1226031Sstas/* 2226031Sstas** 2001 September 15 3226031Sstas** 4226031Sstas** The author disclaims copyright to this source code. In place of 5226031Sstas** a legal notice, here is a blessing: 6226031Sstas** 7226031Sstas** May you do good and not evil. 8226031Sstas** May you find forgiveness for yourself and forgive others. 9226031Sstas** May you share freely, never taking more than you give. 10226031Sstas** 11226031Sstas************************************************************************* 12226031Sstas** This header file defines the interface that the SQLite library 13226031Sstas** presents to client programs. If a C-function, structure, datatype, 14226031Sstas** or constant definition does not appear in this file, then it is 15226031Sstas** not a published API of SQLite, is subject to change without 16226031Sstas** notice, and should not be referenced by programs that use SQLite. 17226031Sstas** 18226031Sstas** Some of the definitions that are in this file are marked as 19226031Sstas** "experimental". Experimental interfaces are normally new 20226031Sstas** features recently added to SQLite. We do not anticipate changes 21226031Sstas** to experimental interfaces but reserve the right to make minor changes 22226031Sstas** if experience from use "in the wild" suggest such changes are prudent. 23226031Sstas** 24226031Sstas** The official C-language API documentation for SQLite is derived 25226031Sstas** from comments in this file. This file is the authoritative source 26226031Sstas** on how SQLite interfaces are suppose to operate. 27226031Sstas** 28226031Sstas** The name of this file under configuration management is "sqlite.h.in". 29226031Sstas** The makefile makes some minor changes to this file (such as inserting 30226031Sstas** the version number) and changes its name to "sqlite3.h" as 31226031Sstas** part of the build process. 32226031Sstas*/ 33226031Sstas#ifndef _SQLITE3_H_ 34226031Sstas#define _SQLITE3_H_ 35226031Sstas#include <stdarg.h> /* Needed for the definition of va_list */ 36226031Sstas 37226031Sstas/* 38226031Sstas** Make sure we can call this stuff from C++. 39226031Sstas*/ 40226031Sstas#ifdef __cplusplus 41226031Sstasextern "C" { 42226031Sstas#endif 43226031Sstas 44226031Sstas 45226031Sstas/* 46226031Sstas** Add the ability to override 'extern' 47226031Sstas*/ 48226031Sstas#ifndef SQLITE_EXTERN 49226031Sstas# define SQLITE_EXTERN extern 50226031Sstas#endif 51226031Sstas 52226031Sstas#ifndef SQLITE_API 53226031Sstas# define SQLITE_API 54226031Sstas#endif 55226031Sstas 56226031Sstas 57226031Sstas/* 58226031Sstas** These no-op macros are used in front of interfaces to mark those 59226031Sstas** interfaces as either deprecated or experimental. New applications 60226031Sstas** should not use deprecated interfaces - they are support for backwards 61226031Sstas** compatibility only. Application writers should be aware that 62226031Sstas** experimental interfaces are subject to change in point releases. 63226031Sstas** 64226031Sstas** These macros used to resolve to various kinds of compiler magic that 65226031Sstas** would generate warning messages when they were used. But that 66226031Sstas** compiler magic ended up generating such a flurry of bug reports 67226031Sstas** that we have taken it all out and gone back to using simple 68226031Sstas** noop macros. 69226031Sstas*/ 70226031Sstas#define SQLITE_DEPRECATED 71226031Sstas#define SQLITE_EXPERIMENTAL 72226031Sstas 73226031Sstas/* 74226031Sstas** Ensure these symbols were not defined by some previous header file. 75226031Sstas*/ 76226031Sstas#ifdef SQLITE_VERSION 77226031Sstas# undef SQLITE_VERSION 78226031Sstas#endif 79226031Sstas#ifdef SQLITE_VERSION_NUMBER 80226031Sstas# undef SQLITE_VERSION_NUMBER 81226031Sstas#endif 82226031Sstas 83226031Sstas/* 84226031Sstas** CAPI3REF: Compile-Time Library Version Numbers 85226031Sstas** 86226031Sstas** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87226031Sstas** evaluates to a string literal that is the SQLite version in the 88226031Sstas** format "X.Y.Z" where X is the major version number (always 3 for 89226031Sstas** SQLite3) and Y is the minor version number and Z is the release number.)^ 90226031Sstas** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91226031Sstas** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92226031Sstas** numbers used in [SQLITE_VERSION].)^ 93226031Sstas** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94226031Sstas** be larger than the release from which it is derived. Either Y will 95226031Sstas** be held constant and Z will be incremented or else Y will be incremented 96226031Sstas** and Z will be reset to zero. 97226031Sstas** 98226031Sstas** Since version 3.6.18, SQLite source code has been stored in the 99226031Sstas** <a href="http://www.fossil-scm.org/">Fossil configuration management 100226128Sstas** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101226031Sstas** a string which identifies a particular check-in of SQLite 102226031Sstas** within its configuration management system. ^The SQLITE_SOURCE_ID 103226031Sstas** string contains the date and time of the check-in (UTC) and an SHA1 104226031Sstas** hash of the entire source tree. 105226031Sstas** 106226031Sstas** See also: [sqlite3_libversion()], 107226031Sstas** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108226031Sstas** [sqlite_version()] and [sqlite_source_id()]. 109226031Sstas*/ 110226128Sstas#define SQLITE_VERSION "3.7.8" 111226128Sstas#define SQLITE_VERSION_NUMBER 3007008 112226128Sstas#define SQLITE_SOURCE_ID "2011-09-19 14:49:19 3e0da808d2f5b4d12046e05980ca04578f581177" 113226031Sstas 114226031Sstas/* 115226031Sstas** CAPI3REF: Run-Time Library Version Numbers 116226031Sstas** KEYWORDS: sqlite3_version, sqlite3_sourceid 117226031Sstas** 118226031Sstas** These interfaces provide the same information as the [SQLITE_VERSION], 119226031Sstas** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120226031Sstas** but are associated with the library instead of the header file. ^(Cautious 121226031Sstas** programmers might include assert() statements in their application to 122226031Sstas** verify that values returned by these interfaces match the macros in 123226031Sstas** the header, and thus insure that the application is 124226031Sstas** compiled with matching library and header files. 125226031Sstas** 126226031Sstas** <blockquote><pre> 127226031Sstas** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128226031Sstas** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129226031Sstas** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130226031Sstas** </pre></blockquote>)^ 131226031Sstas** 132226031Sstas** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133226031Sstas** macro. ^The sqlite3_libversion() function returns a pointer to the 134226031Sstas** to the sqlite3_version[] string constant. The sqlite3_libversion() 135226031Sstas** function is provided for use in DLLs since DLL users usually do not have 136226031Sstas** direct access to string constants within the DLL. ^The 137226031Sstas** sqlite3_libversion_number() function returns an integer equal to 138226128Sstas** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139226128Sstas** a pointer to a string constant whose value is the same as the 140226031Sstas** [SQLITE_SOURCE_ID] C preprocessor macro. 141226031Sstas** 142226031Sstas** See also: [sqlite_version()] and [sqlite_source_id()]. 143226031Sstas*/ 144226031SstasSQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145226031SstasSQLITE_API const char *sqlite3_libversion(void); 146226031SstasSQLITE_API const char *sqlite3_sourceid(void); 147226031SstasSQLITE_API int sqlite3_libversion_number(void); 148226031Sstas 149226031Sstas/* 150226031Sstas** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151226031Sstas** 152226128Sstas** ^The sqlite3_compileoption_used() function returns 0 or 1 153226128Sstas** indicating whether the specified option was defined at 154226128Sstas** compile time. ^The SQLITE_ prefix may be omitted from the 155226128Sstas** option name passed to sqlite3_compileoption_used(). 156226031Sstas** 157226128Sstas** ^The sqlite3_compileoption_get() function allows iterating 158226031Sstas** over the list of options that were defined at compile time by 159226031Sstas** returning the N-th compile time option string. ^If N is out of range, 160226128Sstas** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161226128Sstas** prefix is omitted from any strings returned by 162226031Sstas** sqlite3_compileoption_get(). 163226031Sstas** 164226031Sstas** ^Support for the diagnostic functions sqlite3_compileoption_used() 165226128Sstas** and sqlite3_compileoption_get() may be omitted by specifying the 166226031Sstas** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167226031Sstas** 168226031Sstas** See also: SQL functions [sqlite_compileoption_used()] and 169226031Sstas** [sqlite_compileoption_get()] and the [compile_options pragma]. 170226031Sstas*/ 171226128Sstas#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172226031SstasSQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173226031SstasSQLITE_API const char *sqlite3_compileoption_get(int N); 174226128Sstas#endif 175226031Sstas 176226031Sstas/* 177226031Sstas** CAPI3REF: Test To See If The Library Is Threadsafe 178226031Sstas** 179226031Sstas** ^The sqlite3_threadsafe() function returns zero if and only if 180226031Sstas** SQLite was compiled mutexing code omitted due to the 181226031Sstas** [SQLITE_THREADSAFE] compile-time option being set to 0. 182226031Sstas** 183226031Sstas** SQLite can be compiled with or without mutexes. When 184226031Sstas** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185226031Sstas** are enabled and SQLite is threadsafe. When the 186226128Sstas** [SQLITE_THREADSAFE] macro is 0, 187226031Sstas** the mutexes are omitted. Without the mutexes, it is not safe 188226031Sstas** to use SQLite concurrently from more than one thread. 189226031Sstas** 190226031Sstas** Enabling mutexes incurs a measurable performance penalty. 191226031Sstas** So if speed is of utmost importance, it makes sense to disable 192226031Sstas** the mutexes. But for maximum safety, mutexes should be enabled. 193226031Sstas** ^The default behavior is for mutexes to be enabled. 194226031Sstas** 195226031Sstas** This interface can be used by an application to make sure that the 196226031Sstas** version of SQLite that it is linking against was compiled with 197226031Sstas** the desired setting of the [SQLITE_THREADSAFE] macro. 198226031Sstas** 199226031Sstas** This interface only reports on the compile-time mutex setting 200226031Sstas** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201226031Sstas** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202226031Sstas** can be fully or partially disabled using a call to [sqlite3_config()] 203226031Sstas** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204226031Sstas** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205226031Sstas** sqlite3_threadsafe() function shows only the compile-time setting of 206226031Sstas** thread safety, not any run-time changes to that setting made by 207226031Sstas** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208226031Sstas** is unchanged by calls to sqlite3_config().)^ 209226031Sstas** 210226031Sstas** See the [threading mode] documentation for additional information. 211226031Sstas*/ 212226031SstasSQLITE_API int sqlite3_threadsafe(void); 213226031Sstas 214226031Sstas/* 215226031Sstas** CAPI3REF: Database Connection Handle 216226031Sstas** KEYWORDS: {database connection} {database connections} 217226031Sstas** 218226031Sstas** Each open SQLite database is represented by a pointer to an instance of 219226031Sstas** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220226031Sstas** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221226031Sstas** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 222226031Sstas** is its destructor. There are many other interfaces (such as 223226031Sstas** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 224226031Sstas** [sqlite3_busy_timeout()] to name but three) that are methods on an 225226031Sstas** sqlite3 object. 226226031Sstas*/ 227226031Sstastypedef struct sqlite3 sqlite3; 228226031Sstas 229226031Sstas/* 230226031Sstas** CAPI3REF: 64-Bit Integer Types 231226031Sstas** KEYWORDS: sqlite_int64 sqlite_uint64 232226031Sstas** 233226031Sstas** Because there is no cross-platform way to specify 64-bit integer types 234226031Sstas** SQLite includes typedefs for 64-bit signed and unsigned integers. 235226031Sstas** 236226031Sstas** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 237226031Sstas** The sqlite_int64 and sqlite_uint64 types are supported for backwards 238226031Sstas** compatibility only. 239226031Sstas** 240226031Sstas** ^The sqlite3_int64 and sqlite_int64 types can store integer values 241226031Sstas** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 242226128Sstas** sqlite3_uint64 and sqlite_uint64 types can store integer values 243226031Sstas** between 0 and +18446744073709551615 inclusive. 244226031Sstas*/ 245226031Sstas#ifdef SQLITE_INT64_TYPE 246226031Sstas typedef SQLITE_INT64_TYPE sqlite_int64; 247226031Sstas typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 248226031Sstas#elif defined(_MSC_VER) || defined(__BORLANDC__) 249226031Sstas typedef __int64 sqlite_int64; 250226031Sstas typedef unsigned __int64 sqlite_uint64; 251226031Sstas#else 252226031Sstas typedef long long int sqlite_int64; 253226031Sstas typedef unsigned long long int sqlite_uint64; 254226031Sstas#endif 255226031Sstastypedef sqlite_int64 sqlite3_int64; 256226031Sstastypedef sqlite_uint64 sqlite3_uint64; 257226031Sstas 258226031Sstas/* 259226031Sstas** If compiling for a processor that lacks floating point support, 260226031Sstas** substitute integer for floating-point. 261226031Sstas*/ 262226031Sstas#ifdef SQLITE_OMIT_FLOATING_POINT 263226031Sstas# define double sqlite3_int64 264226031Sstas#endif 265226031Sstas 266226031Sstas/* 267226031Sstas** CAPI3REF: Closing A Database Connection 268226031Sstas** 269226031Sstas** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. 270226031Sstas** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is 271226128Sstas** successfully destroyed and all associated resources are deallocated. 272226031Sstas** 273226031Sstas** Applications must [sqlite3_finalize | finalize] all [prepared statements] 274226031Sstas** and [sqlite3_blob_close | close] all [BLOB handles] associated with 275226031Sstas** the [sqlite3] object prior to attempting to close the object. ^If 276226031Sstas** sqlite3_close() is called on a [database connection] that still has 277226031Sstas** outstanding [prepared statements] or [BLOB handles], then it returns 278226031Sstas** SQLITE_BUSY. 279226031Sstas** 280226031Sstas** ^If [sqlite3_close()] is invoked while a transaction is open, 281226031Sstas** the transaction is automatically rolled back. 282226031Sstas** 283226031Sstas** The C parameter to [sqlite3_close(C)] must be either a NULL 284226031Sstas** pointer or an [sqlite3] object pointer obtained 285226031Sstas** from [sqlite3_open()], [sqlite3_open16()], or 286226031Sstas** [sqlite3_open_v2()], and not previously closed. 287226128Sstas** ^Calling sqlite3_close() with a NULL pointer argument is a 288226031Sstas** harmless no-op. 289226031Sstas*/ 290226031SstasSQLITE_API int sqlite3_close(sqlite3 *); 291226031Sstas 292226031Sstas/* 293226031Sstas** The type for a callback function. 294226031Sstas** This is legacy and deprecated. It is included for historical 295226031Sstas** compatibility and is not documented. 296226031Sstas*/ 297226031Sstastypedef int (*sqlite3_callback)(void*,int,char**, char**); 298226031Sstas 299226031Sstas/* 300226031Sstas** CAPI3REF: One-Step Query Execution Interface 301226031Sstas** 302226031Sstas** The sqlite3_exec() interface is a convenience wrapper around 303226031Sstas** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 304226031Sstas** that allows an application to run multiple statements of SQL 305226128Sstas** without having to use a lot of C code. 306226031Sstas** 307226031Sstas** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 308226031Sstas** semicolon-separate SQL statements passed into its 2nd argument, 309226031Sstas** in the context of the [database connection] passed in as its 1st 310226031Sstas** argument. ^If the callback function of the 3rd argument to 311226031Sstas** sqlite3_exec() is not NULL, then it is invoked for each result row 312226031Sstas** coming out of the evaluated SQL statements. ^The 4th argument to 313226128Sstas** sqlite3_exec() is relayed through to the 1st argument of each 314226031Sstas** callback invocation. ^If the callback pointer to sqlite3_exec() 315226031Sstas** is NULL, then no callback is ever invoked and result rows are 316226031Sstas** ignored. 317226031Sstas** 318226031Sstas** ^If an error occurs while evaluating the SQL statements passed into 319226031Sstas** sqlite3_exec(), then execution of the current statement stops and 320226031Sstas** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 321226031Sstas** is not NULL then any error message is written into memory obtained 322226031Sstas** from [sqlite3_malloc()] and passed back through the 5th parameter. 323226031Sstas** To avoid memory leaks, the application should invoke [sqlite3_free()] 324226031Sstas** on error message strings returned through the 5th parameter of 325226031Sstas** of sqlite3_exec() after the error message string is no longer needed. 326226031Sstas** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 327226031Sstas** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 328226031Sstas** NULL before returning. 329226031Sstas** 330226031Sstas** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 331226031Sstas** routine returns SQLITE_ABORT without invoking the callback again and 332226031Sstas** without running any subsequent SQL statements. 333226031Sstas** 334226031Sstas** ^The 2nd argument to the sqlite3_exec() callback function is the 335226031Sstas** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 336226031Sstas** callback is an array of pointers to strings obtained as if from 337226031Sstas** [sqlite3_column_text()], one for each column. ^If an element of a 338226031Sstas** result row is NULL then the corresponding string pointer for the 339226031Sstas** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 340226031Sstas** sqlite3_exec() callback is an array of pointers to strings where each 341226031Sstas** entry represents the name of corresponding result column as obtained 342226031Sstas** from [sqlite3_column_name()]. 343226031Sstas** 344226031Sstas** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 345226128Sstas** to an empty string, or a pointer that contains only whitespace and/or 346226031Sstas** SQL comments, then no SQL statements are evaluated and the database 347226031Sstas** is not changed. 348226031Sstas** 349226031Sstas** Restrictions: 350226031Sstas** 351226031Sstas** <ul> 352226031Sstas** <li> The application must insure that the 1st parameter to sqlite3_exec() 353226031Sstas** is a valid and open [database connection]. 354226031Sstas** <li> The application must not close [database connection] specified by 355226031Sstas** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 356226031Sstas** <li> The application must not modify the SQL statement text passed into 357226031Sstas** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 358226031Sstas** </ul> 359226031Sstas*/ 360226031SstasSQLITE_API int sqlite3_exec( 361226031Sstas sqlite3*, /* An open database */ 362226031Sstas const char *sql, /* SQL to be evaluated */ 363226031Sstas int (*callback)(void*,int,char**,char**), /* Callback function */ 364226031Sstas void *, /* 1st argument to callback */ 365226031Sstas char **errmsg /* Error msg written here */ 366226031Sstas); 367226031Sstas 368226031Sstas/* 369226031Sstas** CAPI3REF: Result Codes 370226031Sstas** KEYWORDS: SQLITE_OK {error code} {error codes} 371226031Sstas** KEYWORDS: {result code} {result codes} 372226031Sstas** 373226031Sstas** Many SQLite functions return an integer result code from the set shown 374226031Sstas** here in order to indicates success or failure. 375226031Sstas** 376226031Sstas** New error codes may be added in future versions of SQLite. 377226031Sstas** 378226128Sstas** See also: [SQLITE_IOERR_READ | extended result codes], 379226128Sstas** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 380226031Sstas*/ 381226031Sstas#define SQLITE_OK 0 /* Successful result */ 382226031Sstas/* beginning-of-error-codes */ 383226031Sstas#define SQLITE_ERROR 1 /* SQL error or missing database */ 384226031Sstas#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 385226031Sstas#define SQLITE_PERM 3 /* Access permission denied */ 386226031Sstas#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 387226031Sstas#define SQLITE_BUSY 5 /* The database file is locked */ 388226031Sstas#define SQLITE_LOCKED 6 /* A table in the database is locked */ 389226031Sstas#define SQLITE_NOMEM 7 /* A malloc() failed */ 390226031Sstas#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 391226031Sstas#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 392226031Sstas#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 393226031Sstas#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 394226128Sstas#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 395226031Sstas#define SQLITE_FULL 13 /* Insertion failed because database is full */ 396226031Sstas#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 397226128Sstas#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 398226031Sstas#define SQLITE_EMPTY 16 /* Database is empty */ 399226031Sstas#define SQLITE_SCHEMA 17 /* The database schema changed */ 400226031Sstas#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 401226031Sstas#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 402226031Sstas#define SQLITE_MISMATCH 20 /* Data type mismatch */ 403226031Sstas#define SQLITE_MISUSE 21 /* Library used incorrectly */ 404226031Sstas#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 405226031Sstas#define SQLITE_AUTH 23 /* Authorization denied */ 406226031Sstas#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 407226031Sstas#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 408226031Sstas#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 409226031Sstas#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 410226031Sstas#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 411226031Sstas/* end-of-error-codes */ 412226031Sstas 413226031Sstas/* 414226031Sstas** CAPI3REF: Extended Result Codes 415226031Sstas** KEYWORDS: {extended error code} {extended error codes} 416226031Sstas** KEYWORDS: {extended result code} {extended result codes} 417226031Sstas** 418226031Sstas** In its default configuration, SQLite API routines return one of 26 integer 419226031Sstas** [SQLITE_OK | result codes]. However, experience has shown that many of 420226031Sstas** these result codes are too coarse-grained. They do not provide as 421226031Sstas** much information about problems as programmers might like. In an effort to 422226031Sstas** address this, newer versions of SQLite (version 3.3.8 and later) include 423226031Sstas** support for additional result codes that provide more detailed information 424226031Sstas** about errors. The extended result codes are enabled or disabled 425226031Sstas** on a per database connection basis using the 426226031Sstas** [sqlite3_extended_result_codes()] API. 427226031Sstas** 428226031Sstas** Some of the available extended result codes are listed here. 429226031Sstas** One may expect the number of extended result codes will be expand 430226031Sstas** over time. Software that uses extended result codes should expect 431226031Sstas** to see new result codes in future releases of SQLite. 432226031Sstas** 433226031Sstas** The SQLITE_OK result code will never be extended. It will always 434226031Sstas** be exactly zero. 435226031Sstas*/ 436226031Sstas#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 437226031Sstas#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 438226031Sstas#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 439226031Sstas#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 440226031Sstas#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 441226031Sstas#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 442226031Sstas#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 443226031Sstas#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 444226031Sstas#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 445226031Sstas#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 446226031Sstas#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 447226031Sstas#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 448226031Sstas#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 449226031Sstas#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 450226031Sstas#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 451226031Sstas#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 452226031Sstas#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 453226128Sstas#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 454226128Sstas#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 455226128Sstas#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 456226128Sstas#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 457226128Sstas#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 458226128Sstas#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 459226128Sstas#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 460226128Sstas#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 461226128Sstas#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 462226128Sstas#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 463226128Sstas#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 464226031Sstas 465226031Sstas/* 466226031Sstas** CAPI3REF: Flags For File Open Operations 467226031Sstas** 468226031Sstas** These bit values are intended for use in the 469226031Sstas** 3rd parameter to the [sqlite3_open_v2()] interface and 470226128Sstas** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 471226031Sstas*/ 472226031Sstas#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 473226031Sstas#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 474226031Sstas#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 475226031Sstas#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 476226031Sstas#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 477226031Sstas#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 478226128Sstas#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 479226031Sstas#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 480226031Sstas#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 481226031Sstas#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 482226031Sstas#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 483226031Sstas#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 484226031Sstas#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 485226031Sstas#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 486226031Sstas#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 487226031Sstas#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 488226031Sstas#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 489226031Sstas#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 490226128Sstas#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 491226031Sstas 492226128Sstas/* Reserved: 0x00F00000 */ 493226128Sstas 494226031Sstas/* 495226031Sstas** CAPI3REF: Device Characteristics 496226031Sstas** 497226128Sstas** The xDeviceCharacteristics method of the [sqlite3_io_methods] 498226031Sstas** object returns an integer which is a vector of the these 499226031Sstas** bit values expressing I/O characteristics of the mass storage 500226031Sstas** device that holds the file that the [sqlite3_io_methods] 501226031Sstas** refers to. 502226031Sstas** 503226031Sstas** The SQLITE_IOCAP_ATOMIC property means that all writes of 504226031Sstas** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 505226031Sstas** mean that writes of blocks that are nnn bytes in size and 506226031Sstas** are aligned to an address which is an integer multiple of 507226031Sstas** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 508226031Sstas** that when data is appended to a file, the data is appended 509226031Sstas** first then the size of the file is extended, never the other 510226031Sstas** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 511226031Sstas** information is written to disk in the same order as calls 512226031Sstas** to xWrite(). 513226031Sstas*/ 514226128Sstas#define SQLITE_IOCAP_ATOMIC 0x00000001 515226128Sstas#define SQLITE_IOCAP_ATOMIC512 0x00000002 516226128Sstas#define SQLITE_IOCAP_ATOMIC1K 0x00000004 517226128Sstas#define SQLITE_IOCAP_ATOMIC2K 0x00000008 518226128Sstas#define SQLITE_IOCAP_ATOMIC4K 0x00000010 519226128Sstas#define SQLITE_IOCAP_ATOMIC8K 0x00000020 520226128Sstas#define SQLITE_IOCAP_ATOMIC16K 0x00000040 521226128Sstas#define SQLITE_IOCAP_ATOMIC32K 0x00000080 522226128Sstas#define SQLITE_IOCAP_ATOMIC64K 0x00000100 523226128Sstas#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 524226128Sstas#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 525226128Sstas#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 526226031Sstas 527226031Sstas/* 528226031Sstas** CAPI3REF: File Locking Levels 529226031Sstas** 530226031Sstas** SQLite uses one of these integer values as the second 531226031Sstas** argument to calls it makes to the xLock() and xUnlock() methods 532226031Sstas** of an [sqlite3_io_methods] object. 533226031Sstas*/ 534226031Sstas#define SQLITE_LOCK_NONE 0 535226031Sstas#define SQLITE_LOCK_SHARED 1 536226031Sstas#define SQLITE_LOCK_RESERVED 2 537226031Sstas#define SQLITE_LOCK_PENDING 3 538226031Sstas#define SQLITE_LOCK_EXCLUSIVE 4 539226031Sstas 540226031Sstas/* 541226031Sstas** CAPI3REF: Synchronization Type Flags 542226031Sstas** 543226031Sstas** When SQLite invokes the xSync() method of an 544226031Sstas** [sqlite3_io_methods] object it uses a combination of 545226031Sstas** these integer values as the second argument. 546226031Sstas** 547226031Sstas** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 548226031Sstas** sync operation only needs to flush data to mass storage. Inode 549226031Sstas** information need not be flushed. If the lower four bits of the flag 550226031Sstas** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 551226031Sstas** If the lower four bits equal SQLITE_SYNC_FULL, that means 552226031Sstas** to use Mac OS X style fullsync instead of fsync(). 553226128Sstas** 554226128Sstas** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 555226128Sstas** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 556226128Sstas** settings. The [synchronous pragma] determines when calls to the 557226128Sstas** xSync VFS method occur and applies uniformly across all platforms. 558226128Sstas** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 559226128Sstas** energetic or rigorous or forceful the sync operations are and 560226128Sstas** only make a difference on Mac OSX for the default SQLite code. 561226128Sstas** (Third-party VFS implementations might also make the distinction 562226128Sstas** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 563226128Sstas** operating systems natively supported by SQLite, only Mac OSX 564226128Sstas** cares about the difference.) 565226031Sstas*/ 566226031Sstas#define SQLITE_SYNC_NORMAL 0x00002 567226031Sstas#define SQLITE_SYNC_FULL 0x00003 568226031Sstas#define SQLITE_SYNC_DATAONLY 0x00010 569226031Sstas 570226031Sstas/* 571226031Sstas** CAPI3REF: OS Interface Open File Handle 572226031Sstas** 573226128Sstas** An [sqlite3_file] object represents an open file in the 574226031Sstas** [sqlite3_vfs | OS interface layer]. Individual OS interface 575226031Sstas** implementations will 576226031Sstas** want to subclass this object by appending additional fields 577226031Sstas** for their own use. The pMethods entry is a pointer to an 578226031Sstas** [sqlite3_io_methods] object that defines methods for performing 579226031Sstas** I/O operations on the open file. 580226031Sstas*/ 581226031Sstastypedef struct sqlite3_file sqlite3_file; 582226031Sstasstruct sqlite3_file { 583226031Sstas const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 584226031Sstas}; 585226031Sstas 586226031Sstas/* 587226031Sstas** CAPI3REF: OS Interface File Virtual Methods Object 588226031Sstas** 589226128Sstas** Every file opened by the [sqlite3_vfs.xOpen] method populates an 590226031Sstas** [sqlite3_file] object (or, more commonly, a subclass of the 591226031Sstas** [sqlite3_file] object) with a pointer to an instance of this object. 592226031Sstas** This object defines the methods used to perform various operations 593226031Sstas** against the open file represented by the [sqlite3_file] object. 594226031Sstas** 595226128Sstas** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 596226031Sstas** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 597226128Sstas** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 598226128Sstas** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 599226128Sstas** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 600226128Sstas** to NULL. 601226031Sstas** 602226031Sstas** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 603226031Sstas** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 604226031Sstas** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 605226031Sstas** flag may be ORed in to indicate that only the data of the file 606226031Sstas** and not its inode needs to be synced. 607226031Sstas** 608226031Sstas** The integer values to xLock() and xUnlock() are one of 609226031Sstas** <ul> 610226031Sstas** <li> [SQLITE_LOCK_NONE], 611226031Sstas** <li> [SQLITE_LOCK_SHARED], 612226031Sstas** <li> [SQLITE_LOCK_RESERVED], 613226031Sstas** <li> [SQLITE_LOCK_PENDING], or 614226031Sstas** <li> [SQLITE_LOCK_EXCLUSIVE]. 615226031Sstas** </ul> 616226031Sstas** xLock() increases the lock. xUnlock() decreases the lock. 617226031Sstas** The xCheckReservedLock() method checks whether any database connection, 618226031Sstas** either in this process or in some other process, is holding a RESERVED, 619226031Sstas** PENDING, or EXCLUSIVE lock on the file. It returns true 620226031Sstas** if such a lock exists and false otherwise. 621226031Sstas** 622226031Sstas** The xFileControl() method is a generic interface that allows custom 623226031Sstas** VFS implementations to directly control an open file using the 624226031Sstas** [sqlite3_file_control()] interface. The second "op" argument is an 625226031Sstas** integer opcode. The third argument is a generic pointer intended to 626226031Sstas** point to a structure that may contain arguments or space in which to 627226031Sstas** write return values. Potential uses for xFileControl() might be 628226031Sstas** functions to enable blocking locks with timeouts, to change the 629226031Sstas** locking strategy (for example to use dot-file locks), to inquire 630226031Sstas** about the status of a lock, or to break stale locks. The SQLite 631226031Sstas** core reserves all opcodes less than 100 for its own use. 632226031Sstas** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 633226031Sstas** Applications that define a custom xFileControl method should use opcodes 634226128Sstas** greater than 100 to avoid conflicts. VFS implementations should 635226128Sstas** return [SQLITE_NOTFOUND] for file control opcodes that they do not 636226128Sstas** recognize. 637226031Sstas** 638226031Sstas** The xSectorSize() method returns the sector size of the 639226031Sstas** device that underlies the file. The sector size is the 640226031Sstas** minimum write that can be performed without disturbing 641226031Sstas** other bytes in the file. The xDeviceCharacteristics() 642226031Sstas** method returns a bit vector describing behaviors of the 643226031Sstas** underlying device: 644226031Sstas** 645226031Sstas** <ul> 646226031Sstas** <li> [SQLITE_IOCAP_ATOMIC] 647226031Sstas** <li> [SQLITE_IOCAP_ATOMIC512] 648226031Sstas** <li> [SQLITE_IOCAP_ATOMIC1K] 649226031Sstas** <li> [SQLITE_IOCAP_ATOMIC2K] 650226031Sstas** <li> [SQLITE_IOCAP_ATOMIC4K] 651226031Sstas** <li> [SQLITE_IOCAP_ATOMIC8K] 652226031Sstas** <li> [SQLITE_IOCAP_ATOMIC16K] 653226031Sstas** <li> [SQLITE_IOCAP_ATOMIC32K] 654226031Sstas** <li> [SQLITE_IOCAP_ATOMIC64K] 655226031Sstas** <li> [SQLITE_IOCAP_SAFE_APPEND] 656226031Sstas** <li> [SQLITE_IOCAP_SEQUENTIAL] 657226031Sstas** </ul> 658226031Sstas** 659226031Sstas** The SQLITE_IOCAP_ATOMIC property means that all writes of 660226031Sstas** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 661226031Sstas** mean that writes of blocks that are nnn bytes in size and 662226031Sstas** are aligned to an address which is an integer multiple of 663226031Sstas** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 664226031Sstas** that when data is appended to a file, the data is appended 665226031Sstas** first then the size of the file is extended, never the other 666226031Sstas** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 667226031Sstas** information is written to disk in the same order as calls 668226031Sstas** to xWrite(). 669226031Sstas** 670226031Sstas** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 671226031Sstas** in the unread portions of the buffer with zeros. A VFS that 672226031Sstas** fails to zero-fill short reads might seem to work. However, 673226031Sstas** failure to zero-fill short reads will eventually lead to 674226031Sstas** database corruption. 675226031Sstas*/ 676226031Sstastypedef struct sqlite3_io_methods sqlite3_io_methods; 677226031Sstasstruct sqlite3_io_methods { 678226031Sstas int iVersion; 679226031Sstas int (*xClose)(sqlite3_file*); 680226031Sstas int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 681226031Sstas int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 682226031Sstas int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 683226031Sstas int (*xSync)(sqlite3_file*, int flags); 684226031Sstas int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 685226031Sstas int (*xLock)(sqlite3_file*, int); 686226031Sstas int (*xUnlock)(sqlite3_file*, int); 687226031Sstas int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 688226031Sstas int (*xFileControl)(sqlite3_file*, int op, void *pArg); 689226031Sstas int (*xSectorSize)(sqlite3_file*); 690226031Sstas int (*xDeviceCharacteristics)(sqlite3_file*); 691226128Sstas /* Methods above are valid for version 1 */ 692226128Sstas int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 693226128Sstas int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 694226128Sstas void (*xShmBarrier)(sqlite3_file*); 695226128Sstas int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 696226128Sstas /* Methods above are valid for version 2 */ 697226031Sstas /* Additional methods may be added in future releases */ 698226031Sstas}; 699226031Sstas 700226031Sstas/* 701226031Sstas** CAPI3REF: Standard File Control Opcodes 702226031Sstas** 703226031Sstas** These integer constants are opcodes for the xFileControl method 704226031Sstas** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 705226031Sstas** interface. 706226031Sstas** 707226031Sstas** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 708226031Sstas** opcode causes the xFileControl method to write the current state of 709226031Sstas** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 710226031Sstas** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 711226031Sstas** into an integer that the pArg argument points to. This capability 712226031Sstas** is used during testing and only needs to be supported when SQLITE_TEST 713226031Sstas** is defined. 714226128Sstas** 715226128Sstas** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 716226128Sstas** layer a hint of how large the database file will grow to be during the 717226128Sstas** current transaction. This hint is not guaranteed to be accurate but it 718226128Sstas** is often close. The underlying VFS might choose to preallocate database 719226128Sstas** file space based on this hint in order to help writes to the database 720226128Sstas** file run faster. 721226128Sstas** 722226128Sstas** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 723226128Sstas** extends and truncates the database file in chunks of a size specified 724226128Sstas** by the user. The fourth argument to [sqlite3_file_control()] should 725226128Sstas** point to an integer (type int) containing the new chunk-size to use 726226128Sstas** for the nominated database. Allocating database file space in large 727226128Sstas** chunks (say 1MB at a time), may reduce file-system fragmentation and 728226128Sstas** improve performance on some systems. 729226128Sstas** 730226128Sstas** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 731226128Sstas** to the [sqlite3_file] object associated with a particular database 732226128Sstas** connection. See the [sqlite3_file_control()] documentation for 733226128Sstas** additional information. 734226128Sstas** 735226128Sstas** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 736226128Sstas** SQLite and sent to all VFSes in place of a call to the xSync method 737226128Sstas** when the database connection has [PRAGMA synchronous] set to OFF.)^ 738226128Sstas** Some specialized VFSes need this signal in order to operate correctly 739226128Sstas** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 740226128Sstas** VFSes do not need this signal and should silently ignore this opcode. 741226128Sstas** Applications should not call [sqlite3_file_control()] with this 742226128Sstas** opcode as doing so may disrupt the operation of the specialized VFSes 743226128Sstas** that do require it. 744226128Sstas** 745226128Sstas** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 746226128Sstas** retry counts and intervals for certain disk I/O operations for the 747226128Sstas** windows [VFS] in order to work to provide robustness against 748226128Sstas** anti-virus programs. By default, the windows VFS will retry file read, 749226128Sstas** file write, and file delete opertions up to 10 times, with a delay 750226128Sstas** of 25 milliseconds before the first retry and with the delay increasing 751226128Sstas** by an additional 25 milliseconds with each subsequent retry. This 752226128Sstas** opcode allows those to values (10 retries and 25 milliseconds of delay) 753226128Sstas** to be adjusted. The values are changed for all database connections 754226128Sstas** within the same process. The argument is a pointer to an array of two 755226128Sstas** integers where the first integer i the new retry count and the second 756226128Sstas** integer is the delay. If either integer is negative, then the setting 757226128Sstas** is not changed but instead the prior value of that setting is written 758226128Sstas** into the array entry, allowing the current retry settings to be 759226128Sstas** interrogated. The zDbName parameter is ignored. 760226128Sstas** 761226128Sstas** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 762226128Sstas** persistent [WAL | Write AHead Log] setting. By default, the auxiliary 763226128Sstas** write ahead log and shared memory files used for transaction control 764226128Sstas** are automatically deleted when the latest connection to the database 765226128Sstas** closes. Setting persistent WAL mode causes those files to persist after 766226128Sstas** close. Persisting the files is useful when other processes that do not 767226128Sstas** have write permission on the directory containing the database file want 768226128Sstas** to read the database file, as the WAL and shared memory files must exist 769226128Sstas** in order for the database to be readable. The fourth parameter to 770226128Sstas** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 771226128Sstas** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 772226128Sstas** WAL mode. If the integer is -1, then it is overwritten with the current 773226128Sstas** WAL persistence setting. 774226128Sstas** 775226031Sstas*/ 776226031Sstas#define SQLITE_FCNTL_LOCKSTATE 1 777226031Sstas#define SQLITE_GET_LOCKPROXYFILE 2 778226031Sstas#define SQLITE_SET_LOCKPROXYFILE 3 779226031Sstas#define SQLITE_LAST_ERRNO 4 780226128Sstas#define SQLITE_FCNTL_SIZE_HINT 5 781226128Sstas#define SQLITE_FCNTL_CHUNK_SIZE 6 782226128Sstas#define SQLITE_FCNTL_FILE_POINTER 7 783226128Sstas#define SQLITE_FCNTL_SYNC_OMITTED 8 784226128Sstas#define SQLITE_FCNTL_WIN32_AV_RETRY 9 785226128Sstas#define SQLITE_FCNTL_PERSIST_WAL 10 786226031Sstas 787226031Sstas/* 788226031Sstas** CAPI3REF: Mutex Handle 789226031Sstas** 790226031Sstas** The mutex module within SQLite defines [sqlite3_mutex] to be an 791226031Sstas** abstract type for a mutex object. The SQLite core never looks 792226031Sstas** at the internal representation of an [sqlite3_mutex]. It only 793226031Sstas** deals with pointers to the [sqlite3_mutex] object. 794226031Sstas** 795226031Sstas** Mutexes are created using [sqlite3_mutex_alloc()]. 796226031Sstas*/ 797226031Sstastypedef struct sqlite3_mutex sqlite3_mutex; 798226031Sstas 799226031Sstas/* 800226031Sstas** CAPI3REF: OS Interface Object 801226031Sstas** 802226031Sstas** An instance of the sqlite3_vfs object defines the interface between 803226031Sstas** the SQLite core and the underlying operating system. The "vfs" 804226128Sstas** in the name of the object stands for "virtual file system". See 805226128Sstas** the [VFS | VFS documentation] for further information. 806226031Sstas** 807226031Sstas** The value of the iVersion field is initially 1 but may be larger in 808226031Sstas** future versions of SQLite. Additional fields may be appended to this 809226031Sstas** object when the iVersion value is increased. Note that the structure 810226031Sstas** of the sqlite3_vfs object changes in the transaction between 811226031Sstas** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 812226031Sstas** modified. 813226031Sstas** 814226031Sstas** The szOsFile field is the size of the subclassed [sqlite3_file] 815226031Sstas** structure used by this VFS. mxPathname is the maximum length of 816226031Sstas** a pathname in this VFS. 817226031Sstas** 818226031Sstas** Registered sqlite3_vfs objects are kept on a linked list formed by 819226031Sstas** the pNext pointer. The [sqlite3_vfs_register()] 820226031Sstas** and [sqlite3_vfs_unregister()] interfaces manage this list 821226031Sstas** in a thread-safe way. The [sqlite3_vfs_find()] interface 822226031Sstas** searches the list. Neither the application code nor the VFS 823226031Sstas** implementation should use the pNext pointer. 824226031Sstas** 825226031Sstas** The pNext field is the only field in the sqlite3_vfs 826226031Sstas** structure that SQLite will ever modify. SQLite will only access 827226031Sstas** or modify this field while holding a particular static mutex. 828226031Sstas** The application should never modify anything within the sqlite3_vfs 829226031Sstas** object once the object has been registered. 830226031Sstas** 831226031Sstas** The zName field holds the name of the VFS module. The name must 832226031Sstas** be unique across all VFS modules. 833226031Sstas** 834226128Sstas** [[sqlite3_vfs.xOpen]] 835226128Sstas** ^SQLite guarantees that the zFilename parameter to xOpen 836226031Sstas** is either a NULL pointer or string obtained 837226128Sstas** from xFullPathname() with an optional suffix added. 838226128Sstas** ^If a suffix is added to the zFilename parameter, it will 839226128Sstas** consist of a single "-" character followed by no more than 840226128Sstas** 10 alphanumeric and/or "-" characters. 841226128Sstas** ^SQLite further guarantees that 842226031Sstas** the string will be valid and unchanged until xClose() is 843226031Sstas** called. Because of the previous sentence, 844226031Sstas** the [sqlite3_file] can safely store a pointer to the 845226031Sstas** filename if it needs to remember the filename for some reason. 846226128Sstas** If the zFilename parameter to xOpen is a NULL pointer then xOpen 847226128Sstas** must invent its own temporary name for the file. ^Whenever the 848226031Sstas** xFilename parameter is NULL it will also be the case that the 849226031Sstas** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 850226031Sstas** 851226031Sstas** The flags argument to xOpen() includes all bits set in 852226031Sstas** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 853226031Sstas** or [sqlite3_open16()] is used, then flags includes at least 854226128Sstas** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 855226031Sstas** If xOpen() opens a file read-only then it sets *pOutFlags to 856226031Sstas** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 857226031Sstas** 858226128Sstas** ^(SQLite will also add one of the following flags to the xOpen() 859226031Sstas** call, depending on the object being opened: 860226031Sstas** 861226031Sstas** <ul> 862226031Sstas** <li> [SQLITE_OPEN_MAIN_DB] 863226031Sstas** <li> [SQLITE_OPEN_MAIN_JOURNAL] 864226031Sstas** <li> [SQLITE_OPEN_TEMP_DB] 865226031Sstas** <li> [SQLITE_OPEN_TEMP_JOURNAL] 866226031Sstas** <li> [SQLITE_OPEN_TRANSIENT_DB] 867226031Sstas** <li> [SQLITE_OPEN_SUBJOURNAL] 868226031Sstas** <li> [SQLITE_OPEN_MASTER_JOURNAL] 869226128Sstas** <li> [SQLITE_OPEN_WAL] 870226128Sstas** </ul>)^ 871226031Sstas** 872226031Sstas** The file I/O implementation can use the object type flags to 873226031Sstas** change the way it deals with files. For example, an application 874226031Sstas** that does not care about crash recovery or rollback might make 875226031Sstas** the open of a journal file a no-op. Writes to this journal would 876226031Sstas** also be no-ops, and any attempt to read the journal would return 877226031Sstas** SQLITE_IOERR. Or the implementation might recognize that a database 878226031Sstas** file will be doing page-aligned sector reads and writes in a random 879226031Sstas** order and set up its I/O subsystem accordingly. 880226031Sstas** 881226031Sstas** SQLite might also add one of the following flags to the xOpen method: 882226031Sstas** 883226031Sstas** <ul> 884226031Sstas** <li> [SQLITE_OPEN_DELETEONCLOSE] 885226031Sstas** <li> [SQLITE_OPEN_EXCLUSIVE] 886226031Sstas** </ul> 887226031Sstas** 888226031Sstas** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 889226128Sstas** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 890226128Sstas** will be set for TEMP databases and their journals, transient 891226128Sstas** databases, and subjournals. 892226031Sstas** 893226128Sstas** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 894226031Sstas** with the [SQLITE_OPEN_CREATE] flag, which are both directly 895226031Sstas** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 896226128Sstas** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 897226031Sstas** SQLITE_OPEN_CREATE, is used to indicate that file should always 898226031Sstas** be created, and that it is an error if it already exists. 899226128Sstas** It is <i>not</i> used to indicate the file should be opened 900226031Sstas** for exclusive access. 901226031Sstas** 902226128Sstas** ^At least szOsFile bytes of memory are allocated by SQLite 903226031Sstas** to hold the [sqlite3_file] structure passed as the third 904226031Sstas** argument to xOpen. The xOpen method does not have to 905226031Sstas** allocate the structure; it should just fill it in. Note that 906226031Sstas** the xOpen method must set the sqlite3_file.pMethods to either 907226031Sstas** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 908226031Sstas** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 909226031Sstas** element will be valid after xOpen returns regardless of the success 910226031Sstas** or failure of the xOpen call. 911226031Sstas** 912226128Sstas** [[sqlite3_vfs.xAccess]] 913226128Sstas** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 914226031Sstas** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 915226031Sstas** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 916226031Sstas** to test whether a file is at least readable. The file can be a 917226031Sstas** directory. 918226031Sstas** 919226128Sstas** ^SQLite will always allocate at least mxPathname+1 bytes for the 920226031Sstas** output buffer xFullPathname. The exact size of the output buffer 921226031Sstas** is also passed as a parameter to both methods. If the output buffer 922226031Sstas** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 923226031Sstas** handled as a fatal error by SQLite, vfs implementations should endeavor 924226031Sstas** to prevent this by setting mxPathname to a sufficiently large value. 925226031Sstas** 926226128Sstas** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 927226128Sstas** interfaces are not strictly a part of the filesystem, but they are 928226031Sstas** included in the VFS structure for completeness. 929226031Sstas** The xRandomness() function attempts to return nBytes bytes 930226031Sstas** of good-quality randomness into zOut. The return value is 931226031Sstas** the actual number of bytes of randomness obtained. 932226031Sstas** The xSleep() method causes the calling thread to sleep for at 933226128Sstas** least the number of microseconds given. ^The xCurrentTime() 934226128Sstas** method returns a Julian Day Number for the current date and time as 935226128Sstas** a floating point value. 936226128Sstas** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 937226128Sstas** Day Number multiplied by 86400000 (the number of milliseconds in 938226128Sstas** a 24-hour day). 939226128Sstas** ^SQLite will use the xCurrentTimeInt64() method to get the current 940226128Sstas** date and time if that method is available (if iVersion is 2 or 941226128Sstas** greater and the function pointer is not NULL) and will fall back 942226128Sstas** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 943226031Sstas** 944226128Sstas** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 945226128Sstas** are not used by the SQLite core. These optional interfaces are provided 946226128Sstas** by some VFSes to facilitate testing of the VFS code. By overriding 947226128Sstas** system calls with functions under its control, a test program can 948226128Sstas** simulate faults and error conditions that would otherwise be difficult 949226128Sstas** or impossible to induce. The set of system calls that can be overridden 950226128Sstas** varies from one VFS to another, and from one version of the same VFS to the 951226128Sstas** next. Applications that use these interfaces must be prepared for any 952226128Sstas** or all of these interfaces to be NULL or for their behavior to change 953226128Sstas** from one release to the next. Applications must not attempt to access 954226128Sstas** any of these methods if the iVersion of the VFS is less than 3. 955226031Sstas*/ 956226031Sstastypedef struct sqlite3_vfs sqlite3_vfs; 957226128Sstastypedef void (*sqlite3_syscall_ptr)(void); 958226031Sstasstruct sqlite3_vfs { 959226128Sstas int iVersion; /* Structure version number (currently 3) */ 960226031Sstas int szOsFile; /* Size of subclassed sqlite3_file */ 961226031Sstas int mxPathname; /* Maximum file pathname length */ 962226031Sstas sqlite3_vfs *pNext; /* Next registered VFS */ 963226031Sstas const char *zName; /* Name of this virtual file system */ 964226031Sstas void *pAppData; /* Pointer to application-specific data */ 965226031Sstas int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 966226031Sstas int flags, int *pOutFlags); 967226031Sstas int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 968226031Sstas int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 969226031Sstas int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 970226031Sstas void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 971226031Sstas void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 972226031Sstas void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 973226031Sstas void (*xDlClose)(sqlite3_vfs*, void*); 974226031Sstas int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 975226031Sstas int (*xSleep)(sqlite3_vfs*, int microseconds); 976226031Sstas int (*xCurrentTime)(sqlite3_vfs*, double*); 977226031Sstas int (*xGetLastError)(sqlite3_vfs*, int, char *); 978226128Sstas /* 979226128Sstas ** The methods above are in version 1 of the sqlite_vfs object 980226128Sstas ** definition. Those that follow are added in version 2 or later 981226128Sstas */ 982226128Sstas int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 983226128Sstas /* 984226128Sstas ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 985226128Sstas ** Those below are for version 3 and greater. 986226128Sstas */ 987226128Sstas int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 988226128Sstas sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 989226128Sstas const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 990226128Sstas /* 991226128Sstas ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 992226128Sstas ** New fields may be appended in figure versions. The iVersion 993226128Sstas ** value will increment whenever this happens. 994226128Sstas */ 995226031Sstas}; 996226031Sstas 997226031Sstas/* 998226031Sstas** CAPI3REF: Flags for the xAccess VFS method 999226031Sstas** 1000226031Sstas** These integer constants can be used as the third parameter to 1001226031Sstas** the xAccess method of an [sqlite3_vfs] object. They determine 1002226031Sstas** what kind of permissions the xAccess method is looking for. 1003226031Sstas** With SQLITE_ACCESS_EXISTS, the xAccess method 1004226031Sstas** simply checks whether the file exists. 1005226031Sstas** With SQLITE_ACCESS_READWRITE, the xAccess method 1006226128Sstas** checks whether the named directory is both readable and writable 1007226128Sstas** (in other words, if files can be added, removed, and renamed within 1008226128Sstas** the directory). 1009226128Sstas** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1010226128Sstas** [temp_store_directory pragma], though this could change in a future 1011226128Sstas** release of SQLite. 1012226031Sstas** With SQLITE_ACCESS_READ, the xAccess method 1013226128Sstas** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1014226128Sstas** currently unused, though it might be used in a future release of 1015226128Sstas** SQLite. 1016226031Sstas*/ 1017226031Sstas#define SQLITE_ACCESS_EXISTS 0 1018226128Sstas#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1019226128Sstas#define SQLITE_ACCESS_READ 2 /* Unused */ 1020226031Sstas 1021226031Sstas/* 1022226128Sstas** CAPI3REF: Flags for the xShmLock VFS method 1023226128Sstas** 1024226128Sstas** These integer constants define the various locking operations 1025226128Sstas** allowed by the xShmLock method of [sqlite3_io_methods]. The 1026226128Sstas** following are the only legal combinations of flags to the 1027226128Sstas** xShmLock method: 1028226128Sstas** 1029226128Sstas** <ul> 1030226128Sstas** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1031226128Sstas** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1032226128Sstas** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1033226128Sstas** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1034226128Sstas** </ul> 1035226128Sstas** 1036226128Sstas** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1037226128Sstas** was given no the corresponding lock. 1038226128Sstas** 1039226128Sstas** The xShmLock method can transition between unlocked and SHARED or 1040226128Sstas** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1041226128Sstas** and EXCLUSIVE. 1042226128Sstas*/ 1043226128Sstas#define SQLITE_SHM_UNLOCK 1 1044226128Sstas#define SQLITE_SHM_LOCK 2 1045226128Sstas#define SQLITE_SHM_SHARED 4 1046226128Sstas#define SQLITE_SHM_EXCLUSIVE 8 1047226128Sstas 1048226128Sstas/* 1049226128Sstas** CAPI3REF: Maximum xShmLock index 1050226128Sstas** 1051226128Sstas** The xShmLock method on [sqlite3_io_methods] may use values 1052226128Sstas** between 0 and this upper bound as its "offset" argument. 1053226128Sstas** The SQLite core will never attempt to acquire or release a 1054226128Sstas** lock outside of this range 1055226128Sstas*/ 1056226128Sstas#define SQLITE_SHM_NLOCK 8 1057226128Sstas 1058226128Sstas 1059226128Sstas/* 1060226031Sstas** CAPI3REF: Initialize The SQLite Library 1061226031Sstas** 1062226031Sstas** ^The sqlite3_initialize() routine initializes the 1063226031Sstas** SQLite library. ^The sqlite3_shutdown() routine 1064226031Sstas** deallocates any resources that were allocated by sqlite3_initialize(). 1065226031Sstas** These routines are designed to aid in process initialization and 1066226031Sstas** shutdown on embedded systems. Workstation applications using 1067226031Sstas** SQLite normally do not need to invoke either of these routines. 1068226031Sstas** 1069226031Sstas** A call to sqlite3_initialize() is an "effective" call if it is 1070226031Sstas** the first time sqlite3_initialize() is invoked during the lifetime of 1071226031Sstas** the process, or if it is the first time sqlite3_initialize() is invoked 1072226031Sstas** following a call to sqlite3_shutdown(). ^(Only an effective call 1073226031Sstas** of sqlite3_initialize() does any initialization. All other calls 1074226031Sstas** are harmless no-ops.)^ 1075226031Sstas** 1076226031Sstas** A call to sqlite3_shutdown() is an "effective" call if it is the first 1077226031Sstas** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1078226031Sstas** an effective call to sqlite3_shutdown() does any deinitialization. 1079226031Sstas** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1080226031Sstas** 1081226031Sstas** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1082226031Sstas** is not. The sqlite3_shutdown() interface must only be called from a 1083226031Sstas** single thread. All open [database connections] must be closed and all 1084226031Sstas** other SQLite resources must be deallocated prior to invoking 1085226031Sstas** sqlite3_shutdown(). 1086226031Sstas** 1087226031Sstas** Among other things, ^sqlite3_initialize() will invoke 1088226031Sstas** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1089226031Sstas** will invoke sqlite3_os_end(). 1090226031Sstas** 1091226031Sstas** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1092226031Sstas** ^If for some reason, sqlite3_initialize() is unable to initialize 1093226031Sstas** the library (perhaps it is unable to allocate a needed resource such 1094226031Sstas** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1095226031Sstas** 1096226031Sstas** ^The sqlite3_initialize() routine is called internally by many other 1097226031Sstas** SQLite interfaces so that an application usually does not need to 1098226031Sstas** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1099226031Sstas** calls sqlite3_initialize() so the SQLite library will be automatically 1100226031Sstas** initialized when [sqlite3_open()] is called if it has not be initialized 1101226031Sstas** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1102226031Sstas** compile-time option, then the automatic calls to sqlite3_initialize() 1103226031Sstas** are omitted and the application must call sqlite3_initialize() directly 1104226031Sstas** prior to using any other SQLite interface. For maximum portability, 1105226031Sstas** it is recommended that applications always invoke sqlite3_initialize() 1106226031Sstas** directly prior to using any other SQLite interface. Future releases 1107226031Sstas** of SQLite may require this. In other words, the behavior exhibited 1108226031Sstas** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1109226031Sstas** default behavior in some future release of SQLite. 1110226031Sstas** 1111226031Sstas** The sqlite3_os_init() routine does operating-system specific 1112226031Sstas** initialization of the SQLite library. The sqlite3_os_end() 1113226031Sstas** routine undoes the effect of sqlite3_os_init(). Typical tasks 1114226031Sstas** performed by these routines include allocation or deallocation 1115226031Sstas** of static resources, initialization of global variables, 1116226031Sstas** setting up a default [sqlite3_vfs] module, or setting up 1117226031Sstas** a default configuration using [sqlite3_config()]. 1118226031Sstas** 1119226031Sstas** The application should never invoke either sqlite3_os_init() 1120226031Sstas** or sqlite3_os_end() directly. The application should only invoke 1121226031Sstas** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1122226031Sstas** interface is called automatically by sqlite3_initialize() and 1123226031Sstas** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1124226031Sstas** implementations for sqlite3_os_init() and sqlite3_os_end() 1125226031Sstas** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1126226031Sstas** When [custom builds | built for other platforms] 1127226031Sstas** (using the [SQLITE_OS_OTHER=1] compile-time 1128226031Sstas** option) the application must supply a suitable implementation for 1129226031Sstas** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1130226031Sstas** implementation of sqlite3_os_init() or sqlite3_os_end() 1131226031Sstas** must return [SQLITE_OK] on success and some other [error code] upon 1132226031Sstas** failure. 1133226031Sstas*/ 1134226031SstasSQLITE_API int sqlite3_initialize(void); 1135226031SstasSQLITE_API int sqlite3_shutdown(void); 1136226031SstasSQLITE_API int sqlite3_os_init(void); 1137226031SstasSQLITE_API int sqlite3_os_end(void); 1138226031Sstas 1139226031Sstas/* 1140226031Sstas** CAPI3REF: Configuring The SQLite Library 1141226031Sstas** 1142226031Sstas** The sqlite3_config() interface is used to make global configuration 1143226031Sstas** changes to SQLite in order to tune SQLite to the specific needs of 1144226031Sstas** the application. The default configuration is recommended for most 1145226031Sstas** applications and so this routine is usually not necessary. It is 1146226031Sstas** provided to support rare applications with unusual needs. 1147226031Sstas** 1148226031Sstas** The sqlite3_config() interface is not threadsafe. The application 1149226031Sstas** must insure that no other SQLite interfaces are invoked by other 1150226031Sstas** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1151226031Sstas** may only be invoked prior to library initialization using 1152226031Sstas** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1153226031Sstas** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1154226031Sstas** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1155226031Sstas** Note, however, that ^sqlite3_config() can be called as part of the 1156226031Sstas** implementation of an application-defined [sqlite3_os_init()]. 1157226031Sstas** 1158226031Sstas** The first argument to sqlite3_config() is an integer 1159226128Sstas** [configuration option] that determines 1160226031Sstas** what property of SQLite is to be configured. Subsequent arguments 1161226128Sstas** vary depending on the [configuration option] 1162226031Sstas** in the first argument. 1163226031Sstas** 1164226031Sstas** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1165226031Sstas** ^If the option is unknown or SQLite is unable to set the option 1166226031Sstas** then this routine returns a non-zero [error code]. 1167226031Sstas*/ 1168226128SstasSQLITE_API int sqlite3_config(int, ...); 1169226031Sstas 1170226031Sstas/* 1171226031Sstas** CAPI3REF: Configure database connections 1172226031Sstas** 1173226031Sstas** The sqlite3_db_config() interface is used to make configuration 1174226031Sstas** changes to a [database connection]. The interface is similar to 1175226031Sstas** [sqlite3_config()] except that the changes apply to a single 1176226128Sstas** [database connection] (specified in the first argument). 1177226031Sstas** 1178226031Sstas** The second argument to sqlite3_db_config(D,V,...) is the 1179226128Sstas** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1180226128Sstas** that indicates what aspect of the [database connection] is being configured. 1181226128Sstas** Subsequent arguments vary depending on the configuration verb. 1182226031Sstas** 1183226031Sstas** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1184226031Sstas** the call is considered successful. 1185226031Sstas*/ 1186226128SstasSQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1187226031Sstas 1188226031Sstas/* 1189226031Sstas** CAPI3REF: Memory Allocation Routines 1190226031Sstas** 1191226031Sstas** An instance of this object defines the interface between SQLite 1192226031Sstas** and low-level memory allocation routines. 1193226031Sstas** 1194226031Sstas** This object is used in only one place in the SQLite interface. 1195226031Sstas** A pointer to an instance of this object is the argument to 1196226031Sstas** [sqlite3_config()] when the configuration option is 1197226128Sstas** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1198226031Sstas** By creating an instance of this object 1199226031Sstas** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1200226031Sstas** during configuration, an application can specify an alternative 1201226031Sstas** memory allocation subsystem for SQLite to use for all of its 1202226031Sstas** dynamic memory needs. 1203226031Sstas** 1204226031Sstas** Note that SQLite comes with several [built-in memory allocators] 1205226031Sstas** that are perfectly adequate for the overwhelming majority of applications 1206226031Sstas** and that this object is only useful to a tiny minority of applications 1207226031Sstas** with specialized memory allocation requirements. This object is 1208226031Sstas** also used during testing of SQLite in order to specify an alternative 1209226031Sstas** memory allocator that simulates memory out-of-memory conditions in 1210226031Sstas** order to verify that SQLite recovers gracefully from such 1211226031Sstas** conditions. 1212226031Sstas** 1213226128Sstas** The xMalloc, xRealloc, and xFree methods must work like the 1214226128Sstas** malloc(), realloc() and free() functions from the standard C library. 1215226128Sstas** ^SQLite guarantees that the second argument to 1216226031Sstas** xRealloc is always a value returned by a prior call to xRoundup. 1217226031Sstas** 1218226031Sstas** xSize should return the allocated size of a memory allocation 1219226031Sstas** previously obtained from xMalloc or xRealloc. The allocated size 1220226031Sstas** is always at least as big as the requested size but may be larger. 1221226031Sstas** 1222226031Sstas** The xRoundup method returns what would be the allocated size of 1223226031Sstas** a memory allocation given a particular requested size. Most memory 1224226031Sstas** allocators round up memory allocations at least to the next multiple 1225226031Sstas** of 8. Some allocators round up to a larger multiple or to a power of 2. 1226226031Sstas** Every memory allocation request coming in through [sqlite3_malloc()] 1227226128Sstas** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1228226031Sstas** that causes the corresponding memory allocation to fail. 1229226031Sstas** 1230226031Sstas** The xInit method initializes the memory allocator. (For example, 1231226031Sstas** it might allocate any require mutexes or initialize internal data 1232226031Sstas** structures. The xShutdown method is invoked (indirectly) by 1233226031Sstas** [sqlite3_shutdown()] and should deallocate any resources acquired 1234226031Sstas** by xInit. The pAppData pointer is used as the only parameter to 1235226031Sstas** xInit and xShutdown. 1236226031Sstas** 1237226031Sstas** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1238226031Sstas** the xInit method, so the xInit method need not be threadsafe. The 1239226031Sstas** xShutdown method is only called from [sqlite3_shutdown()] so it does 1240226031Sstas** not need to be threadsafe either. For all other methods, SQLite 1241226031Sstas** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1242226031Sstas** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1243226031Sstas** it is by default) and so the methods are automatically serialized. 1244226031Sstas** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1245226031Sstas** methods must be threadsafe or else make their own arrangements for 1246226031Sstas** serialization. 1247226031Sstas** 1248226031Sstas** SQLite will never invoke xInit() more than once without an intervening 1249226031Sstas** call to xShutdown(). 1250226031Sstas*/ 1251226031Sstastypedef struct sqlite3_mem_methods sqlite3_mem_methods; 1252226031Sstasstruct sqlite3_mem_methods { 1253226031Sstas void *(*xMalloc)(int); /* Memory allocation function */ 1254226031Sstas void (*xFree)(void*); /* Free a prior allocation */ 1255226031Sstas void *(*xRealloc)(void*,int); /* Resize an allocation */ 1256226031Sstas int (*xSize)(void*); /* Return the size of an allocation */ 1257226031Sstas int (*xRoundup)(int); /* Round up request size to allocation size */ 1258226031Sstas int (*xInit)(void*); /* Initialize the memory allocator */ 1259226031Sstas void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1260226031Sstas void *pAppData; /* Argument to xInit() and xShutdown() */ 1261226031Sstas}; 1262226031Sstas 1263226031Sstas/* 1264226031Sstas** CAPI3REF: Configuration Options 1265226128Sstas** KEYWORDS: {configuration option} 1266226031Sstas** 1267226031Sstas** These constants are the available integer configuration options that 1268226031Sstas** can be passed as the first argument to the [sqlite3_config()] interface. 1269226031Sstas** 1270226031Sstas** New configuration options may be added in future releases of SQLite. 1271226031Sstas** Existing configuration options might be discontinued. Applications 1272226031Sstas** should check the return code from [sqlite3_config()] to make sure that 1273226031Sstas** the call worked. The [sqlite3_config()] interface will return a 1274226031Sstas** non-zero [error code] if a discontinued or unsupported configuration option 1275226031Sstas** is invoked. 1276226031Sstas** 1277226031Sstas** <dl> 1278226128Sstas** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1279226031Sstas** <dd>There are no arguments to this option. ^This option sets the 1280226031Sstas** [threading mode] to Single-thread. In other words, it disables 1281226031Sstas** all mutexing and puts SQLite into a mode where it can only be used 1282226031Sstas** by a single thread. ^If SQLite is compiled with 1283226031Sstas** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1284226031Sstas** it is not possible to change the [threading mode] from its default 1285226128Sstas** value of Single-thread and so [sqlite3_config()] will return 1286226031Sstas** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1287226031Sstas** configuration option.</dd> 1288226031Sstas** 1289226128Sstas** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1290226031Sstas** <dd>There are no arguments to this option. ^This option sets the 1291226031Sstas** [threading mode] to Multi-thread. In other words, it disables 1292226031Sstas** mutexing on [database connection] and [prepared statement] objects. 1293226031Sstas** The application is responsible for serializing access to 1294226031Sstas** [database connections] and [prepared statements]. But other mutexes 1295226031Sstas** are enabled so that SQLite will be safe to use in a multi-threaded 1296226031Sstas** environment as long as no two threads attempt to use the same 1297226031Sstas** [database connection] at the same time. ^If SQLite is compiled with 1298226031Sstas** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1299226031Sstas** it is not possible to set the Multi-thread [threading mode] and 1300226031Sstas** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1301226031Sstas** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1302226031Sstas** 1303226128Sstas** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1304226031Sstas** <dd>There are no arguments to this option. ^This option sets the 1305226031Sstas** [threading mode] to Serialized. In other words, this option enables 1306226031Sstas** all mutexes including the recursive 1307226031Sstas** mutexes on [database connection] and [prepared statement] objects. 1308226031Sstas** In this mode (which is the default when SQLite is compiled with 1309226031Sstas** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1310226031Sstas** to [database connections] and [prepared statements] so that the 1311226031Sstas** application is free to use the same [database connection] or the 1312226031Sstas** same [prepared statement] in different threads at the same time. 1313226031Sstas** ^If SQLite is compiled with 1314226031Sstas** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1315226031Sstas** it is not possible to set the Serialized [threading mode] and 1316226031Sstas** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1317226031Sstas** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1318226031Sstas** 1319226128Sstas** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1320226031Sstas** <dd> ^(This option takes a single argument which is a pointer to an 1321226031Sstas** instance of the [sqlite3_mem_methods] structure. The argument specifies 1322226031Sstas** alternative low-level memory allocation routines to be used in place of 1323226031Sstas** the memory allocation routines built into SQLite.)^ ^SQLite makes 1324226031Sstas** its own private copy of the content of the [sqlite3_mem_methods] structure 1325226031Sstas** before the [sqlite3_config()] call returns.</dd> 1326226031Sstas** 1327226128Sstas** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1328226031Sstas** <dd> ^(This option takes a single argument which is a pointer to an 1329226031Sstas** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1330226031Sstas** structure is filled with the currently defined memory allocation routines.)^ 1331226031Sstas** This option can be used to overload the default memory allocation 1332226031Sstas** routines with a wrapper that simulations memory allocation failure or 1333226031Sstas** tracks memory usage, for example. </dd> 1334226031Sstas** 1335226128Sstas** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1336226128Sstas** <dd> ^This option takes single argument of type int, interpreted as a 1337226128Sstas** boolean, which enables or disables the collection of memory allocation 1338226128Sstas** statistics. ^(When memory allocation statistics are disabled, the 1339226031Sstas** following SQLite interfaces become non-operational: 1340226031Sstas** <ul> 1341226031Sstas** <li> [sqlite3_memory_used()] 1342226031Sstas** <li> [sqlite3_memory_highwater()] 1343226128Sstas** <li> [sqlite3_soft_heap_limit64()] 1344226031Sstas** <li> [sqlite3_status()] 1345226031Sstas** </ul>)^ 1346226031Sstas** ^Memory allocation statistics are enabled by default unless SQLite is 1347226031Sstas** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1348226031Sstas** allocation statistics are disabled by default. 1349226031Sstas** </dd> 1350226031Sstas** 1351226128Sstas** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1352226031Sstas** <dd> ^This option specifies a static memory buffer that SQLite can use for 1353226031Sstas** scratch memory. There are three arguments: A pointer an 8-byte 1354226128Sstas** aligned memory buffer from which the scratch allocations will be 1355226031Sstas** drawn, the size of each scratch allocation (sz), 1356226031Sstas** and the maximum number of scratch allocations (N). The sz 1357226128Sstas** argument must be a multiple of 16. 1358226031Sstas** The first argument must be a pointer to an 8-byte aligned buffer 1359226031Sstas** of at least sz*N bytes of memory. 1360226128Sstas** ^SQLite will use no more than two scratch buffers per thread. So 1361226128Sstas** N should be set to twice the expected maximum number of threads. 1362226128Sstas** ^SQLite will never require a scratch buffer that is more than 6 1363226128Sstas** times the database page size. ^If SQLite needs needs additional 1364226128Sstas** scratch memory beyond what is provided by this configuration option, then 1365226031Sstas** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1366226031Sstas** 1367226128Sstas** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1368226031Sstas** <dd> ^This option specifies a static memory buffer that SQLite can use for 1369226128Sstas** the database page cache with the default page cache implementation. 1370226031Sstas** This configuration should not be used if an application-define page 1371226031Sstas** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1372226031Sstas** There are three arguments to this option: A pointer to 8-byte aligned 1373226031Sstas** memory, the size of each page buffer (sz), and the number of pages (N). 1374226031Sstas** The sz argument should be the size of the largest database page 1375226031Sstas** (a power of two between 512 and 32768) plus a little extra for each 1376226031Sstas** page header. ^The page header size is 20 to 40 bytes depending on 1377226031Sstas** the host architecture. ^It is harmless, apart from the wasted memory, 1378226031Sstas** to make sz a little too large. The first 1379226031Sstas** argument should point to an allocation of at least sz*N bytes of memory. 1380226031Sstas** ^SQLite will use the memory provided by the first argument to satisfy its 1381226031Sstas** memory needs for the first N pages that it adds to cache. ^If additional 1382226031Sstas** page cache memory is needed beyond what is provided by this option, then 1383226031Sstas** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1384226128Sstas** The pointer in the first argument must 1385226031Sstas** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1386226031Sstas** will be undefined.</dd> 1387226031Sstas** 1388226128Sstas** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1389226031Sstas** <dd> ^This option specifies a static memory buffer that SQLite will use 1390226031Sstas** for all of its dynamic memory allocation needs beyond those provided 1391226031Sstas** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1392226031Sstas** There are three arguments: An 8-byte aligned pointer to the memory, 1393226031Sstas** the number of bytes in the memory buffer, and the minimum allocation size. 1394226031Sstas** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1395226031Sstas** to using its default memory allocator (the system malloc() implementation), 1396226031Sstas** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1397226031Sstas** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1398226031Sstas** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1399226031Sstas** allocator is engaged to handle all of SQLites memory allocation needs. 1400226031Sstas** The first pointer (the memory pointer) must be aligned to an 8-byte 1401226128Sstas** boundary or subsequent behavior of SQLite will be undefined. 1402226128Sstas** The minimum allocation size is capped at 2^12. Reasonable values 1403226128Sstas** for the minimum allocation size are 2^5 through 2^8.</dd> 1404226031Sstas** 1405226128Sstas** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1406226031Sstas** <dd> ^(This option takes a single argument which is a pointer to an 1407226031Sstas** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1408226031Sstas** alternative low-level mutex routines to be used in place 1409226031Sstas** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1410226031Sstas** content of the [sqlite3_mutex_methods] structure before the call to 1411226031Sstas** [sqlite3_config()] returns. ^If SQLite is compiled with 1412226031Sstas** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1413226031Sstas** the entire mutexing subsystem is omitted from the build and hence calls to 1414226031Sstas** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1415226031Sstas** return [SQLITE_ERROR].</dd> 1416226031Sstas** 1417226128Sstas** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1418226031Sstas** <dd> ^(This option takes a single argument which is a pointer to an 1419226031Sstas** instance of the [sqlite3_mutex_methods] structure. The 1420226031Sstas** [sqlite3_mutex_methods] 1421226031Sstas** structure is filled with the currently defined mutex routines.)^ 1422226031Sstas** This option can be used to overload the default mutex allocation 1423226031Sstas** routines with a wrapper used to track mutex usage for performance 1424226031Sstas** profiling or testing, for example. ^If SQLite is compiled with 1425226031Sstas** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1426226031Sstas** the entire mutexing subsystem is omitted from the build and hence calls to 1427226031Sstas** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1428226031Sstas** return [SQLITE_ERROR].</dd> 1429226031Sstas** 1430226128Sstas** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1431226031Sstas** <dd> ^(This option takes two arguments that determine the default 1432226031Sstas** memory allocation for the lookaside memory allocator on each 1433226031Sstas** [database connection]. The first argument is the 1434226031Sstas** size of each lookaside buffer slot and the second is the number of 1435226031Sstas** slots allocated to each database connection.)^ ^(This option sets the 1436226031Sstas** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1437226031Sstas** verb to [sqlite3_db_config()] can be used to change the lookaside 1438226031Sstas** configuration on individual connections.)^ </dd> 1439226031Sstas** 1440226128Sstas** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt> 1441226031Sstas** <dd> ^(This option takes a single argument which is a pointer to 1442226031Sstas** an [sqlite3_pcache_methods] object. This object specifies the interface 1443226031Sstas** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1444226031Sstas** object and uses it for page cache memory allocations.</dd> 1445226031Sstas** 1446226128Sstas** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt> 1447226031Sstas** <dd> ^(This option takes a single argument which is a pointer to an 1448226031Sstas** [sqlite3_pcache_methods] object. SQLite copies of the current 1449226031Sstas** page cache implementation into that object.)^ </dd> 1450226031Sstas** 1451226128Sstas** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1452226128Sstas** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1453226128Sstas** function with a call signature of void(*)(void*,int,const char*), 1454226128Sstas** and a pointer to void. ^If the function pointer is not NULL, it is 1455226128Sstas** invoked by [sqlite3_log()] to process each logging event. ^If the 1456226128Sstas** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1457226128Sstas** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1458226128Sstas** passed through as the first parameter to the application-defined logger 1459226128Sstas** function whenever that function is invoked. ^The second parameter to 1460226128Sstas** the logger function is a copy of the first parameter to the corresponding 1461226128Sstas** [sqlite3_log()] call and is intended to be a [result code] or an 1462226128Sstas** [extended result code]. ^The third parameter passed to the logger is 1463226128Sstas** log message after formatting via [sqlite3_snprintf()]. 1464226128Sstas** The SQLite logging interface is not reentrant; the logger function 1465226128Sstas** supplied by the application must not invoke any SQLite interface. 1466226128Sstas** In a multi-threaded application, the application-defined logger 1467226128Sstas** function must be threadsafe. </dd> 1468226128Sstas** 1469226128Sstas** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1470226128Sstas** <dd> This option takes a single argument of type int. If non-zero, then 1471226128Sstas** URI handling is globally enabled. If the parameter is zero, then URI handling 1472226128Sstas** is globally disabled. If URI handling is globally enabled, all filenames 1473226128Sstas** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1474226128Sstas** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1475226128Sstas** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1476226128Sstas** connection is opened. If it is globally disabled, filenames are 1477226128Sstas** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1478226128Sstas** database connection is opened. By default, URI handling is globally 1479226128Sstas** disabled. The default value may be changed by compiling with the 1480226128Sstas** [SQLITE_USE_URI] symbol defined. 1481226031Sstas** </dl> 1482226031Sstas*/ 1483226031Sstas#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1484226031Sstas#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1485226031Sstas#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1486226031Sstas#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1487226031Sstas#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1488226031Sstas#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1489226031Sstas#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1490226031Sstas#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1491226031Sstas#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1492226031Sstas#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1493226031Sstas#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1494226128Sstas/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1495226031Sstas#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1496226031Sstas#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1497226031Sstas#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1498226031Sstas#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1499226128Sstas#define SQLITE_CONFIG_URI 17 /* int */ 1500226031Sstas 1501226031Sstas/* 1502226128Sstas** CAPI3REF: Database Connection Configuration Options 1503226031Sstas** 1504226031Sstas** These constants are the available integer configuration options that 1505226031Sstas** can be passed as the second argument to the [sqlite3_db_config()] interface. 1506226031Sstas** 1507226031Sstas** New configuration options may be added in future releases of SQLite. 1508226031Sstas** Existing configuration options might be discontinued. Applications 1509226031Sstas** should check the return code from [sqlite3_db_config()] to make sure that 1510226031Sstas** the call worked. ^The [sqlite3_db_config()] interface will return a 1511226031Sstas** non-zero [error code] if a discontinued or unsupported configuration option 1512226031Sstas** is invoked. 1513226031Sstas** 1514226031Sstas** <dl> 1515226031Sstas** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1516226128Sstas** <dd> ^This option takes three additional arguments that determine the 1517226031Sstas** [lookaside memory allocator] configuration for the [database connection]. 1518226031Sstas** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1519226128Sstas** pointer to a memory buffer to use for lookaside memory. 1520226031Sstas** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1521226031Sstas** may be NULL in which case SQLite will allocate the 1522226031Sstas** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1523226031Sstas** size of each lookaside buffer slot. ^The third argument is the number of 1524226031Sstas** slots. The size of the buffer in the first argument must be greater than 1525226031Sstas** or equal to the product of the second and third arguments. The buffer 1526226031Sstas** must be aligned to an 8-byte boundary. ^If the second argument to 1527226031Sstas** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1528226128Sstas** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1529226128Sstas** configuration for a database connection can only be changed when that 1530226128Sstas** connection is not currently using lookaside memory, or in other words 1531226128Sstas** when the "current value" returned by 1532226128Sstas** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1533226128Sstas** Any attempt to change the lookaside memory configuration when lookaside 1534226128Sstas** memory is in use leaves the configuration unchanged and returns 1535226128Sstas** [SQLITE_BUSY].)^</dd> 1536226031Sstas** 1537226128Sstas** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1538226128Sstas** <dd> ^This option is used to enable or disable the enforcement of 1539226128Sstas** [foreign key constraints]. There should be two additional arguments. 1540226128Sstas** The first argument is an integer which is 0 to disable FK enforcement, 1541226128Sstas** positive to enable FK enforcement or negative to leave FK enforcement 1542226128Sstas** unchanged. The second parameter is a pointer to an integer into which 1543226128Sstas** is written 0 or 1 to indicate whether FK enforcement is off or on 1544226128Sstas** following this call. The second parameter may be a NULL pointer, in 1545226128Sstas** which case the FK enforcement setting is not reported back. </dd> 1546226128Sstas** 1547226128Sstas** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1548226128Sstas** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1549226128Sstas** There should be two additional arguments. 1550226128Sstas** The first argument is an integer which is 0 to disable triggers, 1551226128Sstas** positive to enable triggers or negative to leave the setting unchanged. 1552226128Sstas** The second parameter is a pointer to an integer into which 1553226128Sstas** is written 0 or 1 to indicate whether triggers are disabled or enabled 1554226128Sstas** following this call. The second parameter may be a NULL pointer, in 1555226128Sstas** which case the trigger setting is not reported back. </dd> 1556226128Sstas** 1557226031Sstas** </dl> 1558226031Sstas*/ 1559226128Sstas#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1560226128Sstas#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1561226128Sstas#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1562226031Sstas 1563226031Sstas 1564226031Sstas/* 1565226031Sstas** CAPI3REF: Enable Or Disable Extended Result Codes 1566226031Sstas** 1567226031Sstas** ^The sqlite3_extended_result_codes() routine enables or disables the 1568226031Sstas** [extended result codes] feature of SQLite. ^The extended result 1569226031Sstas** codes are disabled by default for historical compatibility. 1570226031Sstas*/ 1571226031SstasSQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1572226031Sstas 1573226031Sstas/* 1574226031Sstas** CAPI3REF: Last Insert Rowid 1575226031Sstas** 1576226031Sstas** ^Each entry in an SQLite table has a unique 64-bit signed 1577226031Sstas** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1578226031Sstas** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1579226031Sstas** names are not also used by explicitly declared columns. ^If 1580226031Sstas** the table has a column of type [INTEGER PRIMARY KEY] then that column 1581226031Sstas** is another alias for the rowid. 1582226031Sstas** 1583226031Sstas** ^This routine returns the [rowid] of the most recent 1584226031Sstas** successful [INSERT] into the database from the [database connection] 1585226128Sstas** in the first argument. ^As of SQLite version 3.7.7, this routines 1586226128Sstas** records the last insert rowid of both ordinary tables and [virtual tables]. 1587226128Sstas** ^If no successful [INSERT]s 1588226031Sstas** have ever occurred on that database connection, zero is returned. 1589226031Sstas** 1590226128Sstas** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1591226128Sstas** method, then this routine will return the [rowid] of the inserted 1592226128Sstas** row as long as the trigger or virtual table method is running. 1593226128Sstas** But once the trigger or virtual table method ends, the value returned 1594226128Sstas** by this routine reverts to what it was before the trigger or virtual 1595226128Sstas** table method began.)^ 1596226031Sstas** 1597226031Sstas** ^An [INSERT] that fails due to a constraint violation is not a 1598226031Sstas** successful [INSERT] and does not change the value returned by this 1599226031Sstas** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1600226031Sstas** and INSERT OR ABORT make no changes to the return value of this 1601226031Sstas** routine when their insertion fails. ^(When INSERT OR REPLACE 1602226031Sstas** encounters a constraint violation, it does not fail. The 1603226031Sstas** INSERT continues to completion after deleting rows that caused 1604226031Sstas** the constraint problem so INSERT OR REPLACE will always change 1605226031Sstas** the return value of this interface.)^ 1606226031Sstas** 1607226031Sstas** ^For the purposes of this routine, an [INSERT] is considered to 1608226031Sstas** be successful even if it is subsequently rolled back. 1609226031Sstas** 1610226031Sstas** This function is accessible to SQL statements via the 1611226031Sstas** [last_insert_rowid() SQL function]. 1612226031Sstas** 1613226031Sstas** If a separate thread performs a new [INSERT] on the same 1614226031Sstas** database connection while the [sqlite3_last_insert_rowid()] 1615226031Sstas** function is running and thus changes the last insert [rowid], 1616226031Sstas** then the value returned by [sqlite3_last_insert_rowid()] is 1617226031Sstas** unpredictable and might not equal either the old or the new 1618226031Sstas** last insert [rowid]. 1619226031Sstas*/ 1620226031SstasSQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1621226031Sstas 1622226031Sstas/* 1623226031Sstas** CAPI3REF: Count The Number Of Rows Modified 1624226031Sstas** 1625226031Sstas** ^This function returns the number of database rows that were changed 1626226031Sstas** or inserted or deleted by the most recently completed SQL statement 1627226031Sstas** on the [database connection] specified by the first parameter. 1628226031Sstas** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1629226031Sstas** or [DELETE] statement are counted. Auxiliary changes caused by 1630226031Sstas** triggers or [foreign key actions] are not counted.)^ Use the 1631226031Sstas** [sqlite3_total_changes()] function to find the total number of changes 1632226031Sstas** including changes caused by triggers and foreign key actions. 1633226031Sstas** 1634226031Sstas** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1635226031Sstas** are not counted. Only real table changes are counted. 1636226031Sstas** 1637226031Sstas** ^(A "row change" is a change to a single row of a single table 1638226031Sstas** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1639226031Sstas** are changed as side effects of [REPLACE] constraint resolution, 1640226031Sstas** rollback, ABORT processing, [DROP TABLE], or by any other 1641226031Sstas** mechanisms do not count as direct row changes.)^ 1642226031Sstas** 1643226031Sstas** A "trigger context" is a scope of execution that begins and 1644226128Sstas** ends with the script of a [CREATE TRIGGER | trigger]. 1645226031Sstas** Most SQL statements are 1646226031Sstas** evaluated outside of any trigger. This is the "top level" 1647226031Sstas** trigger context. If a trigger fires from the top level, a 1648226031Sstas** new trigger context is entered for the duration of that one 1649226031Sstas** trigger. Subtriggers create subcontexts for their duration. 1650226031Sstas** 1651226031Sstas** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1652226031Sstas** not create a new trigger context. 1653226031Sstas** 1654226031Sstas** ^This function returns the number of direct row changes in the 1655226031Sstas** most recent INSERT, UPDATE, or DELETE statement within the same 1656226031Sstas** trigger context. 1657226031Sstas** 1658226031Sstas** ^Thus, when called from the top level, this function returns the 1659226031Sstas** number of changes in the most recent INSERT, UPDATE, or DELETE 1660226031Sstas** that also occurred at the top level. ^(Within the body of a trigger, 1661226031Sstas** the sqlite3_changes() interface can be called to find the number of 1662226031Sstas** changes in the most recently completed INSERT, UPDATE, or DELETE 1663226031Sstas** statement within the body of the same trigger. 1664226031Sstas** However, the number returned does not include changes 1665226031Sstas** caused by subtriggers since those have their own context.)^ 1666226031Sstas** 1667226031Sstas** See also the [sqlite3_total_changes()] interface, the 1668226031Sstas** [count_changes pragma], and the [changes() SQL function]. 1669226031Sstas** 1670226031Sstas** If a separate thread makes changes on the same database connection 1671226031Sstas** while [sqlite3_changes()] is running then the value returned 1672226031Sstas** is unpredictable and not meaningful. 1673226031Sstas*/ 1674226031SstasSQLITE_API int sqlite3_changes(sqlite3*); 1675226031Sstas 1676226031Sstas/* 1677226031Sstas** CAPI3REF: Total Number Of Rows Modified 1678226031Sstas** 1679226031Sstas** ^This function returns the number of row changes caused by [INSERT], 1680226031Sstas** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1681226031Sstas** ^(The count returned by sqlite3_total_changes() includes all changes 1682226031Sstas** from all [CREATE TRIGGER | trigger] contexts and changes made by 1683226031Sstas** [foreign key actions]. However, 1684226031Sstas** the count does not include changes used to implement [REPLACE] constraints, 1685226031Sstas** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1686226031Sstas** count does not include rows of views that fire an [INSTEAD OF trigger], 1687226128Sstas** though if the INSTEAD OF trigger makes changes of its own, those changes 1688226031Sstas** are counted.)^ 1689226031Sstas** ^The sqlite3_total_changes() function counts the changes as soon as 1690226031Sstas** the statement that makes them is completed (when the statement handle 1691226031Sstas** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1692226031Sstas** 1693226031Sstas** See also the [sqlite3_changes()] interface, the 1694226031Sstas** [count_changes pragma], and the [total_changes() SQL function]. 1695226031Sstas** 1696226031Sstas** If a separate thread makes changes on the same database connection 1697226031Sstas** while [sqlite3_total_changes()] is running then the value 1698226031Sstas** returned is unpredictable and not meaningful. 1699226031Sstas*/ 1700226031SstasSQLITE_API int sqlite3_total_changes(sqlite3*); 1701226031Sstas 1702226031Sstas/* 1703226031Sstas** CAPI3REF: Interrupt A Long-Running Query 1704226031Sstas** 1705226031Sstas** ^This function causes any pending database operation to abort and 1706226031Sstas** return at its earliest opportunity. This routine is typically 1707226031Sstas** called in response to a user action such as pressing "Cancel" 1708226031Sstas** or Ctrl-C where the user wants a long query operation to halt 1709226031Sstas** immediately. 1710226031Sstas** 1711226031Sstas** ^It is safe to call this routine from a thread different from the 1712226031Sstas** thread that is currently running the database operation. But it 1713226031Sstas** is not safe to call this routine with a [database connection] that 1714226031Sstas** is closed or might close before sqlite3_interrupt() returns. 1715226031Sstas** 1716226031Sstas** ^If an SQL operation is very nearly finished at the time when 1717226031Sstas** sqlite3_interrupt() is called, then it might not have an opportunity 1718226031Sstas** to be interrupted and might continue to completion. 1719226031Sstas** 1720226031Sstas** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1721226031Sstas** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1722226031Sstas** that is inside an explicit transaction, then the entire transaction 1723226031Sstas** will be rolled back automatically. 1724226031Sstas** 1725226031Sstas** ^The sqlite3_interrupt(D) call is in effect until all currently running 1726226031Sstas** SQL statements on [database connection] D complete. ^Any new SQL statements 1727226128Sstas** that are started after the sqlite3_interrupt() call and before the 1728226031Sstas** running statements reaches zero are interrupted as if they had been 1729226031Sstas** running prior to the sqlite3_interrupt() call. ^New SQL statements 1730226031Sstas** that are started after the running statement count reaches zero are 1731226031Sstas** not effected by the sqlite3_interrupt(). 1732226031Sstas** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1733226031Sstas** SQL statements is a no-op and has no effect on SQL statements 1734226031Sstas** that are started after the sqlite3_interrupt() call returns. 1735226031Sstas** 1736226031Sstas** If the database connection closes while [sqlite3_interrupt()] 1737226031Sstas** is running then bad things will likely happen. 1738226031Sstas*/ 1739226031SstasSQLITE_API void sqlite3_interrupt(sqlite3*); 1740226031Sstas 1741226031Sstas/* 1742226031Sstas** CAPI3REF: Determine If An SQL Statement Is Complete 1743226031Sstas** 1744226031Sstas** These routines are useful during command-line input to determine if the 1745226031Sstas** currently entered text seems to form a complete SQL statement or 1746226031Sstas** if additional input is needed before sending the text into 1747226031Sstas** SQLite for parsing. ^These routines return 1 if the input string 1748226031Sstas** appears to be a complete SQL statement. ^A statement is judged to be 1749226031Sstas** complete if it ends with a semicolon token and is not a prefix of a 1750226031Sstas** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1751226031Sstas** string literals or quoted identifier names or comments are not 1752226031Sstas** independent tokens (they are part of the token in which they are 1753226031Sstas** embedded) and thus do not count as a statement terminator. ^Whitespace 1754226031Sstas** and comments that follow the final semicolon are ignored. 1755226031Sstas** 1756226031Sstas** ^These routines return 0 if the statement is incomplete. ^If a 1757226031Sstas** memory allocation fails, then SQLITE_NOMEM is returned. 1758226031Sstas** 1759226031Sstas** ^These routines do not parse the SQL statements thus 1760226031Sstas** will not detect syntactically incorrect SQL. 1761226031Sstas** 1762226128Sstas** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1763226031Sstas** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1764226031Sstas** automatically by sqlite3_complete16(). If that initialization fails, 1765226031Sstas** then the return value from sqlite3_complete16() will be non-zero 1766226031Sstas** regardless of whether or not the input SQL is complete.)^ 1767226031Sstas** 1768226031Sstas** The input to [sqlite3_complete()] must be a zero-terminated 1769226031Sstas** UTF-8 string. 1770226031Sstas** 1771226031Sstas** The input to [sqlite3_complete16()] must be a zero-terminated 1772226031Sstas** UTF-16 string in native byte order. 1773226031Sstas*/ 1774226031SstasSQLITE_API int sqlite3_complete(const char *sql); 1775226031SstasSQLITE_API int sqlite3_complete16(const void *sql); 1776226031Sstas 1777226031Sstas/* 1778226031Sstas** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1779226031Sstas** 1780226031Sstas** ^This routine sets a callback function that might be invoked whenever 1781226031Sstas** an attempt is made to open a database table that another thread 1782226031Sstas** or process has locked. 1783226031Sstas** 1784226031Sstas** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1785226031Sstas** is returned immediately upon encountering the lock. ^If the busy callback 1786226031Sstas** is not NULL, then the callback might be invoked with two arguments. 1787226031Sstas** 1788226031Sstas** ^The first argument to the busy handler is a copy of the void* pointer which 1789226031Sstas** is the third argument to sqlite3_busy_handler(). ^The second argument to 1790226031Sstas** the busy handler callback is the number of times that the busy handler has 1791226031Sstas** been invoked for this locking event. ^If the 1792226031Sstas** busy callback returns 0, then no additional attempts are made to 1793226031Sstas** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1794226031Sstas** ^If the callback returns non-zero, then another attempt 1795226031Sstas** is made to open the database for reading and the cycle repeats. 1796226031Sstas** 1797226031Sstas** The presence of a busy handler does not guarantee that it will be invoked 1798226031Sstas** when there is lock contention. ^If SQLite determines that invoking the busy 1799226031Sstas** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1800226031Sstas** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1801226031Sstas** Consider a scenario where one process is holding a read lock that 1802226031Sstas** it is trying to promote to a reserved lock and 1803226031Sstas** a second process is holding a reserved lock that it is trying 1804226031Sstas** to promote to an exclusive lock. The first process cannot proceed 1805226031Sstas** because it is blocked by the second and the second process cannot 1806226031Sstas** proceed because it is blocked by the first. If both processes 1807226031Sstas** invoke the busy handlers, neither will make any progress. Therefore, 1808226031Sstas** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1809226031Sstas** will induce the first process to release its read lock and allow 1810226031Sstas** the second process to proceed. 1811226031Sstas** 1812226031Sstas** ^The default busy callback is NULL. 1813226031Sstas** 1814226031Sstas** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1815226031Sstas** when SQLite is in the middle of a large transaction where all the 1816226031Sstas** changes will not fit into the in-memory cache. SQLite will 1817226031Sstas** already hold a RESERVED lock on the database file, but it needs 1818226031Sstas** to promote this lock to EXCLUSIVE so that it can spill cache 1819226031Sstas** pages into the database file without harm to concurrent 1820226031Sstas** readers. ^If it is unable to promote the lock, then the in-memory 1821226031Sstas** cache will be left in an inconsistent state and so the error 1822226031Sstas** code is promoted from the relatively benign [SQLITE_BUSY] to 1823226031Sstas** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1824226031Sstas** forces an automatic rollback of the changes. See the 1825226031Sstas** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1826226031Sstas** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1827226031Sstas** this is important. 1828226031Sstas** 1829226031Sstas** ^(There can only be a single busy handler defined for each 1830226031Sstas** [database connection]. Setting a new busy handler clears any 1831226031Sstas** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1832226031Sstas** will also set or clear the busy handler. 1833226031Sstas** 1834226031Sstas** The busy callback should not take any actions which modify the 1835226031Sstas** database connection that invoked the busy handler. Any such actions 1836226031Sstas** result in undefined behavior. 1837226128Sstas** 1838226031Sstas** A busy handler must not close the database connection 1839226031Sstas** or [prepared statement] that invoked the busy handler. 1840226031Sstas*/ 1841226031SstasSQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1842226031Sstas 1843226031Sstas/* 1844226031Sstas** CAPI3REF: Set A Busy Timeout 1845226031Sstas** 1846226031Sstas** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1847226031Sstas** for a specified amount of time when a table is locked. ^The handler 1848226031Sstas** will sleep multiple times until at least "ms" milliseconds of sleeping 1849226031Sstas** have accumulated. ^After at least "ms" milliseconds of sleeping, 1850226031Sstas** the handler returns 0 which causes [sqlite3_step()] to return 1851226031Sstas** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1852226031Sstas** 1853226031Sstas** ^Calling this routine with an argument less than or equal to zero 1854226031Sstas** turns off all busy handlers. 1855226031Sstas** 1856226031Sstas** ^(There can only be a single busy handler for a particular 1857226031Sstas** [database connection] any any given moment. If another busy handler 1858226031Sstas** was defined (using [sqlite3_busy_handler()]) prior to calling 1859226031Sstas** this routine, that other busy handler is cleared.)^ 1860226031Sstas*/ 1861226031SstasSQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 1862226031Sstas 1863226031Sstas/* 1864226031Sstas** CAPI3REF: Convenience Routines For Running Queries 1865226031Sstas** 1866226128Sstas** This is a legacy interface that is preserved for backwards compatibility. 1867226128Sstas** Use of this interface is not recommended. 1868226128Sstas** 1869226031Sstas** Definition: A <b>result table</b> is memory data structure created by the 1870226031Sstas** [sqlite3_get_table()] interface. A result table records the 1871226031Sstas** complete query results from one or more queries. 1872226031Sstas** 1873226031Sstas** The table conceptually has a number of rows and columns. But 1874226031Sstas** these numbers are not part of the result table itself. These 1875226031Sstas** numbers are obtained separately. Let N be the number of rows 1876226031Sstas** and M be the number of columns. 1877226031Sstas** 1878226031Sstas** A result table is an array of pointers to zero-terminated UTF-8 strings. 1879226031Sstas** There are (N+1)*M elements in the array. The first M pointers point 1880226031Sstas** to zero-terminated strings that contain the names of the columns. 1881226031Sstas** The remaining entries all point to query results. NULL values result 1882226031Sstas** in NULL pointers. All other values are in their UTF-8 zero-terminated 1883226031Sstas** string representation as returned by [sqlite3_column_text()]. 1884226031Sstas** 1885226031Sstas** A result table might consist of one or more memory allocations. 1886226031Sstas** It is not safe to pass a result table directly to [sqlite3_free()]. 1887226031Sstas** A result table should be deallocated using [sqlite3_free_table()]. 1888226031Sstas** 1889226128Sstas** ^(As an example of the result table format, suppose a query result 1890226031Sstas** is as follows: 1891226031Sstas** 1892226031Sstas** <blockquote><pre> 1893226031Sstas** Name | Age 1894226031Sstas** ----------------------- 1895226031Sstas** Alice | 43 1896226031Sstas** Bob | 28 1897226031Sstas** Cindy | 21 1898226031Sstas** </pre></blockquote> 1899226031Sstas** 1900226031Sstas** There are two column (M==2) and three rows (N==3). Thus the 1901226031Sstas** result table has 8 entries. Suppose the result table is stored 1902226031Sstas** in an array names azResult. Then azResult holds this content: 1903226031Sstas** 1904226031Sstas** <blockquote><pre> 1905226031Sstas** azResult[0] = "Name"; 1906226031Sstas** azResult[1] = "Age"; 1907226031Sstas** azResult[2] = "Alice"; 1908226031Sstas** azResult[3] = "43"; 1909226031Sstas** azResult[4] = "Bob"; 1910226031Sstas** azResult[5] = "28"; 1911226031Sstas** azResult[6] = "Cindy"; 1912226031Sstas** azResult[7] = "21"; 1913226128Sstas** </pre></blockquote>)^ 1914226031Sstas** 1915226031Sstas** ^The sqlite3_get_table() function evaluates one or more 1916226031Sstas** semicolon-separated SQL statements in the zero-terminated UTF-8 1917226031Sstas** string of its 2nd parameter and returns a result table to the 1918226031Sstas** pointer given in its 3rd parameter. 1919226031Sstas** 1920226031Sstas** After the application has finished with the result from sqlite3_get_table(), 1921226128Sstas** it must pass the result table pointer to sqlite3_free_table() in order to 1922226031Sstas** release the memory that was malloced. Because of the way the 1923226031Sstas** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1924226031Sstas** function must not try to call [sqlite3_free()] directly. Only 1925226031Sstas** [sqlite3_free_table()] is able to release the memory properly and safely. 1926226031Sstas** 1927226128Sstas** The sqlite3_get_table() interface is implemented as a wrapper around 1928226031Sstas** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1929226031Sstas** to any internal data structures of SQLite. It uses only the public 1930226031Sstas** interface defined here. As a consequence, errors that occur in the 1931226031Sstas** wrapper layer outside of the internal [sqlite3_exec()] call are not 1932226031Sstas** reflected in subsequent calls to [sqlite3_errcode()] or 1933226128Sstas** [sqlite3_errmsg()]. 1934226031Sstas*/ 1935226031SstasSQLITE_API int sqlite3_get_table( 1936226031Sstas sqlite3 *db, /* An open database */ 1937226031Sstas const char *zSql, /* SQL to be evaluated */ 1938226031Sstas char ***pazResult, /* Results of the query */ 1939226031Sstas int *pnRow, /* Number of result rows written here */ 1940226031Sstas int *pnColumn, /* Number of result columns written here */ 1941226031Sstas char **pzErrmsg /* Error msg written here */ 1942226031Sstas); 1943226031SstasSQLITE_API void sqlite3_free_table(char **result); 1944226031Sstas 1945226031Sstas/* 1946226031Sstas** CAPI3REF: Formatted String Printing Functions 1947226031Sstas** 1948226031Sstas** These routines are work-alikes of the "printf()" family of functions 1949226031Sstas** from the standard C library. 1950226031Sstas** 1951226031Sstas** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1952226031Sstas** results into memory obtained from [sqlite3_malloc()]. 1953226031Sstas** The strings returned by these two routines should be 1954226031Sstas** released by [sqlite3_free()]. ^Both routines return a 1955226031Sstas** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1956226031Sstas** memory to hold the resulting string. 1957226031Sstas** 1958226128Sstas** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 1959226031Sstas** the standard C library. The result is written into the 1960226031Sstas** buffer supplied as the second parameter whose size is given by 1961226031Sstas** the first parameter. Note that the order of the 1962226031Sstas** first two parameters is reversed from snprintf().)^ This is an 1963226031Sstas** historical accident that cannot be fixed without breaking 1964226031Sstas** backwards compatibility. ^(Note also that sqlite3_snprintf() 1965226031Sstas** returns a pointer to its buffer instead of the number of 1966226031Sstas** characters actually written into the buffer.)^ We admit that 1967226031Sstas** the number of characters written would be a more useful return 1968226031Sstas** value but we cannot change the implementation of sqlite3_snprintf() 1969226031Sstas** now without breaking compatibility. 1970226031Sstas** 1971226031Sstas** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 1972226031Sstas** guarantees that the buffer is always zero-terminated. ^The first 1973226031Sstas** parameter "n" is the total size of the buffer, including space for 1974226031Sstas** the zero terminator. So the longest string that can be completely 1975226031Sstas** written will be n-1 characters. 1976226031Sstas** 1977226128Sstas** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 1978226128Sstas** 1979226031Sstas** These routines all implement some additional formatting 1980226031Sstas** options that are useful for constructing SQL statements. 1981226031Sstas** All of the usual printf() formatting options apply. In addition, there 1982226031Sstas** is are "%q", "%Q", and "%z" options. 1983226031Sstas** 1984226031Sstas** ^(The %q option works like %s in that it substitutes a null-terminated 1985226031Sstas** string from the argument list. But %q also doubles every '\'' character. 1986226031Sstas** %q is designed for use inside a string literal.)^ By doubling each '\'' 1987226031Sstas** character it escapes that character and allows it to be inserted into 1988226031Sstas** the string. 1989226031Sstas** 1990226031Sstas** For example, assume the string variable zText contains text as follows: 1991226031Sstas** 1992226031Sstas** <blockquote><pre> 1993226031Sstas** char *zText = "It's a happy day!"; 1994226031Sstas** </pre></blockquote> 1995226031Sstas** 1996226031Sstas** One can use this text in an SQL statement as follows: 1997226031Sstas** 1998226031Sstas** <blockquote><pre> 1999226031Sstas** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2000226031Sstas** sqlite3_exec(db, zSQL, 0, 0, 0); 2001226031Sstas** sqlite3_free(zSQL); 2002226031Sstas** </pre></blockquote> 2003226031Sstas** 2004226031Sstas** Because the %q format string is used, the '\'' character in zText 2005226031Sstas** is escaped and the SQL generated is as follows: 2006226031Sstas** 2007226031Sstas** <blockquote><pre> 2008226031Sstas** INSERT INTO table1 VALUES('It''s a happy day!') 2009226031Sstas** </pre></blockquote> 2010226031Sstas** 2011226031Sstas** This is correct. Had we used %s instead of %q, the generated SQL 2012226031Sstas** would have looked like this: 2013226031Sstas** 2014226031Sstas** <blockquote><pre> 2015226031Sstas** INSERT INTO table1 VALUES('It's a happy day!'); 2016226031Sstas** </pre></blockquote> 2017226031Sstas** 2018226031Sstas** This second example is an SQL syntax error. As a general rule you should 2019226031Sstas** always use %q instead of %s when inserting text into a string literal. 2020226031Sstas** 2021226031Sstas** ^(The %Q option works like %q except it also adds single quotes around 2022226031Sstas** the outside of the total string. Additionally, if the parameter in the 2023226031Sstas** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2024226031Sstas** single quotes).)^ So, for example, one could say: 2025226031Sstas** 2026226031Sstas** <blockquote><pre> 2027226031Sstas** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2028226031Sstas** sqlite3_exec(db, zSQL, 0, 0, 0); 2029226031Sstas** sqlite3_free(zSQL); 2030226031Sstas** </pre></blockquote> 2031226031Sstas** 2032226031Sstas** The code above will render a correct SQL statement in the zSQL 2033226031Sstas** variable even if the zText variable is a NULL pointer. 2034226031Sstas** 2035226031Sstas** ^(The "%z" formatting option works like "%s" but with the 2036226031Sstas** addition that after the string has been read and copied into 2037226031Sstas** the result, [sqlite3_free()] is called on the input string.)^ 2038226031Sstas*/ 2039226031SstasSQLITE_API char *sqlite3_mprintf(const char*,...); 2040226031SstasSQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2041226031SstasSQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2042226128SstasSQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2043226031Sstas 2044226031Sstas/* 2045226031Sstas** CAPI3REF: Memory Allocation Subsystem 2046226031Sstas** 2047226031Sstas** The SQLite core uses these three routines for all of its own 2048226031Sstas** internal memory allocation needs. "Core" in the previous sentence 2049226031Sstas** does not include operating-system specific VFS implementation. The 2050226031Sstas** Windows VFS uses native malloc() and free() for some operations. 2051226031Sstas** 2052226031Sstas** ^The sqlite3_malloc() routine returns a pointer to a block 2053226031Sstas** of memory at least N bytes in length, where N is the parameter. 2054226031Sstas** ^If sqlite3_malloc() is unable to obtain sufficient free 2055226031Sstas** memory, it returns a NULL pointer. ^If the parameter N to 2056226031Sstas** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2057226031Sstas** a NULL pointer. 2058226031Sstas** 2059226031Sstas** ^Calling sqlite3_free() with a pointer previously returned 2060226031Sstas** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2061226031Sstas** that it might be reused. ^The sqlite3_free() routine is 2062226031Sstas** a no-op if is called with a NULL pointer. Passing a NULL pointer 2063226031Sstas** to sqlite3_free() is harmless. After being freed, memory 2064226031Sstas** should neither be read nor written. Even reading previously freed 2065226031Sstas** memory might result in a segmentation fault or other severe error. 2066226031Sstas** Memory corruption, a segmentation fault, or other severe error 2067226031Sstas** might result if sqlite3_free() is called with a non-NULL pointer that 2068226031Sstas** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2069226031Sstas** 2070226031Sstas** ^(The sqlite3_realloc() interface attempts to resize a 2071226031Sstas** prior memory allocation to be at least N bytes, where N is the 2072226031Sstas** second parameter. The memory allocation to be resized is the first 2073226031Sstas** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2074226031Sstas** is a NULL pointer then its behavior is identical to calling 2075226031Sstas** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2076226031Sstas** ^If the second parameter to sqlite3_realloc() is zero or 2077226031Sstas** negative then the behavior is exactly the same as calling 2078226031Sstas** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2079226031Sstas** ^sqlite3_realloc() returns a pointer to a memory allocation 2080226031Sstas** of at least N bytes in size or NULL if sufficient memory is unavailable. 2081226031Sstas** ^If M is the size of the prior allocation, then min(N,M) bytes 2082226031Sstas** of the prior allocation are copied into the beginning of buffer returned 2083226031Sstas** by sqlite3_realloc() and the prior allocation is freed. 2084226031Sstas** ^If sqlite3_realloc() returns NULL, then the prior allocation 2085226031Sstas** is not freed. 2086226031Sstas** 2087226031Sstas** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2088226128Sstas** is always aligned to at least an 8 byte boundary, or to a 2089226128Sstas** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2090226128Sstas** option is used. 2091226031Sstas** 2092226031Sstas** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2093226031Sstas** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2094226031Sstas** implementation of these routines to be omitted. That capability 2095226031Sstas** is no longer provided. Only built-in memory allocators can be used. 2096226031Sstas** 2097226031Sstas** The Windows OS interface layer calls 2098226031Sstas** the system malloc() and free() directly when converting 2099226031Sstas** filenames between the UTF-8 encoding used by SQLite 2100226031Sstas** and whatever filename encoding is used by the particular Windows 2101226031Sstas** installation. Memory allocation errors are detected, but 2102226031Sstas** they are reported back as [SQLITE_CANTOPEN] or 2103226031Sstas** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2104226031Sstas** 2105226031Sstas** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2106226031Sstas** must be either NULL or else pointers obtained from a prior 2107226031Sstas** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2108226031Sstas** not yet been released. 2109226031Sstas** 2110226031Sstas** The application must not read or write any part of 2111226031Sstas** a block of memory after it has been released using 2112226031Sstas** [sqlite3_free()] or [sqlite3_realloc()]. 2113226031Sstas*/ 2114226031SstasSQLITE_API void *sqlite3_malloc(int); 2115226031SstasSQLITE_API void *sqlite3_realloc(void*, int); 2116226031SstasSQLITE_API void sqlite3_free(void*); 2117226031Sstas 2118226031Sstas/* 2119226031Sstas** CAPI3REF: Memory Allocator Statistics 2120226031Sstas** 2121226031Sstas** SQLite provides these two interfaces for reporting on the status 2122226031Sstas** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2123226031Sstas** routines, which form the built-in memory allocation subsystem. 2124226031Sstas** 2125226031Sstas** ^The [sqlite3_memory_used()] routine returns the number of bytes 2126226031Sstas** of memory currently outstanding (malloced but not freed). 2127226031Sstas** ^The [sqlite3_memory_highwater()] routine returns the maximum 2128226031Sstas** value of [sqlite3_memory_used()] since the high-water mark 2129226031Sstas** was last reset. ^The values returned by [sqlite3_memory_used()] and 2130226031Sstas** [sqlite3_memory_highwater()] include any overhead 2131226031Sstas** added by SQLite in its implementation of [sqlite3_malloc()], 2132226031Sstas** but not overhead added by the any underlying system library 2133226031Sstas** routines that [sqlite3_malloc()] may call. 2134226031Sstas** 2135226031Sstas** ^The memory high-water mark is reset to the current value of 2136226031Sstas** [sqlite3_memory_used()] if and only if the parameter to 2137226031Sstas** [sqlite3_memory_highwater()] is true. ^The value returned 2138226031Sstas** by [sqlite3_memory_highwater(1)] is the high-water mark 2139226031Sstas** prior to the reset. 2140226031Sstas*/ 2141226031SstasSQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2142226031SstasSQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2143226031Sstas 2144226031Sstas/* 2145226031Sstas** CAPI3REF: Pseudo-Random Number Generator 2146226031Sstas** 2147226031Sstas** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2148226031Sstas** select random [ROWID | ROWIDs] when inserting new records into a table that 2149226031Sstas** already uses the largest possible [ROWID]. The PRNG is also used for 2150226031Sstas** the build-in random() and randomblob() SQL functions. This interface allows 2151226031Sstas** applications to access the same PRNG for other purposes. 2152226031Sstas** 2153226031Sstas** ^A call to this routine stores N bytes of randomness into buffer P. 2154226031Sstas** 2155226031Sstas** ^The first time this routine is invoked (either internally or by 2156226031Sstas** the application) the PRNG is seeded using randomness obtained 2157226031Sstas** from the xRandomness method of the default [sqlite3_vfs] object. 2158226031Sstas** ^On all subsequent invocations, the pseudo-randomness is generated 2159226031Sstas** internally and without recourse to the [sqlite3_vfs] xRandomness 2160226031Sstas** method. 2161226031Sstas*/ 2162226031SstasSQLITE_API void sqlite3_randomness(int N, void *P); 2163226031Sstas 2164226031Sstas/* 2165226031Sstas** CAPI3REF: Compile-Time Authorization Callbacks 2166226031Sstas** 2167226128Sstas** ^This routine registers an authorizer callback with a particular 2168226031Sstas** [database connection], supplied in the first argument. 2169226031Sstas** ^The authorizer callback is invoked as SQL statements are being compiled 2170226031Sstas** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2171226031Sstas** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2172226031Sstas** points during the compilation process, as logic is being created 2173226031Sstas** to perform various actions, the authorizer callback is invoked to 2174226031Sstas** see if those actions are allowed. ^The authorizer callback should 2175226031Sstas** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2176226031Sstas** specific action but allow the SQL statement to continue to be 2177226031Sstas** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2178226031Sstas** rejected with an error. ^If the authorizer callback returns 2179226031Sstas** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2180226031Sstas** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2181226031Sstas** the authorizer will fail with an error message. 2182226031Sstas** 2183226031Sstas** When the callback returns [SQLITE_OK], that means the operation 2184226031Sstas** requested is ok. ^When the callback returns [SQLITE_DENY], the 2185226031Sstas** [sqlite3_prepare_v2()] or equivalent call that triggered the 2186226031Sstas** authorizer will fail with an error message explaining that 2187226128Sstas** access is denied. 2188226031Sstas** 2189226031Sstas** ^The first parameter to the authorizer callback is a copy of the third 2190226031Sstas** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2191226031Sstas** to the callback is an integer [SQLITE_COPY | action code] that specifies 2192226031Sstas** the particular action to be authorized. ^The third through sixth parameters 2193226031Sstas** to the callback are zero-terminated strings that contain additional 2194226031Sstas** details about the action to be authorized. 2195226031Sstas** 2196226031Sstas** ^If the action code is [SQLITE_READ] 2197226031Sstas** and the callback returns [SQLITE_IGNORE] then the 2198226031Sstas** [prepared statement] statement is constructed to substitute 2199226031Sstas** a NULL value in place of the table column that would have 2200226031Sstas** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2201226031Sstas** return can be used to deny an untrusted user access to individual 2202226031Sstas** columns of a table. 2203226031Sstas** ^If the action code is [SQLITE_DELETE] and the callback returns 2204226031Sstas** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2205226031Sstas** [truncate optimization] is disabled and all rows are deleted individually. 2206226031Sstas** 2207226031Sstas** An authorizer is used when [sqlite3_prepare | preparing] 2208226031Sstas** SQL statements from an untrusted source, to ensure that the SQL statements 2209226031Sstas** do not try to access data they are not allowed to see, or that they do not 2210226031Sstas** try to execute malicious statements that damage the database. For 2211226031Sstas** example, an application may allow a user to enter arbitrary 2212226031Sstas** SQL queries for evaluation by a database. But the application does 2213226031Sstas** not want the user to be able to make arbitrary changes to the 2214226031Sstas** database. An authorizer could then be put in place while the 2215226031Sstas** user-entered SQL is being [sqlite3_prepare | prepared] that 2216226031Sstas** disallows everything except [SELECT] statements. 2217226031Sstas** 2218226031Sstas** Applications that need to process SQL from untrusted sources 2219226031Sstas** might also consider lowering resource limits using [sqlite3_limit()] 2220226031Sstas** and limiting database size using the [max_page_count] [PRAGMA] 2221226031Sstas** in addition to using an authorizer. 2222226031Sstas** 2223226031Sstas** ^(Only a single authorizer can be in place on a database connection 2224226031Sstas** at a time. Each call to sqlite3_set_authorizer overrides the 2225226031Sstas** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2226226031Sstas** The authorizer is disabled by default. 2227226031Sstas** 2228226031Sstas** The authorizer callback must not do anything that will modify 2229226031Sstas** the database connection that invoked the authorizer callback. 2230226031Sstas** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2231226031Sstas** database connections for the meaning of "modify" in this paragraph. 2232226031Sstas** 2233226031Sstas** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2234226128Sstas** statement might be re-prepared during [sqlite3_step()] due to a 2235226031Sstas** schema change. Hence, the application should ensure that the 2236226031Sstas** correct authorizer callback remains in place during the [sqlite3_step()]. 2237226031Sstas** 2238226031Sstas** ^Note that the authorizer callback is invoked only during 2239226031Sstas** [sqlite3_prepare()] or its variants. Authorization is not 2240226031Sstas** performed during statement evaluation in [sqlite3_step()], unless 2241226031Sstas** as stated in the previous paragraph, sqlite3_step() invokes 2242226031Sstas** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2243226031Sstas*/ 2244226031SstasSQLITE_API int sqlite3_set_authorizer( 2245226031Sstas sqlite3*, 2246226031Sstas int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2247226031Sstas void *pUserData 2248226031Sstas); 2249226031Sstas 2250226031Sstas/* 2251226031Sstas** CAPI3REF: Authorizer Return Codes 2252226031Sstas** 2253226031Sstas** The [sqlite3_set_authorizer | authorizer callback function] must 2254226031Sstas** return either [SQLITE_OK] or one of these two constants in order 2255226031Sstas** to signal SQLite whether or not the action is permitted. See the 2256226031Sstas** [sqlite3_set_authorizer | authorizer documentation] for additional 2257226031Sstas** information. 2258226128Sstas** 2259226128Sstas** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2260226128Sstas** from the [sqlite3_vtab_on_conflict()] interface. 2261226031Sstas*/ 2262226031Sstas#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2263226031Sstas#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2264226031Sstas 2265226031Sstas/* 2266226031Sstas** CAPI3REF: Authorizer Action Codes 2267226031Sstas** 2268226031Sstas** The [sqlite3_set_authorizer()] interface registers a callback function 2269226031Sstas** that is invoked to authorize certain SQL statement actions. The 2270226031Sstas** second parameter to the callback is an integer code that specifies 2271226031Sstas** what action is being authorized. These are the integer action codes that 2272226031Sstas** the authorizer callback may be passed. 2273226031Sstas** 2274226031Sstas** These action code values signify what kind of operation is to be 2275226031Sstas** authorized. The 3rd and 4th parameters to the authorization 2276226031Sstas** callback function will be parameters or NULL depending on which of these 2277226031Sstas** codes is used as the second parameter. ^(The 5th parameter to the 2278226031Sstas** authorizer callback is the name of the database ("main", "temp", 2279226031Sstas** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2280226031Sstas** is the name of the inner-most trigger or view that is responsible for 2281226031Sstas** the access attempt or NULL if this access attempt is directly from 2282226031Sstas** top-level SQL code. 2283226031Sstas*/ 2284226031Sstas/******************************************* 3rd ************ 4th ***********/ 2285226031Sstas#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2286226031Sstas#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2287226031Sstas#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2288226031Sstas#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2289226031Sstas#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2290226031Sstas#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2291226031Sstas#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2292226031Sstas#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2293226031Sstas#define SQLITE_DELETE 9 /* Table Name NULL */ 2294226031Sstas#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2295226031Sstas#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2296226031Sstas#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2297226031Sstas#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2298226031Sstas#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2299226031Sstas#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2300226031Sstas#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2301226031Sstas#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2302226031Sstas#define SQLITE_INSERT 18 /* Table Name NULL */ 2303226031Sstas#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2304226031Sstas#define SQLITE_READ 20 /* Table Name Column Name */ 2305226031Sstas#define SQLITE_SELECT 21 /* NULL NULL */ 2306226031Sstas#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2307226031Sstas#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2308226031Sstas#define SQLITE_ATTACH 24 /* Filename NULL */ 2309226031Sstas#define SQLITE_DETACH 25 /* Database Name NULL */ 2310226031Sstas#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2311226031Sstas#define SQLITE_REINDEX 27 /* Index Name NULL */ 2312226031Sstas#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2313226031Sstas#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2314226031Sstas#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2315226031Sstas#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2316226031Sstas#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2317226031Sstas#define SQLITE_COPY 0 /* No longer used */ 2318226031Sstas 2319226031Sstas/* 2320226031Sstas** CAPI3REF: Tracing And Profiling Functions 2321226031Sstas** 2322226031Sstas** These routines register callback functions that can be used for 2323226031Sstas** tracing and profiling the execution of SQL statements. 2324226031Sstas** 2325226031Sstas** ^The callback function registered by sqlite3_trace() is invoked at 2326226031Sstas** various times when an SQL statement is being run by [sqlite3_step()]. 2327226031Sstas** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2328226031Sstas** SQL statement text as the statement first begins executing. 2329226031Sstas** ^(Additional sqlite3_trace() callbacks might occur 2330226031Sstas** as each triggered subprogram is entered. The callbacks for triggers 2331226031Sstas** contain a UTF-8 SQL comment that identifies the trigger.)^ 2332226031Sstas** 2333226031Sstas** ^The callback function registered by sqlite3_profile() is invoked 2334226031Sstas** as each SQL statement finishes. ^The profile callback contains 2335226031Sstas** the original statement text and an estimate of wall-clock time 2336226128Sstas** of how long that statement took to run. ^The profile callback 2337226128Sstas** time is in units of nanoseconds, however the current implementation 2338226128Sstas** is only capable of millisecond resolution so the six least significant 2339226128Sstas** digits in the time are meaningless. Future versions of SQLite 2340226128Sstas** might provide greater resolution on the profiler callback. The 2341226128Sstas** sqlite3_profile() function is considered experimental and is 2342226128Sstas** subject to change in future versions of SQLite. 2343226031Sstas*/ 2344226128SstasSQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2345226031SstasSQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2346226031Sstas void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2347226031Sstas 2348226031Sstas/* 2349226031Sstas** CAPI3REF: Query Progress Callbacks 2350226031Sstas** 2351226128Sstas** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2352226128Sstas** function X to be invoked periodically during long running calls to 2353226128Sstas** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2354226128Sstas** database connection D. An example use for this 2355226031Sstas** interface is to keep a GUI updated during a large query. 2356226031Sstas** 2357226128Sstas** ^The parameter P is passed through as the only parameter to the 2358226128Sstas** callback function X. ^The parameter N is the number of 2359226128Sstas** [virtual machine instructions] that are evaluated between successive 2360226128Sstas** invocations of the callback X. 2361226128Sstas** 2362226128Sstas** ^Only a single progress handler may be defined at one time per 2363226128Sstas** [database connection]; setting a new progress handler cancels the 2364226128Sstas** old one. ^Setting parameter X to NULL disables the progress handler. 2365226128Sstas** ^The progress handler is also disabled by setting N to a value less 2366226128Sstas** than 1. 2367226128Sstas** 2368226031Sstas** ^If the progress callback returns non-zero, the operation is 2369226031Sstas** interrupted. This feature can be used to implement a 2370226031Sstas** "Cancel" button on a GUI progress dialog box. 2371226031Sstas** 2372226128Sstas** The progress handler callback must not do anything that will modify 2373226031Sstas** the database connection that invoked the progress handler. 2374226031Sstas** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2375226031Sstas** database connections for the meaning of "modify" in this paragraph. 2376226031Sstas** 2377226031Sstas*/ 2378226031SstasSQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2379226031Sstas 2380226031Sstas/* 2381226031Sstas** CAPI3REF: Opening A New Database Connection 2382226031Sstas** 2383226128Sstas** ^These routines open an SQLite database file as specified by the 2384226031Sstas** filename argument. ^The filename argument is interpreted as UTF-8 for 2385226031Sstas** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2386226031Sstas** order for sqlite3_open16(). ^(A [database connection] handle is usually 2387226031Sstas** returned in *ppDb, even if an error occurs. The only exception is that 2388226031Sstas** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2389226031Sstas** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2390226031Sstas** object.)^ ^(If the database is opened (and/or created) successfully, then 2391226031Sstas** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2392226031Sstas** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2393226031Sstas** an English language description of the error following a failure of any 2394226031Sstas** of the sqlite3_open() routines. 2395226031Sstas** 2396226031Sstas** ^The default encoding for the database will be UTF-8 if 2397226031Sstas** sqlite3_open() or sqlite3_open_v2() is called and 2398226031Sstas** UTF-16 in the native byte order if sqlite3_open16() is used. 2399226031Sstas** 2400226031Sstas** Whether or not an error occurs when it is opened, resources 2401226031Sstas** associated with the [database connection] handle should be released by 2402226031Sstas** passing it to [sqlite3_close()] when it is no longer required. 2403226031Sstas** 2404226031Sstas** The sqlite3_open_v2() interface works like sqlite3_open() 2405226031Sstas** except that it accepts two additional parameters for additional control 2406226031Sstas** over the new database connection. ^(The flags parameter to 2407226031Sstas** sqlite3_open_v2() can take one of 2408226128Sstas** the following three values, optionally combined with the 2409226031Sstas** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2410226128Sstas** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2411226031Sstas** 2412226031Sstas** <dl> 2413226031Sstas** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2414226031Sstas** <dd>The database is opened in read-only mode. If the database does not 2415226031Sstas** already exist, an error is returned.</dd>)^ 2416226031Sstas** 2417226031Sstas** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2418226031Sstas** <dd>The database is opened for reading and writing if possible, or reading 2419226031Sstas** only if the file is write protected by the operating system. In either 2420226031Sstas** case the database must already exist, otherwise an error is returned.</dd>)^ 2421226031Sstas** 2422226031Sstas** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2423226128Sstas** <dd>The database is opened for reading and writing, and is created if 2424226031Sstas** it does not already exist. This is the behavior that is always used for 2425226031Sstas** sqlite3_open() and sqlite3_open16().</dd>)^ 2426226031Sstas** </dl> 2427226031Sstas** 2428226031Sstas** If the 3rd parameter to sqlite3_open_v2() is not one of the 2429226128Sstas** combinations shown above optionally combined with other 2430226128Sstas** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2431226031Sstas** then the behavior is undefined. 2432226031Sstas** 2433226031Sstas** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2434226031Sstas** opens in the multi-thread [threading mode] as long as the single-thread 2435226031Sstas** mode has not been set at compile-time or start-time. ^If the 2436226031Sstas** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2437226031Sstas** in the serialized [threading mode] unless single-thread was 2438226031Sstas** previously selected at compile-time or start-time. 2439226031Sstas** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2440226031Sstas** eligible to use [shared cache mode], regardless of whether or not shared 2441226031Sstas** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2442226031Sstas** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2443226031Sstas** participate in [shared cache mode] even if it is enabled. 2444226031Sstas** 2445226128Sstas** ^The fourth parameter to sqlite3_open_v2() is the name of the 2446226128Sstas** [sqlite3_vfs] object that defines the operating system interface that 2447226128Sstas** the new database connection should use. ^If the fourth parameter is 2448226128Sstas** a NULL pointer then the default [sqlite3_vfs] object is used. 2449226128Sstas** 2450226031Sstas** ^If the filename is ":memory:", then a private, temporary in-memory database 2451226031Sstas** is created for the connection. ^This in-memory database will vanish when 2452226031Sstas** the database connection is closed. Future versions of SQLite might 2453226031Sstas** make use of additional special filenames that begin with the ":" character. 2454226031Sstas** It is recommended that when a database filename actually does begin with 2455226031Sstas** a ":" character you should prefix the filename with a pathname such as 2456226031Sstas** "./" to avoid ambiguity. 2457226031Sstas** 2458226031Sstas** ^If the filename is an empty string, then a private, temporary 2459226031Sstas** on-disk database will be created. ^This private database will be 2460226031Sstas** automatically deleted as soon as the database connection is closed. 2461226031Sstas** 2462226128Sstas** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2463226031Sstas** 2464226128Sstas** ^If [URI filename] interpretation is enabled, and the filename argument 2465226128Sstas** begins with "file:", then the filename is interpreted as a URI. ^URI 2466226128Sstas** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2467226128Sstas** set in the fourth argument to sqlite3_open_v2(), or if it has 2468226128Sstas** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2469226128Sstas** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2470226128Sstas** As of SQLite version 3.7.7, URI filename interpretation is turned off 2471226128Sstas** by default, but future releases of SQLite might enable URI filename 2472226128Sstas** interpretation by default. See "[URI filenames]" for additional 2473226128Sstas** information. 2474226128Sstas** 2475226128Sstas** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2476226128Sstas** authority, then it must be either an empty string or the string 2477226128Sstas** "localhost". ^If the authority is not an empty string or "localhost", an 2478226128Sstas** error is returned to the caller. ^The fragment component of a URI, if 2479226128Sstas** present, is ignored. 2480226128Sstas** 2481226128Sstas** ^SQLite uses the path component of the URI as the name of the disk file 2482226128Sstas** which contains the database. ^If the path begins with a '/' character, 2483226128Sstas** then it is interpreted as an absolute path. ^If the path does not begin 2484226128Sstas** with a '/' (meaning that the authority section is omitted from the URI) 2485226128Sstas** then the path is interpreted as a relative path. 2486226128Sstas** ^On windows, the first component of an absolute path 2487226128Sstas** is a drive specification (e.g. "C:"). 2488226128Sstas** 2489226128Sstas** [[core URI query parameters]] 2490226128Sstas** The query component of a URI may contain parameters that are interpreted 2491226128Sstas** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2492226128Sstas** SQLite interprets the following three query parameters: 2493226128Sstas** 2494226128Sstas** <ul> 2495226128Sstas** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2496226128Sstas** a VFS object that provides the operating system interface that should 2497226128Sstas** be used to access the database file on disk. ^If this option is set to 2498226128Sstas** an empty string the default VFS object is used. ^Specifying an unknown 2499226128Sstas** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2500226128Sstas** present, then the VFS specified by the option takes precedence over 2501226128Sstas** the value passed as the fourth parameter to sqlite3_open_v2(). 2502226128Sstas** 2503226128Sstas** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or 2504226128Sstas** "rwc". Attempting to set it to any other value is an error)^. 2505226128Sstas** ^If "ro" is specified, then the database is opened for read-only 2506226128Sstas** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2507226128Sstas** third argument to sqlite3_prepare_v2(). ^If the mode option is set to 2508226128Sstas** "rw", then the database is opened for read-write (but not create) 2509226128Sstas** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2510226128Sstas** been set. ^Value "rwc" is equivalent to setting both 2511226128Sstas** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is 2512226128Sstas** used, it is an error to specify a value for the mode parameter that is 2513226128Sstas** less restrictive than that specified by the flags passed as the third 2514226128Sstas** parameter. 2515226128Sstas** 2516226128Sstas** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2517226128Sstas** "private". ^Setting it to "shared" is equivalent to setting the 2518226128Sstas** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2519226128Sstas** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2520226128Sstas** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2521226128Sstas** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2522226128Sstas** a URI filename, its value overrides any behaviour requested by setting 2523226128Sstas** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2524226128Sstas** </ul> 2525226128Sstas** 2526226128Sstas** ^Specifying an unknown parameter in the query component of a URI is not an 2527226128Sstas** error. Future versions of SQLite might understand additional query 2528226128Sstas** parameters. See "[query parameters with special meaning to SQLite]" for 2529226128Sstas** additional information. 2530226128Sstas** 2531226128Sstas** [[URI filename examples]] <h3>URI filename examples</h3> 2532226128Sstas** 2533226128Sstas** <table border="1" align=center cellpadding=5> 2534226128Sstas** <tr><th> URI filenames <th> Results 2535226128Sstas** <tr><td> file:data.db <td> 2536226128Sstas** Open the file "data.db" in the current directory. 2537226128Sstas** <tr><td> file:/home/fred/data.db<br> 2538226128Sstas** file:///home/fred/data.db <br> 2539226128Sstas** file://localhost/home/fred/data.db <br> <td> 2540226128Sstas** Open the database file "/home/fred/data.db". 2541226128Sstas** <tr><td> file://darkstar/home/fred/data.db <td> 2542226128Sstas** An error. "darkstar" is not a recognized authority. 2543226128Sstas** <tr><td style="white-space:nowrap"> 2544226128Sstas** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2545226128Sstas** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2546226128Sstas** C:. Note that the %20 escaping in this example is not strictly 2547226128Sstas** necessary - space characters can be used literally 2548226128Sstas** in URI filenames. 2549226128Sstas** <tr><td> file:data.db?mode=ro&cache=private <td> 2550226128Sstas** Open file "data.db" in the current directory for read-only access. 2551226128Sstas** Regardless of whether or not shared-cache mode is enabled by 2552226128Sstas** default, use a private cache. 2553226128Sstas** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2554226128Sstas** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2555226128Sstas** <tr><td> file:data.db?mode=readonly <td> 2556226128Sstas** An error. "readonly" is not a valid option for the "mode" parameter. 2557226128Sstas** </table> 2558226128Sstas** 2559226128Sstas** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2560226128Sstas** query components of a URI. A hexadecimal escape sequence consists of a 2561226128Sstas** percent sign - "%" - followed by exactly two hexadecimal digits 2562226128Sstas** specifying an octet value. ^Before the path or query components of a 2563226128Sstas** URI filename are interpreted, they are encoded using UTF-8 and all 2564226128Sstas** hexadecimal escape sequences replaced by a single byte containing the 2565226128Sstas** corresponding octet. If this process generates an invalid UTF-8 encoding, 2566226128Sstas** the results are undefined. 2567226128Sstas** 2568226031Sstas** <b>Note to Windows users:</b> The encoding used for the filename argument 2569226031Sstas** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2570226031Sstas** codepage is currently defined. Filenames containing international 2571226031Sstas** characters must be converted to UTF-8 prior to passing them into 2572226031Sstas** sqlite3_open() or sqlite3_open_v2(). 2573226031Sstas*/ 2574226031SstasSQLITE_API int sqlite3_open( 2575226031Sstas const char *filename, /* Database filename (UTF-8) */ 2576226031Sstas sqlite3 **ppDb /* OUT: SQLite db handle */ 2577226031Sstas); 2578226031SstasSQLITE_API int sqlite3_open16( 2579226031Sstas const void *filename, /* Database filename (UTF-16) */ 2580226031Sstas sqlite3 **ppDb /* OUT: SQLite db handle */ 2581226031Sstas); 2582226031SstasSQLITE_API int sqlite3_open_v2( 2583226031Sstas const char *filename, /* Database filename (UTF-8) */ 2584226031Sstas sqlite3 **ppDb, /* OUT: SQLite db handle */ 2585226031Sstas int flags, /* Flags */ 2586226031Sstas const char *zVfs /* Name of VFS module to use */ 2587226031Sstas); 2588226031Sstas 2589226031Sstas/* 2590226128Sstas** CAPI3REF: Obtain Values For URI Parameters 2591226128Sstas** 2592226128Sstas** This is a utility routine, useful to VFS implementations, that checks 2593226128Sstas** to see if a database file was a URI that contained a specific query 2594226128Sstas** parameter, and if so obtains the value of the query parameter. 2595226128Sstas** 2596226128Sstas** The zFilename argument is the filename pointer passed into the xOpen() 2597226128Sstas** method of a VFS implementation. The zParam argument is the name of the 2598226128Sstas** query parameter we seek. This routine returns the value of the zParam 2599226128Sstas** parameter if it exists. If the parameter does not exist, this routine 2600226128Sstas** returns a NULL pointer. 2601226128Sstas** 2602226128Sstas** If the zFilename argument to this function is not a pointer that SQLite 2603226128Sstas** passed into the xOpen VFS method, then the behavior of this routine 2604226128Sstas** is undefined and probably undesirable. 2605226128Sstas*/ 2606226128SstasSQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2607226128Sstas 2608226128Sstas 2609226128Sstas/* 2610226031Sstas** CAPI3REF: Error Codes And Messages 2611226031Sstas** 2612226031Sstas** ^The sqlite3_errcode() interface returns the numeric [result code] or 2613226031Sstas** [extended result code] for the most recent failed sqlite3_* API call 2614226031Sstas** associated with a [database connection]. If a prior API call failed 2615226031Sstas** but the most recent API call succeeded, the return value from 2616226031Sstas** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2617226128Sstas** interface is the same except that it always returns the 2618226031Sstas** [extended result code] even when extended result codes are 2619226031Sstas** disabled. 2620226031Sstas** 2621226031Sstas** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2622226031Sstas** text that describes the error, as either UTF-8 or UTF-16 respectively. 2623226031Sstas** ^(Memory to hold the error message string is managed internally. 2624226031Sstas** The application does not need to worry about freeing the result. 2625226031Sstas** However, the error string might be overwritten or deallocated by 2626226031Sstas** subsequent calls to other SQLite interface functions.)^ 2627226031Sstas** 2628226031Sstas** When the serialized [threading mode] is in use, it might be the 2629226031Sstas** case that a second error occurs on a separate thread in between 2630226031Sstas** the time of the first error and the call to these interfaces. 2631226031Sstas** When that happens, the second error will be reported since these 2632226031Sstas** interfaces always report the most recent result. To avoid 2633226031Sstas** this, each thread can obtain exclusive use of the [database connection] D 2634226031Sstas** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2635226031Sstas** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2636226031Sstas** all calls to the interfaces listed here are completed. 2637226031Sstas** 2638226031Sstas** If an interface fails with SQLITE_MISUSE, that means the interface 2639226031Sstas** was invoked incorrectly by the application. In that case, the 2640226031Sstas** error code and message may or may not be set. 2641226031Sstas*/ 2642226031SstasSQLITE_API int sqlite3_errcode(sqlite3 *db); 2643226031SstasSQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2644226031SstasSQLITE_API const char *sqlite3_errmsg(sqlite3*); 2645226031SstasSQLITE_API const void *sqlite3_errmsg16(sqlite3*); 2646226031Sstas 2647226031Sstas/* 2648226031Sstas** CAPI3REF: SQL Statement Object 2649226031Sstas** KEYWORDS: {prepared statement} {prepared statements} 2650226031Sstas** 2651226031Sstas** An instance of this object represents a single SQL statement. 2652226031Sstas** This object is variously known as a "prepared statement" or a 2653226031Sstas** "compiled SQL statement" or simply as a "statement". 2654226031Sstas** 2655226031Sstas** The life of a statement object goes something like this: 2656226031Sstas** 2657226031Sstas** <ol> 2658226031Sstas** <li> Create the object using [sqlite3_prepare_v2()] or a related 2659226031Sstas** function. 2660226031Sstas** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2661226031Sstas** interfaces. 2662226031Sstas** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2663226031Sstas** <li> Reset the statement using [sqlite3_reset()] then go back 2664226031Sstas** to step 2. Do this zero or more times. 2665226031Sstas** <li> Destroy the object using [sqlite3_finalize()]. 2666226031Sstas** </ol> 2667226031Sstas** 2668226031Sstas** Refer to documentation on individual methods above for additional 2669226031Sstas** information. 2670226031Sstas*/ 2671226031Sstastypedef struct sqlite3_stmt sqlite3_stmt; 2672226031Sstas 2673226031Sstas/* 2674226031Sstas** CAPI3REF: Run-time Limits 2675226031Sstas** 2676226031Sstas** ^(This interface allows the size of various constructs to be limited 2677226031Sstas** on a connection by connection basis. The first parameter is the 2678226031Sstas** [database connection] whose limit is to be set or queried. The 2679226031Sstas** second parameter is one of the [limit categories] that define a 2680226031Sstas** class of constructs to be size limited. The third parameter is the 2681226128Sstas** new limit for that construct.)^ 2682226031Sstas** 2683226031Sstas** ^If the new limit is a negative number, the limit is unchanged. 2684226128Sstas** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2685226031Sstas** [limits | hard upper bound] 2686226128Sstas** set at compile-time by a C preprocessor macro called 2687226128Sstas** [limits | SQLITE_MAX_<i>NAME</i>]. 2688226031Sstas** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2689226031Sstas** ^Attempts to increase a limit above its hard upper bound are 2690226031Sstas** silently truncated to the hard upper bound. 2691226031Sstas** 2692226128Sstas** ^Regardless of whether or not the limit was changed, the 2693226128Sstas** [sqlite3_limit()] interface returns the prior value of the limit. 2694226128Sstas** ^Hence, to find the current value of a limit without changing it, 2695226128Sstas** simply invoke this interface with the third parameter set to -1. 2696226128Sstas** 2697226031Sstas** Run-time limits are intended for use in applications that manage 2698226031Sstas** both their own internal database and also databases that are controlled 2699226031Sstas** by untrusted external sources. An example application might be a 2700226031Sstas** web browser that has its own databases for storing history and 2701226031Sstas** separate databases controlled by JavaScript applications downloaded 2702226031Sstas** off the Internet. The internal databases can be given the 2703226031Sstas** large, default limits. Databases managed by external sources can 2704226031Sstas** be given much smaller limits designed to prevent a denial of service 2705226031Sstas** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2706226031Sstas** interface to further control untrusted SQL. The size of the database 2707226031Sstas** created by an untrusted script can be contained using the 2708226031Sstas** [max_page_count] [PRAGMA]. 2709226031Sstas** 2710226031Sstas** New run-time limit categories may be added in future releases. 2711226031Sstas*/ 2712226031SstasSQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 2713226031Sstas 2714226031Sstas/* 2715226031Sstas** CAPI3REF: Run-Time Limit Categories 2716226031Sstas** KEYWORDS: {limit category} {*limit categories} 2717226031Sstas** 2718226031Sstas** These constants define various performance limits 2719226031Sstas** that can be lowered at run-time using [sqlite3_limit()]. 2720226031Sstas** The synopsis of the meanings of the various limits is shown below. 2721226031Sstas** Additional information is available at [limits | Limits in SQLite]. 2722226031Sstas** 2723226031Sstas** <dl> 2724226128Sstas** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2725226128Sstas** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2726226031Sstas** 2727226128Sstas** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2728226031Sstas** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2729226031Sstas** 2730226128Sstas** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2731226031Sstas** <dd>The maximum number of columns in a table definition or in the 2732226031Sstas** result set of a [SELECT] or the maximum number of columns in an index 2733226031Sstas** or in an ORDER BY or GROUP BY clause.</dd>)^ 2734226031Sstas** 2735226128Sstas** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2736226031Sstas** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2737226031Sstas** 2738226128Sstas** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2739226031Sstas** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2740226031Sstas** 2741226128Sstas** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2742226031Sstas** <dd>The maximum number of instructions in a virtual machine program 2743226128Sstas** used to implement an SQL statement. This limit is not currently 2744226128Sstas** enforced, though that might be added in some future release of 2745226128Sstas** SQLite.</dd>)^ 2746226031Sstas** 2747226128Sstas** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2748226031Sstas** <dd>The maximum number of arguments on a function.</dd>)^ 2749226031Sstas** 2750226128Sstas** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2751226031Sstas** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2752226031Sstas** 2753226128Sstas** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2754226031Sstas** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2755226031Sstas** <dd>The maximum length of the pattern argument to the [LIKE] or 2756226031Sstas** [GLOB] operators.</dd>)^ 2757226031Sstas** 2758226128Sstas** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2759226031Sstas** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2760226128Sstas** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2761226031Sstas** 2762226128Sstas** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2763226031Sstas** <dd>The maximum depth of recursion for triggers.</dd>)^ 2764226031Sstas** </dl> 2765226031Sstas*/ 2766226031Sstas#define SQLITE_LIMIT_LENGTH 0 2767226031Sstas#define SQLITE_LIMIT_SQL_LENGTH 1 2768226031Sstas#define SQLITE_LIMIT_COLUMN 2 2769226031Sstas#define SQLITE_LIMIT_EXPR_DEPTH 3 2770226031Sstas#define SQLITE_LIMIT_COMPOUND_SELECT 4 2771226031Sstas#define SQLITE_LIMIT_VDBE_OP 5 2772226031Sstas#define SQLITE_LIMIT_FUNCTION_ARG 6 2773226031Sstas#define SQLITE_LIMIT_ATTACHED 7 2774226031Sstas#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2775226031Sstas#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2776226031Sstas#define SQLITE_LIMIT_TRIGGER_DEPTH 10 2777226031Sstas 2778226031Sstas/* 2779226031Sstas** CAPI3REF: Compiling An SQL Statement 2780226031Sstas** KEYWORDS: {SQL statement compiler} 2781226031Sstas** 2782226031Sstas** To execute an SQL query, it must first be compiled into a byte-code 2783226031Sstas** program using one of these routines. 2784226031Sstas** 2785226031Sstas** The first argument, "db", is a [database connection] obtained from a 2786226031Sstas** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2787226031Sstas** [sqlite3_open16()]. The database connection must not have been closed. 2788226031Sstas** 2789226031Sstas** The second argument, "zSql", is the statement to be compiled, encoded 2790226031Sstas** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2791226031Sstas** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2792226031Sstas** use UTF-16. 2793226031Sstas** 2794226031Sstas** ^If the nByte argument is less than zero, then zSql is read up to the 2795226031Sstas** first zero terminator. ^If nByte is non-negative, then it is the maximum 2796226031Sstas** number of bytes read from zSql. ^When nByte is non-negative, the 2797226031Sstas** zSql string ends at either the first '\000' or '\u0000' character or 2798226031Sstas** the nByte-th byte, whichever comes first. If the caller knows 2799226031Sstas** that the supplied string is nul-terminated, then there is a small 2800226031Sstas** performance advantage to be gained by passing an nByte parameter that 2801226031Sstas** is equal to the number of bytes in the input string <i>including</i> 2802226031Sstas** the nul-terminator bytes. 2803226031Sstas** 2804226031Sstas** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2805226031Sstas** past the end of the first SQL statement in zSql. These routines only 2806226031Sstas** compile the first statement in zSql, so *pzTail is left pointing to 2807226031Sstas** what remains uncompiled. 2808226031Sstas** 2809226031Sstas** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2810226031Sstas** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2811226031Sstas** to NULL. ^If the input text contains no SQL (if the input is an empty 2812226031Sstas** string or a comment) then *ppStmt is set to NULL. 2813226031Sstas** The calling procedure is responsible for deleting the compiled 2814226031Sstas** SQL statement using [sqlite3_finalize()] after it has finished with it. 2815226031Sstas** ppStmt may not be NULL. 2816226031Sstas** 2817226031Sstas** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2818226031Sstas** otherwise an [error code] is returned. 2819226031Sstas** 2820226031Sstas** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2821226031Sstas** recommended for all new programs. The two older interfaces are retained 2822226031Sstas** for backwards compatibility, but their use is discouraged. 2823226031Sstas** ^In the "v2" interfaces, the prepared statement 2824226031Sstas** that is returned (the [sqlite3_stmt] object) contains a copy of the 2825226031Sstas** original SQL text. This causes the [sqlite3_step()] interface to 2826226031Sstas** behave differently in three ways: 2827226031Sstas** 2828226031Sstas** <ol> 2829226031Sstas** <li> 2830226031Sstas** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2831226031Sstas** always used to do, [sqlite3_step()] will automatically recompile the SQL 2832226128Sstas** statement and try to run it again. 2833226031Sstas** </li> 2834226031Sstas** 2835226031Sstas** <li> 2836226031Sstas** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2837226031Sstas** [error codes] or [extended error codes]. ^The legacy behavior was that 2838226031Sstas** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2839226031Sstas** and the application would have to make a second call to [sqlite3_reset()] 2840226031Sstas** in order to find the underlying cause of the problem. With the "v2" prepare 2841226031Sstas** interfaces, the underlying reason for the error is returned immediately. 2842226031Sstas** </li> 2843226031Sstas** 2844226031Sstas** <li> 2845226128Sstas** ^If the specific value bound to [parameter | host parameter] in the 2846226128Sstas** WHERE clause might influence the choice of query plan for a statement, 2847226128Sstas** then the statement will be automatically recompiled, as if there had been 2848226128Sstas** a schema change, on the first [sqlite3_step()] call following any change 2849226128Sstas** to the [sqlite3_bind_text | bindings] of that [parameter]. 2850226128Sstas** ^The specific value of WHERE-clause [parameter] might influence the 2851226128Sstas** choice of query plan if the parameter is the left-hand side of a [LIKE] 2852226128Sstas** or [GLOB] operator or if the parameter is compared to an indexed column 2853226128Sstas** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled. 2854226128Sstas** the 2855226031Sstas** </li> 2856226031Sstas** </ol> 2857226031Sstas*/ 2858226031SstasSQLITE_API int sqlite3_prepare( 2859226031Sstas sqlite3 *db, /* Database handle */ 2860226031Sstas const char *zSql, /* SQL statement, UTF-8 encoded */ 2861226031Sstas int nByte, /* Maximum length of zSql in bytes. */ 2862226031Sstas sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2863226031Sstas const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2864226031Sstas); 2865226031SstasSQLITE_API int sqlite3_prepare_v2( 2866226031Sstas sqlite3 *db, /* Database handle */ 2867226031Sstas const char *zSql, /* SQL statement, UTF-8 encoded */ 2868226031Sstas int nByte, /* Maximum length of zSql in bytes. */ 2869226031Sstas sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2870226031Sstas const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2871226031Sstas); 2872226031SstasSQLITE_API int sqlite3_prepare16( 2873226031Sstas sqlite3 *db, /* Database handle */ 2874226031Sstas const void *zSql, /* SQL statement, UTF-16 encoded */ 2875226031Sstas int nByte, /* Maximum length of zSql in bytes. */ 2876226031Sstas sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2877226031Sstas const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2878226031Sstas); 2879226031SstasSQLITE_API int sqlite3_prepare16_v2( 2880226031Sstas sqlite3 *db, /* Database handle */ 2881226031Sstas const void *zSql, /* SQL statement, UTF-16 encoded */ 2882226031Sstas int nByte, /* Maximum length of zSql in bytes. */ 2883226031Sstas sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2884226031Sstas const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2885226031Sstas); 2886226031Sstas 2887226031Sstas/* 2888226031Sstas** CAPI3REF: Retrieving Statement SQL 2889226031Sstas** 2890226031Sstas** ^This interface can be used to retrieve a saved copy of the original 2891226031Sstas** SQL text used to create a [prepared statement] if that statement was 2892226031Sstas** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2893226031Sstas*/ 2894226031SstasSQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 2895226031Sstas 2896226031Sstas/* 2897226128Sstas** CAPI3REF: Determine If An SQL Statement Writes The Database 2898226128Sstas** 2899226128Sstas** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 2900226128Sstas** and only if the [prepared statement] X makes no direct changes to 2901226128Sstas** the content of the database file. 2902226128Sstas** 2903226128Sstas** Note that [application-defined SQL functions] or 2904226128Sstas** [virtual tables] might change the database indirectly as a side effect. 2905226128Sstas** ^(For example, if an application defines a function "eval()" that 2906226128Sstas** calls [sqlite3_exec()], then the following SQL statement would 2907226128Sstas** change the database file through side-effects: 2908226128Sstas** 2909226128Sstas** <blockquote><pre> 2910226128Sstas** SELECT eval('DELETE FROM t1') FROM t2; 2911226128Sstas** </pre></blockquote> 2912226128Sstas** 2913226128Sstas** But because the [SELECT] statement does not change the database file 2914226128Sstas** directly, sqlite3_stmt_readonly() would still return true.)^ 2915226128Sstas** 2916226128Sstas** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 2917226128Sstas** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 2918226128Sstas** since the statements themselves do not actually modify the database but 2919226128Sstas** rather they control the timing of when other statements modify the 2920226128Sstas** database. ^The [ATTACH] and [DETACH] statements also cause 2921226128Sstas** sqlite3_stmt_readonly() to return true since, while those statements 2922226128Sstas** change the configuration of a database connection, they do not make 2923226128Sstas** changes to the content of the database files on disk. 2924226128Sstas*/ 2925226128SstasSQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 2926226128Sstas 2927226128Sstas/* 2928226031Sstas** CAPI3REF: Dynamically Typed Value Object 2929226031Sstas** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2930226031Sstas** 2931226031Sstas** SQLite uses the sqlite3_value object to represent all values 2932226031Sstas** that can be stored in a database table. SQLite uses dynamic typing 2933226031Sstas** for the values it stores. ^Values stored in sqlite3_value objects 2934226031Sstas** can be integers, floating point values, strings, BLOBs, or NULL. 2935226031Sstas** 2936226031Sstas** An sqlite3_value object may be either "protected" or "unprotected". 2937226031Sstas** Some interfaces require a protected sqlite3_value. Other interfaces 2938226031Sstas** will accept either a protected or an unprotected sqlite3_value. 2939226031Sstas** Every interface that accepts sqlite3_value arguments specifies 2940226031Sstas** whether or not it requires a protected sqlite3_value. 2941226031Sstas** 2942226031Sstas** The terms "protected" and "unprotected" refer to whether or not 2943226128Sstas** a mutex is held. An internal mutex is held for a protected 2944226031Sstas** sqlite3_value object but no mutex is held for an unprotected 2945226031Sstas** sqlite3_value object. If SQLite is compiled to be single-threaded 2946226031Sstas** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2947226128Sstas** or if SQLite is run in one of reduced mutex modes 2948226031Sstas** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2949226031Sstas** then there is no distinction between protected and unprotected 2950226031Sstas** sqlite3_value objects and they can be used interchangeably. However, 2951226031Sstas** for maximum code portability it is recommended that applications 2952226128Sstas** still make the distinction between protected and unprotected 2953226031Sstas** sqlite3_value objects even when not strictly required. 2954226031Sstas** 2955226031Sstas** ^The sqlite3_value objects that are passed as parameters into the 2956226031Sstas** implementation of [application-defined SQL functions] are protected. 2957226031Sstas** ^The sqlite3_value object returned by 2958226031Sstas** [sqlite3_column_value()] is unprotected. 2959226031Sstas** Unprotected sqlite3_value objects may only be used with 2960226031Sstas** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2961226031Sstas** The [sqlite3_value_blob | sqlite3_value_type()] family of 2962226031Sstas** interfaces require protected sqlite3_value objects. 2963226031Sstas*/ 2964226031Sstastypedef struct Mem sqlite3_value; 2965226031Sstas 2966226031Sstas/* 2967226031Sstas** CAPI3REF: SQL Function Context Object 2968226031Sstas** 2969226031Sstas** The context in which an SQL function executes is stored in an 2970226031Sstas** sqlite3_context object. ^A pointer to an sqlite3_context object 2971226031Sstas** is always first parameter to [application-defined SQL functions]. 2972226031Sstas** The application-defined SQL function implementation will pass this 2973226031Sstas** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2974226031Sstas** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2975226031Sstas** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2976226031Sstas** and/or [sqlite3_set_auxdata()]. 2977226031Sstas*/ 2978226031Sstastypedef struct sqlite3_context sqlite3_context; 2979226031Sstas 2980226031Sstas/* 2981226031Sstas** CAPI3REF: Binding Values To Prepared Statements 2982226031Sstas** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2983226031Sstas** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2984226031Sstas** 2985226031Sstas** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 2986226031Sstas** literals may be replaced by a [parameter] that matches one of following 2987226031Sstas** templates: 2988226031Sstas** 2989226031Sstas** <ul> 2990226031Sstas** <li> ? 2991226031Sstas** <li> ?NNN 2992226031Sstas** <li> :VVV 2993226031Sstas** <li> @VVV 2994226031Sstas** <li> $VVV 2995226031Sstas** </ul> 2996226031Sstas** 2997226031Sstas** In the templates above, NNN represents an integer literal, 2998226128Sstas** and VVV represents an alphanumeric identifier.)^ ^The values of these 2999226031Sstas** parameters (also called "host parameter names" or "SQL parameters") 3000226031Sstas** can be set using the sqlite3_bind_*() routines defined here. 3001226031Sstas** 3002226031Sstas** ^The first argument to the sqlite3_bind_*() routines is always 3003226031Sstas** a pointer to the [sqlite3_stmt] object returned from 3004226031Sstas** [sqlite3_prepare_v2()] or its variants. 3005226031Sstas** 3006226031Sstas** ^The second argument is the index of the SQL parameter to be set. 3007226031Sstas** ^The leftmost SQL parameter has an index of 1. ^When the same named 3008226031Sstas** SQL parameter is used more than once, second and subsequent 3009226031Sstas** occurrences have the same index as the first occurrence. 3010226031Sstas** ^The index for named parameters can be looked up using the 3011226031Sstas** [sqlite3_bind_parameter_index()] API if desired. ^The index 3012226031Sstas** for "?NNN" parameters is the value of NNN. 3013226031Sstas** ^The NNN value must be between 1 and the [sqlite3_limit()] 3014226031Sstas** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3015226031Sstas** 3016226031Sstas** ^The third argument is the value to bind to the parameter. 3017226031Sstas** 3018226031Sstas** ^(In those routines that have a fourth argument, its value is the 3019226031Sstas** number of bytes in the parameter. To be clear: the value is the 3020226031Sstas** number of <u>bytes</u> in the value, not the number of characters.)^ 3021226031Sstas** ^If the fourth parameter is negative, the length of the string is 3022226031Sstas** the number of bytes up to the first zero terminator. 3023226031Sstas** 3024226031Sstas** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3025226031Sstas** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3026226128Sstas** string after SQLite has finished with it. ^The destructor is called 3027226128Sstas** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3028226128Sstas** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3029226128Sstas** ^If the fifth argument is 3030226031Sstas** the special value [SQLITE_STATIC], then SQLite assumes that the 3031226031Sstas** information is in static, unmanaged space and does not need to be freed. 3032226031Sstas** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3033226031Sstas** SQLite makes its own private copy of the data immediately, before 3034226031Sstas** the sqlite3_bind_*() routine returns. 3035226031Sstas** 3036226031Sstas** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3037226031Sstas** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3038226031Sstas** (just an integer to hold its size) while it is being processed. 3039226031Sstas** Zeroblobs are intended to serve as placeholders for BLOBs whose 3040226031Sstas** content is later written using 3041226031Sstas** [sqlite3_blob_open | incremental BLOB I/O] routines. 3042226031Sstas** ^A negative value for the zeroblob results in a zero-length BLOB. 3043226031Sstas** 3044226031Sstas** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3045226031Sstas** for the [prepared statement] or with a prepared statement for which 3046226031Sstas** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3047226031Sstas** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3048226031Sstas** routine is passed a [prepared statement] that has been finalized, the 3049226031Sstas** result is undefined and probably harmful. 3050226031Sstas** 3051226031Sstas** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3052226031Sstas** ^Unbound parameters are interpreted as NULL. 3053226031Sstas** 3054226031Sstas** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3055226031Sstas** [error code] if anything goes wrong. 3056226031Sstas** ^[SQLITE_RANGE] is returned if the parameter 3057226031Sstas** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3058226031Sstas** 3059226031Sstas** See also: [sqlite3_bind_parameter_count()], 3060226031Sstas** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3061226031Sstas*/ 3062226031SstasSQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3063226031SstasSQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3064226031SstasSQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3065226031SstasSQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3066226031SstasSQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3067226031SstasSQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3068226031SstasSQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3069226031SstasSQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3070226031SstasSQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3071226031Sstas 3072226031Sstas/* 3073226031Sstas** CAPI3REF: Number Of SQL Parameters 3074226031Sstas** 3075226031Sstas** ^This routine can be used to find the number of [SQL parameters] 3076226031Sstas** in a [prepared statement]. SQL parameters are tokens of the 3077226031Sstas** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3078226031Sstas** placeholders for values that are [sqlite3_bind_blob | bound] 3079226031Sstas** to the parameters at a later time. 3080226031Sstas** 3081226031Sstas** ^(This routine actually returns the index of the largest (rightmost) 3082226031Sstas** parameter. For all forms except ?NNN, this will correspond to the 3083226031Sstas** number of unique parameters. If parameters of the ?NNN form are used, 3084226031Sstas** there may be gaps in the list.)^ 3085226031Sstas** 3086226031Sstas** See also: [sqlite3_bind_blob|sqlite3_bind()], 3087226031Sstas** [sqlite3_bind_parameter_name()], and 3088226031Sstas** [sqlite3_bind_parameter_index()]. 3089226031Sstas*/ 3090226031SstasSQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3091226031Sstas 3092226031Sstas/* 3093226031Sstas** CAPI3REF: Name Of A Host Parameter 3094226031Sstas** 3095226031Sstas** ^The sqlite3_bind_parameter_name(P,N) interface returns 3096226031Sstas** the name of the N-th [SQL parameter] in the [prepared statement] P. 3097226031Sstas** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3098226031Sstas** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3099226031Sstas** respectively. 3100226031Sstas** In other words, the initial ":" or "$" or "@" or "?" 3101226031Sstas** is included as part of the name.)^ 3102226031Sstas** ^Parameters of the form "?" without a following integer have no name 3103226031Sstas** and are referred to as "nameless" or "anonymous parameters". 3104226031Sstas** 3105226031Sstas** ^The first host parameter has an index of 1, not 0. 3106226031Sstas** 3107226031Sstas** ^If the value N is out of range or if the N-th parameter is 3108226031Sstas** nameless, then NULL is returned. ^The returned string is 3109226031Sstas** always in UTF-8 encoding even if the named parameter was 3110226031Sstas** originally specified as UTF-16 in [sqlite3_prepare16()] or 3111226031Sstas** [sqlite3_prepare16_v2()]. 3112226031Sstas** 3113226031Sstas** See also: [sqlite3_bind_blob|sqlite3_bind()], 3114226031Sstas** [sqlite3_bind_parameter_count()], and 3115226031Sstas** [sqlite3_bind_parameter_index()]. 3116226031Sstas*/ 3117226031SstasSQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3118226031Sstas 3119226031Sstas/* 3120226031Sstas** CAPI3REF: Index Of A Parameter With A Given Name 3121226031Sstas** 3122226031Sstas** ^Return the index of an SQL parameter given its name. ^The 3123226031Sstas** index value returned is suitable for use as the second 3124226031Sstas** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3125226031Sstas** is returned if no matching parameter is found. ^The parameter 3126226031Sstas** name must be given in UTF-8 even if the original statement 3127226031Sstas** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3128226031Sstas** 3129226031Sstas** See also: [sqlite3_bind_blob|sqlite3_bind()], 3130226031Sstas** [sqlite3_bind_parameter_count()], and 3131226031Sstas** [sqlite3_bind_parameter_index()]. 3132226031Sstas*/ 3133226031SstasSQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3134226031Sstas 3135226031Sstas/* 3136226031Sstas** CAPI3REF: Reset All Bindings On A Prepared Statement 3137226031Sstas** 3138226031Sstas** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3139226031Sstas** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3140226031Sstas** ^Use this routine to reset all host parameters to NULL. 3141226031Sstas*/ 3142226031SstasSQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3143226031Sstas 3144226031Sstas/* 3145226031Sstas** CAPI3REF: Number Of Columns In A Result Set 3146226031Sstas** 3147226031Sstas** ^Return the number of columns in the result set returned by the 3148226031Sstas** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3149226031Sstas** statement that does not return data (for example an [UPDATE]). 3150226128Sstas** 3151226128Sstas** See also: [sqlite3_data_count()] 3152226031Sstas*/ 3153226031SstasSQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3154226031Sstas 3155226031Sstas/* 3156226031Sstas** CAPI3REF: Column Names In A Result Set 3157226031Sstas** 3158226031Sstas** ^These routines return the name assigned to a particular column 3159226031Sstas** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3160226031Sstas** interface returns a pointer to a zero-terminated UTF-8 string 3161226031Sstas** and sqlite3_column_name16() returns a pointer to a zero-terminated 3162226031Sstas** UTF-16 string. ^The first parameter is the [prepared statement] 3163226031Sstas** that implements the [SELECT] statement. ^The second parameter is the 3164226031Sstas** column number. ^The leftmost column is number 0. 3165226031Sstas** 3166226031Sstas** ^The returned string pointer is valid until either the [prepared statement] 3167226128Sstas** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3168226128Sstas** reprepared by the first call to [sqlite3_step()] for a particular run 3169226128Sstas** or until the next call to 3170226031Sstas** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3171226031Sstas** 3172226031Sstas** ^If sqlite3_malloc() fails during the processing of either routine 3173226031Sstas** (for example during a conversion from UTF-8 to UTF-16) then a 3174226031Sstas** NULL pointer is returned. 3175226031Sstas** 3176226031Sstas** ^The name of a result column is the value of the "AS" clause for 3177226031Sstas** that column, if there is an AS clause. If there is no AS clause 3178226031Sstas** then the name of the column is unspecified and may change from 3179226031Sstas** one release of SQLite to the next. 3180226031Sstas*/ 3181226031SstasSQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3182226031SstasSQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3183226031Sstas 3184226031Sstas/* 3185226031Sstas** CAPI3REF: Source Of Data In A Query Result 3186226031Sstas** 3187226031Sstas** ^These routines provide a means to determine the database, table, and 3188226031Sstas** table column that is the origin of a particular result column in 3189226031Sstas** [SELECT] statement. 3190226031Sstas** ^The name of the database or table or column can be returned as 3191226031Sstas** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3192226031Sstas** the database name, the _table_ routines return the table name, and 3193226031Sstas** the origin_ routines return the column name. 3194226031Sstas** ^The returned string is valid until the [prepared statement] is destroyed 3195226128Sstas** using [sqlite3_finalize()] or until the statement is automatically 3196226128Sstas** reprepared by the first call to [sqlite3_step()] for a particular run 3197226128Sstas** or until the same information is requested 3198226031Sstas** again in a different encoding. 3199226031Sstas** 3200226031Sstas** ^The names returned are the original un-aliased names of the 3201226031Sstas** database, table, and column. 3202226031Sstas** 3203226031Sstas** ^The first argument to these interfaces is a [prepared statement]. 3204226031Sstas** ^These functions return information about the Nth result column returned by 3205226031Sstas** the statement, where N is the second function argument. 3206226031Sstas** ^The left-most column is column 0 for these routines. 3207226031Sstas** 3208226031Sstas** ^If the Nth column returned by the statement is an expression or 3209226031Sstas** subquery and is not a column value, then all of these functions return 3210226031Sstas** NULL. ^These routine might also return NULL if a memory allocation error 3211226031Sstas** occurs. ^Otherwise, they return the name of the attached database, table, 3212226031Sstas** or column that query result column was extracted from. 3213226031Sstas** 3214226031Sstas** ^As with all other SQLite APIs, those whose names end with "16" return 3215226031Sstas** UTF-16 encoded strings and the other functions return UTF-8. 3216226031Sstas** 3217226031Sstas** ^These APIs are only available if the library was compiled with the 3218226031Sstas** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3219226031Sstas** 3220226031Sstas** If two or more threads call one or more of these routines against the same 3221226031Sstas** prepared statement and column at the same time then the results are 3222226031Sstas** undefined. 3223226031Sstas** 3224226031Sstas** If two or more threads call one or more 3225226031Sstas** [sqlite3_column_database_name | column metadata interfaces] 3226226031Sstas** for the same [prepared statement] and result column 3227226031Sstas** at the same time then the results are undefined. 3228226031Sstas*/ 3229226031SstasSQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3230226031SstasSQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3231226031SstasSQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3232226031SstasSQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3233226031SstasSQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3234226031SstasSQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3235226031Sstas 3236226031Sstas/* 3237226031Sstas** CAPI3REF: Declared Datatype Of A Query Result 3238226031Sstas** 3239226031Sstas** ^(The first parameter is a [prepared statement]. 3240226031Sstas** If this statement is a [SELECT] statement and the Nth column of the 3241226031Sstas** returned result set of that [SELECT] is a table column (not an 3242226031Sstas** expression or subquery) then the declared type of the table 3243226031Sstas** column is returned.)^ ^If the Nth column of the result set is an 3244226031Sstas** expression or subquery, then a NULL pointer is returned. 3245226031Sstas** ^The returned string is always UTF-8 encoded. 3246226031Sstas** 3247226031Sstas** ^(For example, given the database schema: 3248226031Sstas** 3249226031Sstas** CREATE TABLE t1(c1 VARIANT); 3250226031Sstas** 3251226031Sstas** and the following statement to be compiled: 3252226031Sstas** 3253226031Sstas** SELECT c1 + 1, c1 FROM t1; 3254226031Sstas** 3255226031Sstas** this routine would return the string "VARIANT" for the second result 3256226031Sstas** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3257226031Sstas** 3258226031Sstas** ^SQLite uses dynamic run-time typing. ^So just because a column 3259226031Sstas** is declared to contain a particular type does not mean that the 3260226031Sstas** data stored in that column is of the declared type. SQLite is 3261226031Sstas** strongly typed, but the typing is dynamic not static. ^Type 3262226031Sstas** is associated with individual values, not with the containers 3263226031Sstas** used to hold those values. 3264226031Sstas*/ 3265226031SstasSQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3266226031SstasSQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3267226031Sstas 3268226031Sstas/* 3269226031Sstas** CAPI3REF: Evaluate An SQL Statement 3270226031Sstas** 3271226031Sstas** After a [prepared statement] has been prepared using either 3272226031Sstas** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3273226031Sstas** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3274226031Sstas** must be called one or more times to evaluate the statement. 3275226031Sstas** 3276226031Sstas** The details of the behavior of the sqlite3_step() interface depend 3277226031Sstas** on whether the statement was prepared using the newer "v2" interface 3278226031Sstas** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3279226031Sstas** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3280226031Sstas** new "v2" interface is recommended for new applications but the legacy 3281226031Sstas** interface will continue to be supported. 3282226031Sstas** 3283226031Sstas** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3284226031Sstas** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3285226031Sstas** ^With the "v2" interface, any of the other [result codes] or 3286226031Sstas** [extended result codes] might be returned as well. 3287226031Sstas** 3288226031Sstas** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3289226031Sstas** database locks it needs to do its job. ^If the statement is a [COMMIT] 3290226031Sstas** or occurs outside of an explicit transaction, then you can retry the 3291226128Sstas** statement. If the statement is not a [COMMIT] and occurs within an 3292226031Sstas** explicit transaction then you should rollback the transaction before 3293226031Sstas** continuing. 3294226031Sstas** 3295226031Sstas** ^[SQLITE_DONE] means that the statement has finished executing 3296226031Sstas** successfully. sqlite3_step() should not be called again on this virtual 3297226031Sstas** machine without first calling [sqlite3_reset()] to reset the virtual 3298226031Sstas** machine back to its initial state. 3299226031Sstas** 3300226031Sstas** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3301226031Sstas** is returned each time a new row of data is ready for processing by the 3302226031Sstas** caller. The values may be accessed using the [column access functions]. 3303226031Sstas** sqlite3_step() is called again to retrieve the next row of data. 3304226031Sstas** 3305226031Sstas** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3306226031Sstas** violation) has occurred. sqlite3_step() should not be called again on 3307226031Sstas** the VM. More information may be found by calling [sqlite3_errmsg()]. 3308226031Sstas** ^With the legacy interface, a more specific error code (for example, 3309226031Sstas** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3310226031Sstas** can be obtained by calling [sqlite3_reset()] on the 3311226031Sstas** [prepared statement]. ^In the "v2" interface, 3312226031Sstas** the more specific error code is returned directly by sqlite3_step(). 3313226031Sstas** 3314226031Sstas** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3315226031Sstas** Perhaps it was called on a [prepared statement] that has 3316226031Sstas** already been [sqlite3_finalize | finalized] or on one that had 3317226031Sstas** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3318226031Sstas** be the case that the same database connection is being used by two or 3319226031Sstas** more threads at the same moment in time. 3320226031Sstas** 3321226128Sstas** For all versions of SQLite up to and including 3.6.23.1, a call to 3322226128Sstas** [sqlite3_reset()] was required after sqlite3_step() returned anything 3323226128Sstas** other than [SQLITE_ROW] before any subsequent invocation of 3324226128Sstas** sqlite3_step(). Failure to reset the prepared statement using 3325226128Sstas** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3326226128Sstas** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3327226128Sstas** calling [sqlite3_reset()] automatically in this circumstance rather 3328226128Sstas** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3329226128Sstas** break because any application that ever receives an SQLITE_MISUSE error 3330226128Sstas** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3331226128Sstas** can be used to restore the legacy behavior. 3332226128Sstas** 3333226031Sstas** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3334226031Sstas** API always returns a generic error code, [SQLITE_ERROR], following any 3335226031Sstas** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3336226031Sstas** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3337226031Sstas** specific [error codes] that better describes the error. 3338226031Sstas** We admit that this is a goofy design. The problem has been fixed 3339226031Sstas** with the "v2" interface. If you prepare all of your SQL statements 3340226031Sstas** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3341226031Sstas** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3342226031Sstas** then the more specific [error codes] are returned directly 3343226031Sstas** by sqlite3_step(). The use of the "v2" interface is recommended. 3344226031Sstas*/ 3345226031SstasSQLITE_API int sqlite3_step(sqlite3_stmt*); 3346226031Sstas 3347226031Sstas/* 3348226031Sstas** CAPI3REF: Number of columns in a result set 3349226031Sstas** 3350226128Sstas** ^The sqlite3_data_count(P) interface returns the number of columns in the 3351226128Sstas** current row of the result set of [prepared statement] P. 3352226128Sstas** ^If prepared statement P does not have results ready to return 3353226128Sstas** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3354226128Sstas** interfaces) then sqlite3_data_count(P) returns 0. 3355226128Sstas** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3356226128Sstas** 3357226128Sstas** See also: [sqlite3_column_count()] 3358226031Sstas*/ 3359226031SstasSQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3360226031Sstas 3361226031Sstas/* 3362226031Sstas** CAPI3REF: Fundamental Datatypes 3363226031Sstas** KEYWORDS: SQLITE_TEXT 3364226031Sstas** 3365226031Sstas** ^(Every value in SQLite has one of five fundamental datatypes: 3366226031Sstas** 3367226031Sstas** <ul> 3368226031Sstas** <li> 64-bit signed integer 3369226031Sstas** <li> 64-bit IEEE floating point number 3370226031Sstas** <li> string 3371226031Sstas** <li> BLOB 3372226031Sstas** <li> NULL 3373226031Sstas** </ul>)^ 3374226031Sstas** 3375226031Sstas** These constants are codes for each of those types. 3376226031Sstas** 3377226031Sstas** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3378226031Sstas** for a completely different meaning. Software that links against both 3379226031Sstas** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3380226031Sstas** SQLITE_TEXT. 3381226031Sstas*/ 3382226031Sstas#define SQLITE_INTEGER 1 3383226031Sstas#define SQLITE_FLOAT 2 3384226031Sstas#define SQLITE_BLOB 4 3385226031Sstas#define SQLITE_NULL 5 3386226031Sstas#ifdef SQLITE_TEXT 3387226031Sstas# undef SQLITE_TEXT 3388226031Sstas#else 3389226031Sstas# define SQLITE_TEXT 3 3390226031Sstas#endif 3391226031Sstas#define SQLITE3_TEXT 3 3392226031Sstas 3393226031Sstas/* 3394226031Sstas** CAPI3REF: Result Values From A Query 3395226031Sstas** KEYWORDS: {column access functions} 3396226031Sstas** 3397226031Sstas** These routines form the "result set" interface. 3398226031Sstas** 3399226031Sstas** ^These routines return information about a single column of the current 3400226031Sstas** result row of a query. ^In every case the first argument is a pointer 3401226031Sstas** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3402226031Sstas** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3403226031Sstas** and the second argument is the index of the column for which information 3404226031Sstas** should be returned. ^The leftmost column of the result set has the index 0. 3405226031Sstas** ^The number of columns in the result can be determined using 3406226031Sstas** [sqlite3_column_count()]. 3407226031Sstas** 3408226031Sstas** If the SQL statement does not currently point to a valid row, or if the 3409226031Sstas** column index is out of range, the result is undefined. 3410226031Sstas** These routines may only be called when the most recent call to 3411226031Sstas** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3412226031Sstas** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3413226031Sstas** If any of these routines are called after [sqlite3_reset()] or 3414226031Sstas** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3415226031Sstas** something other than [SQLITE_ROW], the results are undefined. 3416226031Sstas** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3417226031Sstas** are called from a different thread while any of these routines 3418226031Sstas** are pending, then the results are undefined. 3419226031Sstas** 3420226031Sstas** ^The sqlite3_column_type() routine returns the 3421226031Sstas** [SQLITE_INTEGER | datatype code] for the initial data type 3422226031Sstas** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3423226031Sstas** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3424226031Sstas** returned by sqlite3_column_type() is only meaningful if no type 3425226031Sstas** conversions have occurred as described below. After a type conversion, 3426226031Sstas** the value returned by sqlite3_column_type() is undefined. Future 3427226031Sstas** versions of SQLite may change the behavior of sqlite3_column_type() 3428226031Sstas** following a type conversion. 3429226031Sstas** 3430226031Sstas** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3431226031Sstas** routine returns the number of bytes in that BLOB or string. 3432226031Sstas** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3433226031Sstas** the string to UTF-8 and then returns the number of bytes. 3434226031Sstas** ^If the result is a numeric value then sqlite3_column_bytes() uses 3435226031Sstas** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3436226031Sstas** the number of bytes in that string. 3437226128Sstas** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3438226128Sstas** 3439226128Sstas** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3440226128Sstas** routine returns the number of bytes in that BLOB or string. 3441226128Sstas** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3442226128Sstas** the string to UTF-16 and then returns the number of bytes. 3443226128Sstas** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3444226128Sstas** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3445226128Sstas** the number of bytes in that string. 3446226128Sstas** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3447226128Sstas** 3448226128Sstas** ^The values returned by [sqlite3_column_bytes()] and 3449226128Sstas** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3450226128Sstas** of the string. ^For clarity: the values returned by 3451226128Sstas** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3452226031Sstas** bytes in the string, not the number of characters. 3453226031Sstas** 3454226031Sstas** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3455226031Sstas** even empty strings, are always zero terminated. ^The return 3456226128Sstas** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3457226031Sstas** 3458226031Sstas** ^The object returned by [sqlite3_column_value()] is an 3459226031Sstas** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3460226031Sstas** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3461226031Sstas** If the [unprotected sqlite3_value] object returned by 3462226031Sstas** [sqlite3_column_value()] is used in any other way, including calls 3463226031Sstas** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3464226031Sstas** or [sqlite3_value_bytes()], then the behavior is undefined. 3465226031Sstas** 3466226031Sstas** These routines attempt to convert the value where appropriate. ^For 3467226031Sstas** example, if the internal representation is FLOAT and a text result 3468226031Sstas** is requested, [sqlite3_snprintf()] is used internally to perform the 3469226031Sstas** conversion automatically. ^(The following table details the conversions 3470226031Sstas** that are applied: 3471226031Sstas** 3472226031Sstas** <blockquote> 3473226031Sstas** <table border="1"> 3474226031Sstas** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3475226031Sstas** 3476226031Sstas** <tr><td> NULL <td> INTEGER <td> Result is 0 3477226031Sstas** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3478226031Sstas** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3479226031Sstas** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3480226031Sstas** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3481226031Sstas** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3482226031Sstas** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3483226031Sstas** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3484226031Sstas** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3485226031Sstas** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3486226031Sstas** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3487226031Sstas** <tr><td> TEXT <td> FLOAT <td> Use atof() 3488226031Sstas** <tr><td> TEXT <td> BLOB <td> No change 3489226031Sstas** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3490226031Sstas** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3491226031Sstas** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3492226031Sstas** </table> 3493226031Sstas** </blockquote>)^ 3494226031Sstas** 3495226031Sstas** The table above makes reference to standard C library functions atoi() 3496226031Sstas** and atof(). SQLite does not really use these functions. It has its 3497226031Sstas** own equivalent internal routines. The atoi() and atof() names are 3498226031Sstas** used in the table for brevity and because they are familiar to most 3499226031Sstas** C programmers. 3500226031Sstas** 3501226128Sstas** Note that when type conversions occur, pointers returned by prior 3502226031Sstas** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3503226031Sstas** sqlite3_column_text16() may be invalidated. 3504226128Sstas** Type conversions and pointer invalidations might occur 3505226031Sstas** in the following cases: 3506226031Sstas** 3507226031Sstas** <ul> 3508226031Sstas** <li> The initial content is a BLOB and sqlite3_column_text() or 3509226031Sstas** sqlite3_column_text16() is called. A zero-terminator might 3510226031Sstas** need to be added to the string.</li> 3511226031Sstas** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3512226031Sstas** sqlite3_column_text16() is called. The content must be converted 3513226031Sstas** to UTF-16.</li> 3514226031Sstas** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3515226031Sstas** sqlite3_column_text() is called. The content must be converted 3516226031Sstas** to UTF-8.</li> 3517226128Sstas** </ul> 3518226031Sstas** 3519226031Sstas** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3520226031Sstas** not invalidate a prior pointer, though of course the content of the buffer 3521226128Sstas** that the prior pointer references will have been modified. Other kinds 3522226031Sstas** of conversion are done in place when it is possible, but sometimes they 3523226031Sstas** are not possible and in those cases prior pointers are invalidated. 3524226031Sstas** 3525226128Sstas** The safest and easiest to remember policy is to invoke these routines 3526226031Sstas** in one of the following ways: 3527226031Sstas** 3528226031Sstas** <ul> 3529226031Sstas** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3530226031Sstas** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3531226031Sstas** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3532226128Sstas** </ul> 3533226031Sstas** 3534226031Sstas** In other words, you should call sqlite3_column_text(), 3535226031Sstas** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3536226031Sstas** into the desired format, then invoke sqlite3_column_bytes() or 3537226031Sstas** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3538226031Sstas** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3539226031Sstas** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3540226031Sstas** with calls to sqlite3_column_bytes(). 3541226031Sstas** 3542226031Sstas** ^The pointers returned are valid until a type conversion occurs as 3543226031Sstas** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3544226031Sstas** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3545226031Sstas** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3546226031Sstas** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3547226031Sstas** [sqlite3_free()]. 3548226031Sstas** 3549226031Sstas** ^(If a memory allocation error occurs during the evaluation of any 3550226031Sstas** of these routines, a default value is returned. The default value 3551226031Sstas** is either the integer 0, the floating point number 0.0, or a NULL 3552226031Sstas** pointer. Subsequent calls to [sqlite3_errcode()] will return 3553226031Sstas** [SQLITE_NOMEM].)^ 3554226031Sstas*/ 3555226031SstasSQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3556226031SstasSQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3557226031SstasSQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3558226031SstasSQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3559226031SstasSQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3560226031SstasSQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3561226031SstasSQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3562226031SstasSQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3563226031SstasSQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3564226031SstasSQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3565226031Sstas 3566226031Sstas/* 3567226031Sstas** CAPI3REF: Destroy A Prepared Statement Object 3568226031Sstas** 3569226031Sstas** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3570226128Sstas** ^If the most recent evaluation of the statement encountered no errors 3571226128Sstas** or if the statement is never been evaluated, then sqlite3_finalize() returns 3572226128Sstas** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3573226128Sstas** sqlite3_finalize(S) returns the appropriate [error code] or 3574226128Sstas** [extended error code]. 3575226031Sstas** 3576226128Sstas** ^The sqlite3_finalize(S) routine can be called at any point during 3577226128Sstas** the life cycle of [prepared statement] S: 3578226128Sstas** before statement S is ever evaluated, after 3579226128Sstas** one or more calls to [sqlite3_reset()], or after any call 3580226128Sstas** to [sqlite3_step()] regardless of whether or not the statement has 3581226128Sstas** completed execution. 3582226128Sstas** 3583226128Sstas** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3584226128Sstas** 3585226128Sstas** The application must finalize every [prepared statement] in order to avoid 3586226128Sstas** resource leaks. It is a grievous error for the application to try to use 3587226128Sstas** a prepared statement after it has been finalized. Any use of a prepared 3588226128Sstas** statement after it has been finalized can result in undefined and 3589226128Sstas** undesirable behavior such as segfaults and heap corruption. 3590226031Sstas*/ 3591226031SstasSQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3592226031Sstas 3593226031Sstas/* 3594226031Sstas** CAPI3REF: Reset A Prepared Statement Object 3595226031Sstas** 3596226031Sstas** The sqlite3_reset() function is called to reset a [prepared statement] 3597226031Sstas** object back to its initial state, ready to be re-executed. 3598226031Sstas** ^Any SQL statement variables that had values bound to them using 3599226031Sstas** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3600226031Sstas** Use [sqlite3_clear_bindings()] to reset the bindings. 3601226031Sstas** 3602226031Sstas** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3603226031Sstas** back to the beginning of its program. 3604226031Sstas** 3605226031Sstas** ^If the most recent call to [sqlite3_step(S)] for the 3606226031Sstas** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3607226031Sstas** or if [sqlite3_step(S)] has never before been called on S, 3608226031Sstas** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3609226031Sstas** 3610226031Sstas** ^If the most recent call to [sqlite3_step(S)] for the 3611226031Sstas** [prepared statement] S indicated an error, then 3612226031Sstas** [sqlite3_reset(S)] returns an appropriate [error code]. 3613226031Sstas** 3614226031Sstas** ^The [sqlite3_reset(S)] interface does not change the values 3615226031Sstas** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3616226031Sstas*/ 3617226031SstasSQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3618226031Sstas 3619226031Sstas/* 3620226031Sstas** CAPI3REF: Create Or Redefine SQL Functions 3621226031Sstas** KEYWORDS: {function creation routines} 3622226031Sstas** KEYWORDS: {application-defined SQL function} 3623226031Sstas** KEYWORDS: {application-defined SQL functions} 3624226031Sstas** 3625226128Sstas** ^These functions (collectively known as "function creation routines") 3626226031Sstas** are used to add SQL functions or aggregates or to redefine the behavior 3627226128Sstas** of existing SQL functions or aggregates. The only differences between 3628226128Sstas** these routines are the text encoding expected for 3629226128Sstas** the second parameter (the name of the function being created) 3630226128Sstas** and the presence or absence of a destructor callback for 3631226128Sstas** the application data pointer. 3632226031Sstas** 3633226031Sstas** ^The first parameter is the [database connection] to which the SQL 3634226031Sstas** function is to be added. ^If an application uses more than one database 3635226031Sstas** connection then application-defined SQL functions must be added 3636226031Sstas** to each database connection separately. 3637226031Sstas** 3638226128Sstas** ^The second parameter is the name of the SQL function to be created or 3639226128Sstas** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3640226128Sstas** representation, exclusive of the zero-terminator. ^Note that the name 3641226128Sstas** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3642226128Sstas** ^Any attempt to create a function with a longer name 3643226128Sstas** will result in [SQLITE_MISUSE] being returned. 3644226031Sstas** 3645226031Sstas** ^The third parameter (nArg) 3646226031Sstas** is the number of arguments that the SQL function or 3647226031Sstas** aggregate takes. ^If this parameter is -1, then the SQL function or 3648226031Sstas** aggregate may take any number of arguments between 0 and the limit 3649226031Sstas** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3650226031Sstas** parameter is less than -1 or greater than 127 then the behavior is 3651226031Sstas** undefined. 3652226031Sstas** 3653226128Sstas** ^The fourth parameter, eTextRep, specifies what 3654226031Sstas** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3655226128Sstas** its parameters. Every SQL function implementation must be able to work 3656226128Sstas** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3657226031Sstas** more efficient with one encoding than another. ^An application may 3658226031Sstas** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3659226031Sstas** times with the same function but with different values of eTextRep. 3660226031Sstas** ^When multiple implementations of the same function are available, SQLite 3661226031Sstas** will pick the one that involves the least amount of data conversion. 3662226031Sstas** If there is only a single implementation which does not care what text 3663226031Sstas** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3664226031Sstas** 3665226031Sstas** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3666226031Sstas** function can gain access to this pointer using [sqlite3_user_data()].)^ 3667226031Sstas** 3668226128Sstas** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3669226031Sstas** pointers to C-language functions that implement the SQL function or 3670226031Sstas** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3671226128Sstas** callback only; NULL pointers must be passed as the xStep and xFinal 3672226031Sstas** parameters. ^An aggregate SQL function requires an implementation of xStep 3673226128Sstas** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3674226128Sstas** SQL function or aggregate, pass NULL pointers for all three function 3675226128Sstas** callbacks. 3676226031Sstas** 3677226128Sstas** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3678226128Sstas** then it is destructor for the application data pointer. 3679226128Sstas** The destructor is invoked when the function is deleted, either by being 3680226128Sstas** overloaded or when the database connection closes.)^ 3681226128Sstas** ^The destructor is also invoked if the call to 3682226128Sstas** sqlite3_create_function_v2() fails. 3683226128Sstas** ^When the destructor callback of the tenth parameter is invoked, it 3684226128Sstas** is passed a single argument which is a copy of the application data 3685226128Sstas** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3686226128Sstas** 3687226031Sstas** ^It is permitted to register multiple implementations of the same 3688226031Sstas** functions with the same name but with either differing numbers of 3689226031Sstas** arguments or differing preferred text encodings. ^SQLite will use 3690226031Sstas** the implementation that most closely matches the way in which the 3691226031Sstas** SQL function is used. ^A function implementation with a non-negative 3692226031Sstas** nArg parameter is a better match than a function implementation with 3693226031Sstas** a negative nArg. ^A function where the preferred text encoding 3694226031Sstas** matches the database encoding is a better 3695226128Sstas** match than a function where the encoding is different. 3696226031Sstas** ^A function where the encoding difference is between UTF16le and UTF16be 3697226031Sstas** is a closer match than a function where the encoding difference is 3698226031Sstas** between UTF8 and UTF16. 3699226031Sstas** 3700226031Sstas** ^Built-in functions may be overloaded by new application-defined functions. 3701226031Sstas** 3702226031Sstas** ^An application-defined function is permitted to call other 3703226031Sstas** SQLite interfaces. However, such calls must not 3704226031Sstas** close the database connection nor finalize or reset the prepared 3705226031Sstas** statement in which the function is running. 3706226031Sstas*/ 3707226031SstasSQLITE_API int sqlite3_create_function( 3708226031Sstas sqlite3 *db, 3709226031Sstas const char *zFunctionName, 3710226031Sstas int nArg, 3711226031Sstas int eTextRep, 3712226031Sstas void *pApp, 3713226031Sstas void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3714226031Sstas void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3715226031Sstas void (*xFinal)(sqlite3_context*) 3716226031Sstas); 3717226031SstasSQLITE_API int sqlite3_create_function16( 3718226031Sstas sqlite3 *db, 3719226031Sstas const void *zFunctionName, 3720226031Sstas int nArg, 3721226031Sstas int eTextRep, 3722226031Sstas void *pApp, 3723226031Sstas void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3724226031Sstas void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3725226031Sstas void (*xFinal)(sqlite3_context*) 3726226031Sstas); 3727226128SstasSQLITE_API int sqlite3_create_function_v2( 3728226128Sstas sqlite3 *db, 3729226128Sstas const char *zFunctionName, 3730226128Sstas int nArg, 3731226128Sstas int eTextRep, 3732226128Sstas void *pApp, 3733226128Sstas void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3734226128Sstas void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3735226128Sstas void (*xFinal)(sqlite3_context*), 3736226128Sstas void(*xDestroy)(void*) 3737226128Sstas); 3738226031Sstas 3739226031Sstas/* 3740226031Sstas** CAPI3REF: Text Encodings 3741226031Sstas** 3742226031Sstas** These constant define integer codes that represent the various 3743226031Sstas** text encodings supported by SQLite. 3744226031Sstas*/ 3745226031Sstas#define SQLITE_UTF8 1 3746226031Sstas#define SQLITE_UTF16LE 2 3747226031Sstas#define SQLITE_UTF16BE 3 3748226031Sstas#define SQLITE_UTF16 4 /* Use native byte order */ 3749226031Sstas#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3750226031Sstas#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3751226031Sstas 3752226031Sstas/* 3753226031Sstas** CAPI3REF: Deprecated Functions 3754226031Sstas** DEPRECATED 3755226031Sstas** 3756226031Sstas** These functions are [deprecated]. In order to maintain 3757226128Sstas** backwards compatibility with older code, these functions continue 3758226031Sstas** to be supported. However, new applications should avoid 3759226031Sstas** the use of these functions. To help encourage people to avoid 3760226031Sstas** using these functions, we are not going to tell you what they do. 3761226031Sstas*/ 3762226031Sstas#ifndef SQLITE_OMIT_DEPRECATED 3763226031SstasSQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3764226031SstasSQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3765226031SstasSQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3766226031SstasSQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 3767226031SstasSQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3768226031SstasSQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3769226031Sstas#endif 3770226031Sstas 3771226031Sstas/* 3772226031Sstas** CAPI3REF: Obtaining SQL Function Parameter Values 3773226031Sstas** 3774226031Sstas** The C-language implementation of SQL functions and aggregates uses 3775226031Sstas** this set of interface routines to access the parameter values on 3776226031Sstas** the function or aggregate. 3777226031Sstas** 3778226031Sstas** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3779226031Sstas** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3780226031Sstas** define callbacks that implement the SQL functions and aggregates. 3781226128Sstas** The 3rd parameter to these callbacks is an array of pointers to 3782226031Sstas** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3783226031Sstas** each parameter to the SQL function. These routines are used to 3784226031Sstas** extract values from the [sqlite3_value] objects. 3785226031Sstas** 3786226031Sstas** These routines work only with [protected sqlite3_value] objects. 3787226031Sstas** Any attempt to use these routines on an [unprotected sqlite3_value] 3788226031Sstas** object results in undefined behavior. 3789226031Sstas** 3790226031Sstas** ^These routines work just like the corresponding [column access functions] 3791226031Sstas** except that these routines take a single [protected sqlite3_value] object 3792226031Sstas** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3793226031Sstas** 3794226031Sstas** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3795226031Sstas** in the native byte-order of the host machine. ^The 3796226031Sstas** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3797226031Sstas** extract UTF-16 strings as big-endian and little-endian respectively. 3798226031Sstas** 3799226031Sstas** ^(The sqlite3_value_numeric_type() interface attempts to apply 3800226031Sstas** numeric affinity to the value. This means that an attempt is 3801226031Sstas** made to convert the value to an integer or floating point. If 3802226031Sstas** such a conversion is possible without loss of information (in other 3803226031Sstas** words, if the value is a string that looks like a number) 3804226031Sstas** then the conversion is performed. Otherwise no conversion occurs. 3805226031Sstas** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3806226031Sstas** 3807226031Sstas** Please pay particular attention to the fact that the pointer returned 3808226031Sstas** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3809226031Sstas** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3810226031Sstas** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3811226031Sstas** or [sqlite3_value_text16()]. 3812226031Sstas** 3813226031Sstas** These routines must be called from the same thread as 3814226031Sstas** the SQL function that supplied the [sqlite3_value*] parameters. 3815226031Sstas*/ 3816226031SstasSQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 3817226031SstasSQLITE_API int sqlite3_value_bytes(sqlite3_value*); 3818226031SstasSQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 3819226031SstasSQLITE_API double sqlite3_value_double(sqlite3_value*); 3820226031SstasSQLITE_API int sqlite3_value_int(sqlite3_value*); 3821226031SstasSQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3822226031SstasSQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 3823226031SstasSQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 3824226031SstasSQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 3825226031SstasSQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 3826226031SstasSQLITE_API int sqlite3_value_type(sqlite3_value*); 3827226031SstasSQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 3828226031Sstas 3829226031Sstas/* 3830226031Sstas** CAPI3REF: Obtain Aggregate Function Context 3831226031Sstas** 3832226128Sstas** Implementations of aggregate SQL functions use this 3833226031Sstas** routine to allocate memory for storing their state. 3834226031Sstas** 3835226128Sstas** ^The first time the sqlite3_aggregate_context(C,N) routine is called 3836226031Sstas** for a particular aggregate function, SQLite 3837226031Sstas** allocates N of memory, zeroes out that memory, and returns a pointer 3838226031Sstas** to the new memory. ^On second and subsequent calls to 3839226031Sstas** sqlite3_aggregate_context() for the same aggregate function instance, 3840226031Sstas** the same buffer is returned. Sqlite3_aggregate_context() is normally 3841226031Sstas** called once for each invocation of the xStep callback and then one 3842226031Sstas** last time when the xFinal callback is invoked. ^(When no rows match 3843226031Sstas** an aggregate query, the xStep() callback of the aggregate function 3844226031Sstas** implementation is never called and xFinal() is called exactly once. 3845226031Sstas** In those cases, sqlite3_aggregate_context() might be called for the 3846226031Sstas** first time from within xFinal().)^ 3847226031Sstas** 3848226031Sstas** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 3849226031Sstas** less than or equal to zero or if a memory allocate error occurs. 3850226031Sstas** 3851226031Sstas** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 3852226031Sstas** determined by the N parameter on first successful call. Changing the 3853226031Sstas** value of N in subsequent call to sqlite3_aggregate_context() within 3854226031Sstas** the same aggregate function instance will not resize the memory 3855226031Sstas** allocation.)^ 3856226031Sstas** 3857226128Sstas** ^SQLite automatically frees the memory allocated by 3858226031Sstas** sqlite3_aggregate_context() when the aggregate query concludes. 3859226031Sstas** 3860226031Sstas** The first parameter must be a copy of the 3861226031Sstas** [sqlite3_context | SQL function context] that is the first parameter 3862226031Sstas** to the xStep or xFinal callback routine that implements the aggregate 3863226031Sstas** function. 3864226031Sstas** 3865226031Sstas** This routine must be called from the same thread in which 3866226031Sstas** the aggregate SQL function is running. 3867226031Sstas*/ 3868226031SstasSQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3869226031Sstas 3870226031Sstas/* 3871226031Sstas** CAPI3REF: User Data For Functions 3872226031Sstas** 3873226031Sstas** ^The sqlite3_user_data() interface returns a copy of 3874226031Sstas** the pointer that was the pUserData parameter (the 5th parameter) 3875226031Sstas** of the [sqlite3_create_function()] 3876226031Sstas** and [sqlite3_create_function16()] routines that originally 3877226031Sstas** registered the application defined function. 3878226031Sstas** 3879226031Sstas** This routine must be called from the same thread in which 3880226031Sstas** the application-defined function is running. 3881226031Sstas*/ 3882226031SstasSQLITE_API void *sqlite3_user_data(sqlite3_context*); 3883226031Sstas 3884226031Sstas/* 3885226031Sstas** CAPI3REF: Database Connection For Functions 3886226031Sstas** 3887226031Sstas** ^The sqlite3_context_db_handle() interface returns a copy of 3888226031Sstas** the pointer to the [database connection] (the 1st parameter) 3889226031Sstas** of the [sqlite3_create_function()] 3890226031Sstas** and [sqlite3_create_function16()] routines that originally 3891226031Sstas** registered the application defined function. 3892226031Sstas*/ 3893226031SstasSQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3894226031Sstas 3895226031Sstas/* 3896226031Sstas** CAPI3REF: Function Auxiliary Data 3897226031Sstas** 3898226031Sstas** The following two functions may be used by scalar SQL functions to 3899226031Sstas** associate metadata with argument values. If the same value is passed to 3900226031Sstas** multiple invocations of the same SQL function during query execution, under 3901226031Sstas** some circumstances the associated metadata may be preserved. This may 3902226031Sstas** be used, for example, to add a regular-expression matching scalar 3903226031Sstas** function. The compiled version of the regular expression is stored as 3904226031Sstas** metadata associated with the SQL value passed as the regular expression 3905226031Sstas** pattern. The compiled regular expression can be reused on multiple 3906226031Sstas** invocations of the same function so that the original pattern string 3907226031Sstas** does not need to be recompiled on each invocation. 3908226031Sstas** 3909226031Sstas** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 3910226031Sstas** associated by the sqlite3_set_auxdata() function with the Nth argument 3911226031Sstas** value to the application-defined function. ^If no metadata has been ever 3912226031Sstas** been set for the Nth argument of the function, or if the corresponding 3913226031Sstas** function parameter has changed since the meta-data was set, 3914226031Sstas** then sqlite3_get_auxdata() returns a NULL pointer. 3915226031Sstas** 3916226031Sstas** ^The sqlite3_set_auxdata() interface saves the metadata 3917226031Sstas** pointed to by its 3rd parameter as the metadata for the N-th 3918226031Sstas** argument of the application-defined function. Subsequent 3919226031Sstas** calls to sqlite3_get_auxdata() might return this data, if it has 3920226031Sstas** not been destroyed. 3921226031Sstas** ^If it is not NULL, SQLite will invoke the destructor 3922226031Sstas** function given by the 4th parameter to sqlite3_set_auxdata() on 3923226031Sstas** the metadata when the corresponding function parameter changes 3924226031Sstas** or when the SQL statement completes, whichever comes first. 3925226031Sstas** 3926226031Sstas** SQLite is free to call the destructor and drop metadata on any 3927226031Sstas** parameter of any function at any time. ^The only guarantee is that 3928226031Sstas** the destructor will be called before the metadata is dropped. 3929226031Sstas** 3930226031Sstas** ^(In practice, metadata is preserved between function calls for 3931226031Sstas** expressions that are constant at compile time. This includes literal 3932226031Sstas** values and [parameters].)^ 3933226031Sstas** 3934226031Sstas** These routines must be called from the same thread in which 3935226031Sstas** the SQL function is running. 3936226031Sstas*/ 3937226031SstasSQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 3938226031SstasSQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3939226031Sstas 3940226031Sstas 3941226031Sstas/* 3942226031Sstas** CAPI3REF: Constants Defining Special Destructor Behavior 3943226031Sstas** 3944226031Sstas** These are special values for the destructor that is passed in as the 3945226031Sstas** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 3946226031Sstas** argument is SQLITE_STATIC, it means that the content pointer is constant 3947226031Sstas** and will never change. It does not need to be destroyed. ^The 3948226031Sstas** SQLITE_TRANSIENT value means that the content will likely change in 3949226031Sstas** the near future and that SQLite should make its own private copy of 3950226031Sstas** the content before returning. 3951226031Sstas** 3952226031Sstas** The typedef is necessary to work around problems in certain 3953226031Sstas** C++ compilers. See ticket #2191. 3954226031Sstas*/ 3955226031Sstastypedef void (*sqlite3_destructor_type)(void*); 3956226031Sstas#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3957226031Sstas#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3958226031Sstas 3959226031Sstas/* 3960226031Sstas** CAPI3REF: Setting The Result Of An SQL Function 3961226031Sstas** 3962226031Sstas** These routines are used by the xFunc or xFinal callbacks that 3963226031Sstas** implement SQL functions and aggregates. See 3964226031Sstas** [sqlite3_create_function()] and [sqlite3_create_function16()] 3965226031Sstas** for additional information. 3966226031Sstas** 3967226031Sstas** These functions work very much like the [parameter binding] family of 3968226031Sstas** functions used to bind values to host parameters in prepared statements. 3969226031Sstas** Refer to the [SQL parameter] documentation for additional information. 3970226031Sstas** 3971226031Sstas** ^The sqlite3_result_blob() interface sets the result from 3972226031Sstas** an application-defined function to be the BLOB whose content is pointed 3973226031Sstas** to by the second parameter and which is N bytes long where N is the 3974226031Sstas** third parameter. 3975226031Sstas** 3976226031Sstas** ^The sqlite3_result_zeroblob() interfaces set the result of 3977226031Sstas** the application-defined function to be a BLOB containing all zero 3978226031Sstas** bytes and N bytes in size, where N is the value of the 2nd parameter. 3979226031Sstas** 3980226031Sstas** ^The sqlite3_result_double() interface sets the result from 3981226031Sstas** an application-defined function to be a floating point value specified 3982226031Sstas** by its 2nd argument. 3983226031Sstas** 3984226031Sstas** ^The sqlite3_result_error() and sqlite3_result_error16() functions 3985226031Sstas** cause the implemented SQL function to throw an exception. 3986226031Sstas** ^SQLite uses the string pointed to by the 3987226031Sstas** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3988226031Sstas** as the text of an error message. ^SQLite interprets the error 3989226031Sstas** message string from sqlite3_result_error() as UTF-8. ^SQLite 3990226031Sstas** interprets the string from sqlite3_result_error16() as UTF-16 in native 3991226031Sstas** byte order. ^If the third parameter to sqlite3_result_error() 3992226031Sstas** or sqlite3_result_error16() is negative then SQLite takes as the error 3993226031Sstas** message all text up through the first zero character. 3994226031Sstas** ^If the third parameter to sqlite3_result_error() or 3995226031Sstas** sqlite3_result_error16() is non-negative then SQLite takes that many 3996226031Sstas** bytes (not characters) from the 2nd parameter as the error message. 3997226031Sstas** ^The sqlite3_result_error() and sqlite3_result_error16() 3998226031Sstas** routines make a private copy of the error message text before 3999226031Sstas** they return. Hence, the calling function can deallocate or 4000226031Sstas** modify the text after they return without harm. 4001226031Sstas** ^The sqlite3_result_error_code() function changes the error code 4002226031Sstas** returned by SQLite as a result of an error in a function. ^By default, 4003226031Sstas** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4004226031Sstas** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4005226031Sstas** 4006226031Sstas** ^The sqlite3_result_toobig() interface causes SQLite to throw an error 4007226031Sstas** indicating that a string or BLOB is too long to represent. 4008226031Sstas** 4009226031Sstas** ^The sqlite3_result_nomem() interface causes SQLite to throw an error 4010226031Sstas** indicating that a memory allocation failed. 4011226031Sstas** 4012226031Sstas** ^The sqlite3_result_int() interface sets the return value 4013226031Sstas** of the application-defined function to be the 32-bit signed integer 4014226031Sstas** value given in the 2nd argument. 4015226031Sstas** ^The sqlite3_result_int64() interface sets the return value 4016226031Sstas** of the application-defined function to be the 64-bit signed integer 4017226031Sstas** value given in the 2nd argument. 4018226031Sstas** 4019226031Sstas** ^The sqlite3_result_null() interface sets the return value 4020226031Sstas** of the application-defined function to be NULL. 4021226031Sstas** 4022226031Sstas** ^The sqlite3_result_text(), sqlite3_result_text16(), 4023226031Sstas** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4024226031Sstas** set the return value of the application-defined function to be 4025226031Sstas** a text string which is represented as UTF-8, UTF-16 native byte order, 4026226031Sstas** UTF-16 little endian, or UTF-16 big endian, respectively. 4027226031Sstas** ^SQLite takes the text result from the application from 4028226031Sstas** the 2nd parameter of the sqlite3_result_text* interfaces. 4029226031Sstas** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4030226031Sstas** is negative, then SQLite takes result text from the 2nd parameter 4031226031Sstas** through the first zero character. 4032226031Sstas** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4033226031Sstas** is non-negative, then as many bytes (not characters) of the text 4034226031Sstas** pointed to by the 2nd parameter are taken as the application-defined 4035226031Sstas** function result. 4036226031Sstas** ^If the 4th parameter to the sqlite3_result_text* interfaces 4037226031Sstas** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4038226031Sstas** function as the destructor on the text or BLOB result when it has 4039226031Sstas** finished using that result. 4040226031Sstas** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4041226031Sstas** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4042226031Sstas** assumes that the text or BLOB result is in constant space and does not 4043226031Sstas** copy the content of the parameter nor call a destructor on the content 4044226031Sstas** when it has finished using that result. 4045226031Sstas** ^If the 4th parameter to the sqlite3_result_text* interfaces 4046226031Sstas** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4047226031Sstas** then SQLite makes a copy of the result into space obtained from 4048226031Sstas** from [sqlite3_malloc()] before it returns. 4049226031Sstas** 4050226031Sstas** ^The sqlite3_result_value() interface sets the result of 4051226031Sstas** the application-defined function to be a copy the 4052226031Sstas** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4053226031Sstas** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4054226031Sstas** so that the [sqlite3_value] specified in the parameter may change or 4055226031Sstas** be deallocated after sqlite3_result_value() returns without harm. 4056226031Sstas** ^A [protected sqlite3_value] object may always be used where an 4057226031Sstas** [unprotected sqlite3_value] object is required, so either 4058226031Sstas** kind of [sqlite3_value] object can be used with this interface. 4059226031Sstas** 4060226031Sstas** If these routines are called from within the different thread 4061226031Sstas** than the one containing the application-defined function that received 4062226031Sstas** the [sqlite3_context] pointer, the results are undefined. 4063226031Sstas*/ 4064226031SstasSQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4065226031SstasSQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4066226031SstasSQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4067226031SstasSQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4068226031SstasSQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4069226031SstasSQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4070226031SstasSQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4071226031SstasSQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4072226031SstasSQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4073226031SstasSQLITE_API void sqlite3_result_null(sqlite3_context*); 4074226031SstasSQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4075226031SstasSQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4076226031SstasSQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4077226031SstasSQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4078226031SstasSQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4079226031SstasSQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4080226031Sstas 4081226031Sstas/* 4082226031Sstas** CAPI3REF: Define New Collating Sequences 4083226031Sstas** 4084226128Sstas** ^These functions add, remove, or modify a [collation] associated 4085226128Sstas** with the [database connection] specified as the first argument. 4086226031Sstas** 4087226128Sstas** ^The name of the collation is a UTF-8 string 4088226031Sstas** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4089226128Sstas** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4090226128Sstas** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4091226128Sstas** considered to be the same name. 4092226031Sstas** 4093226128Sstas** ^(The third argument (eTextRep) must be one of the constants: 4094226128Sstas** <ul> 4095226128Sstas** <li> [SQLITE_UTF8], 4096226128Sstas** <li> [SQLITE_UTF16LE], 4097226128Sstas** <li> [SQLITE_UTF16BE], 4098226128Sstas** <li> [SQLITE_UTF16], or 4099226128Sstas** <li> [SQLITE_UTF16_ALIGNED]. 4100226128Sstas** </ul>)^ 4101226128Sstas** ^The eTextRep argument determines the encoding of strings passed 4102226128Sstas** to the collating function callback, xCallback. 4103226128Sstas** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4104226128Sstas** force strings to be UTF16 with native byte order. 4105226128Sstas** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4106226128Sstas** on an even byte address. 4107226031Sstas** 4108226128Sstas** ^The fourth argument, pArg, is an application data pointer that is passed 4109226128Sstas** through as the first argument to the collating function callback. 4110226031Sstas** 4111226128Sstas** ^The fifth argument, xCallback, is a pointer to the collating function. 4112226128Sstas** ^Multiple collating functions can be registered using the same name but 4113226128Sstas** with different eTextRep parameters and SQLite will use whichever 4114226128Sstas** function requires the least amount of data transformation. 4115226128Sstas** ^If the xCallback argument is NULL then the collating function is 4116226128Sstas** deleted. ^When all collating functions having the same name are deleted, 4117226128Sstas** that collation is no longer usable. 4118226031Sstas** 4119226128Sstas** ^The collating function callback is invoked with a copy of the pArg 4120226128Sstas** application data pointer and with two strings in the encoding specified 4121226128Sstas** by the eTextRep argument. The collating function must return an 4122226128Sstas** integer that is negative, zero, or positive 4123226128Sstas** if the first string is less than, equal to, or greater than the second, 4124226128Sstas** respectively. A collating function must always return the same answer 4125226128Sstas** given the same inputs. If two or more collating functions are registered 4126226128Sstas** to the same collation name (using different eTextRep values) then all 4127226128Sstas** must give an equivalent answer when invoked with equivalent strings. 4128226128Sstas** The collating function must obey the following properties for all 4129226128Sstas** strings A, B, and C: 4130226128Sstas** 4131226128Sstas** <ol> 4132226128Sstas** <li> If A==B then B==A. 4133226128Sstas** <li> If A==B and B==C then A==C. 4134226128Sstas** <li> If A<B THEN B>A. 4135226128Sstas** <li> If A<B and B<C then A<C. 4136226128Sstas** </ol> 4137226128Sstas** 4138226128Sstas** If a collating function fails any of the above constraints and that 4139226128Sstas** collating function is registered and used, then the behavior of SQLite 4140226128Sstas** is undefined. 4141226128Sstas** 4142226031Sstas** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4143226128Sstas** with the addition that the xDestroy callback is invoked on pArg when 4144226128Sstas** the collating function is deleted. 4145226128Sstas** ^Collating functions are deleted when they are overridden by later 4146226128Sstas** calls to the collation creation functions or when the 4147226128Sstas** [database connection] is closed using [sqlite3_close()]. 4148226031Sstas** 4149226128Sstas** ^The xDestroy callback is <u>not</u> called if the 4150226128Sstas** sqlite3_create_collation_v2() function fails. Applications that invoke 4151226128Sstas** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4152226128Sstas** check the return code and dispose of the application data pointer 4153226128Sstas** themselves rather than expecting SQLite to deal with it for them. 4154226128Sstas** This is different from every other SQLite interface. The inconsistency 4155226128Sstas** is unfortunate but cannot be changed without breaking backwards 4156226128Sstas** compatibility. 4157226128Sstas** 4158226031Sstas** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4159226031Sstas*/ 4160226031SstasSQLITE_API int sqlite3_create_collation( 4161226128Sstas sqlite3*, 4162226128Sstas const char *zName, 4163226128Sstas int eTextRep, 4164226128Sstas void *pArg, 4165226031Sstas int(*xCompare)(void*,int,const void*,int,const void*) 4166226031Sstas); 4167226031SstasSQLITE_API int sqlite3_create_collation_v2( 4168226128Sstas sqlite3*, 4169226128Sstas const char *zName, 4170226128Sstas int eTextRep, 4171226128Sstas void *pArg, 4172226031Sstas int(*xCompare)(void*,int,const void*,int,const void*), 4173226031Sstas void(*xDestroy)(void*) 4174226031Sstas); 4175226031SstasSQLITE_API int sqlite3_create_collation16( 4176226128Sstas sqlite3*, 4177226031Sstas const void *zName, 4178226128Sstas int eTextRep, 4179226128Sstas void *pArg, 4180226031Sstas int(*xCompare)(void*,int,const void*,int,const void*) 4181226031Sstas); 4182226031Sstas 4183226031Sstas/* 4184226031Sstas** CAPI3REF: Collation Needed Callbacks 4185226031Sstas** 4186226031Sstas** ^To avoid having to register all collation sequences before a database 4187226031Sstas** can be used, a single callback function may be registered with the 4188226031Sstas** [database connection] to be invoked whenever an undefined collation 4189226031Sstas** sequence is required. 4190226031Sstas** 4191226031Sstas** ^If the function is registered using the sqlite3_collation_needed() API, 4192226031Sstas** then it is passed the names of undefined collation sequences as strings 4193226031Sstas** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4194226031Sstas** the names are passed as UTF-16 in machine native byte order. 4195226031Sstas** ^A call to either function replaces the existing collation-needed callback. 4196226031Sstas** 4197226031Sstas** ^(When the callback is invoked, the first argument passed is a copy 4198226031Sstas** of the second argument to sqlite3_collation_needed() or 4199226031Sstas** sqlite3_collation_needed16(). The second argument is the database 4200226031Sstas** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4201226031Sstas** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4202226031Sstas** sequence function required. The fourth parameter is the name of the 4203226031Sstas** required collation sequence.)^ 4204226031Sstas** 4205226031Sstas** The callback function should register the desired collation using 4206226031Sstas** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4207226031Sstas** [sqlite3_create_collation_v2()]. 4208226031Sstas*/ 4209226031SstasSQLITE_API int sqlite3_collation_needed( 4210226128Sstas sqlite3*, 4211226128Sstas void*, 4212226031Sstas void(*)(void*,sqlite3*,int eTextRep,const char*) 4213226031Sstas); 4214226031SstasSQLITE_API int sqlite3_collation_needed16( 4215226128Sstas sqlite3*, 4216226031Sstas void*, 4217226031Sstas void(*)(void*,sqlite3*,int eTextRep,const void*) 4218226031Sstas); 4219226031Sstas 4220226128Sstas#ifdef SQLITE_HAS_CODEC 4221226031Sstas/* 4222226031Sstas** Specify the key for an encrypted database. This routine should be 4223226031Sstas** called right after sqlite3_open(). 4224226031Sstas** 4225226031Sstas** The code to implement this API is not available in the public release 4226226031Sstas** of SQLite. 4227226031Sstas*/ 4228226031SstasSQLITE_API int sqlite3_key( 4229226031Sstas sqlite3 *db, /* Database to be rekeyed */ 4230226031Sstas const void *pKey, int nKey /* The key */ 4231226031Sstas); 4232226031Sstas 4233226031Sstas/* 4234226031Sstas** Change the key on an open database. If the current database is not 4235226031Sstas** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4236226031Sstas** database is decrypted. 4237226031Sstas** 4238226031Sstas** The code to implement this API is not available in the public release 4239226031Sstas** of SQLite. 4240226031Sstas*/ 4241226031SstasSQLITE_API int sqlite3_rekey( 4242226031Sstas sqlite3 *db, /* Database to be rekeyed */ 4243226031Sstas const void *pKey, int nKey /* The new key */ 4244226031Sstas); 4245226031Sstas 4246226031Sstas/* 4247226128Sstas** Specify the activation key for a SEE database. Unless 4248226031Sstas** activated, none of the SEE routines will work. 4249226031Sstas*/ 4250226031SstasSQLITE_API void sqlite3_activate_see( 4251226031Sstas const char *zPassPhrase /* Activation phrase */ 4252226031Sstas); 4253226031Sstas#endif 4254226031Sstas 4255226031Sstas#ifdef SQLITE_ENABLE_CEROD 4256226031Sstas/* 4257226128Sstas** Specify the activation key for a CEROD database. Unless 4258226031Sstas** activated, none of the CEROD routines will work. 4259226031Sstas*/ 4260226031SstasSQLITE_API void sqlite3_activate_cerod( 4261226031Sstas const char *zPassPhrase /* Activation phrase */ 4262226031Sstas); 4263226031Sstas#endif 4264226031Sstas 4265226031Sstas/* 4266226031Sstas** CAPI3REF: Suspend Execution For A Short Time 4267226031Sstas** 4268226128Sstas** The sqlite3_sleep() function causes the current thread to suspend execution 4269226031Sstas** for at least a number of milliseconds specified in its parameter. 4270226031Sstas** 4271226128Sstas** If the operating system does not support sleep requests with 4272226031Sstas** millisecond time resolution, then the time will be rounded up to 4273226128Sstas** the nearest second. The number of milliseconds of sleep actually 4274226031Sstas** requested from the operating system is returned. 4275226031Sstas** 4276226031Sstas** ^SQLite implements this interface by calling the xSleep() 4277226128Sstas** method of the default [sqlite3_vfs] object. If the xSleep() method 4278226128Sstas** of the default VFS is not implemented correctly, or not implemented at 4279226128Sstas** all, then the behavior of sqlite3_sleep() may deviate from the description 4280226128Sstas** in the previous paragraphs. 4281226031Sstas*/ 4282226031SstasSQLITE_API int sqlite3_sleep(int); 4283226031Sstas 4284226031Sstas/* 4285226031Sstas** CAPI3REF: Name Of The Folder Holding Temporary Files 4286226031Sstas** 4287226031Sstas** ^(If this global variable is made to point to a string which is 4288226031Sstas** the name of a folder (a.k.a. directory), then all temporary files 4289226031Sstas** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4290226031Sstas** will be placed in that directory.)^ ^If this variable 4291226031Sstas** is a NULL pointer, then SQLite performs a search for an appropriate 4292226031Sstas** temporary file directory. 4293226031Sstas** 4294226031Sstas** It is not safe to read or modify this variable in more than one 4295226031Sstas** thread at a time. It is not safe to read or modify this variable 4296226031Sstas** if a [database connection] is being used at the same time in a separate 4297226031Sstas** thread. 4298226031Sstas** It is intended that this variable be set once 4299226031Sstas** as part of process initialization and before any SQLite interface 4300226031Sstas** routines have been called and that this variable remain unchanged 4301226031Sstas** thereafter. 4302226031Sstas** 4303226031Sstas** ^The [temp_store_directory pragma] may modify this variable and cause 4304226031Sstas** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4305226031Sstas** the [temp_store_directory pragma] always assumes that any string 4306226128Sstas** that this variable points to is held in memory obtained from 4307226031Sstas** [sqlite3_malloc] and the pragma may attempt to free that memory 4308226031Sstas** using [sqlite3_free]. 4309226031Sstas** Hence, if this variable is modified directly, either it should be 4310226031Sstas** made NULL or made to point to memory obtained from [sqlite3_malloc] 4311226031Sstas** or else the use of the [temp_store_directory pragma] should be avoided. 4312226031Sstas*/ 4313226031SstasSQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4314226031Sstas 4315226031Sstas/* 4316226031Sstas** CAPI3REF: Test For Auto-Commit Mode 4317226031Sstas** KEYWORDS: {autocommit mode} 4318226031Sstas** 4319226031Sstas** ^The sqlite3_get_autocommit() interface returns non-zero or 4320226031Sstas** zero if the given database connection is or is not in autocommit mode, 4321226031Sstas** respectively. ^Autocommit mode is on by default. 4322226031Sstas** ^Autocommit mode is disabled by a [BEGIN] statement. 4323226031Sstas** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4324226031Sstas** 4325226031Sstas** If certain kinds of errors occur on a statement within a multi-statement 4326226031Sstas** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4327226031Sstas** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4328226031Sstas** transaction might be rolled back automatically. The only way to 4329226031Sstas** find out whether SQLite automatically rolled back the transaction after 4330226031Sstas** an error is to use this function. 4331226031Sstas** 4332226031Sstas** If another thread changes the autocommit status of the database 4333226031Sstas** connection while this routine is running, then the return value 4334226031Sstas** is undefined. 4335226031Sstas*/ 4336226031SstasSQLITE_API int sqlite3_get_autocommit(sqlite3*); 4337226031Sstas 4338226031Sstas/* 4339226031Sstas** CAPI3REF: Find The Database Handle Of A Prepared Statement 4340226031Sstas** 4341226031Sstas** ^The sqlite3_db_handle interface returns the [database connection] handle 4342226031Sstas** to which a [prepared statement] belongs. ^The [database connection] 4343226031Sstas** returned by sqlite3_db_handle is the same [database connection] 4344226031Sstas** that was the first argument 4345226031Sstas** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4346226031Sstas** create the statement in the first place. 4347226031Sstas*/ 4348226031SstasSQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4349226031Sstas 4350226031Sstas/* 4351226031Sstas** CAPI3REF: Find the next prepared statement 4352226031Sstas** 4353226031Sstas** ^This interface returns a pointer to the next [prepared statement] after 4354226031Sstas** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4355226031Sstas** then this interface returns a pointer to the first prepared statement 4356226031Sstas** associated with the database connection pDb. ^If no prepared statement 4357226031Sstas** satisfies the conditions of this routine, it returns NULL. 4358226031Sstas** 4359226031Sstas** The [database connection] pointer D in a call to 4360226031Sstas** [sqlite3_next_stmt(D,S)] must refer to an open database 4361226031Sstas** connection and in particular must not be a NULL pointer. 4362226031Sstas*/ 4363226031SstasSQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4364226031Sstas 4365226031Sstas/* 4366226031Sstas** CAPI3REF: Commit And Rollback Notification Callbacks 4367226031Sstas** 4368226031Sstas** ^The sqlite3_commit_hook() interface registers a callback 4369226031Sstas** function to be invoked whenever a transaction is [COMMIT | committed]. 4370226031Sstas** ^Any callback set by a previous call to sqlite3_commit_hook() 4371226031Sstas** for the same database connection is overridden. 4372226031Sstas** ^The sqlite3_rollback_hook() interface registers a callback 4373226031Sstas** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4374226031Sstas** ^Any callback set by a previous call to sqlite3_rollback_hook() 4375226031Sstas** for the same database connection is overridden. 4376226031Sstas** ^The pArg argument is passed through to the callback. 4377226031Sstas** ^If the callback on a commit hook function returns non-zero, 4378226031Sstas** then the commit is converted into a rollback. 4379226031Sstas** 4380226031Sstas** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4381226031Sstas** return the P argument from the previous call of the same function 4382226031Sstas** on the same [database connection] D, or NULL for 4383226031Sstas** the first call for each function on D. 4384226031Sstas** 4385226031Sstas** The callback implementation must not do anything that will modify 4386226031Sstas** the database connection that invoked the callback. Any actions 4387226031Sstas** to modify the database connection must be deferred until after the 4388226031Sstas** completion of the [sqlite3_step()] call that triggered the commit 4389226031Sstas** or rollback hook in the first place. 4390226031Sstas** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4391226031Sstas** database connections for the meaning of "modify" in this paragraph. 4392226031Sstas** 4393226031Sstas** ^Registering a NULL function disables the callback. 4394226031Sstas** 4395226031Sstas** ^When the commit hook callback routine returns zero, the [COMMIT] 4396226031Sstas** operation is allowed to continue normally. ^If the commit hook 4397226031Sstas** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4398226031Sstas** ^The rollback hook is invoked on a rollback that results from a commit 4399226031Sstas** hook returning non-zero, just as it would be with any other rollback. 4400226031Sstas** 4401226031Sstas** ^For the purposes of this API, a transaction is said to have been 4402226031Sstas** rolled back if an explicit "ROLLBACK" statement is executed, or 4403226031Sstas** an error or constraint causes an implicit rollback to occur. 4404226031Sstas** ^The rollback callback is not invoked if a transaction is 4405226031Sstas** automatically rolled back because the database connection is closed. 4406226031Sstas** 4407226031Sstas** See also the [sqlite3_update_hook()] interface. 4408226031Sstas*/ 4409226031SstasSQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4410226031SstasSQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4411226031Sstas 4412226031Sstas/* 4413226031Sstas** CAPI3REF: Data Change Notification Callbacks 4414226031Sstas** 4415226031Sstas** ^The sqlite3_update_hook() interface registers a callback function 4416226031Sstas** with the [database connection] identified by the first argument 4417226031Sstas** to be invoked whenever a row is updated, inserted or deleted. 4418226031Sstas** ^Any callback set by a previous call to this function 4419226031Sstas** for the same database connection is overridden. 4420226031Sstas** 4421226031Sstas** ^The second argument is a pointer to the function to invoke when a 4422226031Sstas** row is updated, inserted or deleted. 4423226031Sstas** ^The first argument to the callback is a copy of the third argument 4424226031Sstas** to sqlite3_update_hook(). 4425226031Sstas** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4426226031Sstas** or [SQLITE_UPDATE], depending on the operation that caused the callback 4427226031Sstas** to be invoked. 4428226031Sstas** ^The third and fourth arguments to the callback contain pointers to the 4429226031Sstas** database and table name containing the affected row. 4430226031Sstas** ^The final callback parameter is the [rowid] of the row. 4431226031Sstas** ^In the case of an update, this is the [rowid] after the update takes place. 4432226031Sstas** 4433226031Sstas** ^(The update hook is not invoked when internal system tables are 4434226031Sstas** modified (i.e. sqlite_master and sqlite_sequence).)^ 4435226031Sstas** 4436226031Sstas** ^In the current implementation, the update hook 4437226031Sstas** is not invoked when duplication rows are deleted because of an 4438226031Sstas** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4439226031Sstas** invoked when rows are deleted using the [truncate optimization]. 4440226031Sstas** The exceptions defined in this paragraph might change in a future 4441226031Sstas** release of SQLite. 4442226031Sstas** 4443226031Sstas** The update hook implementation must not do anything that will modify 4444226031Sstas** the database connection that invoked the update hook. Any actions 4445226031Sstas** to modify the database connection must be deferred until after the 4446226031Sstas** completion of the [sqlite3_step()] call that triggered the update hook. 4447226031Sstas** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4448226031Sstas** database connections for the meaning of "modify" in this paragraph. 4449226031Sstas** 4450226031Sstas** ^The sqlite3_update_hook(D,C,P) function 4451226031Sstas** returns the P argument from the previous call 4452226031Sstas** on the same [database connection] D, or NULL for 4453226031Sstas** the first call on D. 4454226031Sstas** 4455226031Sstas** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4456226031Sstas** interfaces. 4457226031Sstas*/ 4458226031SstasSQLITE_API void *sqlite3_update_hook( 4459226128Sstas sqlite3*, 4460226031Sstas void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4461226031Sstas void* 4462226031Sstas); 4463226031Sstas 4464226031Sstas/* 4465226031Sstas** CAPI3REF: Enable Or Disable Shared Pager Cache 4466226031Sstas** KEYWORDS: {shared cache} 4467226031Sstas** 4468226031Sstas** ^(This routine enables or disables the sharing of the database cache 4469226031Sstas** and schema data structures between [database connection | connections] 4470226031Sstas** to the same database. Sharing is enabled if the argument is true 4471226031Sstas** and disabled if the argument is false.)^ 4472226031Sstas** 4473226031Sstas** ^Cache sharing is enabled and disabled for an entire process. 4474226031Sstas** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4475226031Sstas** sharing was enabled or disabled for each thread separately. 4476226031Sstas** 4477226031Sstas** ^(The cache sharing mode set by this interface effects all subsequent 4478226031Sstas** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4479226031Sstas** Existing database connections continue use the sharing mode 4480226031Sstas** that was in effect at the time they were opened.)^ 4481226031Sstas** 4482226031Sstas** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4483226031Sstas** successfully. An [error code] is returned otherwise.)^ 4484226031Sstas** 4485226031Sstas** ^Shared cache is disabled by default. But this might change in 4486226031Sstas** future releases of SQLite. Applications that care about shared 4487226031Sstas** cache setting should set it explicitly. 4488226031Sstas** 4489226031Sstas** See Also: [SQLite Shared-Cache Mode] 4490226031Sstas*/ 4491226031SstasSQLITE_API int sqlite3_enable_shared_cache(int); 4492226031Sstas 4493226031Sstas/* 4494226031Sstas** CAPI3REF: Attempt To Free Heap Memory 4495226031Sstas** 4496226031Sstas** ^The sqlite3_release_memory() interface attempts to free N bytes 4497226031Sstas** of heap memory by deallocating non-essential memory allocations 4498226031Sstas** held by the database library. Memory used to cache database 4499226031Sstas** pages to improve performance is an example of non-essential memory. 4500226031Sstas** ^sqlite3_release_memory() returns the number of bytes actually freed, 4501226031Sstas** which might be more or less than the amount requested. 4502226128Sstas** ^The sqlite3_release_memory() routine is a no-op returning zero 4503226128Sstas** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4504226031Sstas*/ 4505226031SstasSQLITE_API int sqlite3_release_memory(int); 4506226031Sstas 4507226031Sstas/* 4508226031Sstas** CAPI3REF: Impose A Limit On Heap Size 4509226031Sstas** 4510226128Sstas** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4511226128Sstas** soft limit on the amount of heap memory that may be allocated by SQLite. 4512226128Sstas** ^SQLite strives to keep heap memory utilization below the soft heap 4513226128Sstas** limit by reducing the number of pages held in the page cache 4514226128Sstas** as heap memory usages approaches the limit. 4515226128Sstas** ^The soft heap limit is "soft" because even though SQLite strives to stay 4516226128Sstas** below the limit, it will exceed the limit rather than generate 4517226128Sstas** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4518226128Sstas** is advisory only. 4519226031Sstas** 4520226128Sstas** ^The return value from sqlite3_soft_heap_limit64() is the size of 4521226128Sstas** the soft heap limit prior to the call. ^If the argument N is negative 4522226128Sstas** then no change is made to the soft heap limit. Hence, the current 4523226128Sstas** size of the soft heap limit can be determined by invoking 4524226128Sstas** sqlite3_soft_heap_limit64() with a negative argument. 4525226031Sstas** 4526226128Sstas** ^If the argument N is zero then the soft heap limit is disabled. 4527226031Sstas** 4528226128Sstas** ^(The soft heap limit is not enforced in the current implementation 4529226128Sstas** if one or more of following conditions are true: 4530226031Sstas** 4531226128Sstas** <ul> 4532226128Sstas** <li> The soft heap limit is set to zero. 4533226128Sstas** <li> Memory accounting is disabled using a combination of the 4534226128Sstas** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4535226128Sstas** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4536226128Sstas** <li> An alternative page cache implementation is specified using 4537226128Sstas** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...). 4538226128Sstas** <li> The page cache allocates from its own memory pool supplied 4539226128Sstas** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4540226128Sstas** from the heap. 4541226128Sstas** </ul>)^ 4542226128Sstas** 4543226128Sstas** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4544226128Sstas** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4545226128Sstas** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4546226128Sstas** the soft heap limit is enforced on every memory allocation. Without 4547226128Sstas** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4548226128Sstas** when memory is allocated by the page cache. Testing suggests that because 4549226128Sstas** the page cache is the predominate memory user in SQLite, most 4550226128Sstas** applications will achieve adequate soft heap limit enforcement without 4551226128Sstas** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4552226128Sstas** 4553226128Sstas** The circumstances under which SQLite will enforce the soft heap limit may 4554226128Sstas** changes in future releases of SQLite. 4555226031Sstas*/ 4556226128SstasSQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4557226031Sstas 4558226031Sstas/* 4559226128Sstas** CAPI3REF: Deprecated Soft Heap Limit Interface 4560226128Sstas** DEPRECATED 4561226128Sstas** 4562226128Sstas** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4563226128Sstas** interface. This routine is provided for historical compatibility 4564226128Sstas** only. All new applications should use the 4565226128Sstas** [sqlite3_soft_heap_limit64()] interface rather than this one. 4566226128Sstas*/ 4567226128SstasSQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4568226128Sstas 4569226128Sstas 4570226128Sstas/* 4571226031Sstas** CAPI3REF: Extract Metadata About A Column Of A Table 4572226031Sstas** 4573226031Sstas** ^This routine returns metadata about a specific column of a specific 4574226031Sstas** database table accessible using the [database connection] handle 4575226031Sstas** passed as the first function argument. 4576226031Sstas** 4577226031Sstas** ^The column is identified by the second, third and fourth parameters to 4578226031Sstas** this function. ^The second parameter is either the name of the database 4579226031Sstas** (i.e. "main", "temp", or an attached database) containing the specified 4580226031Sstas** table or NULL. ^If it is NULL, then all attached databases are searched 4581226031Sstas** for the table using the same algorithm used by the database engine to 4582226031Sstas** resolve unqualified table references. 4583226031Sstas** 4584226031Sstas** ^The third and fourth parameters to this function are the table and column 4585226031Sstas** name of the desired column, respectively. Neither of these parameters 4586226031Sstas** may be NULL. 4587226031Sstas** 4588226031Sstas** ^Metadata is returned by writing to the memory locations passed as the 5th 4589226031Sstas** and subsequent parameters to this function. ^Any of these arguments may be 4590226031Sstas** NULL, in which case the corresponding element of metadata is omitted. 4591226031Sstas** 4592226031Sstas** ^(<blockquote> 4593226031Sstas** <table border="1"> 4594226031Sstas** <tr><th> Parameter <th> Output<br>Type <th> Description 4595226031Sstas** 4596226031Sstas** <tr><td> 5th <td> const char* <td> Data type 4597226031Sstas** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4598226031Sstas** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4599226031Sstas** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4600226031Sstas** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4601226031Sstas** </table> 4602226031Sstas** </blockquote>)^ 4603226031Sstas** 4604226031Sstas** ^The memory pointed to by the character pointers returned for the 4605226031Sstas** declaration type and collation sequence is valid only until the next 4606226031Sstas** call to any SQLite API function. 4607226031Sstas** 4608226031Sstas** ^If the specified table is actually a view, an [error code] is returned. 4609226031Sstas** 4610226031Sstas** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4611226031Sstas** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4612226031Sstas** parameters are set for the explicitly declared column. ^(If there is no 4613226031Sstas** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4614226031Sstas** parameters are set as follows: 4615226031Sstas** 4616226031Sstas** <pre> 4617226031Sstas** data type: "INTEGER" 4618226031Sstas** collation sequence: "BINARY" 4619226031Sstas** not null: 0 4620226031Sstas** primary key: 1 4621226031Sstas** auto increment: 0 4622226031Sstas** </pre>)^ 4623226031Sstas** 4624226031Sstas** ^(This function may load one or more schemas from database files. If an 4625226031Sstas** error occurs during this process, or if the requested table or column 4626226031Sstas** cannot be found, an [error code] is returned and an error message left 4627226031Sstas** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4628226031Sstas** 4629226031Sstas** ^This API is only available if the library was compiled with the 4630226031Sstas** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4631226031Sstas*/ 4632226031SstasSQLITE_API int sqlite3_table_column_metadata( 4633226031Sstas sqlite3 *db, /* Connection handle */ 4634226031Sstas const char *zDbName, /* Database name or NULL */ 4635226031Sstas const char *zTableName, /* Table name */ 4636226031Sstas const char *zColumnName, /* Column name */ 4637226031Sstas char const **pzDataType, /* OUTPUT: Declared data type */ 4638226031Sstas char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4639226031Sstas int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4640226031Sstas int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4641226031Sstas int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4642226031Sstas); 4643226031Sstas 4644226031Sstas/* 4645226031Sstas** CAPI3REF: Load An Extension 4646226031Sstas** 4647226031Sstas** ^This interface loads an SQLite extension library from the named file. 4648226031Sstas** 4649226031Sstas** ^The sqlite3_load_extension() interface attempts to load an 4650226031Sstas** SQLite extension library contained in the file zFile. 4651226031Sstas** 4652226031Sstas** ^The entry point is zProc. 4653226031Sstas** ^zProc may be 0, in which case the name of the entry point 4654226031Sstas** defaults to "sqlite3_extension_init". 4655226031Sstas** ^The sqlite3_load_extension() interface returns 4656226031Sstas** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4657226031Sstas** ^If an error occurs and pzErrMsg is not 0, then the 4658226031Sstas** [sqlite3_load_extension()] interface shall attempt to 4659226031Sstas** fill *pzErrMsg with error message text stored in memory 4660226031Sstas** obtained from [sqlite3_malloc()]. The calling function 4661226031Sstas** should free this memory by calling [sqlite3_free()]. 4662226031Sstas** 4663226031Sstas** ^Extension loading must be enabled using 4664226031Sstas** [sqlite3_enable_load_extension()] prior to calling this API, 4665226031Sstas** otherwise an error will be returned. 4666226031Sstas** 4667226031Sstas** See also the [load_extension() SQL function]. 4668226031Sstas*/ 4669226031SstasSQLITE_API int sqlite3_load_extension( 4670226031Sstas sqlite3 *db, /* Load the extension into this database connection */ 4671226031Sstas const char *zFile, /* Name of the shared library containing extension */ 4672226031Sstas const char *zProc, /* Entry point. Derived from zFile if 0 */ 4673226031Sstas char **pzErrMsg /* Put error message here if not 0 */ 4674226031Sstas); 4675226031Sstas 4676226031Sstas/* 4677226031Sstas** CAPI3REF: Enable Or Disable Extension Loading 4678226031Sstas** 4679226031Sstas** ^So as not to open security holes in older applications that are 4680226031Sstas** unprepared to deal with extension loading, and as a means of disabling 4681226031Sstas** extension loading while evaluating user-entered SQL, the following API 4682226031Sstas** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4683226031Sstas** 4684226031Sstas** ^Extension loading is off by default. See ticket #1863. 4685226031Sstas** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4686226031Sstas** to turn extension loading on and call it with onoff==0 to turn 4687226031Sstas** it back off again. 4688226031Sstas*/ 4689226031SstasSQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4690226031Sstas 4691226031Sstas/* 4692226128Sstas** CAPI3REF: Automatically Load Statically Linked Extensions 4693226031Sstas** 4694226128Sstas** ^This interface causes the xEntryPoint() function to be invoked for 4695226128Sstas** each new [database connection] that is created. The idea here is that 4696226128Sstas** xEntryPoint() is the entry point for a statically linked SQLite extension 4697226128Sstas** that is to be automatically loaded into all new database connections. 4698226031Sstas** 4699226128Sstas** ^(Even though the function prototype shows that xEntryPoint() takes 4700226128Sstas** no arguments and returns void, SQLite invokes xEntryPoint() with three 4701226128Sstas** arguments and expects and integer result as if the signature of the 4702226128Sstas** entry point where as follows: 4703226031Sstas** 4704226128Sstas** <blockquote><pre> 4705226128Sstas** int xEntryPoint( 4706226128Sstas** sqlite3 *db, 4707226128Sstas** const char **pzErrMsg, 4708226128Sstas** const struct sqlite3_api_routines *pThunk 4709226128Sstas** ); 4710226128Sstas** </pre></blockquote>)^ 4711226128Sstas** 4712226128Sstas** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 4713226128Sstas** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 4714226128Sstas** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 4715226128Sstas** is NULL before calling the xEntryPoint(). ^SQLite will invoke 4716226128Sstas** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 4717226128Sstas** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 4718226128Sstas** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 4719226128Sstas** 4720226128Sstas** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 4721226128Sstas** on the list of automatic extensions is a harmless no-op. ^No entry point 4722226128Sstas** will be called more than once for each database connection that is opened. 4723226128Sstas** 4724226128Sstas** See also: [sqlite3_reset_auto_extension()]. 4725226031Sstas*/ 4726226031SstasSQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4727226031Sstas 4728226031Sstas/* 4729226031Sstas** CAPI3REF: Reset Automatic Extension Loading 4730226031Sstas** 4731226128Sstas** ^This interface disables all automatic extensions previously 4732226128Sstas** registered using [sqlite3_auto_extension()]. 4733226031Sstas*/ 4734226031SstasSQLITE_API void sqlite3_reset_auto_extension(void); 4735226031Sstas 4736226031Sstas/* 4737226031Sstas** The interface to the virtual-table mechanism is currently considered 4738226031Sstas** to be experimental. The interface might change in incompatible ways. 4739226031Sstas** If this is a problem for you, do not use the interface at this time. 4740226031Sstas** 4741226031Sstas** When the virtual-table mechanism stabilizes, we will declare the 4742226031Sstas** interface fixed, support it indefinitely, and remove this comment. 4743226031Sstas*/ 4744226031Sstas 4745226031Sstas/* 4746226031Sstas** Structures used by the virtual table interface 4747226031Sstas*/ 4748226031Sstastypedef struct sqlite3_vtab sqlite3_vtab; 4749226031Sstastypedef struct sqlite3_index_info sqlite3_index_info; 4750226031Sstastypedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4751226031Sstastypedef struct sqlite3_module sqlite3_module; 4752226031Sstas 4753226031Sstas/* 4754226031Sstas** CAPI3REF: Virtual Table Object 4755226031Sstas** KEYWORDS: sqlite3_module {virtual table module} 4756226031Sstas** 4757226128Sstas** This structure, sometimes called a "virtual table module", 4758226128Sstas** defines the implementation of a [virtual tables]. 4759226031Sstas** This structure consists mostly of methods for the module. 4760226031Sstas** 4761226031Sstas** ^A virtual table module is created by filling in a persistent 4762226031Sstas** instance of this structure and passing a pointer to that instance 4763226031Sstas** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4764226031Sstas** ^The registration remains valid until it is replaced by a different 4765226031Sstas** module or until the [database connection] closes. The content 4766226031Sstas** of this structure must not change while it is registered with 4767226031Sstas** any database connection. 4768226031Sstas*/ 4769226031Sstasstruct sqlite3_module { 4770226031Sstas int iVersion; 4771226031Sstas int (*xCreate)(sqlite3*, void *pAux, 4772226031Sstas int argc, const char *const*argv, 4773226031Sstas sqlite3_vtab **ppVTab, char**); 4774226031Sstas int (*xConnect)(sqlite3*, void *pAux, 4775226031Sstas int argc, const char *const*argv, 4776226031Sstas sqlite3_vtab **ppVTab, char**); 4777226031Sstas int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4778226031Sstas int (*xDisconnect)(sqlite3_vtab *pVTab); 4779226031Sstas int (*xDestroy)(sqlite3_vtab *pVTab); 4780226031Sstas int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4781226031Sstas int (*xClose)(sqlite3_vtab_cursor*); 4782226031Sstas int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4783226031Sstas int argc, sqlite3_value **argv); 4784226031Sstas int (*xNext)(sqlite3_vtab_cursor*); 4785226031Sstas int (*xEof)(sqlite3_vtab_cursor*); 4786226031Sstas int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4787226031Sstas int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4788226031Sstas int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4789226031Sstas int (*xBegin)(sqlite3_vtab *pVTab); 4790226031Sstas int (*xSync)(sqlite3_vtab *pVTab); 4791226031Sstas int (*xCommit)(sqlite3_vtab *pVTab); 4792226031Sstas int (*xRollback)(sqlite3_vtab *pVTab); 4793226031Sstas int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4794226031Sstas void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4795226031Sstas void **ppArg); 4796226031Sstas int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4797226128Sstas /* The methods above are in version 1 of the sqlite_module object. Those 4798226128Sstas ** below are for version 2 and greater. */ 4799226128Sstas int (*xSavepoint)(sqlite3_vtab *pVTab, int); 4800226128Sstas int (*xRelease)(sqlite3_vtab *pVTab, int); 4801226128Sstas int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 4802226031Sstas}; 4803226031Sstas 4804226031Sstas/* 4805226031Sstas** CAPI3REF: Virtual Table Indexing Information 4806226031Sstas** KEYWORDS: sqlite3_index_info 4807226031Sstas** 4808226128Sstas** The sqlite3_index_info structure and its substructures is used as part 4809226128Sstas** of the [virtual table] interface to 4810226031Sstas** pass information into and receive the reply from the [xBestIndex] 4811226031Sstas** method of a [virtual table module]. The fields under **Inputs** are the 4812226031Sstas** inputs to xBestIndex and are read-only. xBestIndex inserts its 4813226031Sstas** results into the **Outputs** fields. 4814226031Sstas** 4815226031Sstas** ^(The aConstraint[] array records WHERE clause constraints of the form: 4816226031Sstas** 4817226128Sstas** <blockquote>column OP expr</blockquote> 4818226031Sstas** 4819226031Sstas** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 4820226128Sstas** stored in aConstraint[].op using one of the 4821226128Sstas** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 4822226128Sstas** ^(The index of the column is stored in 4823226031Sstas** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 4824226031Sstas** expr on the right-hand side can be evaluated (and thus the constraint 4825226031Sstas** is usable) and false if it cannot.)^ 4826226031Sstas** 4827226031Sstas** ^The optimizer automatically inverts terms of the form "expr OP column" 4828226031Sstas** and makes other simplifications to the WHERE clause in an attempt to 4829226031Sstas** get as many WHERE clause terms into the form shown above as possible. 4830226031Sstas** ^The aConstraint[] array only reports WHERE clause terms that are 4831226031Sstas** relevant to the particular virtual table being queried. 4832226031Sstas** 4833226031Sstas** ^Information about the ORDER BY clause is stored in aOrderBy[]. 4834226031Sstas** ^Each term of aOrderBy records a column of the ORDER BY clause. 4835226031Sstas** 4836226031Sstas** The [xBestIndex] method must fill aConstraintUsage[] with information 4837226031Sstas** about what parameters to pass to xFilter. ^If argvIndex>0 then 4838226031Sstas** the right-hand side of the corresponding aConstraint[] is evaluated 4839226031Sstas** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 4840226031Sstas** is true, then the constraint is assumed to be fully handled by the 4841226031Sstas** virtual table and is not checked again by SQLite.)^ 4842226031Sstas** 4843226031Sstas** ^The idxNum and idxPtr values are recorded and passed into the 4844226031Sstas** [xFilter] method. 4845226031Sstas** ^[sqlite3_free()] is used to free idxPtr if and only if 4846226031Sstas** needToFreeIdxPtr is true. 4847226031Sstas** 4848226031Sstas** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4849226031Sstas** the correct order to satisfy the ORDER BY clause so that no separate 4850226031Sstas** sorting step is required. 4851226031Sstas** 4852226031Sstas** ^The estimatedCost value is an estimate of the cost of doing the 4853226031Sstas** particular lookup. A full scan of a table with N entries should have 4854226031Sstas** a cost of N. A binary search of a table of N entries should have a 4855226031Sstas** cost of approximately log(N). 4856226031Sstas*/ 4857226031Sstasstruct sqlite3_index_info { 4858226031Sstas /* Inputs */ 4859226031Sstas int nConstraint; /* Number of entries in aConstraint */ 4860226031Sstas struct sqlite3_index_constraint { 4861226031Sstas int iColumn; /* Column on left-hand side of constraint */ 4862226031Sstas unsigned char op; /* Constraint operator */ 4863226031Sstas unsigned char usable; /* True if this constraint is usable */ 4864226031Sstas int iTermOffset; /* Used internally - xBestIndex should ignore */ 4865226031Sstas } *aConstraint; /* Table of WHERE clause constraints */ 4866226031Sstas int nOrderBy; /* Number of terms in the ORDER BY clause */ 4867226031Sstas struct sqlite3_index_orderby { 4868226031Sstas int iColumn; /* Column number */ 4869226031Sstas unsigned char desc; /* True for DESC. False for ASC. */ 4870226031Sstas } *aOrderBy; /* The ORDER BY clause */ 4871226031Sstas /* Outputs */ 4872226031Sstas struct sqlite3_index_constraint_usage { 4873226031Sstas int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4874226031Sstas unsigned char omit; /* Do not code a test for this constraint */ 4875226031Sstas } *aConstraintUsage; 4876226031Sstas int idxNum; /* Number used to identify the index */ 4877226031Sstas char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4878226031Sstas int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4879226031Sstas int orderByConsumed; /* True if output is already ordered */ 4880226031Sstas double estimatedCost; /* Estimated cost of using this index */ 4881226031Sstas}; 4882226128Sstas 4883226128Sstas/* 4884226128Sstas** CAPI3REF: Virtual Table Constraint Operator Codes 4885226128Sstas** 4886226128Sstas** These macros defined the allowed values for the 4887226128Sstas** [sqlite3_index_info].aConstraint[].op field. Each value represents 4888226128Sstas** an operator that is part of a constraint term in the wHERE clause of 4889226128Sstas** a query that uses a [virtual table]. 4890226128Sstas*/ 4891226031Sstas#define SQLITE_INDEX_CONSTRAINT_EQ 2 4892226031Sstas#define SQLITE_INDEX_CONSTRAINT_GT 4 4893226031Sstas#define SQLITE_INDEX_CONSTRAINT_LE 8 4894226031Sstas#define SQLITE_INDEX_CONSTRAINT_LT 16 4895226031Sstas#define SQLITE_INDEX_CONSTRAINT_GE 32 4896226031Sstas#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4897226031Sstas 4898226031Sstas/* 4899226031Sstas** CAPI3REF: Register A Virtual Table Implementation 4900226031Sstas** 4901226031Sstas** ^These routines are used to register a new [virtual table module] name. 4902226031Sstas** ^Module names must be registered before 4903226031Sstas** creating a new [virtual table] using the module and before using a 4904226031Sstas** preexisting [virtual table] for the module. 4905226031Sstas** 4906226031Sstas** ^The module name is registered on the [database connection] specified 4907226128Sstas** by the first parameter. ^The name of the module is given by the 4908226031Sstas** second parameter. ^The third parameter is a pointer to 4909226031Sstas** the implementation of the [virtual table module]. ^The fourth 4910226031Sstas** parameter is an arbitrary client data pointer that is passed through 4911226031Sstas** into the [xCreate] and [xConnect] methods of the virtual table module 4912226031Sstas** when a new virtual table is be being created or reinitialized. 4913226031Sstas** 4914226031Sstas** ^The sqlite3_create_module_v2() interface has a fifth parameter which 4915226031Sstas** is a pointer to a destructor for the pClientData. ^SQLite will 4916226031Sstas** invoke the destructor function (if it is not NULL) when SQLite 4917226128Sstas** no longer needs the pClientData pointer. ^The destructor will also 4918226128Sstas** be invoked if the call to sqlite3_create_module_v2() fails. 4919226128Sstas** ^The sqlite3_create_module() 4920226031Sstas** interface is equivalent to sqlite3_create_module_v2() with a NULL 4921226031Sstas** destructor. 4922226031Sstas*/ 4923226128SstasSQLITE_API int sqlite3_create_module( 4924226031Sstas sqlite3 *db, /* SQLite connection to register module with */ 4925226031Sstas const char *zName, /* Name of the module */ 4926226031Sstas const sqlite3_module *p, /* Methods for the module */ 4927226031Sstas void *pClientData /* Client data for xCreate/xConnect */ 4928226031Sstas); 4929226128SstasSQLITE_API int sqlite3_create_module_v2( 4930226031Sstas sqlite3 *db, /* SQLite connection to register module with */ 4931226031Sstas const char *zName, /* Name of the module */ 4932226031Sstas const sqlite3_module *p, /* Methods for the module */ 4933226031Sstas void *pClientData, /* Client data for xCreate/xConnect */ 4934226031Sstas void(*xDestroy)(void*) /* Module destructor function */ 4935226031Sstas); 4936226031Sstas 4937226031Sstas/* 4938226031Sstas** CAPI3REF: Virtual Table Instance Object 4939226031Sstas** KEYWORDS: sqlite3_vtab 4940226031Sstas** 4941226031Sstas** Every [virtual table module] implementation uses a subclass 4942226031Sstas** of this object to describe a particular instance 4943226031Sstas** of the [virtual table]. Each subclass will 4944226031Sstas** be tailored to the specific needs of the module implementation. 4945226031Sstas** The purpose of this superclass is to define certain fields that are 4946226031Sstas** common to all module implementations. 4947226031Sstas** 4948226031Sstas** ^Virtual tables methods can set an error message by assigning a 4949226031Sstas** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4950226031Sstas** take care that any prior string is freed by a call to [sqlite3_free()] 4951226031Sstas** prior to assigning a new string to zErrMsg. ^After the error message 4952226031Sstas** is delivered up to the client application, the string will be automatically 4953226031Sstas** freed by sqlite3_free() and the zErrMsg field will be zeroed. 4954226031Sstas*/ 4955226031Sstasstruct sqlite3_vtab { 4956226031Sstas const sqlite3_module *pModule; /* The module for this virtual table */ 4957226031Sstas int nRef; /* NO LONGER USED */ 4958226031Sstas char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4959226031Sstas /* Virtual table implementations will typically add additional fields */ 4960226031Sstas}; 4961226031Sstas 4962226031Sstas/* 4963226031Sstas** CAPI3REF: Virtual Table Cursor Object 4964226031Sstas** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 4965226031Sstas** 4966226031Sstas** Every [virtual table module] implementation uses a subclass of the 4967226031Sstas** following structure to describe cursors that point into the 4968226031Sstas** [virtual table] and are used 4969226031Sstas** to loop through the virtual table. Cursors are created using the 4970226031Sstas** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 4971226031Sstas** by the [sqlite3_module.xClose | xClose] method. Cursors are used 4972226031Sstas** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 4973226031Sstas** of the module. Each module implementation will define 4974226031Sstas** the content of a cursor structure to suit its own needs. 4975226031Sstas** 4976226031Sstas** This superclass exists in order to define fields of the cursor that 4977226031Sstas** are common to all implementations. 4978226031Sstas*/ 4979226031Sstasstruct sqlite3_vtab_cursor { 4980226031Sstas sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4981226031Sstas /* Virtual table implementations will typically add additional fields */ 4982226031Sstas}; 4983226031Sstas 4984226031Sstas/* 4985226031Sstas** CAPI3REF: Declare The Schema Of A Virtual Table 4986226031Sstas** 4987226031Sstas** ^The [xCreate] and [xConnect] methods of a 4988226031Sstas** [virtual table module] call this interface 4989226031Sstas** to declare the format (the names and datatypes of the columns) of 4990226031Sstas** the virtual tables they implement. 4991226031Sstas*/ 4992226128SstasSQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 4993226031Sstas 4994226031Sstas/* 4995226031Sstas** CAPI3REF: Overload A Function For A Virtual Table 4996226031Sstas** 4997226031Sstas** ^(Virtual tables can provide alternative implementations of functions 4998226128Sstas** using the [xFindFunction] method of the [virtual table module]. 4999226031Sstas** But global versions of those functions 5000226031Sstas** must exist in order to be overloaded.)^ 5001226031Sstas** 5002226031Sstas** ^(This API makes sure a global version of a function with a particular 5003226031Sstas** name and number of parameters exists. If no such function exists 5004226031Sstas** before this API is called, a new function is created.)^ ^The implementation 5005226031Sstas** of the new function always causes an exception to be thrown. So 5006226031Sstas** the new function is not good for anything by itself. Its only 5007226031Sstas** purpose is to be a placeholder function that can be overloaded 5008226031Sstas** by a [virtual table]. 5009226031Sstas*/ 5010226128SstasSQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5011226031Sstas 5012226031Sstas/* 5013226031Sstas** The interface to the virtual-table mechanism defined above (back up 5014226031Sstas** to a comment remarkably similar to this one) is currently considered 5015226031Sstas** to be experimental. The interface might change in incompatible ways. 5016226031Sstas** If this is a problem for you, do not use the interface at this time. 5017226031Sstas** 5018226031Sstas** When the virtual-table mechanism stabilizes, we will declare the 5019226031Sstas** interface fixed, support it indefinitely, and remove this comment. 5020226031Sstas*/ 5021226031Sstas 5022226031Sstas/* 5023226031Sstas** CAPI3REF: A Handle To An Open BLOB 5024226031Sstas** KEYWORDS: {BLOB handle} {BLOB handles} 5025226031Sstas** 5026226031Sstas** An instance of this object represents an open BLOB on which 5027226031Sstas** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5028226031Sstas** ^Objects of this type are created by [sqlite3_blob_open()] 5029226031Sstas** and destroyed by [sqlite3_blob_close()]. 5030226031Sstas** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5031226031Sstas** can be used to read or write small subsections of the BLOB. 5032226031Sstas** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5033226031Sstas*/ 5034226031Sstastypedef struct sqlite3_blob sqlite3_blob; 5035226031Sstas 5036226031Sstas/* 5037226031Sstas** CAPI3REF: Open A BLOB For Incremental I/O 5038226031Sstas** 5039226031Sstas** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5040226031Sstas** in row iRow, column zColumn, table zTable in database zDb; 5041226031Sstas** in other words, the same BLOB that would be selected by: 5042226031Sstas** 5043226031Sstas** <pre> 5044226031Sstas** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5045226031Sstas** </pre>)^ 5046226031Sstas** 5047226031Sstas** ^If the flags parameter is non-zero, then the BLOB is opened for read 5048226031Sstas** and write access. ^If it is zero, the BLOB is opened for read access. 5049226128Sstas** ^It is not possible to open a column that is part of an index or primary 5050226128Sstas** key for writing. ^If [foreign key constraints] are enabled, it is 5051226031Sstas** not possible to open a column that is part of a [child key] for writing. 5052226031Sstas** 5053226031Sstas** ^Note that the database name is not the filename that contains 5054226031Sstas** the database but rather the symbolic name of the database that 5055226031Sstas** appears after the AS keyword when the database is connected using [ATTACH]. 5056226031Sstas** ^For the main database file, the database name is "main". 5057226031Sstas** ^For TEMP tables, the database name is "temp". 5058226031Sstas** 5059226031Sstas** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5060226031Sstas** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5061226031Sstas** to be a null pointer.)^ 5062226031Sstas** ^This function sets the [database connection] error code and message 5063226031Sstas** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5064226031Sstas** functions. ^Note that the *ppBlob variable is always initialized in a 5065226031Sstas** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5066226031Sstas** regardless of the success or failure of this routine. 5067226031Sstas** 5068226031Sstas** ^(If the row that a BLOB handle points to is modified by an 5069226031Sstas** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5070226031Sstas** then the BLOB handle is marked as "expired". 5071226031Sstas** This is true if any column of the row is changed, even a column 5072226031Sstas** other than the one the BLOB handle is open on.)^ 5073226031Sstas** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5074226128Sstas** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5075226031Sstas** ^(Changes written into a BLOB prior to the BLOB expiring are not 5076226031Sstas** rolled back by the expiration of the BLOB. Such changes will eventually 5077226031Sstas** commit if the transaction continues to completion.)^ 5078226031Sstas** 5079226031Sstas** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5080226031Sstas** the opened blob. ^The size of a blob may not be changed by this 5081226031Sstas** interface. Use the [UPDATE] SQL command to change the size of a 5082226031Sstas** blob. 5083226031Sstas** 5084226031Sstas** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5085226031Sstas** and the built-in [zeroblob] SQL function can be used, if desired, 5086226031Sstas** to create an empty, zero-filled blob in which to read or write using 5087226031Sstas** this interface. 5088226031Sstas** 5089226031Sstas** To avoid a resource leak, every open [BLOB handle] should eventually 5090226031Sstas** be released by a call to [sqlite3_blob_close()]. 5091226031Sstas*/ 5092226031SstasSQLITE_API int sqlite3_blob_open( 5093226031Sstas sqlite3*, 5094226031Sstas const char *zDb, 5095226031Sstas const char *zTable, 5096226031Sstas const char *zColumn, 5097226031Sstas sqlite3_int64 iRow, 5098226031Sstas int flags, 5099226031Sstas sqlite3_blob **ppBlob 5100226031Sstas); 5101226031Sstas 5102226031Sstas/* 5103226128Sstas** CAPI3REF: Move a BLOB Handle to a New Row 5104226128Sstas** 5105226128Sstas** ^This function is used to move an existing blob handle so that it points 5106226128Sstas** to a different row of the same database table. ^The new row is identified 5107226128Sstas** by the rowid value passed as the second argument. Only the row can be 5108226128Sstas** changed. ^The database, table and column on which the blob handle is open 5109226128Sstas** remain the same. Moving an existing blob handle to a new row can be 5110226128Sstas** faster than closing the existing handle and opening a new one. 5111226128Sstas** 5112226128Sstas** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5113226128Sstas** it must exist and there must be either a blob or text value stored in 5114226128Sstas** the nominated column.)^ ^If the new row is not present in the table, or if 5115226128Sstas** it does not contain a blob or text value, or if another error occurs, an 5116226128Sstas** SQLite error code is returned and the blob handle is considered aborted. 5117226128Sstas** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5118226128Sstas** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5119226128Sstas** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5120226128Sstas** always returns zero. 5121226128Sstas** 5122226128Sstas** ^This function sets the database handle error code and message. 5123226128Sstas*/ 5124226128SstasSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5125226128Sstas 5126226128Sstas/* 5127226031Sstas** CAPI3REF: Close A BLOB Handle 5128226031Sstas** 5129226031Sstas** ^Closes an open [BLOB handle]. 5130226031Sstas** 5131226031Sstas** ^Closing a BLOB shall cause the current transaction to commit 5132226031Sstas** if there are no other BLOBs, no pending prepared statements, and the 5133226031Sstas** database connection is in [autocommit mode]. 5134226031Sstas** ^If any writes were made to the BLOB, they might be held in cache 5135226031Sstas** until the close operation if they will fit. 5136226031Sstas** 5137226031Sstas** ^(Closing the BLOB often forces the changes 5138226031Sstas** out to disk and so if any I/O errors occur, they will likely occur 5139226031Sstas** at the time when the BLOB is closed. Any errors that occur during 5140226031Sstas** closing are reported as a non-zero return value.)^ 5141226031Sstas** 5142226031Sstas** ^(The BLOB is closed unconditionally. Even if this routine returns 5143226031Sstas** an error code, the BLOB is still closed.)^ 5144226031Sstas** 5145226031Sstas** ^Calling this routine with a null pointer (such as would be returned 5146226031Sstas** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5147226031Sstas*/ 5148226031SstasSQLITE_API int sqlite3_blob_close(sqlite3_blob *); 5149226031Sstas 5150226031Sstas/* 5151226031Sstas** CAPI3REF: Return The Size Of An Open BLOB 5152226031Sstas** 5153226128Sstas** ^Returns the size in bytes of the BLOB accessible via the 5154226031Sstas** successfully opened [BLOB handle] in its only argument. ^The 5155226031Sstas** incremental blob I/O routines can only read or overwriting existing 5156226031Sstas** blob content; they cannot change the size of a blob. 5157226031Sstas** 5158226031Sstas** This routine only works on a [BLOB handle] which has been created 5159226031Sstas** by a prior successful call to [sqlite3_blob_open()] and which has not 5160226031Sstas** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5161226031Sstas** to this routine results in undefined and probably undesirable behavior. 5162226031Sstas*/ 5163226031SstasSQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 5164226031Sstas 5165226031Sstas/* 5166226031Sstas** CAPI3REF: Read Data From A BLOB Incrementally 5167226031Sstas** 5168226031Sstas** ^(This function is used to read data from an open [BLOB handle] into a 5169226031Sstas** caller-supplied buffer. N bytes of data are copied into buffer Z 5170226031Sstas** from the open BLOB, starting at offset iOffset.)^ 5171226031Sstas** 5172226031Sstas** ^If offset iOffset is less than N bytes from the end of the BLOB, 5173226031Sstas** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5174226031Sstas** less than zero, [SQLITE_ERROR] is returned and no data is read. 5175226031Sstas** ^The size of the blob (and hence the maximum value of N+iOffset) 5176226031Sstas** can be determined using the [sqlite3_blob_bytes()] interface. 5177226031Sstas** 5178226031Sstas** ^An attempt to read from an expired [BLOB handle] fails with an 5179226031Sstas** error code of [SQLITE_ABORT]. 5180226031Sstas** 5181226031Sstas** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5182226031Sstas** Otherwise, an [error code] or an [extended error code] is returned.)^ 5183226031Sstas** 5184226031Sstas** This routine only works on a [BLOB handle] which has been created 5185226031Sstas** by a prior successful call to [sqlite3_blob_open()] and which has not 5186226031Sstas** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5187226031Sstas** to this routine results in undefined and probably undesirable behavior. 5188226031Sstas** 5189226031Sstas** See also: [sqlite3_blob_write()]. 5190226031Sstas*/ 5191226031SstasSQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5192226031Sstas 5193226031Sstas/* 5194226031Sstas** CAPI3REF: Write Data Into A BLOB Incrementally 5195226031Sstas** 5196226031Sstas** ^This function is used to write data into an open [BLOB handle] from a 5197226031Sstas** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5198226031Sstas** into the open BLOB, starting at offset iOffset. 5199226031Sstas** 5200226031Sstas** ^If the [BLOB handle] passed as the first argument was not opened for 5201226031Sstas** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5202226031Sstas** this function returns [SQLITE_READONLY]. 5203226031Sstas** 5204226031Sstas** ^This function may only modify the contents of the BLOB; it is 5205226031Sstas** not possible to increase the size of a BLOB using this API. 5206226031Sstas** ^If offset iOffset is less than N bytes from the end of the BLOB, 5207226031Sstas** [SQLITE_ERROR] is returned and no data is written. ^If N is 5208226031Sstas** less than zero [SQLITE_ERROR] is returned and no data is written. 5209226031Sstas** The size of the BLOB (and hence the maximum value of N+iOffset) 5210226031Sstas** can be determined using the [sqlite3_blob_bytes()] interface. 5211226031Sstas** 5212226031Sstas** ^An attempt to write to an expired [BLOB handle] fails with an 5213226031Sstas** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5214226031Sstas** before the [BLOB handle] expired are not rolled back by the 5215226031Sstas** expiration of the handle, though of course those changes might 5216226031Sstas** have been overwritten by the statement that expired the BLOB handle 5217226031Sstas** or by other independent statements. 5218226031Sstas** 5219226031Sstas** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5220226031Sstas** Otherwise, an [error code] or an [extended error code] is returned.)^ 5221226031Sstas** 5222226031Sstas** This routine only works on a [BLOB handle] which has been created 5223226031Sstas** by a prior successful call to [sqlite3_blob_open()] and which has not 5224226031Sstas** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5225226031Sstas** to this routine results in undefined and probably undesirable behavior. 5226226031Sstas** 5227226031Sstas** See also: [sqlite3_blob_read()]. 5228226031Sstas*/ 5229226031SstasSQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5230226031Sstas 5231226031Sstas/* 5232226031Sstas** CAPI3REF: Virtual File System Objects 5233226031Sstas** 5234226031Sstas** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5235226031Sstas** that SQLite uses to interact 5236226031Sstas** with the underlying operating system. Most SQLite builds come with a 5237226031Sstas** single default VFS that is appropriate for the host computer. 5238226031Sstas** New VFSes can be registered and existing VFSes can be unregistered. 5239226031Sstas** The following interfaces are provided. 5240226031Sstas** 5241226031Sstas** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5242226031Sstas** ^Names are case sensitive. 5243226031Sstas** ^Names are zero-terminated UTF-8 strings. 5244226031Sstas** ^If there is no match, a NULL pointer is returned. 5245226031Sstas** ^If zVfsName is NULL then the default VFS is returned. 5246226031Sstas** 5247226031Sstas** ^New VFSes are registered with sqlite3_vfs_register(). 5248226031Sstas** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5249226031Sstas** ^The same VFS can be registered multiple times without injury. 5250226031Sstas** ^To make an existing VFS into the default VFS, register it again 5251226031Sstas** with the makeDflt flag set. If two different VFSes with the 5252226031Sstas** same name are registered, the behavior is undefined. If a 5253226031Sstas** VFS is registered with a name that is NULL or an empty string, 5254226031Sstas** then the behavior is undefined. 5255226031Sstas** 5256226031Sstas** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5257226031Sstas** ^(If the default VFS is unregistered, another VFS is chosen as 5258226031Sstas** the default. The choice for the new VFS is arbitrary.)^ 5259226031Sstas*/ 5260226031SstasSQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5261226031SstasSQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5262226031SstasSQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5263226031Sstas 5264226031Sstas/* 5265226031Sstas** CAPI3REF: Mutexes 5266226031Sstas** 5267226031Sstas** The SQLite core uses these routines for thread 5268226031Sstas** synchronization. Though they are intended for internal 5269226031Sstas** use by SQLite, code that links against SQLite is 5270226031Sstas** permitted to use any of these routines. 5271226031Sstas** 5272226031Sstas** The SQLite source code contains multiple implementations 5273226031Sstas** of these mutex routines. An appropriate implementation 5274226031Sstas** is selected automatically at compile-time. ^(The following 5275226031Sstas** implementations are available in the SQLite core: 5276226031Sstas** 5277226031Sstas** <ul> 5278226031Sstas** <li> SQLITE_MUTEX_OS2 5279226031Sstas** <li> SQLITE_MUTEX_PTHREAD 5280226031Sstas** <li> SQLITE_MUTEX_W32 5281226031Sstas** <li> SQLITE_MUTEX_NOOP 5282226031Sstas** </ul>)^ 5283226031Sstas** 5284226031Sstas** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5285226031Sstas** that does no real locking and is appropriate for use in 5286226031Sstas** a single-threaded application. ^The SQLITE_MUTEX_OS2, 5287226031Sstas** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5288226031Sstas** are appropriate for use on OS/2, Unix, and Windows. 5289226031Sstas** 5290226031Sstas** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5291226031Sstas** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5292226031Sstas** implementation is included with the library. In this case the 5293226031Sstas** application must supply a custom mutex implementation using the 5294226031Sstas** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5295226031Sstas** before calling sqlite3_initialize() or any other public sqlite3_ 5296226031Sstas** function that calls sqlite3_initialize().)^ 5297226031Sstas** 5298226031Sstas** ^The sqlite3_mutex_alloc() routine allocates a new 5299226031Sstas** mutex and returns a pointer to it. ^If it returns NULL 5300226031Sstas** that means that a mutex could not be allocated. ^SQLite 5301226031Sstas** will unwind its stack and return an error. ^(The argument 5302226031Sstas** to sqlite3_mutex_alloc() is one of these integer constants: 5303226031Sstas** 5304226031Sstas** <ul> 5305226031Sstas** <li> SQLITE_MUTEX_FAST 5306226031Sstas** <li> SQLITE_MUTEX_RECURSIVE 5307226031Sstas** <li> SQLITE_MUTEX_STATIC_MASTER 5308226031Sstas** <li> SQLITE_MUTEX_STATIC_MEM 5309226031Sstas** <li> SQLITE_MUTEX_STATIC_MEM2 5310226031Sstas** <li> SQLITE_MUTEX_STATIC_PRNG 5311226031Sstas** <li> SQLITE_MUTEX_STATIC_LRU 5312226031Sstas** <li> SQLITE_MUTEX_STATIC_LRU2 5313226031Sstas** </ul>)^ 5314226031Sstas** 5315226031Sstas** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5316226031Sstas** cause sqlite3_mutex_alloc() to create 5317226031Sstas** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5318226031Sstas** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5319226031Sstas** The mutex implementation does not need to make a distinction 5320226031Sstas** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5321226031Sstas** not want to. ^SQLite will only request a recursive mutex in 5322226031Sstas** cases where it really needs one. ^If a faster non-recursive mutex 5323226031Sstas** implementation is available on the host platform, the mutex subsystem 5324226031Sstas** might return such a mutex in response to SQLITE_MUTEX_FAST. 5325226031Sstas** 5326226031Sstas** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5327226031Sstas** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5328226031Sstas** a pointer to a static preexisting mutex. ^Six static mutexes are 5329226031Sstas** used by the current version of SQLite. Future versions of SQLite 5330226031Sstas** may add additional static mutexes. Static mutexes are for internal 5331226031Sstas** use by SQLite only. Applications that use SQLite mutexes should 5332226031Sstas** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5333226031Sstas** SQLITE_MUTEX_RECURSIVE. 5334226031Sstas** 5335226031Sstas** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5336226031Sstas** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5337226031Sstas** returns a different mutex on every call. ^But for the static 5338226031Sstas** mutex types, the same mutex is returned on every call that has 5339226031Sstas** the same type number. 5340226031Sstas** 5341226031Sstas** ^The sqlite3_mutex_free() routine deallocates a previously 5342226031Sstas** allocated dynamic mutex. ^SQLite is careful to deallocate every 5343226031Sstas** dynamic mutex that it allocates. The dynamic mutexes must not be in 5344226031Sstas** use when they are deallocated. Attempting to deallocate a static 5345226031Sstas** mutex results in undefined behavior. ^SQLite never deallocates 5346226031Sstas** a static mutex. 5347226031Sstas** 5348226031Sstas** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5349226031Sstas** to enter a mutex. ^If another thread is already within the mutex, 5350226031Sstas** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5351226031Sstas** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5352226031Sstas** upon successful entry. ^(Mutexes created using 5353226031Sstas** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5354226031Sstas** In such cases the, 5355226031Sstas** mutex must be exited an equal number of times before another thread 5356226031Sstas** can enter.)^ ^(If the same thread tries to enter any other 5357226031Sstas** kind of mutex more than once, the behavior is undefined. 5358226031Sstas** SQLite will never exhibit 5359226031Sstas** such behavior in its own use of mutexes.)^ 5360226031Sstas** 5361226031Sstas** ^(Some systems (for example, Windows 95) do not support the operation 5362226031Sstas** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5363226031Sstas** will always return SQLITE_BUSY. The SQLite core only ever uses 5364226031Sstas** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5365226031Sstas** 5366226031Sstas** ^The sqlite3_mutex_leave() routine exits a mutex that was 5367226031Sstas** previously entered by the same thread. ^(The behavior 5368226031Sstas** is undefined if the mutex is not currently entered by the 5369226031Sstas** calling thread or is not currently allocated. SQLite will 5370226031Sstas** never do either.)^ 5371226031Sstas** 5372226031Sstas** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5373226031Sstas** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5374226031Sstas** behave as no-ops. 5375226031Sstas** 5376226031Sstas** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5377226031Sstas*/ 5378226031SstasSQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5379226031SstasSQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5380226031SstasSQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5381226031SstasSQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5382226031SstasSQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5383226031Sstas 5384226031Sstas/* 5385226031Sstas** CAPI3REF: Mutex Methods Object 5386226031Sstas** 5387226031Sstas** An instance of this structure defines the low-level routines 5388226031Sstas** used to allocate and use mutexes. 5389226031Sstas** 5390226031Sstas** Usually, the default mutex implementations provided by SQLite are 5391226031Sstas** sufficient, however the user has the option of substituting a custom 5392226031Sstas** implementation for specialized deployments or systems for which SQLite 5393226031Sstas** does not provide a suitable implementation. In this case, the user 5394226031Sstas** creates and populates an instance of this structure to pass 5395226031Sstas** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5396226031Sstas** Additionally, an instance of this structure can be used as an 5397226031Sstas** output variable when querying the system for the current mutex 5398226031Sstas** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5399226031Sstas** 5400226031Sstas** ^The xMutexInit method defined by this structure is invoked as 5401226031Sstas** part of system initialization by the sqlite3_initialize() function. 5402226128Sstas** ^The xMutexInit routine is called by SQLite exactly once for each 5403226031Sstas** effective call to [sqlite3_initialize()]. 5404226031Sstas** 5405226031Sstas** ^The xMutexEnd method defined by this structure is invoked as 5406226031Sstas** part of system shutdown by the sqlite3_shutdown() function. The 5407226031Sstas** implementation of this method is expected to release all outstanding 5408226031Sstas** resources obtained by the mutex methods implementation, especially 5409226031Sstas** those obtained by the xMutexInit method. ^The xMutexEnd() 5410226031Sstas** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5411226031Sstas** 5412226031Sstas** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5413226031Sstas** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5414226031Sstas** xMutexNotheld) implement the following interfaces (respectively): 5415226031Sstas** 5416226031Sstas** <ul> 5417226031Sstas** <li> [sqlite3_mutex_alloc()] </li> 5418226031Sstas** <li> [sqlite3_mutex_free()] </li> 5419226031Sstas** <li> [sqlite3_mutex_enter()] </li> 5420226031Sstas** <li> [sqlite3_mutex_try()] </li> 5421226031Sstas** <li> [sqlite3_mutex_leave()] </li> 5422226031Sstas** <li> [sqlite3_mutex_held()] </li> 5423226031Sstas** <li> [sqlite3_mutex_notheld()] </li> 5424226031Sstas** </ul>)^ 5425226031Sstas** 5426226031Sstas** The only difference is that the public sqlite3_XXX functions enumerated 5427226031Sstas** above silently ignore any invocations that pass a NULL pointer instead 5428226031Sstas** of a valid mutex handle. The implementations of the methods defined 5429226031Sstas** by this structure are not required to handle this case, the results 5430226031Sstas** of passing a NULL pointer instead of a valid mutex handle are undefined 5431226031Sstas** (i.e. it is acceptable to provide an implementation that segfaults if 5432226031Sstas** it is passed a NULL pointer). 5433226031Sstas** 5434226031Sstas** The xMutexInit() method must be threadsafe. ^It must be harmless to 5435226128Sstas** invoke xMutexInit() multiple times within the same process and without 5436226031Sstas** intervening calls to xMutexEnd(). Second and subsequent calls to 5437226031Sstas** xMutexInit() must be no-ops. 5438226031Sstas** 5439226031Sstas** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5440226031Sstas** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5441226031Sstas** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5442226031Sstas** memory allocation for a fast or recursive mutex. 5443226031Sstas** 5444226031Sstas** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5445226031Sstas** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5446226031Sstas** If xMutexInit fails in any way, it is expected to clean up after itself 5447226031Sstas** prior to returning. 5448226031Sstas*/ 5449226031Sstastypedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5450226031Sstasstruct sqlite3_mutex_methods { 5451226031Sstas int (*xMutexInit)(void); 5452226031Sstas int (*xMutexEnd)(void); 5453226031Sstas sqlite3_mutex *(*xMutexAlloc)(int); 5454226031Sstas void (*xMutexFree)(sqlite3_mutex *); 5455226031Sstas void (*xMutexEnter)(sqlite3_mutex *); 5456226031Sstas int (*xMutexTry)(sqlite3_mutex *); 5457226031Sstas void (*xMutexLeave)(sqlite3_mutex *); 5458226031Sstas int (*xMutexHeld)(sqlite3_mutex *); 5459226031Sstas int (*xMutexNotheld)(sqlite3_mutex *); 5460226031Sstas}; 5461226031Sstas 5462226031Sstas/* 5463226031Sstas** CAPI3REF: Mutex Verification Routines 5464226031Sstas** 5465226031Sstas** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5466226031Sstas** are intended for use inside assert() statements. ^The SQLite core 5467226031Sstas** never uses these routines except inside an assert() and applications 5468226031Sstas** are advised to follow the lead of the core. ^The SQLite core only 5469226031Sstas** provides implementations for these routines when it is compiled 5470226031Sstas** with the SQLITE_DEBUG flag. ^External mutex implementations 5471226031Sstas** are only required to provide these routines if SQLITE_DEBUG is 5472226031Sstas** defined and if NDEBUG is not defined. 5473226031Sstas** 5474226031Sstas** ^These routines should return true if the mutex in their argument 5475226031Sstas** is held or not held, respectively, by the calling thread. 5476226031Sstas** 5477226031Sstas** ^The implementation is not required to provided versions of these 5478226031Sstas** routines that actually work. If the implementation does not provide working 5479226031Sstas** versions of these routines, it should at least provide stubs that always 5480226031Sstas** return true so that one does not get spurious assertion failures. 5481226031Sstas** 5482226031Sstas** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5483226031Sstas** the routine should return 1. This seems counter-intuitive since 5484226128Sstas** clearly the mutex cannot be held if it does not exist. But 5485226031Sstas** the reason the mutex does not exist is because the build is not 5486226031Sstas** using mutexes. And we do not want the assert() containing the 5487226031Sstas** call to sqlite3_mutex_held() to fail, so a non-zero return is 5488226031Sstas** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5489226031Sstas** interface should also return 1 when given a NULL pointer. 5490226031Sstas*/ 5491226031Sstas#ifndef NDEBUG 5492226031SstasSQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 5493226031SstasSQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 5494226031Sstas#endif 5495226031Sstas 5496226031Sstas/* 5497226031Sstas** CAPI3REF: Mutex Types 5498226031Sstas** 5499226031Sstas** The [sqlite3_mutex_alloc()] interface takes a single argument 5500226031Sstas** which is one of these integer constants. 5501226031Sstas** 5502226031Sstas** The set of static mutexes may change from one SQLite release to the 5503226031Sstas** next. Applications that override the built-in mutex logic must be 5504226031Sstas** prepared to accommodate additional static mutexes. 5505226031Sstas*/ 5506226031Sstas#define SQLITE_MUTEX_FAST 0 5507226031Sstas#define SQLITE_MUTEX_RECURSIVE 1 5508226031Sstas#define SQLITE_MUTEX_STATIC_MASTER 2 5509226031Sstas#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5510226031Sstas#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5511226031Sstas#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5512226031Sstas#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5513226031Sstas#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5514226128Sstas#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5515226128Sstas#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5516226031Sstas 5517226031Sstas/* 5518226031Sstas** CAPI3REF: Retrieve the mutex for a database connection 5519226031Sstas** 5520226128Sstas** ^This interface returns a pointer the [sqlite3_mutex] object that 5521226031Sstas** serializes access to the [database connection] given in the argument 5522226031Sstas** when the [threading mode] is Serialized. 5523226031Sstas** ^If the [threading mode] is Single-thread or Multi-thread then this 5524226031Sstas** routine returns a NULL pointer. 5525226031Sstas*/ 5526226031SstasSQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5527226031Sstas 5528226031Sstas/* 5529226031Sstas** CAPI3REF: Low-Level Control Of Database Files 5530226031Sstas** 5531226031Sstas** ^The [sqlite3_file_control()] interface makes a direct call to the 5532226031Sstas** xFileControl method for the [sqlite3_io_methods] object associated 5533226031Sstas** with a particular database identified by the second argument. ^The 5534226128Sstas** name of the database is "main" for the main database or "temp" for the 5535226031Sstas** TEMP database, or the name that appears after the AS keyword for 5536226031Sstas** databases that are added using the [ATTACH] SQL command. 5537226031Sstas** ^A NULL pointer can be used in place of "main" to refer to the 5538226031Sstas** main database file. 5539226031Sstas** ^The third and fourth parameters to this routine 5540226031Sstas** are passed directly through to the second and third parameters of 5541226031Sstas** the xFileControl method. ^The return value of the xFileControl 5542226031Sstas** method becomes the return value of this routine. 5543226031Sstas** 5544226128Sstas** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5545226128Sstas** a pointer to the underlying [sqlite3_file] object to be written into 5546226128Sstas** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5547226128Sstas** case is a short-circuit path which does not actually invoke the 5548226128Sstas** underlying sqlite3_io_methods.xFileControl method. 5549226128Sstas** 5550226031Sstas** ^If the second parameter (zDbName) does not match the name of any 5551226031Sstas** open database file, then SQLITE_ERROR is returned. ^This error 5552226031Sstas** code is not remembered and will not be recalled by [sqlite3_errcode()] 5553226031Sstas** or [sqlite3_errmsg()]. The underlying xFileControl method might 5554226031Sstas** also return SQLITE_ERROR. There is no way to distinguish between 5555226031Sstas** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5556226031Sstas** xFileControl method. 5557226031Sstas** 5558226031Sstas** See also: [SQLITE_FCNTL_LOCKSTATE] 5559226031Sstas*/ 5560226031SstasSQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5561226031Sstas 5562226031Sstas/* 5563226031Sstas** CAPI3REF: Testing Interface 5564226031Sstas** 5565226031Sstas** ^The sqlite3_test_control() interface is used to read out internal 5566226031Sstas** state of SQLite and to inject faults into SQLite for testing 5567226031Sstas** purposes. ^The first parameter is an operation code that determines 5568226031Sstas** the number, meaning, and operation of all subsequent parameters. 5569226031Sstas** 5570226031Sstas** This interface is not for use by applications. It exists solely 5571226031Sstas** for verifying the correct operation of the SQLite library. Depending 5572226031Sstas** on how the SQLite library is compiled, this interface might not exist. 5573226031Sstas** 5574226031Sstas** The details of the operation codes, their meanings, the parameters 5575226031Sstas** they take, and what they do are all subject to change without notice. 5576226031Sstas** Unlike most of the SQLite API, this function is not guaranteed to 5577226031Sstas** operate consistently from one release to the next. 5578226031Sstas*/ 5579226031SstasSQLITE_API int sqlite3_test_control(int op, ...); 5580226031Sstas 5581226031Sstas/* 5582226031Sstas** CAPI3REF: Testing Interface Operation Codes 5583226031Sstas** 5584226031Sstas** These constants are the valid operation code parameters used 5585226031Sstas** as the first argument to [sqlite3_test_control()]. 5586226031Sstas** 5587226031Sstas** These parameters and their meanings are subject to change 5588226031Sstas** without notice. These values are for testing purposes only. 5589226031Sstas** Applications should not use any of these parameters or the 5590226031Sstas** [sqlite3_test_control()] interface. 5591226031Sstas*/ 5592226031Sstas#define SQLITE_TESTCTRL_FIRST 5 5593226031Sstas#define SQLITE_TESTCTRL_PRNG_SAVE 5 5594226031Sstas#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5595226031Sstas#define SQLITE_TESTCTRL_PRNG_RESET 7 5596226031Sstas#define SQLITE_TESTCTRL_BITVEC_TEST 8 5597226031Sstas#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5598226031Sstas#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5599226031Sstas#define SQLITE_TESTCTRL_PENDING_BYTE 11 5600226031Sstas#define SQLITE_TESTCTRL_ASSERT 12 5601226031Sstas#define SQLITE_TESTCTRL_ALWAYS 13 5602226031Sstas#define SQLITE_TESTCTRL_RESERVE 14 5603226031Sstas#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5604226031Sstas#define SQLITE_TESTCTRL_ISKEYWORD 16 5605226128Sstas#define SQLITE_TESTCTRL_PGHDRSZ 17 5606226128Sstas#define SQLITE_TESTCTRL_SCRATCHMALLOC 18 5607226128Sstas#define SQLITE_TESTCTRL_LOCALTIME_FAULT 19 5608226128Sstas#define SQLITE_TESTCTRL_LAST 19 5609226031Sstas 5610226031Sstas/* 5611226031Sstas** CAPI3REF: SQLite Runtime Status 5612226031Sstas** 5613226031Sstas** ^This interface is used to retrieve runtime status information 5614226128Sstas** about the performance of SQLite, and optionally to reset various 5615226031Sstas** highwater marks. ^The first argument is an integer code for 5616226031Sstas** the specific parameter to measure. ^(Recognized integer codes 5617226128Sstas** are of the form [status parameters | SQLITE_STATUS_...].)^ 5618226031Sstas** ^The current value of the parameter is returned into *pCurrent. 5619226031Sstas** ^The highest recorded value is returned in *pHighwater. ^If the 5620226031Sstas** resetFlag is true, then the highest record value is reset after 5621226031Sstas** *pHighwater is written. ^(Some parameters do not record the highest 5622226031Sstas** value. For those parameters 5623226031Sstas** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5624226031Sstas** ^(Other parameters record only the highwater mark and not the current 5625226031Sstas** value. For these latter parameters nothing is written into *pCurrent.)^ 5626226031Sstas** 5627226128Sstas** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5628226031Sstas** non-zero [error code] on failure. 5629226031Sstas** 5630226031Sstas** This routine is threadsafe but is not atomic. This routine can be 5631226031Sstas** called while other threads are running the same or different SQLite 5632226031Sstas** interfaces. However the values returned in *pCurrent and 5633226031Sstas** *pHighwater reflect the status of SQLite at different points in time 5634226031Sstas** and it is possible that another thread might change the parameter 5635226031Sstas** in between the times when *pCurrent and *pHighwater are written. 5636226031Sstas** 5637226031Sstas** See also: [sqlite3_db_status()] 5638226031Sstas*/ 5639226128SstasSQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5640226031Sstas 5641226031Sstas 5642226031Sstas/* 5643226031Sstas** CAPI3REF: Status Parameters 5644226128Sstas** KEYWORDS: {status parameters} 5645226031Sstas** 5646226031Sstas** These integer constants designate various run-time status parameters 5647226031Sstas** that can be returned by [sqlite3_status()]. 5648226031Sstas** 5649226031Sstas** <dl> 5650226128Sstas** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5651226031Sstas** <dd>This parameter is the current amount of memory checked out 5652226031Sstas** using [sqlite3_malloc()], either directly or indirectly. The 5653226031Sstas** figure includes calls made to [sqlite3_malloc()] by the application 5654226031Sstas** and internal memory usage by the SQLite library. Scratch memory 5655226031Sstas** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5656226031Sstas** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5657226031Sstas** this parameter. The amount returned is the sum of the allocation 5658226031Sstas** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5659226031Sstas** 5660226128Sstas** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5661226031Sstas** <dd>This parameter records the largest memory allocation request 5662226031Sstas** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5663226031Sstas** internal equivalents). Only the value returned in the 5664226128Sstas** *pHighwater parameter to [sqlite3_status()] is of interest. 5665226031Sstas** The value written into the *pCurrent parameter is undefined.</dd>)^ 5666226031Sstas** 5667226128Sstas** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5668226128Sstas** <dd>This parameter records the number of separate memory allocations 5669226128Sstas** currently checked out.</dd>)^ 5670226128Sstas** 5671226128Sstas** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5672226031Sstas** <dd>This parameter returns the number of pages used out of the 5673226128Sstas** [pagecache memory allocator] that was configured using 5674226031Sstas** [SQLITE_CONFIG_PAGECACHE]. The 5675226031Sstas** value returned is in pages, not in bytes.</dd>)^ 5676226031Sstas** 5677226128Sstas** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 5678226031Sstas** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5679226031Sstas** <dd>This parameter returns the number of bytes of page cache 5680226128Sstas** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5681226031Sstas** buffer and where forced to overflow to [sqlite3_malloc()]. The 5682226031Sstas** returned value includes allocations that overflowed because they 5683226031Sstas** where too large (they were larger than the "sz" parameter to 5684226031Sstas** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5685226031Sstas** no space was left in the page cache.</dd>)^ 5686226031Sstas** 5687226128Sstas** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5688226031Sstas** <dd>This parameter records the largest memory allocation request 5689226031Sstas** handed to [pagecache memory allocator]. Only the value returned in the 5690226128Sstas** *pHighwater parameter to [sqlite3_status()] is of interest. 5691226031Sstas** The value written into the *pCurrent parameter is undefined.</dd>)^ 5692226031Sstas** 5693226128Sstas** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5694226031Sstas** <dd>This parameter returns the number of allocations used out of the 5695226031Sstas** [scratch memory allocator] configured using 5696226031Sstas** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5697226031Sstas** in bytes. Since a single thread may only have one scratch allocation 5698226031Sstas** outstanding at time, this parameter also reports the number of threads 5699226031Sstas** using scratch memory at the same time.</dd>)^ 5700226031Sstas** 5701226128Sstas** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5702226031Sstas** <dd>This parameter returns the number of bytes of scratch memory 5703226128Sstas** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5704226031Sstas** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5705226031Sstas** returned include overflows because the requested allocation was too 5706226031Sstas** larger (that is, because the requested allocation was larger than the 5707226031Sstas** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5708226031Sstas** slots were available. 5709226031Sstas** </dd>)^ 5710226031Sstas** 5711226128Sstas** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5712226031Sstas** <dd>This parameter records the largest memory allocation request 5713226031Sstas** handed to [scratch memory allocator]. Only the value returned in the 5714226128Sstas** *pHighwater parameter to [sqlite3_status()] is of interest. 5715226031Sstas** The value written into the *pCurrent parameter is undefined.</dd>)^ 5716226031Sstas** 5717226128Sstas** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 5718226031Sstas** <dd>This parameter records the deepest parser stack. It is only 5719226031Sstas** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 5720226031Sstas** </dl> 5721226031Sstas** 5722226031Sstas** New status parameters may be added from time to time. 5723226031Sstas*/ 5724226031Sstas#define SQLITE_STATUS_MEMORY_USED 0 5725226031Sstas#define SQLITE_STATUS_PAGECACHE_USED 1 5726226031Sstas#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5727226031Sstas#define SQLITE_STATUS_SCRATCH_USED 3 5728226031Sstas#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5729226031Sstas#define SQLITE_STATUS_MALLOC_SIZE 5 5730226031Sstas#define SQLITE_STATUS_PARSER_STACK 6 5731226031Sstas#define SQLITE_STATUS_PAGECACHE_SIZE 7 5732226031Sstas#define SQLITE_STATUS_SCRATCH_SIZE 8 5733226128Sstas#define SQLITE_STATUS_MALLOC_COUNT 9 5734226031Sstas 5735226031Sstas/* 5736226031Sstas** CAPI3REF: Database Connection Status 5737226031Sstas** 5738226128Sstas** ^This interface is used to retrieve runtime status information 5739226031Sstas** about a single [database connection]. ^The first argument is the 5740226031Sstas** database connection object to be interrogated. ^The second argument 5741226128Sstas** is an integer constant, taken from the set of 5742226128Sstas** [SQLITE_DBSTATUS options], that 5743226128Sstas** determines the parameter to interrogate. The set of 5744226128Sstas** [SQLITE_DBSTATUS options] is likely 5745226128Sstas** to grow in future releases of SQLite. 5746226031Sstas** 5747226031Sstas** ^The current value of the requested parameter is written into *pCur 5748226031Sstas** and the highest instantaneous value is written into *pHiwtr. ^If 5749226031Sstas** the resetFlg is true, then the highest instantaneous value is 5750226031Sstas** reset back down to the current value. 5751226031Sstas** 5752226128Sstas** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 5753226128Sstas** non-zero [error code] on failure. 5754226128Sstas** 5755226031Sstas** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5756226031Sstas*/ 5757226128SstasSQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5758226031Sstas 5759226031Sstas/* 5760226031Sstas** CAPI3REF: Status Parameters for database connections 5761226128Sstas** KEYWORDS: {SQLITE_DBSTATUS options} 5762226031Sstas** 5763226031Sstas** These constants are the available integer "verbs" that can be passed as 5764226031Sstas** the second argument to the [sqlite3_db_status()] interface. 5765226031Sstas** 5766226031Sstas** New verbs may be added in future releases of SQLite. Existing verbs 5767226031Sstas** might be discontinued. Applications should check the return code from 5768226031Sstas** [sqlite3_db_status()] to make sure that the call worked. 5769226031Sstas** The [sqlite3_db_status()] interface will return a non-zero error code 5770226031Sstas** if a discontinued or unsupported verb is invoked. 5771226031Sstas** 5772226031Sstas** <dl> 5773226128Sstas** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 5774226031Sstas** <dd>This parameter returns the number of lookaside memory slots currently 5775226031Sstas** checked out.</dd>)^ 5776226128Sstas** 5777226128Sstas** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 5778226128Sstas** <dd>This parameter returns the number malloc attempts that were 5779226128Sstas** satisfied using lookaside memory. Only the high-water value is meaningful; 5780226128Sstas** the current value is always zero.)^ 5781226128Sstas** 5782226128Sstas** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 5783226128Sstas** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 5784226128Sstas** <dd>This parameter returns the number malloc attempts that might have 5785226128Sstas** been satisfied using lookaside memory but failed due to the amount of 5786226128Sstas** memory requested being larger than the lookaside slot size. 5787226128Sstas** Only the high-water value is meaningful; 5788226128Sstas** the current value is always zero.)^ 5789226128Sstas** 5790226128Sstas** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 5791226128Sstas** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 5792226128Sstas** <dd>This parameter returns the number malloc attempts that might have 5793226128Sstas** been satisfied using lookaside memory but failed due to all lookaside 5794226128Sstas** memory already being in use. 5795226128Sstas** Only the high-water value is meaningful; 5796226128Sstas** the current value is always zero.)^ 5797226128Sstas** 5798226128Sstas** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 5799226128Sstas** <dd>This parameter returns the approximate number of of bytes of heap 5800226128Sstas** memory used by all pager caches associated with the database connection.)^ 5801226128Sstas** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 5802226128Sstas** 5803226128Sstas** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 5804226128Sstas** <dd>This parameter returns the approximate number of of bytes of heap 5805226128Sstas** memory used to store the schema for all databases associated 5806226128Sstas** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 5807226128Sstas** ^The full amount of memory used by the schemas is reported, even if the 5808226128Sstas** schema memory is shared with other database connections due to 5809226128Sstas** [shared cache mode] being enabled. 5810226128Sstas** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 5811226128Sstas** 5812226128Sstas** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 5813226128Sstas** <dd>This parameter returns the approximate number of of bytes of heap 5814226128Sstas** and lookaside memory used by all prepared statements associated with 5815226128Sstas** the database connection.)^ 5816226128Sstas** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 5817226128Sstas** </dd> 5818226031Sstas** </dl> 5819226031Sstas*/ 5820226128Sstas#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 5821226128Sstas#define SQLITE_DBSTATUS_CACHE_USED 1 5822226128Sstas#define SQLITE_DBSTATUS_SCHEMA_USED 2 5823226128Sstas#define SQLITE_DBSTATUS_STMT_USED 3 5824226128Sstas#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 5825226128Sstas#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 5826226128Sstas#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 5827226128Sstas#define SQLITE_DBSTATUS_MAX 6 /* Largest defined DBSTATUS */ 5828226031Sstas 5829226031Sstas 5830226031Sstas/* 5831226031Sstas** CAPI3REF: Prepared Statement Status 5832226031Sstas** 5833226031Sstas** ^(Each prepared statement maintains various 5834226128Sstas** [SQLITE_STMTSTATUS counters] that measure the number 5835226031Sstas** of times it has performed specific operations.)^ These counters can 5836226031Sstas** be used to monitor the performance characteristics of the prepared 5837226031Sstas** statements. For example, if the number of table steps greatly exceeds 5838226031Sstas** the number of table searches or result rows, that would tend to indicate 5839226031Sstas** that the prepared statement is using a full table scan rather than 5840226128Sstas** an index. 5841226031Sstas** 5842226031Sstas** ^(This interface is used to retrieve and reset counter values from 5843226031Sstas** a [prepared statement]. The first argument is the prepared statement 5844226031Sstas** object to be interrogated. The second argument 5845226128Sstas** is an integer code for a specific [SQLITE_STMTSTATUS counter] 5846226031Sstas** to be interrogated.)^ 5847226031Sstas** ^The current value of the requested counter is returned. 5848226031Sstas** ^If the resetFlg is true, then the counter is reset to zero after this 5849226031Sstas** interface call returns. 5850226031Sstas** 5851226031Sstas** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5852226031Sstas*/ 5853226128SstasSQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5854226031Sstas 5855226031Sstas/* 5856226031Sstas** CAPI3REF: Status Parameters for prepared statements 5857226128Sstas** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 5858226031Sstas** 5859226031Sstas** These preprocessor macros define integer codes that name counter 5860226031Sstas** values associated with the [sqlite3_stmt_status()] interface. 5861226031Sstas** The meanings of the various counters are as follows: 5862226031Sstas** 5863226031Sstas** <dl> 5864226128Sstas** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5865226031Sstas** <dd>^This is the number of times that SQLite has stepped forward in 5866226031Sstas** a table as part of a full table scan. Large numbers for this counter 5867226128Sstas** may indicate opportunities for performance improvement through 5868226031Sstas** careful use of indices.</dd> 5869226031Sstas** 5870226128Sstas** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 5871226031Sstas** <dd>^This is the number of sort operations that have occurred. 5872226031Sstas** A non-zero value in this counter may indicate an opportunity to 5873226031Sstas** improvement performance through careful use of indices.</dd> 5874226031Sstas** 5875226128Sstas** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 5876226128Sstas** <dd>^This is the number of rows inserted into transient indices that 5877226128Sstas** were created automatically in order to help joins run faster. 5878226128Sstas** A non-zero value in this counter may indicate an opportunity to 5879226128Sstas** improvement performance by adding permanent indices that do not 5880226128Sstas** need to be reinitialized each time the statement is run.</dd> 5881226128Sstas** 5882226031Sstas** </dl> 5883226031Sstas*/ 5884226031Sstas#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5885226031Sstas#define SQLITE_STMTSTATUS_SORT 2 5886226128Sstas#define SQLITE_STMTSTATUS_AUTOINDEX 3 5887226031Sstas 5888226031Sstas/* 5889226031Sstas** CAPI3REF: Custom Page Cache Object 5890226031Sstas** 5891226031Sstas** The sqlite3_pcache type is opaque. It is implemented by 5892226031Sstas** the pluggable module. The SQLite core has no knowledge of 5893226031Sstas** its size or internal structure and never deals with the 5894226031Sstas** sqlite3_pcache object except by holding and passing pointers 5895226031Sstas** to the object. 5896226031Sstas** 5897226031Sstas** See [sqlite3_pcache_methods] for additional information. 5898226031Sstas*/ 5899226031Sstastypedef struct sqlite3_pcache sqlite3_pcache; 5900226031Sstas 5901226031Sstas/* 5902226031Sstas** CAPI3REF: Application Defined Page Cache. 5903226031Sstas** KEYWORDS: {page cache} 5904226031Sstas** 5905226031Sstas** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5906226128Sstas** register an alternative page cache implementation by passing in an 5907226128Sstas** instance of the sqlite3_pcache_methods structure.)^ 5908226128Sstas** In many applications, most of the heap memory allocated by 5909226128Sstas** SQLite is used for the page cache. 5910226128Sstas** By implementing a 5911226128Sstas** custom page cache using this API, an application can better control 5912226128Sstas** the amount of memory consumed by SQLite, the way in which 5913226128Sstas** that memory is allocated and released, and the policies used to 5914226128Sstas** determine exactly which parts of a database file are cached and for 5915226031Sstas** how long. 5916226031Sstas** 5917226128Sstas** The alternative page cache mechanism is an 5918226128Sstas** extreme measure that is only needed by the most demanding applications. 5919226128Sstas** The built-in page cache is recommended for most uses. 5920226128Sstas** 5921226031Sstas** ^(The contents of the sqlite3_pcache_methods structure are copied to an 5922226031Sstas** internal buffer by SQLite within the call to [sqlite3_config]. Hence 5923226031Sstas** the application may discard the parameter after the call to 5924226031Sstas** [sqlite3_config()] returns.)^ 5925226031Sstas** 5926226128Sstas** [[the xInit() page cache method]] 5927226128Sstas** ^(The xInit() method is called once for each effective 5928226128Sstas** call to [sqlite3_initialize()])^ 5929226031Sstas** (usually only once during the lifetime of the process). ^(The xInit() 5930226031Sstas** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ 5931226128Sstas** The intent of the xInit() method is to set up global data structures 5932226128Sstas** required by the custom page cache implementation. 5933226128Sstas** ^(If the xInit() method is NULL, then the 5934226128Sstas** built-in default page cache is used instead of the application defined 5935226128Sstas** page cache.)^ 5936226031Sstas** 5937226128Sstas** [[the xShutdown() page cache method]] 5938226128Sstas** ^The xShutdown() method is called by [sqlite3_shutdown()]. 5939226128Sstas** It can be used to clean up 5940226031Sstas** any outstanding resources before process shutdown, if required. 5941226128Sstas** ^The xShutdown() method may be NULL. 5942226031Sstas** 5943226128Sstas** ^SQLite automatically serializes calls to the xInit method, 5944226128Sstas** so the xInit method need not be threadsafe. ^The 5945226031Sstas** xShutdown method is only called from [sqlite3_shutdown()] so it does 5946226031Sstas** not need to be threadsafe either. All other methods must be threadsafe 5947226031Sstas** in multithreaded applications. 5948226031Sstas** 5949226031Sstas** ^SQLite will never invoke xInit() more than once without an intervening 5950226031Sstas** call to xShutdown(). 5951226031Sstas** 5952226128Sstas** [[the xCreate() page cache methods]] 5953226128Sstas** ^SQLite invokes the xCreate() method to construct a new cache instance. 5954226128Sstas** SQLite will typically create one cache instance for each open database file, 5955226031Sstas** though this is not guaranteed. ^The 5956226031Sstas** first parameter, szPage, is the size in bytes of the pages that must 5957226031Sstas** be allocated by the cache. ^szPage will not be a power of two. ^szPage 5958226031Sstas** will the page size of the database file that is to be cached plus an 5959226128Sstas** increment (here called "R") of less than 250. SQLite will use the 5960226031Sstas** extra R bytes on each page to store metadata about the underlying 5961226031Sstas** database page on disk. The value of R depends 5962226031Sstas** on the SQLite version, the target platform, and how SQLite was compiled. 5963226128Sstas** ^(R is constant for a particular build of SQLite. Except, there are two 5964226128Sstas** distinct values of R when SQLite is compiled with the proprietary 5965226128Sstas** ZIPVFS extension.)^ ^The second argument to 5966226031Sstas** xCreate(), bPurgeable, is true if the cache being created will 5967226031Sstas** be used to cache database pages of a file stored on disk, or 5968226128Sstas** false if it is used for an in-memory database. The cache implementation 5969226031Sstas** does not have to do anything special based with the value of bPurgeable; 5970226031Sstas** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 5971226031Sstas** never invoke xUnpin() except to deliberately delete a page. 5972226128Sstas** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 5973226128Sstas** false will always have the "discard" flag set to true. 5974226128Sstas** ^Hence, a cache created with bPurgeable false will 5975226031Sstas** never contain any unpinned pages. 5976226031Sstas** 5977226128Sstas** [[the xCachesize() page cache method]] 5978226031Sstas** ^(The xCachesize() method may be called at any time by SQLite to set the 5979226031Sstas** suggested maximum cache-size (number of pages stored by) the cache 5980226031Sstas** instance passed as the first argument. This is the value configured using 5981226128Sstas** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 5982226031Sstas** parameter, the implementation is not required to do anything with this 5983226031Sstas** value; it is advisory only. 5984226031Sstas** 5985226128Sstas** [[the xPagecount() page cache methods]] 5986226128Sstas** The xPagecount() method must return the number of pages currently 5987226128Sstas** stored in the cache, both pinned and unpinned. 5988226128Sstas** 5989226128Sstas** [[the xFetch() page cache methods]] 5990226128Sstas** The xFetch() method locates a page in the cache and returns a pointer to 5991226128Sstas** the page, or a NULL pointer. 5992226128Sstas** A "page", in this context, means a buffer of szPage bytes aligned at an 5993226128Sstas** 8-byte boundary. The page to be fetched is determined by the key. ^The 5994226128Sstas** minimum key value is 1. After it has been retrieved using xFetch, the page 5995226031Sstas** is considered to be "pinned". 5996226031Sstas** 5997226128Sstas** If the requested page is already in the page cache, then the page cache 5998226031Sstas** implementation must return a pointer to the page buffer with its content 5999226128Sstas** intact. If the requested page is not already in the cache, then the 6000226128Sstas** cache implementation should use the value of the createFlag 6001226128Sstas** parameter to help it determined what action to take: 6002226031Sstas** 6003226031Sstas** <table border=1 width=85% align=center> 6004226031Sstas** <tr><th> createFlag <th> Behaviour when page is not already in cache 6005226031Sstas** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6006226031Sstas** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6007226031Sstas** Otherwise return NULL. 6008226031Sstas** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6009226031Sstas** NULL if allocating a new page is effectively impossible. 6010226128Sstas** </table> 6011226031Sstas** 6012226128Sstas** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6013226128Sstas** will only use a createFlag of 2 after a prior call with a createFlag of 1 6014226128Sstas** failed.)^ In between the to xFetch() calls, SQLite may 6015226031Sstas** attempt to unpin one or more cache pages by spilling the content of 6016226128Sstas** pinned pages to disk and synching the operating system disk cache. 6017226031Sstas** 6018226128Sstas** [[the xUnpin() page cache method]] 6019226031Sstas** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6020226128Sstas** as its second argument. If the third parameter, discard, is non-zero, 6021226128Sstas** then the page must be evicted from the cache. 6022226128Sstas** ^If the discard parameter is 6023226128Sstas** zero, then the page may be discarded or retained at the discretion of 6024226128Sstas** page cache implementation. ^The page cache implementation 6025226031Sstas** may choose to evict unpinned pages at any time. 6026226031Sstas** 6027226128Sstas** The cache must not perform any reference counting. A single 6028226128Sstas** call to xUnpin() unpins the page regardless of the number of prior calls 6029226128Sstas** to xFetch(). 6030226031Sstas** 6031226128Sstas** [[the xRekey() page cache methods]] 6032226128Sstas** The xRekey() method is used to change the key value associated with the 6033226128Sstas** page passed as the second argument. If the cache 6034226128Sstas** previously contains an entry associated with newKey, it must be 6035226031Sstas** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6036226031Sstas** to be pinned. 6037226031Sstas** 6038226128Sstas** When SQLite calls the xTruncate() method, the cache must discard all 6039226031Sstas** existing cache entries with page numbers (keys) greater than or equal 6040226128Sstas** to the value of the iLimit parameter passed to xTruncate(). If any 6041226031Sstas** of these pages are pinned, they are implicitly unpinned, meaning that 6042226031Sstas** they can be safely discarded. 6043226031Sstas** 6044226128Sstas** [[the xDestroy() page cache method]] 6045226031Sstas** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6046226031Sstas** All resources associated with the specified cache should be freed. ^After 6047226031Sstas** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6048226031Sstas** handle invalid, and will not use it with any other sqlite3_pcache_methods 6049226031Sstas** functions. 6050226031Sstas*/ 6051226031Sstastypedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6052226031Sstasstruct sqlite3_pcache_methods { 6053226031Sstas void *pArg; 6054226031Sstas int (*xInit)(void*); 6055226031Sstas void (*xShutdown)(void*); 6056226031Sstas sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6057226031Sstas void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6058226031Sstas int (*xPagecount)(sqlite3_pcache*); 6059226031Sstas void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6060226031Sstas void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6061226031Sstas void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6062226031Sstas void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6063226031Sstas void (*xDestroy)(sqlite3_pcache*); 6064226031Sstas}; 6065226031Sstas 6066226031Sstas/* 6067226031Sstas** CAPI3REF: Online Backup Object 6068226031Sstas** 6069226031Sstas** The sqlite3_backup object records state information about an ongoing 6070226031Sstas** online backup operation. ^The sqlite3_backup object is created by 6071226031Sstas** a call to [sqlite3_backup_init()] and is destroyed by a call to 6072226031Sstas** [sqlite3_backup_finish()]. 6073226031Sstas** 6074226031Sstas** See Also: [Using the SQLite Online Backup API] 6075226031Sstas*/ 6076226031Sstastypedef struct sqlite3_backup sqlite3_backup; 6077226031Sstas 6078226031Sstas/* 6079226031Sstas** CAPI3REF: Online Backup API. 6080226031Sstas** 6081226031Sstas** The backup API copies the content of one database into another. 6082226031Sstas** It is useful either for creating backups of databases or 6083226128Sstas** for copying in-memory databases to or from persistent files. 6084226031Sstas** 6085226031Sstas** See Also: [Using the SQLite Online Backup API] 6086226031Sstas** 6087226128Sstas** ^SQLite holds a write transaction open on the destination database file 6088226128Sstas** for the duration of the backup operation. 6089226128Sstas** ^The source database is read-locked only while it is being read; 6090226128Sstas** it is not locked continuously for the entire backup operation. 6091226128Sstas** ^Thus, the backup may be performed on a live source database without 6092226128Sstas** preventing other database connections from 6093226031Sstas** reading or writing to the source database while the backup is underway. 6094226128Sstas** 6095226128Sstas** ^(To perform a backup operation: 6096226031Sstas** <ol> 6097226031Sstas** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6098226128Sstas** backup, 6099226128Sstas** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6100226031Sstas** the data between the two databases, and finally 6101226128Sstas** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6102226128Sstas** associated with the backup operation. 6103226031Sstas** </ol>)^ 6104226031Sstas** There should be exactly one call to sqlite3_backup_finish() for each 6105226031Sstas** successful call to sqlite3_backup_init(). 6106226031Sstas** 6107226128Sstas** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6108226031Sstas** 6109226128Sstas** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6110226128Sstas** [database connection] associated with the destination database 6111226031Sstas** and the database name, respectively. 6112226031Sstas** ^The database name is "main" for the main database, "temp" for the 6113226031Sstas** temporary database, or the name specified after the AS keyword in 6114226031Sstas** an [ATTACH] statement for an attached database. 6115226128Sstas** ^The S and M arguments passed to 6116226031Sstas** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6117226031Sstas** and database name of the source database, respectively. 6118226031Sstas** ^The source and destination [database connections] (parameters S and D) 6119226128Sstas** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6120226031Sstas** an error. 6121226031Sstas** 6122226031Sstas** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6123226128Sstas** returned and an error code and error message are stored in the 6124226031Sstas** destination [database connection] D. 6125226031Sstas** ^The error code and message for the failed call to sqlite3_backup_init() 6126226031Sstas** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6127226031Sstas** [sqlite3_errmsg16()] functions. 6128226031Sstas** ^A successful call to sqlite3_backup_init() returns a pointer to an 6129226031Sstas** [sqlite3_backup] object. 6130226031Sstas** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6131226128Sstas** sqlite3_backup_finish() functions to perform the specified backup 6132226031Sstas** operation. 6133226031Sstas** 6134226128Sstas** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6135226031Sstas** 6136226128Sstas** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6137226031Sstas** the source and destination databases specified by [sqlite3_backup] object B. 6138226128Sstas** ^If N is negative, all remaining source pages are copied. 6139226031Sstas** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6140226128Sstas** are still more pages to be copied, then the function returns [SQLITE_OK]. 6141226031Sstas** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6142226031Sstas** from source to destination, then it returns [SQLITE_DONE]. 6143226031Sstas** ^If an error occurs while running sqlite3_backup_step(B,N), 6144226031Sstas** then an [error code] is returned. ^As well as [SQLITE_OK] and 6145226031Sstas** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6146226031Sstas** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6147226031Sstas** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6148226031Sstas** 6149226128Sstas** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6150226128Sstas** <ol> 6151226128Sstas** <li> the destination database was opened read-only, or 6152226128Sstas** <li> the destination database is using write-ahead-log journaling 6153226128Sstas** and the destination and source page sizes differ, or 6154226128Sstas** <li> the destination database is an in-memory database and the 6155226128Sstas** destination and source page sizes differ. 6156226128Sstas** </ol>)^ 6157226031Sstas** 6158226031Sstas** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6159226031Sstas** the [sqlite3_busy_handler | busy-handler function] 6160226128Sstas** is invoked (if one is specified). ^If the 6161226128Sstas** busy-handler returns non-zero before the lock is available, then 6162226031Sstas** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6163226031Sstas** sqlite3_backup_step() can be retried later. ^If the source 6164226031Sstas** [database connection] 6165226031Sstas** is being used to write to the source database when sqlite3_backup_step() 6166226031Sstas** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6167226031Sstas** case the call to sqlite3_backup_step() can be retried later on. ^(If 6168226031Sstas** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6169226128Sstas** [SQLITE_READONLY] is returned, then 6170226128Sstas** there is no point in retrying the call to sqlite3_backup_step(). These 6171226128Sstas** errors are considered fatal.)^ The application must accept 6172226128Sstas** that the backup operation has failed and pass the backup operation handle 6173226031Sstas** to the sqlite3_backup_finish() to release associated resources. 6174226031Sstas** 6175226031Sstas** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6176226128Sstas** on the destination file. ^The exclusive lock is not released until either 6177226128Sstas** sqlite3_backup_finish() is called or the backup operation is complete 6178226031Sstas** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6179226031Sstas** sqlite3_backup_step() obtains a [shared lock] on the source database that 6180226031Sstas** lasts for the duration of the sqlite3_backup_step() call. 6181226031Sstas** ^Because the source database is not locked between calls to 6182226031Sstas** sqlite3_backup_step(), the source database may be modified mid-way 6183226031Sstas** through the backup process. ^If the source database is modified by an 6184226031Sstas** external process or via a database connection other than the one being 6185226031Sstas** used by the backup operation, then the backup will be automatically 6186226128Sstas** restarted by the next call to sqlite3_backup_step(). ^If the source 6187226031Sstas** database is modified by the using the same database connection as is used 6188226031Sstas** by the backup operation, then the backup database is automatically 6189226031Sstas** updated at the same time. 6190226031Sstas** 6191226128Sstas** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6192226031Sstas** 6193226128Sstas** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6194226031Sstas** application wishes to abandon the backup operation, the application 6195226031Sstas** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6196226031Sstas** ^The sqlite3_backup_finish() interfaces releases all 6197226128Sstas** resources associated with the [sqlite3_backup] object. 6198226031Sstas** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6199226031Sstas** active write-transaction on the destination database is rolled back. 6200226031Sstas** The [sqlite3_backup] object is invalid 6201226031Sstas** and may not be used following a call to sqlite3_backup_finish(). 6202226031Sstas** 6203226031Sstas** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6204226031Sstas** sqlite3_backup_step() errors occurred, regardless or whether or not 6205226031Sstas** sqlite3_backup_step() completed. 6206226031Sstas** ^If an out-of-memory condition or IO error occurred during any prior 6207226031Sstas** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6208226031Sstas** sqlite3_backup_finish() returns the corresponding [error code]. 6209226031Sstas** 6210226031Sstas** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6211226031Sstas** is not a permanent error and does not affect the return value of 6212226031Sstas** sqlite3_backup_finish(). 6213226031Sstas** 6214226128Sstas** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6215226128Sstas** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6216226031Sstas** 6217226031Sstas** ^Each call to sqlite3_backup_step() sets two values inside 6218226031Sstas** the [sqlite3_backup] object: the number of pages still to be backed 6219226128Sstas** up and the total number of pages in the source database file. 6220226031Sstas** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6221226031Sstas** retrieve these two values, respectively. 6222226031Sstas** 6223226031Sstas** ^The values returned by these functions are only updated by 6224226031Sstas** sqlite3_backup_step(). ^If the source database is modified during a backup 6225226031Sstas** operation, then the values are not updated to account for any extra 6226226031Sstas** pages that need to be updated or the size of the source database file 6227226031Sstas** changing. 6228226031Sstas** 6229226031Sstas** <b>Concurrent Usage of Database Handles</b> 6230226031Sstas** 6231226031Sstas** ^The source [database connection] may be used by the application for other 6232226031Sstas** purposes while a backup operation is underway or being initialized. 6233226031Sstas** ^If SQLite is compiled and configured to support threadsafe database 6234226031Sstas** connections, then the source database connection may be used concurrently 6235226031Sstas** from within other threads. 6236226031Sstas** 6237226128Sstas** However, the application must guarantee that the destination 6238226128Sstas** [database connection] is not passed to any other API (by any thread) after 6239226031Sstas** sqlite3_backup_init() is called and before the corresponding call to 6240226031Sstas** sqlite3_backup_finish(). SQLite does not currently check to see 6241226031Sstas** if the application incorrectly accesses the destination [database connection] 6242226031Sstas** and so no error code is reported, but the operations may malfunction 6243226031Sstas** nevertheless. Use of the destination database connection while a 6244226031Sstas** backup is in progress might also also cause a mutex deadlock. 6245226031Sstas** 6246226031Sstas** If running in [shared cache mode], the application must 6247226031Sstas** guarantee that the shared cache used by the destination database 6248226031Sstas** is not accessed while the backup is running. In practice this means 6249226128Sstas** that the application must guarantee that the disk file being 6250226031Sstas** backed up to is not accessed by any connection within the process, 6251226031Sstas** not just the specific connection that was passed to sqlite3_backup_init(). 6252226031Sstas** 6253226128Sstas** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6254226031Sstas** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6255226031Sstas** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6256226031Sstas** APIs are not strictly speaking threadsafe. If they are invoked at the 6257226031Sstas** same time as another thread is invoking sqlite3_backup_step() it is 6258226031Sstas** possible that they return invalid values. 6259226031Sstas*/ 6260226031SstasSQLITE_API sqlite3_backup *sqlite3_backup_init( 6261226031Sstas sqlite3 *pDest, /* Destination database handle */ 6262226031Sstas const char *zDestName, /* Destination database name */ 6263226031Sstas sqlite3 *pSource, /* Source database handle */ 6264226031Sstas const char *zSourceName /* Source database name */ 6265226031Sstas); 6266226031SstasSQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6267226031SstasSQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6268226031SstasSQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6269226031SstasSQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6270226031Sstas 6271226031Sstas/* 6272226031Sstas** CAPI3REF: Unlock Notification 6273226031Sstas** 6274226031Sstas** ^When running in shared-cache mode, a database operation may fail with 6275226031Sstas** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6276226031Sstas** individual tables within the shared-cache cannot be obtained. See 6277226128Sstas** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6278226128Sstas** ^This API may be used to register a callback that SQLite will invoke 6279226031Sstas** when the connection currently holding the required lock relinquishes it. 6280226031Sstas** ^This API is only available if the library was compiled with the 6281226031Sstas** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6282226031Sstas** 6283226031Sstas** See Also: [Using the SQLite Unlock Notification Feature]. 6284226031Sstas** 6285226031Sstas** ^Shared-cache locks are released when a database connection concludes 6286226128Sstas** its current transaction, either by committing it or rolling it back. 6287226031Sstas** 6288226031Sstas** ^When a connection (known as the blocked connection) fails to obtain a 6289226031Sstas** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6290226031Sstas** identity of the database connection (the blocking connection) that 6291226128Sstas** has locked the required resource is stored internally. ^After an 6292226031Sstas** application receives an SQLITE_LOCKED error, it may call the 6293226128Sstas** sqlite3_unlock_notify() method with the blocked connection handle as 6294226031Sstas** the first argument to register for a callback that will be invoked 6295226031Sstas** when the blocking connections current transaction is concluded. ^The 6296226031Sstas** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6297226031Sstas** call that concludes the blocking connections transaction. 6298226031Sstas** 6299226031Sstas** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6300226031Sstas** there is a chance that the blocking connection will have already 6301226031Sstas** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6302226031Sstas** If this happens, then the specified callback is invoked immediately, 6303226031Sstas** from within the call to sqlite3_unlock_notify().)^ 6304226031Sstas** 6305226031Sstas** ^If the blocked connection is attempting to obtain a write-lock on a 6306226031Sstas** shared-cache table, and more than one other connection currently holds 6307226128Sstas** a read-lock on the same table, then SQLite arbitrarily selects one of 6308226031Sstas** the other connections to use as the blocking connection. 6309226031Sstas** 6310226128Sstas** ^(There may be at most one unlock-notify callback registered by a 6311226031Sstas** blocked connection. If sqlite3_unlock_notify() is called when the 6312226031Sstas** blocked connection already has a registered unlock-notify callback, 6313226031Sstas** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6314226031Sstas** called with a NULL pointer as its second argument, then any existing 6315226128Sstas** unlock-notify callback is canceled. ^The blocked connections 6316226031Sstas** unlock-notify callback may also be canceled by closing the blocked 6317226031Sstas** connection using [sqlite3_close()]. 6318226031Sstas** 6319226031Sstas** The unlock-notify callback is not reentrant. If an application invokes 6320226031Sstas** any sqlite3_xxx API functions from within an unlock-notify callback, a 6321226031Sstas** crash or deadlock may be the result. 6322226031Sstas** 6323226031Sstas** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6324226031Sstas** returns SQLITE_OK. 6325226031Sstas** 6326226031Sstas** <b>Callback Invocation Details</b> 6327226031Sstas** 6328226128Sstas** When an unlock-notify callback is registered, the application provides a 6329226031Sstas** single void* pointer that is passed to the callback when it is invoked. 6330226031Sstas** However, the signature of the callback function allows SQLite to pass 6331226031Sstas** it an array of void* context pointers. The first argument passed to 6332226031Sstas** an unlock-notify callback is a pointer to an array of void* pointers, 6333226031Sstas** and the second is the number of entries in the array. 6334226031Sstas** 6335226031Sstas** When a blocking connections transaction is concluded, there may be 6336226031Sstas** more than one blocked connection that has registered for an unlock-notify 6337226031Sstas** callback. ^If two or more such blocked connections have specified the 6338226031Sstas** same callback function, then instead of invoking the callback function 6339226031Sstas** multiple times, it is invoked once with the set of void* context pointers 6340226031Sstas** specified by the blocked connections bundled together into an array. 6341226128Sstas** This gives the application an opportunity to prioritize any actions 6342226031Sstas** related to the set of unblocked database connections. 6343226031Sstas** 6344226031Sstas** <b>Deadlock Detection</b> 6345226031Sstas** 6346226128Sstas** Assuming that after registering for an unlock-notify callback a 6347226031Sstas** database waits for the callback to be issued before taking any further 6348226031Sstas** action (a reasonable assumption), then using this API may cause the 6349226031Sstas** application to deadlock. For example, if connection X is waiting for 6350226031Sstas** connection Y's transaction to be concluded, and similarly connection 6351226031Sstas** Y is waiting on connection X's transaction, then neither connection 6352226031Sstas** will proceed and the system may remain deadlocked indefinitely. 6353226031Sstas** 6354226031Sstas** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6355226031Sstas** detection. ^If a given call to sqlite3_unlock_notify() would put the 6356226031Sstas** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6357226031Sstas** unlock-notify callback is registered. The system is said to be in 6358226031Sstas** a deadlocked state if connection A has registered for an unlock-notify 6359226031Sstas** callback on the conclusion of connection B's transaction, and connection 6360226031Sstas** B has itself registered for an unlock-notify callback when connection 6361226031Sstas** A's transaction is concluded. ^Indirect deadlock is also detected, so 6362226031Sstas** the system is also considered to be deadlocked if connection B has 6363226031Sstas** registered for an unlock-notify callback on the conclusion of connection 6364226031Sstas** C's transaction, where connection C is waiting on connection A. ^Any 6365226031Sstas** number of levels of indirection are allowed. 6366226031Sstas** 6367226031Sstas** <b>The "DROP TABLE" Exception</b> 6368226031Sstas** 6369226128Sstas** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6370226031Sstas** always appropriate to call sqlite3_unlock_notify(). There is however, 6371226031Sstas** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6372226031Sstas** SQLite checks if there are any currently executing SELECT statements 6373226031Sstas** that belong to the same connection. If there are, SQLITE_LOCKED is 6374226031Sstas** returned. In this case there is no "blocking connection", so invoking 6375226031Sstas** sqlite3_unlock_notify() results in the unlock-notify callback being 6376226031Sstas** invoked immediately. If the application then re-attempts the "DROP TABLE" 6377226031Sstas** or "DROP INDEX" query, an infinite loop might be the result. 6378226031Sstas** 6379226031Sstas** One way around this problem is to check the extended error code returned 6380226031Sstas** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6381226031Sstas** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6382226128Sstas** the special "DROP TABLE/INDEX" case, the extended error code is just 6383226031Sstas** SQLITE_LOCKED.)^ 6384226031Sstas*/ 6385226031SstasSQLITE_API int sqlite3_unlock_notify( 6386226031Sstas sqlite3 *pBlocked, /* Waiting connection */ 6387226031Sstas void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6388226031Sstas void *pNotifyArg /* Argument to pass to xNotify */ 6389226031Sstas); 6390226031Sstas 6391226031Sstas 6392226031Sstas/* 6393226031Sstas** CAPI3REF: String Comparison 6394226031Sstas** 6395226031Sstas** ^The [sqlite3_strnicmp()] API allows applications and extensions to 6396226031Sstas** compare the contents of two buffers containing UTF-8 strings in a 6397226128Sstas** case-independent fashion, using the same definition of case independence 6398226031Sstas** that SQLite uses internally when comparing identifiers. 6399226031Sstas*/ 6400226031SstasSQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 6401226031Sstas 6402226031Sstas/* 6403226031Sstas** CAPI3REF: Error Logging Interface 6404226031Sstas** 6405226031Sstas** ^The [sqlite3_log()] interface writes a message into the error log 6406226031Sstas** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6407226031Sstas** ^If logging is enabled, the zFormat string and subsequent arguments are 6408226128Sstas** used with [sqlite3_snprintf()] to generate the final output string. 6409226031Sstas** 6410226031Sstas** The sqlite3_log() interface is intended for use by extensions such as 6411226031Sstas** virtual tables, collating functions, and SQL functions. While there is 6412226031Sstas** nothing to prevent an application from calling sqlite3_log(), doing so 6413226031Sstas** is considered bad form. 6414226031Sstas** 6415226031Sstas** The zFormat string must not be NULL. 6416226031Sstas** 6417226031Sstas** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6418226031Sstas** will not use dynamically allocated memory. The log message is stored in 6419226031Sstas** a fixed-length buffer on the stack. If the log message is longer than 6420226031Sstas** a few hundred characters, it will be truncated to the length of the 6421226031Sstas** buffer. 6422226031Sstas*/ 6423226031SstasSQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 6424226031Sstas 6425226031Sstas/* 6426226128Sstas** CAPI3REF: Write-Ahead Log Commit Hook 6427226128Sstas** 6428226128Sstas** ^The [sqlite3_wal_hook()] function is used to register a callback that 6429226128Sstas** will be invoked each time a database connection commits data to a 6430226128Sstas** [write-ahead log] (i.e. whenever a transaction is committed in 6431226128Sstas** [journal_mode | journal_mode=WAL mode]). 6432226128Sstas** 6433226128Sstas** ^The callback is invoked by SQLite after the commit has taken place and 6434226128Sstas** the associated write-lock on the database released, so the implementation 6435226128Sstas** may read, write or [checkpoint] the database as required. 6436226128Sstas** 6437226128Sstas** ^The first parameter passed to the callback function when it is invoked 6438226128Sstas** is a copy of the third parameter passed to sqlite3_wal_hook() when 6439226128Sstas** registering the callback. ^The second is a copy of the database handle. 6440226128Sstas** ^The third parameter is the name of the database that was written to - 6441226128Sstas** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6442226128Sstas** is the number of pages currently in the write-ahead log file, 6443226128Sstas** including those that were just committed. 6444226128Sstas** 6445226128Sstas** The callback function should normally return [SQLITE_OK]. ^If an error 6446226128Sstas** code is returned, that error will propagate back up through the 6447226128Sstas** SQLite code base to cause the statement that provoked the callback 6448226128Sstas** to report an error, though the commit will have still occurred. If the 6449226128Sstas** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6450226128Sstas** that does not correspond to any valid SQLite error code, the results 6451226128Sstas** are undefined. 6452226128Sstas** 6453226128Sstas** A single database handle may have at most a single write-ahead log callback 6454226128Sstas** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6455226128Sstas** previously registered write-ahead log callback. ^Note that the 6456226128Sstas** [sqlite3_wal_autocheckpoint()] interface and the 6457226128Sstas** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6458226128Sstas** those overwrite any prior [sqlite3_wal_hook()] settings. 6459226128Sstas*/ 6460226128SstasSQLITE_API void *sqlite3_wal_hook( 6461226128Sstas sqlite3*, 6462226128Sstas int(*)(void *,sqlite3*,const char*,int), 6463226128Sstas void* 6464226128Sstas); 6465226128Sstas 6466226128Sstas/* 6467226128Sstas** CAPI3REF: Configure an auto-checkpoint 6468226128Sstas** 6469226128Sstas** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6470226128Sstas** [sqlite3_wal_hook()] that causes any database on [database connection] D 6471226128Sstas** to automatically [checkpoint] 6472226128Sstas** after committing a transaction if there are N or 6473226128Sstas** more frames in the [write-ahead log] file. ^Passing zero or 6474226128Sstas** a negative value as the nFrame parameter disables automatic 6475226128Sstas** checkpoints entirely. 6476226128Sstas** 6477226128Sstas** ^The callback registered by this function replaces any existing callback 6478226128Sstas** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6479226128Sstas** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6480226128Sstas** configured by this function. 6481226128Sstas** 6482226128Sstas** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6483226128Sstas** from SQL. 6484226128Sstas** 6485226128Sstas** ^Every new [database connection] defaults to having the auto-checkpoint 6486226128Sstas** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6487226128Sstas** pages. The use of this interface 6488226128Sstas** is only necessary if the default setting is found to be suboptimal 6489226128Sstas** for a particular application. 6490226128Sstas*/ 6491226128SstasSQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6492226128Sstas 6493226128Sstas/* 6494226128Sstas** CAPI3REF: Checkpoint a database 6495226128Sstas** 6496226128Sstas** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6497226128Sstas** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6498226128Sstas** empty string, then a checkpoint is run on all databases of 6499226128Sstas** connection D. ^If the database connection D is not in 6500226128Sstas** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6501226128Sstas** 6502226128Sstas** ^The [wal_checkpoint pragma] can be used to invoke this interface 6503226128Sstas** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6504226128Sstas** [wal_autocheckpoint pragma] can be used to cause this interface to be 6505226128Sstas** run whenever the WAL reaches a certain size threshold. 6506226128Sstas** 6507226128Sstas** See also: [sqlite3_wal_checkpoint_v2()] 6508226128Sstas*/ 6509226128SstasSQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6510226128Sstas 6511226128Sstas/* 6512226128Sstas** CAPI3REF: Checkpoint a database 6513226128Sstas** 6514226128Sstas** Run a checkpoint operation on WAL database zDb attached to database 6515226128Sstas** handle db. The specific operation is determined by the value of the 6516226128Sstas** eMode parameter: 6517226128Sstas** 6518226128Sstas** <dl> 6519226128Sstas** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6520226128Sstas** Checkpoint as many frames as possible without waiting for any database 6521226128Sstas** readers or writers to finish. Sync the db file if all frames in the log 6522226128Sstas** are checkpointed. This mode is the same as calling 6523226128Sstas** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6524226128Sstas** 6525226128Sstas** <dt>SQLITE_CHECKPOINT_FULL<dd> 6526226128Sstas** This mode blocks (calls the busy-handler callback) until there is no 6527226128Sstas** database writer and all readers are reading from the most recent database 6528226128Sstas** snapshot. It then checkpoints all frames in the log file and syncs the 6529226128Sstas** database file. This call blocks database writers while it is running, 6530226128Sstas** but not database readers. 6531226128Sstas** 6532226128Sstas** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6533226128Sstas** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6534226128Sstas** checkpointing the log file it blocks (calls the busy-handler callback) 6535226128Sstas** until all readers are reading from the database file only. This ensures 6536226128Sstas** that the next client to write to the database file restarts the log file 6537226128Sstas** from the beginning. This call blocks database writers while it is running, 6538226128Sstas** but not database readers. 6539226128Sstas** </dl> 6540226128Sstas** 6541226128Sstas** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6542226128Sstas** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6543226128Sstas** the total number of checkpointed frames (including any that were already 6544226128Sstas** checkpointed when this function is called). *pnLog and *pnCkpt may be 6545226128Sstas** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6546226128Sstas** If no values are available because of an error, they are both set to -1 6547226128Sstas** before returning to communicate this to the caller. 6548226128Sstas** 6549226128Sstas** All calls obtain an exclusive "checkpoint" lock on the database file. If 6550226128Sstas** any other process is running a checkpoint operation at the same time, the 6551226128Sstas** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6552226128Sstas** busy-handler configured, it will not be invoked in this case. 6553226128Sstas** 6554226128Sstas** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6555226128Sstas** "writer" lock on the database file. If the writer lock cannot be obtained 6556226128Sstas** immediately, and a busy-handler is configured, it is invoked and the writer 6557226128Sstas** lock retried until either the busy-handler returns 0 or the lock is 6558226128Sstas** successfully obtained. The busy-handler is also invoked while waiting for 6559226128Sstas** database readers as described above. If the busy-handler returns 0 before 6560226128Sstas** the writer lock is obtained or while waiting for database readers, the 6561226128Sstas** checkpoint operation proceeds from that point in the same way as 6562226128Sstas** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6563226128Sstas** without blocking any further. SQLITE_BUSY is returned in this case. 6564226128Sstas** 6565226128Sstas** If parameter zDb is NULL or points to a zero length string, then the 6566226128Sstas** specified operation is attempted on all WAL databases. In this case the 6567226128Sstas** values written to output parameters *pnLog and *pnCkpt are undefined. If 6568226128Sstas** an SQLITE_BUSY error is encountered when processing one or more of the 6569226128Sstas** attached WAL databases, the operation is still attempted on any remaining 6570226128Sstas** attached databases and SQLITE_BUSY is returned to the caller. If any other 6571226128Sstas** error occurs while processing an attached database, processing is abandoned 6572226128Sstas** and the error code returned to the caller immediately. If no error 6573226128Sstas** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6574226128Sstas** databases, SQLITE_OK is returned. 6575226128Sstas** 6576226128Sstas** If database zDb is the name of an attached database that is not in WAL 6577226128Sstas** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6578226128Sstas** zDb is not NULL (or a zero length string) and is not the name of any 6579226128Sstas** attached database, SQLITE_ERROR is returned to the caller. 6580226128Sstas*/ 6581226128SstasSQLITE_API int sqlite3_wal_checkpoint_v2( 6582226128Sstas sqlite3 *db, /* Database handle */ 6583226128Sstas const char *zDb, /* Name of attached database (or NULL) */ 6584226128Sstas int eMode, /* SQLITE_CHECKPOINT_* value */ 6585226128Sstas int *pnLog, /* OUT: Size of WAL log in frames */ 6586226128Sstas int *pnCkpt /* OUT: Total number of frames checkpointed */ 6587226128Sstas); 6588226128Sstas 6589226128Sstas/* 6590226128Sstas** CAPI3REF: Checkpoint operation parameters 6591226128Sstas** 6592226128Sstas** These constants can be used as the 3rd parameter to 6593226128Sstas** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6594226128Sstas** documentation for additional information about the meaning and use of 6595226128Sstas** each of these values. 6596226128Sstas*/ 6597226128Sstas#define SQLITE_CHECKPOINT_PASSIVE 0 6598226128Sstas#define SQLITE_CHECKPOINT_FULL 1 6599226128Sstas#define SQLITE_CHECKPOINT_RESTART 2 6600226128Sstas 6601226128Sstas/* 6602226128Sstas** CAPI3REF: Virtual Table Interface Configuration 6603226128Sstas** 6604226128Sstas** This function may be called by either the [xConnect] or [xCreate] method 6605226128Sstas** of a [virtual table] implementation to configure 6606226128Sstas** various facets of the virtual table interface. 6607226128Sstas** 6608226128Sstas** If this interface is invoked outside the context of an xConnect or 6609226128Sstas** xCreate virtual table method then the behavior is undefined. 6610226128Sstas** 6611226128Sstas** At present, there is only one option that may be configured using 6612226128Sstas** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 6613226128Sstas** may be added in the future. 6614226128Sstas*/ 6615226128SstasSQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 6616226128Sstas 6617226128Sstas/* 6618226128Sstas** CAPI3REF: Virtual Table Configuration Options 6619226128Sstas** 6620226128Sstas** These macros define the various options to the 6621226128Sstas** [sqlite3_vtab_config()] interface that [virtual table] implementations 6622226128Sstas** can use to customize and optimize their behavior. 6623226128Sstas** 6624226128Sstas** <dl> 6625226128Sstas** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 6626226128Sstas** <dd>Calls of the form 6627226128Sstas** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 6628226128Sstas** where X is an integer. If X is zero, then the [virtual table] whose 6629226128Sstas** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 6630226128Sstas** support constraints. In this configuration (which is the default) if 6631226128Sstas** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 6632226128Sstas** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 6633226128Sstas** specified as part of the users SQL statement, regardless of the actual 6634226128Sstas** ON CONFLICT mode specified. 6635226128Sstas** 6636226128Sstas** If X is non-zero, then the virtual table implementation guarantees 6637226128Sstas** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 6638226128Sstas** any modifications to internal or persistent data structures have been made. 6639226128Sstas** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 6640226128Sstas** is able to roll back a statement or database transaction, and abandon 6641226128Sstas** or continue processing the current SQL statement as appropriate. 6642226128Sstas** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 6643226128Sstas** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 6644226128Sstas** had been ABORT. 6645226128Sstas** 6646226128Sstas** Virtual table implementations that are required to handle OR REPLACE 6647226128Sstas** must do so within the [xUpdate] method. If a call to the 6648226128Sstas** [sqlite3_vtab_on_conflict()] function indicates that the current ON 6649226128Sstas** CONFLICT policy is REPLACE, the virtual table implementation should 6650226128Sstas** silently replace the appropriate rows within the xUpdate callback and 6651226128Sstas** return SQLITE_OK. Or, if this is not possible, it may return 6652226128Sstas** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 6653226128Sstas** constraint handling. 6654226128Sstas** </dl> 6655226128Sstas*/ 6656226128Sstas#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 6657226128Sstas 6658226128Sstas/* 6659226128Sstas** CAPI3REF: Determine The Virtual Table Conflict Policy 6660226128Sstas** 6661226128Sstas** This function may only be called from within a call to the [xUpdate] method 6662226128Sstas** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 6663226128Sstas** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 6664226128Sstas** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 6665226128Sstas** of the SQL statement that triggered the call to the [xUpdate] method of the 6666226128Sstas** [virtual table]. 6667226128Sstas*/ 6668226128SstasSQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 6669226128Sstas 6670226128Sstas/* 6671226128Sstas** CAPI3REF: Conflict resolution modes 6672226128Sstas** 6673226128Sstas** These constants are returned by [sqlite3_vtab_on_conflict()] to 6674226128Sstas** inform a [virtual table] implementation what the [ON CONFLICT] mode 6675226128Sstas** is for the SQL statement being evaluated. 6676226128Sstas** 6677226128Sstas** Note that the [SQLITE_IGNORE] constant is also used as a potential 6678226128Sstas** return value from the [sqlite3_set_authorizer()] callback and that 6679226128Sstas** [SQLITE_ABORT] is also a [result code]. 6680226128Sstas*/ 6681226128Sstas#define SQLITE_ROLLBACK 1 6682226128Sstas/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 6683226128Sstas#define SQLITE_FAIL 3 6684226128Sstas/* #define SQLITE_ABORT 4 // Also an error code */ 6685226128Sstas#define SQLITE_REPLACE 5 6686226128Sstas 6687226128Sstas 6688226128Sstas 6689226128Sstas/* 6690226031Sstas** Undo the hack that converts floating point types to integer for 6691226031Sstas** builds on processors without floating point support. 6692226031Sstas*/ 6693226031Sstas#ifdef SQLITE_OMIT_FLOATING_POINT 6694226031Sstas# undef double 6695226031Sstas#endif 6696226031Sstas 6697226031Sstas#ifdef __cplusplus 6698226031Sstas} /* End of the 'extern "C"' block */ 6699226031Sstas#endif 6700226031Sstas#endif 6701226031Sstas 6702226128Sstas/* 6703226128Sstas** 2010 August 30 6704226128Sstas** 6705226128Sstas** The author disclaims copyright to this source code. In place of 6706226128Sstas** a legal notice, here is a blessing: 6707226128Sstas** 6708226128Sstas** May you do good and not evil. 6709226128Sstas** May you find forgiveness for yourself and forgive others. 6710226128Sstas** May you share freely, never taking more than you give. 6711226128Sstas** 6712226128Sstas************************************************************************* 6713226128Sstas*/ 6714226128Sstas 6715226128Sstas#ifndef _SQLITE3RTREE_H_ 6716226128Sstas#define _SQLITE3RTREE_H_ 6717226128Sstas 6718226128Sstas 6719226128Sstas#ifdef __cplusplus 6720226128Sstasextern "C" { 6721226128Sstas#endif 6722226128Sstas 6723226128Sstastypedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 6724226128Sstas 6725226128Sstas/* 6726226128Sstas** Register a geometry callback named zGeom that can be used as part of an 6727226128Sstas** R-Tree geometry query as follows: 6728226128Sstas** 6729226128Sstas** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 6730226128Sstas*/ 6731226128SstasSQLITE_API int sqlite3_rtree_geometry_callback( 6732226128Sstas sqlite3 *db, 6733226128Sstas const char *zGeom, 6734226128Sstas int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes), 6735226128Sstas void *pContext 6736226128Sstas); 6737226128Sstas 6738226128Sstas 6739226128Sstas/* 6740226128Sstas** A pointer to a structure of the following type is passed as the first 6741226128Sstas** argument to callbacks registered using rtree_geometry_callback(). 6742226128Sstas*/ 6743226128Sstasstruct sqlite3_rtree_geometry { 6744226128Sstas void *pContext; /* Copy of pContext passed to s_r_g_c() */ 6745226128Sstas int nParam; /* Size of array aParam[] */ 6746226128Sstas double *aParam; /* Parameters passed to SQL geom function */ 6747226128Sstas void *pUser; /* Callback implementation user data */ 6748226128Sstas void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 6749226128Sstas}; 6750226128Sstas 6751226128Sstas 6752226128Sstas#ifdef __cplusplus 6753226128Sstas} /* end of the 'extern "C"' block */ 6754226128Sstas#endif 6755226128Sstas 6756226128Sstas#endif /* ifndef _SQLITE3RTREE_H_ */ 6757226128Sstas 6758