6529 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6530 void (*xDestroy)(sqlite3_pcache*); 6531}; 6532 6533 6534/* 6535** CAPI3REF: Online Backup Object 6536** 6537** The sqlite3_backup object records state information about an ongoing 6538** online backup operation. ^The sqlite3_backup object is created by 6539** a call to [sqlite3_backup_init()] and is destroyed by a call to 6540** [sqlite3_backup_finish()]. 6541** 6542** See Also: [Using the SQLite Online Backup API] 6543*/ 6544typedef struct sqlite3_backup sqlite3_backup; 6545 6546/* 6547** CAPI3REF: Online Backup API. 6548** 6549** The backup API copies the content of one database into another. 6550** It is useful either for creating backups of databases or 6551** for copying in-memory databases to or from persistent files. 6552** 6553** See Also: [Using the SQLite Online Backup API] 6554** 6555** ^SQLite holds a write transaction open on the destination database file 6556** for the duration of the backup operation. 6557** ^The source database is read-locked only while it is being read; 6558** it is not locked continuously for the entire backup operation. 6559** ^Thus, the backup may be performed on a live source database without 6560** preventing other database connections from 6561** reading or writing to the source database while the backup is underway. 6562** 6563** ^(To perform a backup operation: 6564** <ol> 6565** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6566** backup, 6567** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6568** the data between the two databases, and finally 6569** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6570** associated with the backup operation. 6571** </ol>)^ 6572** There should be exactly one call to sqlite3_backup_finish() for each 6573** successful call to sqlite3_backup_init(). 6574** 6575** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6576** 6577** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6578** [database connection] associated with the destination database 6579** and the database name, respectively. 6580** ^The database name is "main" for the main database, "temp" for the 6581** temporary database, or the name specified after the AS keyword in 6582** an [ATTACH] statement for an attached database. 6583** ^The S and M arguments passed to 6584** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6585** and database name of the source database, respectively. 6586** ^The source and destination [database connections] (parameters S and D) 6587** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6588** an error. 6589** 6590** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6591** returned and an error code and error message are stored in the 6592** destination [database connection] D. 6593** ^The error code and message for the failed call to sqlite3_backup_init() 6594** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6595** [sqlite3_errmsg16()] functions. 6596** ^A successful call to sqlite3_backup_init() returns a pointer to an 6597** [sqlite3_backup] object. 6598** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6599** sqlite3_backup_finish() functions to perform the specified backup 6600** operation. 6601** 6602** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6603** 6604** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6605** the source and destination databases specified by [sqlite3_backup] object B. 6606** ^If N is negative, all remaining source pages are copied. 6607** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6608** are still more pages to be copied, then the function returns [SQLITE_OK]. 6609** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6610** from source to destination, then it returns [SQLITE_DONE]. 6611** ^If an error occurs while running sqlite3_backup_step(B,N), 6612** then an [error code] is returned. ^As well as [SQLITE_OK] and 6613** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6614** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6615** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6616** 6617** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6618** <ol> 6619** <li> the destination database was opened read-only, or 6620** <li> the destination database is using write-ahead-log journaling 6621** and the destination and source page sizes differ, or 6622** <li> the destination database is an in-memory database and the 6623** destination and source page sizes differ. 6624** </ol>)^ 6625** 6626** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6627** the [sqlite3_busy_handler | busy-handler function] 6628** is invoked (if one is specified). ^If the 6629** busy-handler returns non-zero before the lock is available, then 6630** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6631** sqlite3_backup_step() can be retried later. ^If the source 6632** [database connection] 6633** is being used to write to the source database when sqlite3_backup_step() 6634** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6635** case the call to sqlite3_backup_step() can be retried later on. ^(If 6636** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6637** [SQLITE_READONLY] is returned, then 6638** there is no point in retrying the call to sqlite3_backup_step(). These 6639** errors are considered fatal.)^ The application must accept 6640** that the backup operation has failed and pass the backup operation handle 6641** to the sqlite3_backup_finish() to release associated resources. 6642** 6643** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6644** on the destination file. ^The exclusive lock is not released until either 6645** sqlite3_backup_finish() is called or the backup operation is complete 6646** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6647** sqlite3_backup_step() obtains a [shared lock] on the source database that 6648** lasts for the duration of the sqlite3_backup_step() call. 6649** ^Because the source database is not locked between calls to 6650** sqlite3_backup_step(), the source database may be modified mid-way 6651** through the backup process. ^If the source database is modified by an 6652** external process or via a database connection other than the one being 6653** used by the backup operation, then the backup will be automatically 6654** restarted by the next call to sqlite3_backup_step(). ^If the source 6655** database is modified by the using the same database connection as is used 6656** by the backup operation, then the backup database is automatically 6657** updated at the same time. 6658** 6659** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6660** 6661** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6662** application wishes to abandon the backup operation, the application 6663** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6664** ^The sqlite3_backup_finish() interfaces releases all 6665** resources associated with the [sqlite3_backup] object. 6666** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6667** active write-transaction on the destination database is rolled back. 6668** The [sqlite3_backup] object is invalid 6669** and may not be used following a call to sqlite3_backup_finish(). 6670** 6671** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6672** sqlite3_backup_step() errors occurred, regardless or whether or not 6673** sqlite3_backup_step() completed. 6674** ^If an out-of-memory condition or IO error occurred during any prior 6675** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6676** sqlite3_backup_finish() returns the corresponding [error code]. 6677** 6678** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6679** is not a permanent error and does not affect the return value of 6680** sqlite3_backup_finish(). 6681** 6682** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6683** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6684** 6685** ^Each call to sqlite3_backup_step() sets two values inside 6686** the [sqlite3_backup] object: the number of pages still to be backed 6687** up and the total number of pages in the source database file. 6688** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6689** retrieve these two values, respectively. 6690** 6691** ^The values returned by these functions are only updated by 6692** sqlite3_backup_step(). ^If the source database is modified during a backup 6693** operation, then the values are not updated to account for any extra 6694** pages that need to be updated or the size of the source database file 6695** changing. 6696** 6697** <b>Concurrent Usage of Database Handles</b> 6698** 6699** ^The source [database connection] may be used by the application for other 6700** purposes while a backup operation is underway or being initialized. 6701** ^If SQLite is compiled and configured to support threadsafe database 6702** connections, then the source database connection may be used concurrently 6703** from within other threads. 6704** 6705** However, the application must guarantee that the destination 6706** [database connection] is not passed to any other API (by any thread) after 6707** sqlite3_backup_init() is called and before the corresponding call to 6708** sqlite3_backup_finish(). SQLite does not currently check to see 6709** if the application incorrectly accesses the destination [database connection] 6710** and so no error code is reported, but the operations may malfunction 6711** nevertheless. Use of the destination database connection while a 6712** backup is in progress might also also cause a mutex deadlock. 6713** 6714** If running in [shared cache mode], the application must 6715** guarantee that the shared cache used by the destination database 6716** is not accessed while the backup is running. In practice this means 6717** that the application must guarantee that the disk file being 6718** backed up to is not accessed by any connection within the process, 6719** not just the specific connection that was passed to sqlite3_backup_init(). 6720** 6721** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6722** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6723** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6724** APIs are not strictly speaking threadsafe. If they are invoked at the 6725** same time as another thread is invoking sqlite3_backup_step() it is 6726** possible that they return invalid values. 6727*/ 6728SQLITE_API sqlite3_backup *sqlite3_backup_init( 6729 sqlite3 *pDest, /* Destination database handle */ 6730 const char *zDestName, /* Destination database name */ 6731 sqlite3 *pSource, /* Source database handle */ 6732 const char *zSourceName /* Source database name */ 6733); 6734SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6735SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6736SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6737SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6738 6739/* 6740** CAPI3REF: Unlock Notification 6741** 6742** ^When running in shared-cache mode, a database operation may fail with 6743** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6744** individual tables within the shared-cache cannot be obtained. See 6745** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6746** ^This API may be used to register a callback that SQLite will invoke 6747** when the connection currently holding the required lock relinquishes it. 6748** ^This API is only available if the library was compiled with the 6749** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6750** 6751** See Also: [Using the SQLite Unlock Notification Feature]. 6752** 6753** ^Shared-cache locks are released when a database connection concludes 6754** its current transaction, either by committing it or rolling it back. 6755** 6756** ^When a connection (known as the blocked connection) fails to obtain a 6757** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6758** identity of the database connection (the blocking connection) that 6759** has locked the required resource is stored internally. ^After an 6760** application receives an SQLITE_LOCKED error, it may call the 6761** sqlite3_unlock_notify() method with the blocked connection handle as 6762** the first argument to register for a callback that will be invoked 6763** when the blocking connections current transaction is concluded. ^The 6764** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6765** call that concludes the blocking connections transaction. 6766** 6767** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6768** there is a chance that the blocking connection will have already 6769** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6770** If this happens, then the specified callback is invoked immediately, 6771** from within the call to sqlite3_unlock_notify().)^ 6772** 6773** ^If the blocked connection is attempting to obtain a write-lock on a 6774** shared-cache table, and more than one other connection currently holds 6775** a read-lock on the same table, then SQLite arbitrarily selects one of 6776** the other connections to use as the blocking connection. 6777** 6778** ^(There may be at most one unlock-notify callback registered by a 6779** blocked connection. If sqlite3_unlock_notify() is called when the 6780** blocked connection already has a registered unlock-notify callback, 6781** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6782** called with a NULL pointer as its second argument, then any existing 6783** unlock-notify callback is canceled. ^The blocked connections 6784** unlock-notify callback may also be canceled by closing the blocked 6785** connection using [sqlite3_close()]. 6786** 6787** The unlock-notify callback is not reentrant. If an application invokes 6788** any sqlite3_xxx API functions from within an unlock-notify callback, a 6789** crash or deadlock may be the result. 6790** 6791** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6792** returns SQLITE_OK. 6793** 6794** <b>Callback Invocation Details</b> 6795** 6796** When an unlock-notify callback is registered, the application provides a 6797** single void* pointer that is passed to the callback when it is invoked. 6798** However, the signature of the callback function allows SQLite to pass 6799** it an array of void* context pointers. The first argument passed to 6800** an unlock-notify callback is a pointer to an array of void* pointers, 6801** and the second is the number of entries in the array. 6802** 6803** When a blocking connections transaction is concluded, there may be 6804** more than one blocked connection that has registered for an unlock-notify 6805** callback. ^If two or more such blocked connections have specified the 6806** same callback function, then instead of invoking the callback function 6807** multiple times, it is invoked once with the set of void* context pointers 6808** specified by the blocked connections bundled together into an array. 6809** This gives the application an opportunity to prioritize any actions 6810** related to the set of unblocked database connections. 6811** 6812** <b>Deadlock Detection</b> 6813** 6814** Assuming that after registering for an unlock-notify callback a 6815** database waits for the callback to be issued before taking any further 6816** action (a reasonable assumption), then using this API may cause the 6817** application to deadlock. For example, if connection X is waiting for 6818** connection Y's transaction to be concluded, and similarly connection 6819** Y is waiting on connection X's transaction, then neither connection 6820** will proceed and the system may remain deadlocked indefinitely. 6821** 6822** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6823** detection. ^If a given call to sqlite3_unlock_notify() would put the 6824** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6825** unlock-notify callback is registered. The system is said to be in 6826** a deadlocked state if connection A has registered for an unlock-notify 6827** callback on the conclusion of connection B's transaction, and connection 6828** B has itself registered for an unlock-notify callback when connection 6829** A's transaction is concluded. ^Indirect deadlock is also detected, so 6830** the system is also considered to be deadlocked if connection B has 6831** registered for an unlock-notify callback on the conclusion of connection 6832** C's transaction, where connection C is waiting on connection A. ^Any 6833** number of levels of indirection are allowed. 6834** 6835** <b>The "DROP TABLE" Exception</b> 6836** 6837** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6838** always appropriate to call sqlite3_unlock_notify(). There is however, 6839** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6840** SQLite checks if there are any currently executing SELECT statements 6841** that belong to the same connection. If there are, SQLITE_LOCKED is 6842** returned. In this case there is no "blocking connection", so invoking 6843** sqlite3_unlock_notify() results in the unlock-notify callback being 6844** invoked immediately. If the application then re-attempts the "DROP TABLE" 6845** or "DROP INDEX" query, an infinite loop might be the result. 6846** 6847** One way around this problem is to check the extended error code returned 6848** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6849** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6850** the special "DROP TABLE/INDEX" case, the extended error code is just 6851** SQLITE_LOCKED.)^ 6852*/ 6853SQLITE_API int sqlite3_unlock_notify( 6854 sqlite3 *pBlocked, /* Waiting connection */ 6855 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6856 void *pNotifyArg /* Argument to pass to xNotify */ 6857); 6858 6859 6860/* 6861** CAPI3REF: String Comparison 6862** 6863** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 6864** and extensions to compare the contents of two buffers containing UTF-8 6865** strings in a case-independent fashion, using the same definition of "case 6866** independence" that SQLite uses internally when comparing identifiers. 6867*/ 6868SQLITE_API int sqlite3_stricmp(const char *, const char *); 6869SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 6870 6871/* 6872** CAPI3REF: String Globbing 6873* 6874** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 6875** the glob pattern P, and it returns non-zero if string X does not match 6876** the glob pattern P. ^The definition of glob pattern matching used in 6877** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 6878** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 6879** sensitive. 6880** 6881** Note that this routine returns zero on a match and non-zero if the strings 6882** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 6883*/ 6884SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 6885 6886/* 6887** CAPI3REF: Error Logging Interface 6888** 6889** ^The [sqlite3_log()] interface writes a message into the [error log] 6890** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6891** ^If logging is enabled, the zFormat string and subsequent arguments are 6892** used with [sqlite3_snprintf()] to generate the final output string. 6893** 6894** The sqlite3_log() interface is intended for use by extensions such as 6895** virtual tables, collating functions, and SQL functions. While there is 6896** nothing to prevent an application from calling sqlite3_log(), doing so 6897** is considered bad form. 6898** 6899** The zFormat string must not be NULL. 6900** 6901** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6902** will not use dynamically allocated memory. The log message is stored in 6903** a fixed-length buffer on the stack. If the log message is longer than 6904** a few hundred characters, it will be truncated to the length of the 6905** buffer. 6906*/ 6907SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 6908 6909/* 6910** CAPI3REF: Write-Ahead Log Commit Hook 6911** 6912** ^The [sqlite3_wal_hook()] function is used to register a callback that 6913** will be invoked each time a database connection commits data to a 6914** [write-ahead log] (i.e. whenever a transaction is committed in 6915** [journal_mode | journal_mode=WAL mode]). 6916** 6917** ^The callback is invoked by SQLite after the commit has taken place and 6918** the associated write-lock on the database released, so the implementation 6919** may read, write or [checkpoint] the database as required. 6920** 6921** ^The first parameter passed to the callback function when it is invoked 6922** is a copy of the third parameter passed to sqlite3_wal_hook() when 6923** registering the callback. ^The second is a copy of the database handle. 6924** ^The third parameter is the name of the database that was written to - 6925** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6926** is the number of pages currently in the write-ahead log file, 6927** including those that were just committed. 6928** 6929** The callback function should normally return [SQLITE_OK]. ^If an error 6930** code is returned, that error will propagate back up through the 6931** SQLite code base to cause the statement that provoked the callback 6932** to report an error, though the commit will have still occurred. If the 6933** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6934** that does not correspond to any valid SQLite error code, the results 6935** are undefined. 6936** 6937** A single database handle may have at most a single write-ahead log callback 6938** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6939** previously registered write-ahead log callback. ^Note that the 6940** [sqlite3_wal_autocheckpoint()] interface and the 6941** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6942** those overwrite any prior [sqlite3_wal_hook()] settings. 6943*/ 6944SQLITE_API void *sqlite3_wal_hook( 6945 sqlite3*, 6946 int(*)(void *,sqlite3*,const char*,int), 6947 void* 6948); 6949 6950/* 6951** CAPI3REF: Configure an auto-checkpoint 6952** 6953** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6954** [sqlite3_wal_hook()] that causes any database on [database connection] D 6955** to automatically [checkpoint] 6956** after committing a transaction if there are N or 6957** more frames in the [write-ahead log] file. ^Passing zero or 6958** a negative value as the nFrame parameter disables automatic 6959** checkpoints entirely. 6960** 6961** ^The callback registered by this function replaces any existing callback 6962** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6963** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6964** configured by this function. 6965** 6966** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6967** from SQL. 6968** 6969** ^Every new [database connection] defaults to having the auto-checkpoint 6970** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6971** pages. The use of this interface 6972** is only necessary if the default setting is found to be suboptimal 6973** for a particular application. 6974*/ 6975SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6976 6977/* 6978** CAPI3REF: Checkpoint a database 6979** 6980** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6981** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6982** empty string, then a checkpoint is run on all databases of 6983** connection D. ^If the database connection D is not in 6984** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6985** 6986** ^The [wal_checkpoint pragma] can be used to invoke this interface 6987** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6988** [wal_autocheckpoint pragma] can be used to cause this interface to be 6989** run whenever the WAL reaches a certain size threshold. 6990** 6991** See also: [sqlite3_wal_checkpoint_v2()] 6992*/ 6993SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6994 6995/* 6996** CAPI3REF: Checkpoint a database 6997** 6998** Run a checkpoint operation on WAL database zDb attached to database 6999** handle db. The specific operation is determined by the value of the 7000** eMode parameter: 7001** 7002** <dl> 7003** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7004** Checkpoint as many frames as possible without waiting for any database 7005** readers or writers to finish. Sync the db file if all frames in the log 7006** are checkpointed. This mode is the same as calling 7007** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 7008** 7009** <dt>SQLITE_CHECKPOINT_FULL<dd> 7010** This mode blocks (calls the busy-handler callback) until there is no 7011** database writer and all readers are reading from the most recent database 7012** snapshot. It then checkpoints all frames in the log file and syncs the 7013** database file. This call blocks database writers while it is running, 7014** but not database readers. 7015** 7016** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7017** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7018** checkpointing the log file it blocks (calls the busy-handler callback) 7019** until all readers are reading from the database file only. This ensures 7020** that the next client to write to the database file restarts the log file 7021** from the beginning. This call blocks database writers while it is running, 7022** but not database readers. 7023** </dl> 7024** 7025** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7026** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7027** the total number of checkpointed frames (including any that were already 7028** checkpointed when this function is called). *pnLog and *pnCkpt may be 7029** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7030** If no values are available because of an error, they are both set to -1 7031** before returning to communicate this to the caller. 7032** 7033** All calls obtain an exclusive "checkpoint" lock on the database file. If 7034** any other process is running a checkpoint operation at the same time, the 7035** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7036** busy-handler configured, it will not be invoked in this case. 7037** 7038** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7039** "writer" lock on the database file. If the writer lock cannot be obtained 7040** immediately, and a busy-handler is configured, it is invoked and the writer 7041** lock retried until either the busy-handler returns 0 or the lock is 7042** successfully obtained. The busy-handler is also invoked while waiting for 7043** database readers as described above. If the busy-handler returns 0 before 7044** the writer lock is obtained or while waiting for database readers, the 7045** checkpoint operation proceeds from that point in the same way as 7046** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7047** without blocking any further. SQLITE_BUSY is returned in this case. 7048** 7049** If parameter zDb is NULL or points to a zero length string, then the 7050** specified operation is attempted on all WAL databases. In this case the 7051** values written to output parameters *pnLog and *pnCkpt are undefined. If 7052** an SQLITE_BUSY error is encountered when processing one or more of the 7053** attached WAL databases, the operation is still attempted on any remaining 7054** attached databases and SQLITE_BUSY is returned to the caller. If any other 7055** error occurs while processing an attached database, processing is abandoned 7056** and the error code returned to the caller immediately. If no error 7057** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7058** databases, SQLITE_OK is returned. 7059** 7060** If database zDb is the name of an attached database that is not in WAL 7061** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7062** zDb is not NULL (or a zero length string) and is not the name of any 7063** attached database, SQLITE_ERROR is returned to the caller. 7064*/ 7065SQLITE_API int sqlite3_wal_checkpoint_v2( 7066 sqlite3 *db, /* Database handle */ 7067 const char *zDb, /* Name of attached database (or NULL) */ 7068 int eMode, /* SQLITE_CHECKPOINT_* value */ 7069 int *pnLog, /* OUT: Size of WAL log in frames */ 7070 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7071); 7072 7073/* 7074** CAPI3REF: Checkpoint operation parameters 7075** 7076** These constants can be used as the 3rd parameter to 7077** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7078** documentation for additional information about the meaning and use of 7079** each of these values. 7080*/ 7081#define SQLITE_CHECKPOINT_PASSIVE 0 7082#define SQLITE_CHECKPOINT_FULL 1 7083#define SQLITE_CHECKPOINT_RESTART 2 7084 7085/* 7086** CAPI3REF: Virtual Table Interface Configuration 7087** 7088** This function may be called by either the [xConnect] or [xCreate] method 7089** of a [virtual table] implementation to configure 7090** various facets of the virtual table interface. 7091** 7092** If this interface is invoked outside the context of an xConnect or 7093** xCreate virtual table method then the behavior is undefined. 7094** 7095** At present, there is only one option that may be configured using 7096** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7097** may be added in the future. 7098*/ 7099SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7100 7101/* 7102** CAPI3REF: Virtual Table Configuration Options 7103** 7104** These macros define the various options to the 7105** [sqlite3_vtab_config()] interface that [virtual table] implementations 7106** can use to customize and optimize their behavior. 7107** 7108** <dl> 7109** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7110** <dd>Calls of the form 7111** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7112** where X is an integer. If X is zero, then the [virtual table] whose 7113** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7114** support constraints. In this configuration (which is the default) if 7115** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7116** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7117** specified as part of the users SQL statement, regardless of the actual 7118** ON CONFLICT mode specified. 7119** 7120** If X is non-zero, then the virtual table implementation guarantees 7121** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7122** any modifications to internal or persistent data structures have been made. 7123** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7124** is able to roll back a statement or database transaction, and abandon 7125** or continue processing the current SQL statement as appropriate. 7126** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7127** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7128** had been ABORT. 7129** 7130** Virtual table implementations that are required to handle OR REPLACE 7131** must do so within the [xUpdate] method. If a call to the 7132** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7133** CONFLICT policy is REPLACE, the virtual table implementation should 7134** silently replace the appropriate rows within the xUpdate callback and 7135** return SQLITE_OK. Or, if this is not possible, it may return 7136** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7137** constraint handling. 7138** </dl> 7139*/ 7140#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7141 7142/* 7143** CAPI3REF: Determine The Virtual Table Conflict Policy 7144** 7145** This function may only be called from within a call to the [xUpdate] method 7146** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7147** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7148** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7149** of the SQL statement that triggered the call to the [xUpdate] method of the 7150** [virtual table]. 7151*/ 7152SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 7153 7154/* 7155** CAPI3REF: Conflict resolution modes 7156** 7157** These constants are returned by [sqlite3_vtab_on_conflict()] to 7158** inform a [virtual table] implementation what the [ON CONFLICT] mode 7159** is for the SQL statement being evaluated. 7160** 7161** Note that the [SQLITE_IGNORE] constant is also used as a potential 7162** return value from the [sqlite3_set_authorizer()] callback and that 7163** [SQLITE_ABORT] is also a [result code]. 7164*/ 7165#define SQLITE_ROLLBACK 1 7166/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7167#define SQLITE_FAIL 3 7168/* #define SQLITE_ABORT 4 // Also an error code */ 7169#define SQLITE_REPLACE 5 7170 7171 7172 7173/* 7174** Undo the hack that converts floating point types to integer for 7175** builds on processors without floating point support. 7176*/ 7177#ifdef SQLITE_OMIT_FLOATING_POINT 7178# undef double 7179#endif 7180 7181#ifdef __cplusplus 7182} /* End of the 'extern "C"' block */ 7183#endif 7184#endif 7185 7186/* 7187** 2010 August 30 7188** 7189** The author disclaims copyright to this source code. In place of 7190** a legal notice, here is a blessing: 7191** 7192** May you do good and not evil. 7193** May you find forgiveness for yourself and forgive others. 7194** May you share freely, never taking more than you give. 7195** 7196************************************************************************* 7197*/ 7198 7199#ifndef _SQLITE3RTREE_H_ 7200#define _SQLITE3RTREE_H_ 7201 7202 7203#ifdef __cplusplus 7204extern "C" { 7205#endif 7206 7207typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7208 7209/* 7210** Register a geometry callback named zGeom that can be used as part of an 7211** R-Tree geometry query as follows: 7212** 7213** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7214*/ 7215SQLITE_API int sqlite3_rtree_geometry_callback( 7216 sqlite3 *db, 7217 const char *zGeom, 7218#ifdef SQLITE_RTREE_INT_ONLY 7219 int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), 7220#else 7221 int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), 7222#endif 7223 void *pContext 7224); 7225 7226 7227/* 7228** A pointer to a structure of the following type is passed as the first 7229** argument to callbacks registered using rtree_geometry_callback(). 7230*/ 7231struct sqlite3_rtree_geometry { 7232 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7233 int nParam; /* Size of array aParam[] */ 7234 double *aParam; /* Parameters passed to SQL geom function */ 7235 void *pUser; /* Callback implementation user data */ 7236 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7237}; 7238 7239 7240#ifdef __cplusplus 7241} /* end of the 'extern "C"' block */ 7242#endif 7243 7244#endif /* ifndef _SQLITE3RTREE_H_ */ 7245 7246