1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are suppose to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef _SQLITE3_H_ 34#define _SQLITE3_H_ 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52/* 53** These no-op macros are used in front of interfaces to mark those 54** interfaces as either deprecated or experimental. New applications 55** should not use deprecated interfaces - they are support for backwards 56** compatibility only. Application writers should be aware that 57** experimental interfaces are subject to change in point releases. 58** 59** These macros used to resolve to various kinds of compiler magic that 60** would generate warning messages when they were used. But that 61** compiler magic ended up generating such a flurry of bug reports 62** that we have taken it all out and gone back to using simple 63** noop macros. 64*/ 65#define SQLITE_DEPRECATED 66#define SQLITE_EXPERIMENTAL 67 68/* 69** Ensure these symbols were not defined by some previous header file. 70*/ 71#ifdef SQLITE_VERSION 72# undef SQLITE_VERSION 73#endif 74#ifdef SQLITE_VERSION_NUMBER 75# undef SQLITE_VERSION_NUMBER 76#endif 77 78/* 79** CAPI3REF: Compile-Time Library Version Numbers 80** 81** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 82** evaluates to a string literal that is the SQLite version in the 83** format "X.Y.Z" where X is the major version number (always 3 for 84** SQLite3) and Y is the minor version number and Z is the release number.)^ 85** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 86** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 87** numbers used in [SQLITE_VERSION].)^ 88** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 89** be larger than the release from which it is derived. Either Y will 90** be held constant and Z will be incremented or else Y will be incremented 91** and Z will be reset to zero. 92** 93** Since version 3.6.18, SQLite source code has been stored in the 94** <a href="http://www.fossil-scm.org/">Fossil configuration management 95** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 96** a string which identifies a particular check-in of SQLite 97** within its configuration management system. ^The SQLITE_SOURCE_ID 98** string contains the date and time of the check-in (UTC) and an SHA1 99** hash of the entire source tree. 100** 101** See also: [sqlite3_libversion()], 102** [sqlite3_libversion_number()], [sqlite3_sourceid()], 103** [sqlite_version()] and [sqlite_source_id()]. 104*/ 105#define SQLITE_VERSION "--VERS--" 106#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 107#define SQLITE_SOURCE_ID "--SOURCE-ID--" 108 109/* 110** CAPI3REF: Run-Time Library Version Numbers 111** KEYWORDS: sqlite3_version, sqlite3_sourceid 112** 113** These interfaces provide the same information as the [SQLITE_VERSION], 114** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 115** but are associated with the library instead of the header file. ^(Cautious 116** programmers might include assert() statements in their application to 117** verify that values returned by these interfaces match the macros in 118** the header, and thus insure that the application is 119** compiled with matching library and header files. 120** 121** <blockquote><pre> 122** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 123** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 124** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 125** </pre></blockquote>)^ 126** 127** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 128** macro. ^The sqlite3_libversion() function returns a pointer to the 129** to the sqlite3_version[] string constant. The sqlite3_libversion() 130** function is provided for use in DLLs since DLL users usually do not have 131** direct access to string constants within the DLL. ^The 132** sqlite3_libversion_number() function returns an integer equal to 133** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 134** a pointer to a string constant whose value is the same as the 135** [SQLITE_SOURCE_ID] C preprocessor macro. 136** 137** See also: [sqlite_version()] and [sqlite_source_id()]. 138*/ 139SQLITE_EXTERN const char sqlite3_version[]; 140const char *sqlite3_libversion(void); 141const char *sqlite3_sourceid(void); 142int sqlite3_libversion_number(void); 143 144/* 145** CAPI3REF: Run-Time Library Compilation Options Diagnostics 146** 147** ^The sqlite3_compileoption_used() function returns 0 or 1 148** indicating whether the specified option was defined at 149** compile time. ^The SQLITE_ prefix may be omitted from the 150** option name passed to sqlite3_compileoption_used(). 151** 152** ^The sqlite3_compileoption_get() function allows iterating 153** over the list of options that were defined at compile time by 154** returning the N-th compile time option string. ^If N is out of range, 155** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 156** prefix is omitted from any strings returned by 157** sqlite3_compileoption_get(). 158** 159** ^Support for the diagnostic functions sqlite3_compileoption_used() 160** and sqlite3_compileoption_get() may be omitted by specifying the 161** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 162** 163** See also: SQL functions [sqlite_compileoption_used()] and 164** [sqlite_compileoption_get()] and the [compile_options pragma]. 165*/ 166#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 167int sqlite3_compileoption_used(const char *zOptName); 168const char *sqlite3_compileoption_get(int N); 169#endif 170 171/* 172** CAPI3REF: Test To See If The Library Is Threadsafe 173** 174** ^The sqlite3_threadsafe() function returns zero if and only if 175** SQLite was compiled with mutexing code omitted due to the 176** [SQLITE_THREADSAFE] compile-time option being set to 0. 177** 178** SQLite can be compiled with or without mutexes. When 179** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 180** are enabled and SQLite is threadsafe. When the 181** [SQLITE_THREADSAFE] macro is 0, 182** the mutexes are omitted. Without the mutexes, it is not safe 183** to use SQLite concurrently from more than one thread. 184** 185** Enabling mutexes incurs a measurable performance penalty. 186** So if speed is of utmost importance, it makes sense to disable 187** the mutexes. But for maximum safety, mutexes should be enabled. 188** ^The default behavior is for mutexes to be enabled. 189** 190** This interface can be used by an application to make sure that the 191** version of SQLite that it is linking against was compiled with 192** the desired setting of the [SQLITE_THREADSAFE] macro. 193** 194** This interface only reports on the compile-time mutex setting 195** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 196** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 197** can be fully or partially disabled using a call to [sqlite3_config()] 198** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 199** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 200** sqlite3_threadsafe() function shows only the compile-time setting of 201** thread safety, not any run-time changes to that setting made by 202** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 203** is unchanged by calls to sqlite3_config().)^ 204** 205** See the [threading mode] documentation for additional information. 206*/ 207int sqlite3_threadsafe(void); 208 209/* 210** CAPI3REF: Database Connection Handle 211** KEYWORDS: {database connection} {database connections} 212** 213** Each open SQLite database is represented by a pointer to an instance of 214** the opaque structure named "sqlite3". It is useful to think of an sqlite3 215** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 216** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 217** is its destructor. There are many other interfaces (such as 218** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 219** [sqlite3_busy_timeout()] to name but three) that are methods on an 220** sqlite3 object. 221*/ 222typedef struct sqlite3 sqlite3; 223 224/* 225** CAPI3REF: 64-Bit Integer Types 226** KEYWORDS: sqlite_int64 sqlite_uint64 227** 228** Because there is no cross-platform way to specify 64-bit integer types 229** SQLite includes typedefs for 64-bit signed and unsigned integers. 230** 231** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 232** The sqlite_int64 and sqlite_uint64 types are supported for backwards 233** compatibility only. 234** 235** ^The sqlite3_int64 and sqlite_int64 types can store integer values 236** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 237** sqlite3_uint64 and sqlite_uint64 types can store integer values 238** between 0 and +18446744073709551615 inclusive. 239*/ 240#ifdef SQLITE_INT64_TYPE 241 typedef SQLITE_INT64_TYPE sqlite_int64; 242 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 243#elif defined(_MSC_VER) || defined(__BORLANDC__) 244 typedef __int64 sqlite_int64; 245 typedef unsigned __int64 sqlite_uint64; 246#else 247 typedef long long int sqlite_int64; 248 typedef unsigned long long int sqlite_uint64; 249#endif 250typedef sqlite_int64 sqlite3_int64; 251typedef sqlite_uint64 sqlite3_uint64; 252 253/* 254** If compiling for a processor that lacks floating point support, 255** substitute integer for floating-point. 256*/ 257#ifdef SQLITE_OMIT_FLOATING_POINT 258# define double sqlite3_int64 259#endif 260 261/* 262** CAPI3REF: Closing A Database Connection 263** 264** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. 265** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is 266** successfully destroyed and all associated resources are deallocated. 267** 268** Applications must [sqlite3_finalize | finalize] all [prepared statements] 269** and [sqlite3_blob_close | close] all [BLOB handles] associated with 270** the [sqlite3] object prior to attempting to close the object. ^If 271** sqlite3_close() is called on a [database connection] that still has 272** outstanding [prepared statements] or [BLOB handles], then it returns 273** SQLITE_BUSY. 274** 275** ^If [sqlite3_close()] is invoked while a transaction is open, 276** the transaction is automatically rolled back. 277** 278** The C parameter to [sqlite3_close(C)] must be either a NULL 279** pointer or an [sqlite3] object pointer obtained 280** from [sqlite3_open()], [sqlite3_open16()], or 281** [sqlite3_open_v2()], and not previously closed. 282** ^Calling sqlite3_close() with a NULL pointer argument is a 283** harmless no-op. 284*/ 285int sqlite3_close(sqlite3 *); 286 287/* 288** The type for a callback function. 289** This is legacy and deprecated. It is included for historical 290** compatibility and is not documented. 291*/ 292typedef int (*sqlite3_callback)(void*,int,char**, char**); 293 294/* 295** CAPI3REF: One-Step Query Execution Interface 296** 297** The sqlite3_exec() interface is a convenience wrapper around 298** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 299** that allows an application to run multiple statements of SQL 300** without having to use a lot of C code. 301** 302** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 303** semicolon-separate SQL statements passed into its 2nd argument, 304** in the context of the [database connection] passed in as its 1st 305** argument. ^If the callback function of the 3rd argument to 306** sqlite3_exec() is not NULL, then it is invoked for each result row 307** coming out of the evaluated SQL statements. ^The 4th argument to 308** sqlite3_exec() is relayed through to the 1st argument of each 309** callback invocation. ^If the callback pointer to sqlite3_exec() 310** is NULL, then no callback is ever invoked and result rows are 311** ignored. 312** 313** ^If an error occurs while evaluating the SQL statements passed into 314** sqlite3_exec(), then execution of the current statement stops and 315** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 316** is not NULL then any error message is written into memory obtained 317** from [sqlite3_malloc()] and passed back through the 5th parameter. 318** To avoid memory leaks, the application should invoke [sqlite3_free()] 319** on error message strings returned through the 5th parameter of 320** of sqlite3_exec() after the error message string is no longer needed. 321** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 322** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 323** NULL before returning. 324** 325** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 326** routine returns SQLITE_ABORT without invoking the callback again and 327** without running any subsequent SQL statements. 328** 329** ^The 2nd argument to the sqlite3_exec() callback function is the 330** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 331** callback is an array of pointers to strings obtained as if from 332** [sqlite3_column_text()], one for each column. ^If an element of a 333** result row is NULL then the corresponding string pointer for the 334** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 335** sqlite3_exec() callback is an array of pointers to strings where each 336** entry represents the name of corresponding result column as obtained 337** from [sqlite3_column_name()]. 338** 339** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 340** to an empty string, or a pointer that contains only whitespace and/or 341** SQL comments, then no SQL statements are evaluated and the database 342** is not changed. 343** 344** Restrictions: 345** 346** <ul> 347** <li> The application must insure that the 1st parameter to sqlite3_exec() 348** is a valid and open [database connection]. 349** <li> The application must not close [database connection] specified by 350** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 351** <li> The application must not modify the SQL statement text passed into 352** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 353** </ul> 354*/ 355int sqlite3_exec( 356 sqlite3*, /* An open database */ 357 const char *sql, /* SQL to be evaluated */ 358 int (*callback)(void*,int,char**,char**), /* Callback function */ 359 void *, /* 1st argument to callback */ 360 char **errmsg /* Error msg written here */ 361); 362 363/* 364** CAPI3REF: Result Codes 365** KEYWORDS: SQLITE_OK {error code} {error codes} 366** KEYWORDS: {result code} {result codes} 367** 368** Many SQLite functions return an integer result code from the set shown 369** here in order to indicate success or failure. 370** 371** New error codes may be added in future versions of SQLite. 372** 373** See also: [SQLITE_IOERR_READ | extended result codes], 374** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 375*/ 376#define SQLITE_OK 0 /* Successful result */ 377/* beginning-of-error-codes */ 378#define SQLITE_ERROR 1 /* SQL error or missing database */ 379#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 380#define SQLITE_PERM 3 /* Access permission denied */ 381#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 382#define SQLITE_BUSY 5 /* The database file is locked */ 383#define SQLITE_LOCKED 6 /* A table in the database is locked */ 384#define SQLITE_NOMEM 7 /* A malloc() failed */ 385#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 386#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 387#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 388#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 389#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 390#define SQLITE_FULL 13 /* Insertion failed because database is full */ 391#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 392#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 393#define SQLITE_EMPTY 16 /* Database is empty */ 394#define SQLITE_SCHEMA 17 /* The database schema changed */ 395#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 396#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 397#define SQLITE_MISMATCH 20 /* Data type mismatch */ 398#define SQLITE_MISUSE 21 /* Library used incorrectly */ 399#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 400#define SQLITE_AUTH 23 /* Authorization denied */ 401#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 402#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 403#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 404#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 405#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 406/* end-of-error-codes */ 407 408/* 409** CAPI3REF: Extended Result Codes 410** KEYWORDS: {extended error code} {extended error codes} 411** KEYWORDS: {extended result code} {extended result codes} 412** 413** In its default configuration, SQLite API routines return one of 26 integer 414** [SQLITE_OK | result codes]. However, experience has shown that many of 415** these result codes are too coarse-grained. They do not provide as 416** much information about problems as programmers might like. In an effort to 417** address this, newer versions of SQLite (version 3.3.8 and later) include 418** support for additional result codes that provide more detailed information 419** about errors. The extended result codes are enabled or disabled 420** on a per database connection basis using the 421** [sqlite3_extended_result_codes()] API. 422** 423** Some of the available extended result codes are listed here. 424** One may expect the number of extended result codes will be expand 425** over time. Software that uses extended result codes should expect 426** to see new result codes in future releases of SQLite. 427** 428** The SQLITE_OK result code will never be extended. It will always 429** be exactly zero. 430*/ 431#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 432#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 433#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 434#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 435#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 436#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 437#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 438#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 439#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 440#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 441#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 442#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 443#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 444#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 445#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 446#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 447#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 448#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 449#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 450#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 451#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 452#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 453#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 454#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 455#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 456#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 457#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 458#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 459 460/* 461** CAPI3REF: Flags For File Open Operations 462** 463** These bit values are intended for use in the 464** 3rd parameter to the [sqlite3_open_v2()] interface and 465** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 466*/ 467#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 468#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 469#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 470#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 471#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 472#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 473#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 474#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 475#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 476#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 477#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 478#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 479#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 480#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 481#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 482#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 483#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 484#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 485#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 486 487/* Reserved: 0x00F00000 */ 488 489/* 490** CAPI3REF: Device Characteristics 491** 492** The xDeviceCharacteristics method of the [sqlite3_io_methods] 493** object returns an integer which is a vector of the these 494** bit values expressing I/O characteristics of the mass storage 495** device that holds the file that the [sqlite3_io_methods] 496** refers to. 497** 498** The SQLITE_IOCAP_ATOMIC property means that all writes of 499** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 500** mean that writes of blocks that are nnn bytes in size and 501** are aligned to an address which is an integer multiple of 502** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 503** that when data is appended to a file, the data is appended 504** first then the size of the file is extended, never the other 505** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 506** information is written to disk in the same order as calls 507** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 508** after reboot following a crash or power loss, the only bytes in a 509** file that were written at the application level might have changed 510** and that adjacent bytes, even bytes within the same sector are 511** guaranteed to be unchanged. 512*/ 513#define SQLITE_IOCAP_ATOMIC 0x00000001 514#define SQLITE_IOCAP_ATOMIC512 0x00000002 515#define SQLITE_IOCAP_ATOMIC1K 0x00000004 516#define SQLITE_IOCAP_ATOMIC2K 0x00000008 517#define SQLITE_IOCAP_ATOMIC4K 0x00000010 518#define SQLITE_IOCAP_ATOMIC8K 0x00000020 519#define SQLITE_IOCAP_ATOMIC16K 0x00000040 520#define SQLITE_IOCAP_ATOMIC32K 0x00000080 521#define SQLITE_IOCAP_ATOMIC64K 0x00000100 522#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 523#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 524#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 525#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 526 527/* 528** CAPI3REF: File Locking Levels 529** 530** SQLite uses one of these integer values as the second 531** argument to calls it makes to the xLock() and xUnlock() methods 532** of an [sqlite3_io_methods] object. 533*/ 534#define SQLITE_LOCK_NONE 0 535#define SQLITE_LOCK_SHARED 1 536#define SQLITE_LOCK_RESERVED 2 537#define SQLITE_LOCK_PENDING 3 538#define SQLITE_LOCK_EXCLUSIVE 4 539 540/* 541** CAPI3REF: Synchronization Type Flags 542** 543** When SQLite invokes the xSync() method of an 544** [sqlite3_io_methods] object it uses a combination of 545** these integer values as the second argument. 546** 547** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 548** sync operation only needs to flush data to mass storage. Inode 549** information need not be flushed. If the lower four bits of the flag 550** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 551** If the lower four bits equal SQLITE_SYNC_FULL, that means 552** to use Mac OS X style fullsync instead of fsync(). 553** 554** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 555** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 556** settings. The [synchronous pragma] determines when calls to the 557** xSync VFS method occur and applies uniformly across all platforms. 558** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 559** energetic or rigorous or forceful the sync operations are and 560** only make a difference on Mac OSX for the default SQLite code. 561** (Third-party VFS implementations might also make the distinction 562** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 563** operating systems natively supported by SQLite, only Mac OSX 564** cares about the difference.) 565*/ 566#define SQLITE_SYNC_NORMAL 0x00002 567#define SQLITE_SYNC_FULL 0x00003 568#define SQLITE_SYNC_DATAONLY 0x00010 569 570/* 571** CAPI3REF: OS Interface Open File Handle 572** 573** An [sqlite3_file] object represents an open file in the 574** [sqlite3_vfs | OS interface layer]. Individual OS interface 575** implementations will 576** want to subclass this object by appending additional fields 577** for their own use. The pMethods entry is a pointer to an 578** [sqlite3_io_methods] object that defines methods for performing 579** I/O operations on the open file. 580*/ 581typedef struct sqlite3_file sqlite3_file; 582struct sqlite3_file { 583 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 584}; 585 586/* 587** CAPI3REF: OS Interface File Virtual Methods Object 588** 589** Every file opened by the [sqlite3_vfs.xOpen] method populates an 590** [sqlite3_file] object (or, more commonly, a subclass of the 591** [sqlite3_file] object) with a pointer to an instance of this object. 592** This object defines the methods used to perform various operations 593** against the open file represented by the [sqlite3_file] object. 594** 595** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 596** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 597** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 598** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 599** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 600** to NULL. 601** 602** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 603** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 604** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 605** flag may be ORed in to indicate that only the data of the file 606** and not its inode needs to be synced. 607** 608** The integer values to xLock() and xUnlock() are one of 609** <ul> 610** <li> [SQLITE_LOCK_NONE], 611** <li> [SQLITE_LOCK_SHARED], 612** <li> [SQLITE_LOCK_RESERVED], 613** <li> [SQLITE_LOCK_PENDING], or 614** <li> [SQLITE_LOCK_EXCLUSIVE]. 615** </ul> 616** xLock() increases the lock. xUnlock() decreases the lock. 617** The xCheckReservedLock() method checks whether any database connection, 618** either in this process or in some other process, is holding a RESERVED, 619** PENDING, or EXCLUSIVE lock on the file. It returns true 620** if such a lock exists and false otherwise. 621** 622** The xFileControl() method is a generic interface that allows custom 623** VFS implementations to directly control an open file using the 624** [sqlite3_file_control()] interface. The second "op" argument is an 625** integer opcode. The third argument is a generic pointer intended to 626** point to a structure that may contain arguments or space in which to 627** write return values. Potential uses for xFileControl() might be 628** functions to enable blocking locks with timeouts, to change the 629** locking strategy (for example to use dot-file locks), to inquire 630** about the status of a lock, or to break stale locks. The SQLite 631** core reserves all opcodes less than 100 for its own use. 632** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 633** Applications that define a custom xFileControl method should use opcodes 634** greater than 100 to avoid conflicts. VFS implementations should 635** return [SQLITE_NOTFOUND] for file control opcodes that they do not 636** recognize. 637** 638** The xSectorSize() method returns the sector size of the 639** device that underlies the file. The sector size is the 640** minimum write that can be performed without disturbing 641** other bytes in the file. The xDeviceCharacteristics() 642** method returns a bit vector describing behaviors of the 643** underlying device: 644** 645** <ul> 646** <li> [SQLITE_IOCAP_ATOMIC] 647** <li> [SQLITE_IOCAP_ATOMIC512] 648** <li> [SQLITE_IOCAP_ATOMIC1K] 649** <li> [SQLITE_IOCAP_ATOMIC2K] 650** <li> [SQLITE_IOCAP_ATOMIC4K] 651** <li> [SQLITE_IOCAP_ATOMIC8K] 652** <li> [SQLITE_IOCAP_ATOMIC16K] 653** <li> [SQLITE_IOCAP_ATOMIC32K] 654** <li> [SQLITE_IOCAP_ATOMIC64K] 655** <li> [SQLITE_IOCAP_SAFE_APPEND] 656** <li> [SQLITE_IOCAP_SEQUENTIAL] 657** </ul> 658** 659** The SQLITE_IOCAP_ATOMIC property means that all writes of 660** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 661** mean that writes of blocks that are nnn bytes in size and 662** are aligned to an address which is an integer multiple of 663** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 664** that when data is appended to a file, the data is appended 665** first then the size of the file is extended, never the other 666** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 667** information is written to disk in the same order as calls 668** to xWrite(). 669** 670** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 671** in the unread portions of the buffer with zeros. A VFS that 672** fails to zero-fill short reads might seem to work. However, 673** failure to zero-fill short reads will eventually lead to 674** database corruption. 675*/ 676typedef struct sqlite3_io_methods sqlite3_io_methods; 677struct sqlite3_io_methods { 678 int iVersion; 679 int (*xClose)(sqlite3_file*); 680 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 681 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 682 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 683 int (*xSync)(sqlite3_file*, int flags); 684 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 685 int (*xLock)(sqlite3_file*, int); 686 int (*xUnlock)(sqlite3_file*, int); 687 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 688 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 689 int (*xSectorSize)(sqlite3_file*); 690 int (*xDeviceCharacteristics)(sqlite3_file*); 691 /* Methods above are valid for version 1 */ 692 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 693 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 694 void (*xShmBarrier)(sqlite3_file*); 695 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 696 /* Methods above are valid for version 2 */ 697 /* Additional methods may be added in future releases */ 698}; 699 700/* 701** CAPI3REF: Standard File Control Opcodes 702** 703** These integer constants are opcodes for the xFileControl method 704** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 705** interface. 706** 707** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 708** opcode causes the xFileControl method to write the current state of 709** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 710** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 711** into an integer that the pArg argument points to. This capability 712** is used during testing and only needs to be supported when SQLITE_TEST 713** is defined. 714** 715** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 716** layer a hint of how large the database file will grow to be during the 717** current transaction. This hint is not guaranteed to be accurate but it 718** is often close. The underlying VFS might choose to preallocate database 719** file space based on this hint in order to help writes to the database 720** file run faster. 721** 722** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 723** extends and truncates the database file in chunks of a size specified 724** by the user. The fourth argument to [sqlite3_file_control()] should 725** point to an integer (type int) containing the new chunk-size to use 726** for the nominated database. Allocating database file space in large 727** chunks (say 1MB at a time), may reduce file-system fragmentation and 728** improve performance on some systems. 729** 730** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 731** to the [sqlite3_file] object associated with a particular database 732** connection. See the [sqlite3_file_control()] documentation for 733** additional information. 734** 735** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 736** SQLite and sent to all VFSes in place of a call to the xSync method 737** when the database connection has [PRAGMA synchronous] set to OFF.)^ 738** Some specialized VFSes need this signal in order to operate correctly 739** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 740** VFSes do not need this signal and should silently ignore this opcode. 741** Applications should not call [sqlite3_file_control()] with this 742** opcode as doing so may disrupt the operation of the specialized VFSes 743** that do require it. 744** 745** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 746** retry counts and intervals for certain disk I/O operations for the 747** windows [VFS] in order to provide robustness in the presence of 748** anti-virus programs. By default, the windows VFS will retry file read, 749** file write, and file delete operations up to 10 times, with a delay 750** of 25 milliseconds before the first retry and with the delay increasing 751** by an additional 25 milliseconds with each subsequent retry. This 752** opcode allows these two values (10 retries and 25 milliseconds of delay) 753** to be adjusted. The values are changed for all database connections 754** within the same process. The argument is a pointer to an array of two 755** integers where the first integer i the new retry count and the second 756** integer is the delay. If either integer is negative, then the setting 757** is not changed but instead the prior value of that setting is written 758** into the array entry, allowing the current retry settings to be 759** interrogated. The zDbName parameter is ignored. 760** 761** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 762** persistent [WAL | Write AHead Log] setting. By default, the auxiliary 763** write ahead log and shared memory files used for transaction control 764** are automatically deleted when the latest connection to the database 765** closes. Setting persistent WAL mode causes those files to persist after 766** close. Persisting the files is useful when other processes that do not 767** have write permission on the directory containing the database file want 768** to read the database file, as the WAL and shared memory files must exist 769** in order for the database to be readable. The fourth parameter to 770** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 771** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 772** WAL mode. If the integer is -1, then it is overwritten with the current 773** WAL persistence setting. 774** 775** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 776** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 777** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 778** xDeviceCharacteristics methods. The fourth parameter to 779** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 780** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 781** mode. If the integer is -1, then it is overwritten with the current 782** zero-damage mode setting. 783** 784** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 785** a write transaction to indicate that, unless it is rolled back for some 786** reason, the entire database file will be overwritten by the current 787** transaction. This is used by VACUUM operations. 788** 789** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 790** all [VFSes] in the VFS stack. The names are of all VFS shims and the 791** final bottom-level VFS are written into memory obtained from 792** [sqlite3_malloc()] and the result is stored in the char* variable 793** that the fourth parameter of [sqlite3_file_control()] points to. 794** The caller is responsible for freeing the memory when done. As with 795** all file-control actions, there is no guarantee that this will actually 796** do anything. Callers should initialize the char* variable to a NULL 797** pointer in case this file-control is not implemented. This file-control 798** is intended for diagnostic use only. 799*/ 800#define SQLITE_FCNTL_LOCKSTATE 1 801#define SQLITE_GET_LOCKPROXYFILE 2 802#define SQLITE_SET_LOCKPROXYFILE 3 803#define SQLITE_LAST_ERRNO 4 804#define SQLITE_FCNTL_SIZE_HINT 5 805#define SQLITE_FCNTL_CHUNK_SIZE 6 806#define SQLITE_FCNTL_FILE_POINTER 7 807#define SQLITE_FCNTL_SYNC_OMITTED 8 808#define SQLITE_FCNTL_WIN32_AV_RETRY 9 809#define SQLITE_FCNTL_PERSIST_WAL 10 810#define SQLITE_FCNTL_OVERWRITE 11 811#define SQLITE_FCNTL_VFSNAME 12 812#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 813 814/* 815** CAPI3REF: Mutex Handle 816** 817** The mutex module within SQLite defines [sqlite3_mutex] to be an 818** abstract type for a mutex object. The SQLite core never looks 819** at the internal representation of an [sqlite3_mutex]. It only 820** deals with pointers to the [sqlite3_mutex] object. 821** 822** Mutexes are created using [sqlite3_mutex_alloc()]. 823*/ 824typedef struct sqlite3_mutex sqlite3_mutex; 825 826/* 827** CAPI3REF: OS Interface Object 828** 829** An instance of the sqlite3_vfs object defines the interface between 830** the SQLite core and the underlying operating system. The "vfs" 831** in the name of the object stands for "virtual file system". See 832** the [VFS | VFS documentation] for further information. 833** 834** The value of the iVersion field is initially 1 but may be larger in 835** future versions of SQLite. Additional fields may be appended to this 836** object when the iVersion value is increased. Note that the structure 837** of the sqlite3_vfs object changes in the transaction between 838** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 839** modified. 840** 841** The szOsFile field is the size of the subclassed [sqlite3_file] 842** structure used by this VFS. mxPathname is the maximum length of 843** a pathname in this VFS. 844** 845** Registered sqlite3_vfs objects are kept on a linked list formed by 846** the pNext pointer. The [sqlite3_vfs_register()] 847** and [sqlite3_vfs_unregister()] interfaces manage this list 848** in a thread-safe way. The [sqlite3_vfs_find()] interface 849** searches the list. Neither the application code nor the VFS 850** implementation should use the pNext pointer. 851** 852** The pNext field is the only field in the sqlite3_vfs 853** structure that SQLite will ever modify. SQLite will only access 854** or modify this field while holding a particular static mutex. 855** The application should never modify anything within the sqlite3_vfs 856** object once the object has been registered. 857** 858** The zName field holds the name of the VFS module. The name must 859** be unique across all VFS modules. 860** 861** [[sqlite3_vfs.xOpen]] 862** ^SQLite guarantees that the zFilename parameter to xOpen 863** is either a NULL pointer or string obtained 864** from xFullPathname() with an optional suffix added. 865** ^If a suffix is added to the zFilename parameter, it will 866** consist of a single "-" character followed by no more than 867** 11 alphanumeric and/or "-" characters. 868** ^SQLite further guarantees that 869** the string will be valid and unchanged until xClose() is 870** called. Because of the previous sentence, 871** the [sqlite3_file] can safely store a pointer to the 872** filename if it needs to remember the filename for some reason. 873** If the zFilename parameter to xOpen is a NULL pointer then xOpen 874** must invent its own temporary name for the file. ^Whenever the 875** xFilename parameter is NULL it will also be the case that the 876** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 877** 878** The flags argument to xOpen() includes all bits set in 879** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 880** or [sqlite3_open16()] is used, then flags includes at least 881** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 882** If xOpen() opens a file read-only then it sets *pOutFlags to 883** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 884** 885** ^(SQLite will also add one of the following flags to the xOpen() 886** call, depending on the object being opened: 887** 888** <ul> 889** <li> [SQLITE_OPEN_MAIN_DB] 890** <li> [SQLITE_OPEN_MAIN_JOURNAL] 891** <li> [SQLITE_OPEN_TEMP_DB] 892** <li> [SQLITE_OPEN_TEMP_JOURNAL] 893** <li> [SQLITE_OPEN_TRANSIENT_DB] 894** <li> [SQLITE_OPEN_SUBJOURNAL] 895** <li> [SQLITE_OPEN_MASTER_JOURNAL] 896** <li> [SQLITE_OPEN_WAL] 897** </ul>)^ 898** 899** The file I/O implementation can use the object type flags to 900** change the way it deals with files. For example, an application 901** that does not care about crash recovery or rollback might make 902** the open of a journal file a no-op. Writes to this journal would 903** also be no-ops, and any attempt to read the journal would return 904** SQLITE_IOERR. Or the implementation might recognize that a database 905** file will be doing page-aligned sector reads and writes in a random 906** order and set up its I/O subsystem accordingly. 907** 908** SQLite might also add one of the following flags to the xOpen method: 909** 910** <ul> 911** <li> [SQLITE_OPEN_DELETEONCLOSE] 912** <li> [SQLITE_OPEN_EXCLUSIVE] 913** </ul> 914** 915** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 916** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 917** will be set for TEMP databases and their journals, transient 918** databases, and subjournals. 919** 920** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 921** with the [SQLITE_OPEN_CREATE] flag, which are both directly 922** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 923** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 924** SQLITE_OPEN_CREATE, is used to indicate that file should always 925** be created, and that it is an error if it already exists. 926** It is <i>not</i> used to indicate the file should be opened 927** for exclusive access. 928** 929** ^At least szOsFile bytes of memory are allocated by SQLite 930** to hold the [sqlite3_file] structure passed as the third 931** argument to xOpen. The xOpen method does not have to 932** allocate the structure; it should just fill it in. Note that 933** the xOpen method must set the sqlite3_file.pMethods to either 934** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 935** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 936** element will be valid after xOpen returns regardless of the success 937** or failure of the xOpen call. 938** 939** [[sqlite3_vfs.xAccess]] 940** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 941** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 942** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 943** to test whether a file is at least readable. The file can be a 944** directory. 945** 946** ^SQLite will always allocate at least mxPathname+1 bytes for the 947** output buffer xFullPathname. The exact size of the output buffer 948** is also passed as a parameter to both methods. If the output buffer 949** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 950** handled as a fatal error by SQLite, vfs implementations should endeavor 951** to prevent this by setting mxPathname to a sufficiently large value. 952** 953** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 954** interfaces are not strictly a part of the filesystem, but they are 955** included in the VFS structure for completeness. 956** The xRandomness() function attempts to return nBytes bytes 957** of good-quality randomness into zOut. The return value is 958** the actual number of bytes of randomness obtained. 959** The xSleep() method causes the calling thread to sleep for at 960** least the number of microseconds given. ^The xCurrentTime() 961** method returns a Julian Day Number for the current date and time as 962** a floating point value. 963** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 964** Day Number multiplied by 86400000 (the number of milliseconds in 965** a 24-hour day). 966** ^SQLite will use the xCurrentTimeInt64() method to get the current 967** date and time if that method is available (if iVersion is 2 or 968** greater and the function pointer is not NULL) and will fall back 969** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 970** 971** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 972** are not used by the SQLite core. These optional interfaces are provided 973** by some VFSes to facilitate testing of the VFS code. By overriding 974** system calls with functions under its control, a test program can 975** simulate faults and error conditions that would otherwise be difficult 976** or impossible to induce. The set of system calls that can be overridden 977** varies from one VFS to another, and from one version of the same VFS to the 978** next. Applications that use these interfaces must be prepared for any 979** or all of these interfaces to be NULL or for their behavior to change 980** from one release to the next. Applications must not attempt to access 981** any of these methods if the iVersion of the VFS is less than 3. 982*/ 983typedef struct sqlite3_vfs sqlite3_vfs; 984typedef void (*sqlite3_syscall_ptr)(void); 985struct sqlite3_vfs { 986 int iVersion; /* Structure version number (currently 3) */ 987 int szOsFile; /* Size of subclassed sqlite3_file */ 988 int mxPathname; /* Maximum file pathname length */ 989 sqlite3_vfs *pNext; /* Next registered VFS */ 990 const char *zName; /* Name of this virtual file system */ 991 void *pAppData; /* Pointer to application-specific data */ 992 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 993 int flags, int *pOutFlags); 994 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 995 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 996 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 997 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 998 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 999 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1000 void (*xDlClose)(sqlite3_vfs*, void*); 1001 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1002 int (*xSleep)(sqlite3_vfs*, int microseconds); 1003 int (*xCurrentTime)(sqlite3_vfs*, double*); 1004 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1005 /* 1006 ** The methods above are in version 1 of the sqlite_vfs object 1007 ** definition. Those that follow are added in version 2 or later 1008 */ 1009 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1010 /* 1011 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1012 ** Those below are for version 3 and greater. 1013 */ 1014 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1015 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1016 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1017 /* 1018 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1019 ** New fields may be appended in figure versions. The iVersion 1020 ** value will increment whenever this happens. 1021 */ 1022}; 1023 1024/* 1025** CAPI3REF: Flags for the xAccess VFS method 1026** 1027** These integer constants can be used as the third parameter to 1028** the xAccess method of an [sqlite3_vfs] object. They determine 1029** what kind of permissions the xAccess method is looking for. 1030** With SQLITE_ACCESS_EXISTS, the xAccess method 1031** simply checks whether the file exists. 1032** With SQLITE_ACCESS_READWRITE, the xAccess method 1033** checks whether the named directory is both readable and writable 1034** (in other words, if files can be added, removed, and renamed within 1035** the directory). 1036** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1037** [temp_store_directory pragma], though this could change in a future 1038** release of SQLite. 1039** With SQLITE_ACCESS_READ, the xAccess method 1040** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1041** currently unused, though it might be used in a future release of 1042** SQLite. 1043*/ 1044#define SQLITE_ACCESS_EXISTS 0 1045#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1046#define SQLITE_ACCESS_READ 2 /* Unused */ 1047 1048/* 1049** CAPI3REF: Flags for the xShmLock VFS method 1050** 1051** These integer constants define the various locking operations 1052** allowed by the xShmLock method of [sqlite3_io_methods]. The 1053** following are the only legal combinations of flags to the 1054** xShmLock method: 1055** 1056** <ul> 1057** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1058** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1059** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1060** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1061** </ul> 1062** 1063** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1064** was given no the corresponding lock. 1065** 1066** The xShmLock method can transition between unlocked and SHARED or 1067** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1068** and EXCLUSIVE. 1069*/ 1070#define SQLITE_SHM_UNLOCK 1 1071#define SQLITE_SHM_LOCK 2 1072#define SQLITE_SHM_SHARED 4 1073#define SQLITE_SHM_EXCLUSIVE 8 1074 1075/* 1076** CAPI3REF: Maximum xShmLock index 1077** 1078** The xShmLock method on [sqlite3_io_methods] may use values 1079** between 0 and this upper bound as its "offset" argument. 1080** The SQLite core will never attempt to acquire or release a 1081** lock outside of this range 1082*/ 1083#define SQLITE_SHM_NLOCK 8 1084 1085 1086/* 1087** CAPI3REF: Initialize The SQLite Library 1088** 1089** ^The sqlite3_initialize() routine initializes the 1090** SQLite library. ^The sqlite3_shutdown() routine 1091** deallocates any resources that were allocated by sqlite3_initialize(). 1092** These routines are designed to aid in process initialization and 1093** shutdown on embedded systems. Workstation applications using 1094** SQLite normally do not need to invoke either of these routines. 1095** 1096** A call to sqlite3_initialize() is an "effective" call if it is 1097** the first time sqlite3_initialize() is invoked during the lifetime of 1098** the process, or if it is the first time sqlite3_initialize() is invoked 1099** following a call to sqlite3_shutdown(). ^(Only an effective call 1100** of sqlite3_initialize() does any initialization. All other calls 1101** are harmless no-ops.)^ 1102** 1103** A call to sqlite3_shutdown() is an "effective" call if it is the first 1104** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1105** an effective call to sqlite3_shutdown() does any deinitialization. 1106** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1107** 1108** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1109** is not. The sqlite3_shutdown() interface must only be called from a 1110** single thread. All open [database connections] must be closed and all 1111** other SQLite resources must be deallocated prior to invoking 1112** sqlite3_shutdown(). 1113** 1114** Among other things, ^sqlite3_initialize() will invoke 1115** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1116** will invoke sqlite3_os_end(). 1117** 1118** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1119** ^If for some reason, sqlite3_initialize() is unable to initialize 1120** the library (perhaps it is unable to allocate a needed resource such 1121** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1122** 1123** ^The sqlite3_initialize() routine is called internally by many other 1124** SQLite interfaces so that an application usually does not need to 1125** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1126** calls sqlite3_initialize() so the SQLite library will be automatically 1127** initialized when [sqlite3_open()] is called if it has not be initialized 1128** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1129** compile-time option, then the automatic calls to sqlite3_initialize() 1130** are omitted and the application must call sqlite3_initialize() directly 1131** prior to using any other SQLite interface. For maximum portability, 1132** it is recommended that applications always invoke sqlite3_initialize() 1133** directly prior to using any other SQLite interface. Future releases 1134** of SQLite may require this. In other words, the behavior exhibited 1135** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1136** default behavior in some future release of SQLite. 1137** 1138** The sqlite3_os_init() routine does operating-system specific 1139** initialization of the SQLite library. The sqlite3_os_end() 1140** routine undoes the effect of sqlite3_os_init(). Typical tasks 1141** performed by these routines include allocation or deallocation 1142** of static resources, initialization of global variables, 1143** setting up a default [sqlite3_vfs] module, or setting up 1144** a default configuration using [sqlite3_config()]. 1145** 1146** The application should never invoke either sqlite3_os_init() 1147** or sqlite3_os_end() directly. The application should only invoke 1148** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1149** interface is called automatically by sqlite3_initialize() and 1150** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1151** implementations for sqlite3_os_init() and sqlite3_os_end() 1152** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1153** When [custom builds | built for other platforms] 1154** (using the [SQLITE_OS_OTHER=1] compile-time 1155** option) the application must supply a suitable implementation for 1156** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1157** implementation of sqlite3_os_init() or sqlite3_os_end() 1158** must return [SQLITE_OK] on success and some other [error code] upon 1159** failure. 1160*/ 1161int sqlite3_initialize(void); 1162int sqlite3_shutdown(void); 1163int sqlite3_os_init(void); 1164int sqlite3_os_end(void); 1165 1166/* 1167** CAPI3REF: Configuring The SQLite Library 1168** 1169** The sqlite3_config() interface is used to make global configuration 1170** changes to SQLite in order to tune SQLite to the specific needs of 1171** the application. The default configuration is recommended for most 1172** applications and so this routine is usually not necessary. It is 1173** provided to support rare applications with unusual needs. 1174** 1175** The sqlite3_config() interface is not threadsafe. The application 1176** must insure that no other SQLite interfaces are invoked by other 1177** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1178** may only be invoked prior to library initialization using 1179** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1180** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1181** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1182** Note, however, that ^sqlite3_config() can be called as part of the 1183** implementation of an application-defined [sqlite3_os_init()]. 1184** 1185** The first argument to sqlite3_config() is an integer 1186** [configuration option] that determines 1187** what property of SQLite is to be configured. Subsequent arguments 1188** vary depending on the [configuration option] 1189** in the first argument. 1190** 1191** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1192** ^If the option is unknown or SQLite is unable to set the option 1193** then this routine returns a non-zero [error code]. 1194*/ 1195int sqlite3_config(int, ...); 1196 1197/* 1198** CAPI3REF: Configure database connections 1199** 1200** The sqlite3_db_config() interface is used to make configuration 1201** changes to a [database connection]. The interface is similar to 1202** [sqlite3_config()] except that the changes apply to a single 1203** [database connection] (specified in the first argument). 1204** 1205** The second argument to sqlite3_db_config(D,V,...) is the 1206** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1207** that indicates what aspect of the [database connection] is being configured. 1208** Subsequent arguments vary depending on the configuration verb. 1209** 1210** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1211** the call is considered successful. 1212*/ 1213int sqlite3_db_config(sqlite3*, int op, ...); 1214 1215/* 1216** CAPI3REF: Memory Allocation Routines 1217** 1218** An instance of this object defines the interface between SQLite 1219** and low-level memory allocation routines. 1220** 1221** This object is used in only one place in the SQLite interface. 1222** A pointer to an instance of this object is the argument to 1223** [sqlite3_config()] when the configuration option is 1224** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1225** By creating an instance of this object 1226** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1227** during configuration, an application can specify an alternative 1228** memory allocation subsystem for SQLite to use for all of its 1229** dynamic memory needs. 1230** 1231** Note that SQLite comes with several [built-in memory allocators] 1232** that are perfectly adequate for the overwhelming majority of applications 1233** and that this object is only useful to a tiny minority of applications 1234** with specialized memory allocation requirements. This object is 1235** also used during testing of SQLite in order to specify an alternative 1236** memory allocator that simulates memory out-of-memory conditions in 1237** order to verify that SQLite recovers gracefully from such 1238** conditions. 1239** 1240** The xMalloc, xRealloc, and xFree methods must work like the 1241** malloc(), realloc() and free() functions from the standard C library. 1242** ^SQLite guarantees that the second argument to 1243** xRealloc is always a value returned by a prior call to xRoundup. 1244** 1245** xSize should return the allocated size of a memory allocation 1246** previously obtained from xMalloc or xRealloc. The allocated size 1247** is always at least as big as the requested size but may be larger. 1248** 1249** The xRoundup method returns what would be the allocated size of 1250** a memory allocation given a particular requested size. Most memory 1251** allocators round up memory allocations at least to the next multiple 1252** of 8. Some allocators round up to a larger multiple or to a power of 2. 1253** Every memory allocation request coming in through [sqlite3_malloc()] 1254** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1255** that causes the corresponding memory allocation to fail. 1256** 1257** The xInit method initializes the memory allocator. (For example, 1258** it might allocate any require mutexes or initialize internal data 1259** structures. The xShutdown method is invoked (indirectly) by 1260** [sqlite3_shutdown()] and should deallocate any resources acquired 1261** by xInit. The pAppData pointer is used as the only parameter to 1262** xInit and xShutdown. 1263** 1264** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1265** the xInit method, so the xInit method need not be threadsafe. The 1266** xShutdown method is only called from [sqlite3_shutdown()] so it does 1267** not need to be threadsafe either. For all other methods, SQLite 1268** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1269** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1270** it is by default) and so the methods are automatically serialized. 1271** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1272** methods must be threadsafe or else make their own arrangements for 1273** serialization. 1274** 1275** SQLite will never invoke xInit() more than once without an intervening 1276** call to xShutdown(). 1277*/ 1278typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1279struct sqlite3_mem_methods { 1280 void *(*xMalloc)(int); /* Memory allocation function */ 1281 void (*xFree)(void*); /* Free a prior allocation */ 1282 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1283 int (*xSize)(void*); /* Return the size of an allocation */ 1284 int (*xRoundup)(int); /* Round up request size to allocation size */ 1285 int (*xInit)(void*); /* Initialize the memory allocator */ 1286 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1287 void *pAppData; /* Argument to xInit() and xShutdown() */ 1288}; 1289 1290/* 1291** CAPI3REF: Configuration Options 1292** KEYWORDS: {configuration option} 1293** 1294** These constants are the available integer configuration options that 1295** can be passed as the first argument to the [sqlite3_config()] interface. 1296** 1297** New configuration options may be added in future releases of SQLite. 1298** Existing configuration options might be discontinued. Applications 1299** should check the return code from [sqlite3_config()] to make sure that 1300** the call worked. The [sqlite3_config()] interface will return a 1301** non-zero [error code] if a discontinued or unsupported configuration option 1302** is invoked. 1303** 1304** <dl> 1305** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1306** <dd>There are no arguments to this option. ^This option sets the 1307** [threading mode] to Single-thread. In other words, it disables 1308** all mutexing and puts SQLite into a mode where it can only be used 1309** by a single thread. ^If SQLite is compiled with 1310** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1311** it is not possible to change the [threading mode] from its default 1312** value of Single-thread and so [sqlite3_config()] will return 1313** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1314** configuration option.</dd> 1315** 1316** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1317** <dd>There are no arguments to this option. ^This option sets the 1318** [threading mode] to Multi-thread. In other words, it disables 1319** mutexing on [database connection] and [prepared statement] objects. 1320** The application is responsible for serializing access to 1321** [database connections] and [prepared statements]. But other mutexes 1322** are enabled so that SQLite will be safe to use in a multi-threaded 1323** environment as long as no two threads attempt to use the same 1324** [database connection] at the same time. ^If SQLite is compiled with 1325** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1326** it is not possible to set the Multi-thread [threading mode] and 1327** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1328** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1329** 1330** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1331** <dd>There are no arguments to this option. ^This option sets the 1332** [threading mode] to Serialized. In other words, this option enables 1333** all mutexes including the recursive 1334** mutexes on [database connection] and [prepared statement] objects. 1335** In this mode (which is the default when SQLite is compiled with 1336** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1337** to [database connections] and [prepared statements] so that the 1338** application is free to use the same [database connection] or the 1339** same [prepared statement] in different threads at the same time. 1340** ^If SQLite is compiled with 1341** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1342** it is not possible to set the Serialized [threading mode] and 1343** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1344** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1345** 1346** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1347** <dd> ^(This option takes a single argument which is a pointer to an 1348** instance of the [sqlite3_mem_methods] structure. The argument specifies 1349** alternative low-level memory allocation routines to be used in place of 1350** the memory allocation routines built into SQLite.)^ ^SQLite makes 1351** its own private copy of the content of the [sqlite3_mem_methods] structure 1352** before the [sqlite3_config()] call returns.</dd> 1353** 1354** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1355** <dd> ^(This option takes a single argument which is a pointer to an 1356** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1357** structure is filled with the currently defined memory allocation routines.)^ 1358** This option can be used to overload the default memory allocation 1359** routines with a wrapper that simulations memory allocation failure or 1360** tracks memory usage, for example. </dd> 1361** 1362** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1363** <dd> ^This option takes single argument of type int, interpreted as a 1364** boolean, which enables or disables the collection of memory allocation 1365** statistics. ^(When memory allocation statistics are disabled, the 1366** following SQLite interfaces become non-operational: 1367** <ul> 1368** <li> [sqlite3_memory_used()] 1369** <li> [sqlite3_memory_highwater()] 1370** <li> [sqlite3_soft_heap_limit64()] 1371** <li> [sqlite3_status()] 1372** </ul>)^ 1373** ^Memory allocation statistics are enabled by default unless SQLite is 1374** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1375** allocation statistics are disabled by default. 1376** </dd> 1377** 1378** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1379** <dd> ^This option specifies a static memory buffer that SQLite can use for 1380** scratch memory. There are three arguments: A pointer an 8-byte 1381** aligned memory buffer from which the scratch allocations will be 1382** drawn, the size of each scratch allocation (sz), 1383** and the maximum number of scratch allocations (N). The sz 1384** argument must be a multiple of 16. 1385** The first argument must be a pointer to an 8-byte aligned buffer 1386** of at least sz*N bytes of memory. 1387** ^SQLite will use no more than two scratch buffers per thread. So 1388** N should be set to twice the expected maximum number of threads. 1389** ^SQLite will never require a scratch buffer that is more than 6 1390** times the database page size. ^If SQLite needs needs additional 1391** scratch memory beyond what is provided by this configuration option, then 1392** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1393** 1394** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1395** <dd> ^This option specifies a static memory buffer that SQLite can use for 1396** the database page cache with the default page cache implementation. 1397** This configuration should not be used if an application-define page 1398** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1399** There are three arguments to this option: A pointer to 8-byte aligned 1400** memory, the size of each page buffer (sz), and the number of pages (N). 1401** The sz argument should be the size of the largest database page 1402** (a power of two between 512 and 32768) plus a little extra for each 1403** page header. ^The page header size is 20 to 40 bytes depending on 1404** the host architecture. ^It is harmless, apart from the wasted memory, 1405** to make sz a little too large. The first 1406** argument should point to an allocation of at least sz*N bytes of memory. 1407** ^SQLite will use the memory provided by the first argument to satisfy its 1408** memory needs for the first N pages that it adds to cache. ^If additional 1409** page cache memory is needed beyond what is provided by this option, then 1410** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1411** The pointer in the first argument must 1412** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1413** will be undefined.</dd> 1414** 1415** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1416** <dd> ^This option specifies a static memory buffer that SQLite will use 1417** for all of its dynamic memory allocation needs beyond those provided 1418** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1419** There are three arguments: An 8-byte aligned pointer to the memory, 1420** the number of bytes in the memory buffer, and the minimum allocation size. 1421** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1422** to using its default memory allocator (the system malloc() implementation), 1423** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1424** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1425** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1426** allocator is engaged to handle all of SQLites memory allocation needs. 1427** The first pointer (the memory pointer) must be aligned to an 8-byte 1428** boundary or subsequent behavior of SQLite will be undefined. 1429** The minimum allocation size is capped at 2**12. Reasonable values 1430** for the minimum allocation size are 2**5 through 2**8.</dd> 1431** 1432** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1433** <dd> ^(This option takes a single argument which is a pointer to an 1434** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1435** alternative low-level mutex routines to be used in place 1436** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1437** content of the [sqlite3_mutex_methods] structure before the call to 1438** [sqlite3_config()] returns. ^If SQLite is compiled with 1439** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1440** the entire mutexing subsystem is omitted from the build and hence calls to 1441** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1442** return [SQLITE_ERROR].</dd> 1443** 1444** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1445** <dd> ^(This option takes a single argument which is a pointer to an 1446** instance of the [sqlite3_mutex_methods] structure. The 1447** [sqlite3_mutex_methods] 1448** structure is filled with the currently defined mutex routines.)^ 1449** This option can be used to overload the default mutex allocation 1450** routines with a wrapper used to track mutex usage for performance 1451** profiling or testing, for example. ^If SQLite is compiled with 1452** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1453** the entire mutexing subsystem is omitted from the build and hence calls to 1454** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1455** return [SQLITE_ERROR].</dd> 1456** 1457** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1458** <dd> ^(This option takes two arguments that determine the default 1459** memory allocation for the lookaside memory allocator on each 1460** [database connection]. The first argument is the 1461** size of each lookaside buffer slot and the second is the number of 1462** slots allocated to each database connection.)^ ^(This option sets the 1463** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1464** verb to [sqlite3_db_config()] can be used to change the lookaside 1465** configuration on individual connections.)^ </dd> 1466** 1467** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1468** <dd> ^(This option takes a single argument which is a pointer to 1469** an [sqlite3_pcache_methods2] object. This object specifies the interface 1470** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1471** object and uses it for page cache memory allocations.</dd> 1472** 1473** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1474** <dd> ^(This option takes a single argument which is a pointer to an 1475** [sqlite3_pcache_methods2] object. SQLite copies of the current 1476** page cache implementation into that object.)^ </dd> 1477** 1478** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1479** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1480** function with a call signature of void(*)(void*,int,const char*), 1481** and a pointer to void. ^If the function pointer is not NULL, it is 1482** invoked by [sqlite3_log()] to process each logging event. ^If the 1483** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1484** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1485** passed through as the first parameter to the application-defined logger 1486** function whenever that function is invoked. ^The second parameter to 1487** the logger function is a copy of the first parameter to the corresponding 1488** [sqlite3_log()] call and is intended to be a [result code] or an 1489** [extended result code]. ^The third parameter passed to the logger is 1490** log message after formatting via [sqlite3_snprintf()]. 1491** The SQLite logging interface is not reentrant; the logger function 1492** supplied by the application must not invoke any SQLite interface. 1493** In a multi-threaded application, the application-defined logger 1494** function must be threadsafe. </dd> 1495** 1496** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1497** <dd> This option takes a single argument of type int. If non-zero, then 1498** URI handling is globally enabled. If the parameter is zero, then URI handling 1499** is globally disabled. If URI handling is globally enabled, all filenames 1500** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1501** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1502** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1503** connection is opened. If it is globally disabled, filenames are 1504** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1505** database connection is opened. By default, URI handling is globally 1506** disabled. The default value may be changed by compiling with the 1507** [SQLITE_USE_URI] symbol defined. 1508** 1509** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1510** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFNIG_GETPCACHE 1511** <dd> These options are obsolete and should not be used by new code. 1512** They are retained for backwards compatibility but are now no-ops. 1513** </dl> 1514*/ 1515#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1516#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1517#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1518#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1519#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1520#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1521#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1522#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1523#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1524#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1525#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1526/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1527#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1528#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1529#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1530#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1531#define SQLITE_CONFIG_URI 17 /* int */ 1532#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1533#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1534 1535/* 1536** CAPI3REF: Database Connection Configuration Options 1537** 1538** These constants are the available integer configuration options that 1539** can be passed as the second argument to the [sqlite3_db_config()] interface. 1540** 1541** New configuration options may be added in future releases of SQLite. 1542** Existing configuration options might be discontinued. Applications 1543** should check the return code from [sqlite3_db_config()] to make sure that 1544** the call worked. ^The [sqlite3_db_config()] interface will return a 1545** non-zero [error code] if a discontinued or unsupported configuration option 1546** is invoked. 1547** 1548** <dl> 1549** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1550** <dd> ^This option takes three additional arguments that determine the 1551** [lookaside memory allocator] configuration for the [database connection]. 1552** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1553** pointer to a memory buffer to use for lookaside memory. 1554** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1555** may be NULL in which case SQLite will allocate the 1556** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1557** size of each lookaside buffer slot. ^The third argument is the number of 1558** slots. The size of the buffer in the first argument must be greater than 1559** or equal to the product of the second and third arguments. The buffer 1560** must be aligned to an 8-byte boundary. ^If the second argument to 1561** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1562** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1563** configuration for a database connection can only be changed when that 1564** connection is not currently using lookaside memory, or in other words 1565** when the "current value" returned by 1566** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1567** Any attempt to change the lookaside memory configuration when lookaside 1568** memory is in use leaves the configuration unchanged and returns 1569** [SQLITE_BUSY].)^</dd> 1570** 1571** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1572** <dd> ^This option is used to enable or disable the enforcement of 1573** [foreign key constraints]. There should be two additional arguments. 1574** The first argument is an integer which is 0 to disable FK enforcement, 1575** positive to enable FK enforcement or negative to leave FK enforcement 1576** unchanged. The second parameter is a pointer to an integer into which 1577** is written 0 or 1 to indicate whether FK enforcement is off or on 1578** following this call. The second parameter may be a NULL pointer, in 1579** which case the FK enforcement setting is not reported back. </dd> 1580** 1581** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1582** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1583** There should be two additional arguments. 1584** The first argument is an integer which is 0 to disable triggers, 1585** positive to enable triggers or negative to leave the setting unchanged. 1586** The second parameter is a pointer to an integer into which 1587** is written 0 or 1 to indicate whether triggers are disabled or enabled 1588** following this call. The second parameter may be a NULL pointer, in 1589** which case the trigger setting is not reported back. </dd> 1590** 1591** </dl> 1592*/ 1593#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1594#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1595#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1596 1597 1598/* 1599** CAPI3REF: Enable Or Disable Extended Result Codes 1600** 1601** ^The sqlite3_extended_result_codes() routine enables or disables the 1602** [extended result codes] feature of SQLite. ^The extended result 1603** codes are disabled by default for historical compatibility. 1604*/ 1605int sqlite3_extended_result_codes(sqlite3*, int onoff); 1606 1607/* 1608** CAPI3REF: Last Insert Rowid 1609** 1610** ^Each entry in an SQLite table has a unique 64-bit signed 1611** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1612** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1613** names are not also used by explicitly declared columns. ^If 1614** the table has a column of type [INTEGER PRIMARY KEY] then that column 1615** is another alias for the rowid. 1616** 1617** ^This routine returns the [rowid] of the most recent 1618** successful [INSERT] into the database from the [database connection] 1619** in the first argument. ^As of SQLite version 3.7.7, this routines 1620** records the last insert rowid of both ordinary tables and [virtual tables]. 1621** ^If no successful [INSERT]s 1622** have ever occurred on that database connection, zero is returned. 1623** 1624** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1625** method, then this routine will return the [rowid] of the inserted 1626** row as long as the trigger or virtual table method is running. 1627** But once the trigger or virtual table method ends, the value returned 1628** by this routine reverts to what it was before the trigger or virtual 1629** table method began.)^ 1630** 1631** ^An [INSERT] that fails due to a constraint violation is not a 1632** successful [INSERT] and does not change the value returned by this 1633** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1634** and INSERT OR ABORT make no changes to the return value of this 1635** routine when their insertion fails. ^(When INSERT OR REPLACE 1636** encounters a constraint violation, it does not fail. The 1637** INSERT continues to completion after deleting rows that caused 1638** the constraint problem so INSERT OR REPLACE will always change 1639** the return value of this interface.)^ 1640** 1641** ^For the purposes of this routine, an [INSERT] is considered to 1642** be successful even if it is subsequently rolled back. 1643** 1644** This function is accessible to SQL statements via the 1645** [last_insert_rowid() SQL function]. 1646** 1647** If a separate thread performs a new [INSERT] on the same 1648** database connection while the [sqlite3_last_insert_rowid()] 1649** function is running and thus changes the last insert [rowid], 1650** then the value returned by [sqlite3_last_insert_rowid()] is 1651** unpredictable and might not equal either the old or the new 1652** last insert [rowid]. 1653*/ 1654sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1655 1656/* 1657** CAPI3REF: Count The Number Of Rows Modified 1658** 1659** ^This function returns the number of database rows that were changed 1660** or inserted or deleted by the most recently completed SQL statement 1661** on the [database connection] specified by the first parameter. 1662** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1663** or [DELETE] statement are counted. Auxiliary changes caused by 1664** triggers or [foreign key actions] are not counted.)^ Use the 1665** [sqlite3_total_changes()] function to find the total number of changes 1666** including changes caused by triggers and foreign key actions. 1667** 1668** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1669** are not counted. Only real table changes are counted. 1670** 1671** ^(A "row change" is a change to a single row of a single table 1672** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1673** are changed as side effects of [REPLACE] constraint resolution, 1674** rollback, ABORT processing, [DROP TABLE], or by any other 1675** mechanisms do not count as direct row changes.)^ 1676** 1677** A "trigger context" is a scope of execution that begins and 1678** ends with the script of a [CREATE TRIGGER | trigger]. 1679** Most SQL statements are 1680** evaluated outside of any trigger. This is the "top level" 1681** trigger context. If a trigger fires from the top level, a 1682** new trigger context is entered for the duration of that one 1683** trigger. Subtriggers create subcontexts for their duration. 1684** 1685** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1686** not create a new trigger context. 1687** 1688** ^This function returns the number of direct row changes in the 1689** most recent INSERT, UPDATE, or DELETE statement within the same 1690** trigger context. 1691** 1692** ^Thus, when called from the top level, this function returns the 1693** number of changes in the most recent INSERT, UPDATE, or DELETE 1694** that also occurred at the top level. ^(Within the body of a trigger, 1695** the sqlite3_changes() interface can be called to find the number of 1696** changes in the most recently completed INSERT, UPDATE, or DELETE 1697** statement within the body of the same trigger. 1698** However, the number returned does not include changes 1699** caused by subtriggers since those have their own context.)^ 1700** 1701** See also the [sqlite3_total_changes()] interface, the 1702** [count_changes pragma], and the [changes() SQL function]. 1703** 1704** If a separate thread makes changes on the same database connection 1705** while [sqlite3_changes()] is running then the value returned 1706** is unpredictable and not meaningful. 1707*/ 1708int sqlite3_changes(sqlite3*); 1709 1710/* 1711** CAPI3REF: Total Number Of Rows Modified 1712** 1713** ^This function returns the number of row changes caused by [INSERT], 1714** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1715** ^(The count returned by sqlite3_total_changes() includes all changes 1716** from all [CREATE TRIGGER | trigger] contexts and changes made by 1717** [foreign key actions]. However, 1718** the count does not include changes used to implement [REPLACE] constraints, 1719** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1720** count does not include rows of views that fire an [INSTEAD OF trigger], 1721** though if the INSTEAD OF trigger makes changes of its own, those changes 1722** are counted.)^ 1723** ^The sqlite3_total_changes() function counts the changes as soon as 1724** the statement that makes them is completed (when the statement handle 1725** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1726** 1727** See also the [sqlite3_changes()] interface, the 1728** [count_changes pragma], and the [total_changes() SQL function]. 1729** 1730** If a separate thread makes changes on the same database connection 1731** while [sqlite3_total_changes()] is running then the value 1732** returned is unpredictable and not meaningful. 1733*/ 1734int sqlite3_total_changes(sqlite3*); 1735 1736/* 1737** CAPI3REF: Interrupt A Long-Running Query 1738** 1739** ^This function causes any pending database operation to abort and 1740** return at its earliest opportunity. This routine is typically 1741** called in response to a user action such as pressing "Cancel" 1742** or Ctrl-C where the user wants a long query operation to halt 1743** immediately. 1744** 1745** ^It is safe to call this routine from a thread different from the 1746** thread that is currently running the database operation. But it 1747** is not safe to call this routine with a [database connection] that 1748** is closed or might close before sqlite3_interrupt() returns. 1749** 1750** ^If an SQL operation is very nearly finished at the time when 1751** sqlite3_interrupt() is called, then it might not have an opportunity 1752** to be interrupted and might continue to completion. 1753** 1754** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1755** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1756** that is inside an explicit transaction, then the entire transaction 1757** will be rolled back automatically. 1758** 1759** ^The sqlite3_interrupt(D) call is in effect until all currently running 1760** SQL statements on [database connection] D complete. ^Any new SQL statements 1761** that are started after the sqlite3_interrupt() call and before the 1762** running statements reaches zero are interrupted as if they had been 1763** running prior to the sqlite3_interrupt() call. ^New SQL statements 1764** that are started after the running statement count reaches zero are 1765** not effected by the sqlite3_interrupt(). 1766** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1767** SQL statements is a no-op and has no effect on SQL statements 1768** that are started after the sqlite3_interrupt() call returns. 1769** 1770** If the database connection closes while [sqlite3_interrupt()] 1771** is running then bad things will likely happen. 1772*/ 1773void sqlite3_interrupt(sqlite3*); 1774 1775/* 1776** CAPI3REF: Determine If An SQL Statement Is Complete 1777** 1778** These routines are useful during command-line input to determine if the 1779** currently entered text seems to form a complete SQL statement or 1780** if additional input is needed before sending the text into 1781** SQLite for parsing. ^These routines return 1 if the input string 1782** appears to be a complete SQL statement. ^A statement is judged to be 1783** complete if it ends with a semicolon token and is not a prefix of a 1784** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1785** string literals or quoted identifier names or comments are not 1786** independent tokens (they are part of the token in which they are 1787** embedded) and thus do not count as a statement terminator. ^Whitespace 1788** and comments that follow the final semicolon are ignored. 1789** 1790** ^These routines return 0 if the statement is incomplete. ^If a 1791** memory allocation fails, then SQLITE_NOMEM is returned. 1792** 1793** ^These routines do not parse the SQL statements thus 1794** will not detect syntactically incorrect SQL. 1795** 1796** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1797** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1798** automatically by sqlite3_complete16(). If that initialization fails, 1799** then the return value from sqlite3_complete16() will be non-zero 1800** regardless of whether or not the input SQL is complete.)^ 1801** 1802** The input to [sqlite3_complete()] must be a zero-terminated 1803** UTF-8 string. 1804** 1805** The input to [sqlite3_complete16()] must be a zero-terminated 1806** UTF-16 string in native byte order. 1807*/ 1808int sqlite3_complete(const char *sql); 1809int sqlite3_complete16(const void *sql); 1810 1811/* 1812** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1813** 1814** ^This routine sets a callback function that might be invoked whenever 1815** an attempt is made to open a database table that another thread 1816** or process has locked. 1817** 1818** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1819** is returned immediately upon encountering the lock. ^If the busy callback 1820** is not NULL, then the callback might be invoked with two arguments. 1821** 1822** ^The first argument to the busy handler is a copy of the void* pointer which 1823** is the third argument to sqlite3_busy_handler(). ^The second argument to 1824** the busy handler callback is the number of times that the busy handler has 1825** been invoked for this locking event. ^If the 1826** busy callback returns 0, then no additional attempts are made to 1827** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1828** ^If the callback returns non-zero, then another attempt 1829** is made to open the database for reading and the cycle repeats. 1830** 1831** The presence of a busy handler does not guarantee that it will be invoked 1832** when there is lock contention. ^If SQLite determines that invoking the busy 1833** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1834** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1835** Consider a scenario where one process is holding a read lock that 1836** it is trying to promote to a reserved lock and 1837** a second process is holding a reserved lock that it is trying 1838** to promote to an exclusive lock. The first process cannot proceed 1839** because it is blocked by the second and the second process cannot 1840** proceed because it is blocked by the first. If both processes 1841** invoke the busy handlers, neither will make any progress. Therefore, 1842** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1843** will induce the first process to release its read lock and allow 1844** the second process to proceed. 1845** 1846** ^The default busy callback is NULL. 1847** 1848** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1849** when SQLite is in the middle of a large transaction where all the 1850** changes will not fit into the in-memory cache. SQLite will 1851** already hold a RESERVED lock on the database file, but it needs 1852** to promote this lock to EXCLUSIVE so that it can spill cache 1853** pages into the database file without harm to concurrent 1854** readers. ^If it is unable to promote the lock, then the in-memory 1855** cache will be left in an inconsistent state and so the error 1856** code is promoted from the relatively benign [SQLITE_BUSY] to 1857** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1858** forces an automatic rollback of the changes. See the 1859** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1860** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1861** this is important. 1862** 1863** ^(There can only be a single busy handler defined for each 1864** [database connection]. Setting a new busy handler clears any 1865** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1866** will also set or clear the busy handler. 1867** 1868** The busy callback should not take any actions which modify the 1869** database connection that invoked the busy handler. Any such actions 1870** result in undefined behavior. 1871** 1872** A busy handler must not close the database connection 1873** or [prepared statement] that invoked the busy handler. 1874*/ 1875int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1876 1877/* 1878** CAPI3REF: Set A Busy Timeout 1879** 1880** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1881** for a specified amount of time when a table is locked. ^The handler 1882** will sleep multiple times until at least "ms" milliseconds of sleeping 1883** have accumulated. ^After at least "ms" milliseconds of sleeping, 1884** the handler returns 0 which causes [sqlite3_step()] to return 1885** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1886** 1887** ^Calling this routine with an argument less than or equal to zero 1888** turns off all busy handlers. 1889** 1890** ^(There can only be a single busy handler for a particular 1891** [database connection] any any given moment. If another busy handler 1892** was defined (using [sqlite3_busy_handler()]) prior to calling 1893** this routine, that other busy handler is cleared.)^ 1894*/ 1895int sqlite3_busy_timeout(sqlite3*, int ms); 1896 1897/* 1898** CAPI3REF: Convenience Routines For Running Queries 1899** 1900** This is a legacy interface that is preserved for backwards compatibility. 1901** Use of this interface is not recommended. 1902** 1903** Definition: A <b>result table</b> is memory data structure created by the 1904** [sqlite3_get_table()] interface. A result table records the 1905** complete query results from one or more queries. 1906** 1907** The table conceptually has a number of rows and columns. But 1908** these numbers are not part of the result table itself. These 1909** numbers are obtained separately. Let N be the number of rows 1910** and M be the number of columns. 1911** 1912** A result table is an array of pointers to zero-terminated UTF-8 strings. 1913** There are (N+1)*M elements in the array. The first M pointers point 1914** to zero-terminated strings that contain the names of the columns. 1915** The remaining entries all point to query results. NULL values result 1916** in NULL pointers. All other values are in their UTF-8 zero-terminated 1917** string representation as returned by [sqlite3_column_text()]. 1918** 1919** A result table might consist of one or more memory allocations. 1920** It is not safe to pass a result table directly to [sqlite3_free()]. 1921** A result table should be deallocated using [sqlite3_free_table()]. 1922** 1923** ^(As an example of the result table format, suppose a query result 1924** is as follows: 1925** 1926** <blockquote><pre> 1927** Name | Age 1928** ----------------------- 1929** Alice | 43 1930** Bob | 28 1931** Cindy | 21 1932** </pre></blockquote> 1933** 1934** There are two column (M==2) and three rows (N==3). Thus the 1935** result table has 8 entries. Suppose the result table is stored 1936** in an array names azResult. Then azResult holds this content: 1937** 1938** <blockquote><pre> 1939** azResult[0] = "Name"; 1940** azResult[1] = "Age"; 1941** azResult[2] = "Alice"; 1942** azResult[3] = "43"; 1943** azResult[4] = "Bob"; 1944** azResult[5] = "28"; 1945** azResult[6] = "Cindy"; 1946** azResult[7] = "21"; 1947** </pre></blockquote>)^ 1948** 1949** ^The sqlite3_get_table() function evaluates one or more 1950** semicolon-separated SQL statements in the zero-terminated UTF-8 1951** string of its 2nd parameter and returns a result table to the 1952** pointer given in its 3rd parameter. 1953** 1954** After the application has finished with the result from sqlite3_get_table(), 1955** it must pass the result table pointer to sqlite3_free_table() in order to 1956** release the memory that was malloced. Because of the way the 1957** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1958** function must not try to call [sqlite3_free()] directly. Only 1959** [sqlite3_free_table()] is able to release the memory properly and safely. 1960** 1961** The sqlite3_get_table() interface is implemented as a wrapper around 1962** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1963** to any internal data structures of SQLite. It uses only the public 1964** interface defined here. As a consequence, errors that occur in the 1965** wrapper layer outside of the internal [sqlite3_exec()] call are not 1966** reflected in subsequent calls to [sqlite3_errcode()] or 1967** [sqlite3_errmsg()]. 1968*/ 1969int sqlite3_get_table( 1970 sqlite3 *db, /* An open database */ 1971 const char *zSql, /* SQL to be evaluated */ 1972 char ***pazResult, /* Results of the query */ 1973 int *pnRow, /* Number of result rows written here */ 1974 int *pnColumn, /* Number of result columns written here */ 1975 char **pzErrmsg /* Error msg written here */ 1976); 1977void sqlite3_free_table(char **result); 1978 1979/* 1980** CAPI3REF: Formatted String Printing Functions 1981** 1982** These routines are work-alikes of the "printf()" family of functions 1983** from the standard C library. 1984** 1985** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1986** results into memory obtained from [sqlite3_malloc()]. 1987** The strings returned by these two routines should be 1988** released by [sqlite3_free()]. ^Both routines return a 1989** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1990** memory to hold the resulting string. 1991** 1992** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 1993** the standard C library. The result is written into the 1994** buffer supplied as the second parameter whose size is given by 1995** the first parameter. Note that the order of the 1996** first two parameters is reversed from snprintf().)^ This is an 1997** historical accident that cannot be fixed without breaking 1998** backwards compatibility. ^(Note also that sqlite3_snprintf() 1999** returns a pointer to its buffer instead of the number of 2000** characters actually written into the buffer.)^ We admit that 2001** the number of characters written would be a more useful return 2002** value but we cannot change the implementation of sqlite3_snprintf() 2003** now without breaking compatibility. 2004** 2005** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2006** guarantees that the buffer is always zero-terminated. ^The first 2007** parameter "n" is the total size of the buffer, including space for 2008** the zero terminator. So the longest string that can be completely 2009** written will be n-1 characters. 2010** 2011** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2012** 2013** These routines all implement some additional formatting 2014** options that are useful for constructing SQL statements. 2015** All of the usual printf() formatting options apply. In addition, there 2016** is are "%q", "%Q", and "%z" options. 2017** 2018** ^(The %q option works like %s in that it substitutes a nul-terminated 2019** string from the argument list. But %q also doubles every '\'' character. 2020** %q is designed for use inside a string literal.)^ By doubling each '\'' 2021** character it escapes that character and allows it to be inserted into 2022** the string. 2023** 2024** For example, assume the string variable zText contains text as follows: 2025** 2026** <blockquote><pre> 2027** char *zText = "It's a happy day!"; 2028** </pre></blockquote> 2029** 2030** One can use this text in an SQL statement as follows: 2031** 2032** <blockquote><pre> 2033** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2034** sqlite3_exec(db, zSQL, 0, 0, 0); 2035** sqlite3_free(zSQL); 2036** </pre></blockquote> 2037** 2038** Because the %q format string is used, the '\'' character in zText 2039** is escaped and the SQL generated is as follows: 2040** 2041** <blockquote><pre> 2042** INSERT INTO table1 VALUES('It''s a happy day!') 2043** </pre></blockquote> 2044** 2045** This is correct. Had we used %s instead of %q, the generated SQL 2046** would have looked like this: 2047** 2048** <blockquote><pre> 2049** INSERT INTO table1 VALUES('It's a happy day!'); 2050** </pre></blockquote> 2051** 2052** This second example is an SQL syntax error. As a general rule you should 2053** always use %q instead of %s when inserting text into a string literal. 2054** 2055** ^(The %Q option works like %q except it also adds single quotes around 2056** the outside of the total string. Additionally, if the parameter in the 2057** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2058** single quotes).)^ So, for example, one could say: 2059** 2060** <blockquote><pre> 2061** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2062** sqlite3_exec(db, zSQL, 0, 0, 0); 2063** sqlite3_free(zSQL); 2064** </pre></blockquote> 2065** 2066** The code above will render a correct SQL statement in the zSQL 2067** variable even if the zText variable is a NULL pointer. 2068** 2069** ^(The "%z" formatting option works like "%s" but with the 2070** addition that after the string has been read and copied into 2071** the result, [sqlite3_free()] is called on the input string.)^ 2072*/ 2073char *sqlite3_mprintf(const char*,...); 2074char *sqlite3_vmprintf(const char*, va_list); 2075char *sqlite3_snprintf(int,char*,const char*, ...); 2076char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2077 2078/* 2079** CAPI3REF: Memory Allocation Subsystem 2080** 2081** The SQLite core uses these three routines for all of its own 2082** internal memory allocation needs. "Core" in the previous sentence 2083** does not include operating-system specific VFS implementation. The 2084** Windows VFS uses native malloc() and free() for some operations. 2085** 2086** ^The sqlite3_malloc() routine returns a pointer to a block 2087** of memory at least N bytes in length, where N is the parameter. 2088** ^If sqlite3_malloc() is unable to obtain sufficient free 2089** memory, it returns a NULL pointer. ^If the parameter N to 2090** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2091** a NULL pointer. 2092** 2093** ^Calling sqlite3_free() with a pointer previously returned 2094** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2095** that it might be reused. ^The sqlite3_free() routine is 2096** a no-op if is called with a NULL pointer. Passing a NULL pointer 2097** to sqlite3_free() is harmless. After being freed, memory 2098** should neither be read nor written. Even reading previously freed 2099** memory might result in a segmentation fault or other severe error. 2100** Memory corruption, a segmentation fault, or other severe error 2101** might result if sqlite3_free() is called with a non-NULL pointer that 2102** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2103** 2104** ^(The sqlite3_realloc() interface attempts to resize a 2105** prior memory allocation to be at least N bytes, where N is the 2106** second parameter. The memory allocation to be resized is the first 2107** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2108** is a NULL pointer then its behavior is identical to calling 2109** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2110** ^If the second parameter to sqlite3_realloc() is zero or 2111** negative then the behavior is exactly the same as calling 2112** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2113** ^sqlite3_realloc() returns a pointer to a memory allocation 2114** of at least N bytes in size or NULL if sufficient memory is unavailable. 2115** ^If M is the size of the prior allocation, then min(N,M) bytes 2116** of the prior allocation are copied into the beginning of buffer returned 2117** by sqlite3_realloc() and the prior allocation is freed. 2118** ^If sqlite3_realloc() returns NULL, then the prior allocation 2119** is not freed. 2120** 2121** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2122** is always aligned to at least an 8 byte boundary, or to a 2123** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2124** option is used. 2125** 2126** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2127** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2128** implementation of these routines to be omitted. That capability 2129** is no longer provided. Only built-in memory allocators can be used. 2130** 2131** The Windows OS interface layer calls 2132** the system malloc() and free() directly when converting 2133** filenames between the UTF-8 encoding used by SQLite 2134** and whatever filename encoding is used by the particular Windows 2135** installation. Memory allocation errors are detected, but 2136** they are reported back as [SQLITE_CANTOPEN] or 2137** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2138** 2139** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2140** must be either NULL or else pointers obtained from a prior 2141** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2142** not yet been released. 2143** 2144** The application must not read or write any part of 2145** a block of memory after it has been released using 2146** [sqlite3_free()] or [sqlite3_realloc()]. 2147*/ 2148void *sqlite3_malloc(int); 2149void *sqlite3_realloc(void*, int); 2150void sqlite3_free(void*); 2151 2152/* 2153** CAPI3REF: Memory Allocator Statistics 2154** 2155** SQLite provides these two interfaces for reporting on the status 2156** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2157** routines, which form the built-in memory allocation subsystem. 2158** 2159** ^The [sqlite3_memory_used()] routine returns the number of bytes 2160** of memory currently outstanding (malloced but not freed). 2161** ^The [sqlite3_memory_highwater()] routine returns the maximum 2162** value of [sqlite3_memory_used()] since the high-water mark 2163** was last reset. ^The values returned by [sqlite3_memory_used()] and 2164** [sqlite3_memory_highwater()] include any overhead 2165** added by SQLite in its implementation of [sqlite3_malloc()], 2166** but not overhead added by the any underlying system library 2167** routines that [sqlite3_malloc()] may call. 2168** 2169** ^The memory high-water mark is reset to the current value of 2170** [sqlite3_memory_used()] if and only if the parameter to 2171** [sqlite3_memory_highwater()] is true. ^The value returned 2172** by [sqlite3_memory_highwater(1)] is the high-water mark 2173** prior to the reset. 2174*/ 2175sqlite3_int64 sqlite3_memory_used(void); 2176sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2177 2178/* 2179** CAPI3REF: Pseudo-Random Number Generator 2180** 2181** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2182** select random [ROWID | ROWIDs] when inserting new records into a table that 2183** already uses the largest possible [ROWID]. The PRNG is also used for 2184** the build-in random() and randomblob() SQL functions. This interface allows 2185** applications to access the same PRNG for other purposes. 2186** 2187** ^A call to this routine stores N bytes of randomness into buffer P. 2188** 2189** ^The first time this routine is invoked (either internally or by 2190** the application) the PRNG is seeded using randomness obtained 2191** from the xRandomness method of the default [sqlite3_vfs] object. 2192** ^On all subsequent invocations, the pseudo-randomness is generated 2193** internally and without recourse to the [sqlite3_vfs] xRandomness 2194** method. 2195*/ 2196void sqlite3_randomness(int N, void *P); 2197 2198/* 2199** CAPI3REF: Compile-Time Authorization Callbacks 2200** 2201** ^This routine registers an authorizer callback with a particular 2202** [database connection], supplied in the first argument. 2203** ^The authorizer callback is invoked as SQL statements are being compiled 2204** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2205** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2206** points during the compilation process, as logic is being created 2207** to perform various actions, the authorizer callback is invoked to 2208** see if those actions are allowed. ^The authorizer callback should 2209** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2210** specific action but allow the SQL statement to continue to be 2211** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2212** rejected with an error. ^If the authorizer callback returns 2213** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2214** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2215** the authorizer will fail with an error message. 2216** 2217** When the callback returns [SQLITE_OK], that means the operation 2218** requested is ok. ^When the callback returns [SQLITE_DENY], the 2219** [sqlite3_prepare_v2()] or equivalent call that triggered the 2220** authorizer will fail with an error message explaining that 2221** access is denied. 2222** 2223** ^The first parameter to the authorizer callback is a copy of the third 2224** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2225** to the callback is an integer [SQLITE_COPY | action code] that specifies 2226** the particular action to be authorized. ^The third through sixth parameters 2227** to the callback are zero-terminated strings that contain additional 2228** details about the action to be authorized. 2229** 2230** ^If the action code is [SQLITE_READ] 2231** and the callback returns [SQLITE_IGNORE] then the 2232** [prepared statement] statement is constructed to substitute 2233** a NULL value in place of the table column that would have 2234** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2235** return can be used to deny an untrusted user access to individual 2236** columns of a table. 2237** ^If the action code is [SQLITE_DELETE] and the callback returns 2238** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2239** [truncate optimization] is disabled and all rows are deleted individually. 2240** 2241** An authorizer is used when [sqlite3_prepare | preparing] 2242** SQL statements from an untrusted source, to ensure that the SQL statements 2243** do not try to access data they are not allowed to see, or that they do not 2244** try to execute malicious statements that damage the database. For 2245** example, an application may allow a user to enter arbitrary 2246** SQL queries for evaluation by a database. But the application does 2247** not want the user to be able to make arbitrary changes to the 2248** database. An authorizer could then be put in place while the 2249** user-entered SQL is being [sqlite3_prepare | prepared] that 2250** disallows everything except [SELECT] statements. 2251** 2252** Applications that need to process SQL from untrusted sources 2253** might also consider lowering resource limits using [sqlite3_limit()] 2254** and limiting database size using the [max_page_count] [PRAGMA] 2255** in addition to using an authorizer. 2256** 2257** ^(Only a single authorizer can be in place on a database connection 2258** at a time. Each call to sqlite3_set_authorizer overrides the 2259** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2260** The authorizer is disabled by default. 2261** 2262** The authorizer callback must not do anything that will modify 2263** the database connection that invoked the authorizer callback. 2264** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2265** database connections for the meaning of "modify" in this paragraph. 2266** 2267** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2268** statement might be re-prepared during [sqlite3_step()] due to a 2269** schema change. Hence, the application should ensure that the 2270** correct authorizer callback remains in place during the [sqlite3_step()]. 2271** 2272** ^Note that the authorizer callback is invoked only during 2273** [sqlite3_prepare()] or its variants. Authorization is not 2274** performed during statement evaluation in [sqlite3_step()], unless 2275** as stated in the previous paragraph, sqlite3_step() invokes 2276** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2277*/ 2278int sqlite3_set_authorizer( 2279 sqlite3*, 2280 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2281 void *pUserData 2282); 2283 2284/* 2285** CAPI3REF: Authorizer Return Codes 2286** 2287** The [sqlite3_set_authorizer | authorizer callback function] must 2288** return either [SQLITE_OK] or one of these two constants in order 2289** to signal SQLite whether or not the action is permitted. See the 2290** [sqlite3_set_authorizer | authorizer documentation] for additional 2291** information. 2292** 2293** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2294** from the [sqlite3_vtab_on_conflict()] interface. 2295*/ 2296#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2297#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2298 2299/* 2300** CAPI3REF: Authorizer Action Codes 2301** 2302** The [sqlite3_set_authorizer()] interface registers a callback function 2303** that is invoked to authorize certain SQL statement actions. The 2304** second parameter to the callback is an integer code that specifies 2305** what action is being authorized. These are the integer action codes that 2306** the authorizer callback may be passed. 2307** 2308** These action code values signify what kind of operation is to be 2309** authorized. The 3rd and 4th parameters to the authorization 2310** callback function will be parameters or NULL depending on which of these 2311** codes is used as the second parameter. ^(The 5th parameter to the 2312** authorizer callback is the name of the database ("main", "temp", 2313** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2314** is the name of the inner-most trigger or view that is responsible for 2315** the access attempt or NULL if this access attempt is directly from 2316** top-level SQL code. 2317*/ 2318/******************************************* 3rd ************ 4th ***********/ 2319#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2320#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2321#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2322#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2323#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2324#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2325#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2326#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2327#define SQLITE_DELETE 9 /* Table Name NULL */ 2328#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2329#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2330#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2331#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2332#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2333#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2334#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2335#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2336#define SQLITE_INSERT 18 /* Table Name NULL */ 2337#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2338#define SQLITE_READ 20 /* Table Name Column Name */ 2339#define SQLITE_SELECT 21 /* NULL NULL */ 2340#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2341#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2342#define SQLITE_ATTACH 24 /* Filename NULL */ 2343#define SQLITE_DETACH 25 /* Database Name NULL */ 2344#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2345#define SQLITE_REINDEX 27 /* Index Name NULL */ 2346#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2347#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2348#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2349#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2350#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2351#define SQLITE_COPY 0 /* No longer used */ 2352 2353/* 2354** CAPI3REF: Tracing And Profiling Functions 2355** 2356** These routines register callback functions that can be used for 2357** tracing and profiling the execution of SQL statements. 2358** 2359** ^The callback function registered by sqlite3_trace() is invoked at 2360** various times when an SQL statement is being run by [sqlite3_step()]. 2361** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2362** SQL statement text as the statement first begins executing. 2363** ^(Additional sqlite3_trace() callbacks might occur 2364** as each triggered subprogram is entered. The callbacks for triggers 2365** contain a UTF-8 SQL comment that identifies the trigger.)^ 2366** 2367** ^The callback function registered by sqlite3_profile() is invoked 2368** as each SQL statement finishes. ^The profile callback contains 2369** the original statement text and an estimate of wall-clock time 2370** of how long that statement took to run. ^The profile callback 2371** time is in units of nanoseconds, however the current implementation 2372** is only capable of millisecond resolution so the six least significant 2373** digits in the time are meaningless. Future versions of SQLite 2374** might provide greater resolution on the profiler callback. The 2375** sqlite3_profile() function is considered experimental and is 2376** subject to change in future versions of SQLite. 2377*/ 2378void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2379SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2380 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2381 2382/* 2383** CAPI3REF: Query Progress Callbacks 2384** 2385** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2386** function X to be invoked periodically during long running calls to 2387** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2388** database connection D. An example use for this 2389** interface is to keep a GUI updated during a large query. 2390** 2391** ^The parameter P is passed through as the only parameter to the 2392** callback function X. ^The parameter N is the number of 2393** [virtual machine instructions] that are evaluated between successive 2394** invocations of the callback X. 2395** 2396** ^Only a single progress handler may be defined at one time per 2397** [database connection]; setting a new progress handler cancels the 2398** old one. ^Setting parameter X to NULL disables the progress handler. 2399** ^The progress handler is also disabled by setting N to a value less 2400** than 1. 2401** 2402** ^If the progress callback returns non-zero, the operation is 2403** interrupted. This feature can be used to implement a 2404** "Cancel" button on a GUI progress dialog box. 2405** 2406** The progress handler callback must not do anything that will modify 2407** the database connection that invoked the progress handler. 2408** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2409** database connections for the meaning of "modify" in this paragraph. 2410** 2411*/ 2412void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2413 2414/* 2415** CAPI3REF: Opening A New Database Connection 2416** 2417** ^These routines open an SQLite database file as specified by the 2418** filename argument. ^The filename argument is interpreted as UTF-8 for 2419** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2420** order for sqlite3_open16(). ^(A [database connection] handle is usually 2421** returned in *ppDb, even if an error occurs. The only exception is that 2422** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2423** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2424** object.)^ ^(If the database is opened (and/or created) successfully, then 2425** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2426** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2427** an English language description of the error following a failure of any 2428** of the sqlite3_open() routines. 2429** 2430** ^The default encoding for the database will be UTF-8 if 2431** sqlite3_open() or sqlite3_open_v2() is called and 2432** UTF-16 in the native byte order if sqlite3_open16() is used. 2433** 2434** Whether or not an error occurs when it is opened, resources 2435** associated with the [database connection] handle should be released by 2436** passing it to [sqlite3_close()] when it is no longer required. 2437** 2438** The sqlite3_open_v2() interface works like sqlite3_open() 2439** except that it accepts two additional parameters for additional control 2440** over the new database connection. ^(The flags parameter to 2441** sqlite3_open_v2() can take one of 2442** the following three values, optionally combined with the 2443** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2444** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2445** 2446** <dl> 2447** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2448** <dd>The database is opened in read-only mode. If the database does not 2449** already exist, an error is returned.</dd>)^ 2450** 2451** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2452** <dd>The database is opened for reading and writing if possible, or reading 2453** only if the file is write protected by the operating system. In either 2454** case the database must already exist, otherwise an error is returned.</dd>)^ 2455** 2456** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2457** <dd>The database is opened for reading and writing, and is created if 2458** it does not already exist. This is the behavior that is always used for 2459** sqlite3_open() and sqlite3_open16().</dd>)^ 2460** </dl> 2461** 2462** If the 3rd parameter to sqlite3_open_v2() is not one of the 2463** combinations shown above optionally combined with other 2464** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2465** then the behavior is undefined. 2466** 2467** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2468** opens in the multi-thread [threading mode] as long as the single-thread 2469** mode has not been set at compile-time or start-time. ^If the 2470** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2471** in the serialized [threading mode] unless single-thread was 2472** previously selected at compile-time or start-time. 2473** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2474** eligible to use [shared cache mode], regardless of whether or not shared 2475** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2476** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2477** participate in [shared cache mode] even if it is enabled. 2478** 2479** ^The fourth parameter to sqlite3_open_v2() is the name of the 2480** [sqlite3_vfs] object that defines the operating system interface that 2481** the new database connection should use. ^If the fourth parameter is 2482** a NULL pointer then the default [sqlite3_vfs] object is used. 2483** 2484** ^If the filename is ":memory:", then a private, temporary in-memory database 2485** is created for the connection. ^This in-memory database will vanish when 2486** the database connection is closed. Future versions of SQLite might 2487** make use of additional special filenames that begin with the ":" character. 2488** It is recommended that when a database filename actually does begin with 2489** a ":" character you should prefix the filename with a pathname such as 2490** "./" to avoid ambiguity. 2491** 2492** ^If the filename is an empty string, then a private, temporary 2493** on-disk database will be created. ^This private database will be 2494** automatically deleted as soon as the database connection is closed. 2495** 2496** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2497** 2498** ^If [URI filename] interpretation is enabled, and the filename argument 2499** begins with "file:", then the filename is interpreted as a URI. ^URI 2500** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2501** set in the fourth argument to sqlite3_open_v2(), or if it has 2502** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2503** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2504** As of SQLite version 3.7.7, URI filename interpretation is turned off 2505** by default, but future releases of SQLite might enable URI filename 2506** interpretation by default. See "[URI filenames]" for additional 2507** information. 2508** 2509** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2510** authority, then it must be either an empty string or the string 2511** "localhost". ^If the authority is not an empty string or "localhost", an 2512** error is returned to the caller. ^The fragment component of a URI, if 2513** present, is ignored. 2514** 2515** ^SQLite uses the path component of the URI as the name of the disk file 2516** which contains the database. ^If the path begins with a '/' character, 2517** then it is interpreted as an absolute path. ^If the path does not begin 2518** with a '/' (meaning that the authority section is omitted from the URI) 2519** then the path is interpreted as a relative path. 2520** ^On windows, the first component of an absolute path 2521** is a drive specification (e.g. "C:"). 2522** 2523** [[core URI query parameters]] 2524** The query component of a URI may contain parameters that are interpreted 2525** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2526** SQLite interprets the following three query parameters: 2527** 2528** <ul> 2529** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2530** a VFS object that provides the operating system interface that should 2531** be used to access the database file on disk. ^If this option is set to 2532** an empty string the default VFS object is used. ^Specifying an unknown 2533** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2534** present, then the VFS specified by the option takes precedence over 2535** the value passed as the fourth parameter to sqlite3_open_v2(). 2536** 2537** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or 2538** "rwc". Attempting to set it to any other value is an error)^. 2539** ^If "ro" is specified, then the database is opened for read-only 2540** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2541** third argument to sqlite3_prepare_v2(). ^If the mode option is set to 2542** "rw", then the database is opened for read-write (but not create) 2543** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2544** been set. ^Value "rwc" is equivalent to setting both 2545** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is 2546** used, it is an error to specify a value for the mode parameter that is 2547** less restrictive than that specified by the flags passed as the third 2548** parameter. 2549** 2550** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2551** "private". ^Setting it to "shared" is equivalent to setting the 2552** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2553** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2554** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2555** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2556** a URI filename, its value overrides any behaviour requested by setting 2557** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2558** </ul> 2559** 2560** ^Specifying an unknown parameter in the query component of a URI is not an 2561** error. Future versions of SQLite might understand additional query 2562** parameters. See "[query parameters with special meaning to SQLite]" for 2563** additional information. 2564** 2565** [[URI filename examples]] <h3>URI filename examples</h3> 2566** 2567** <table border="1" align=center cellpadding=5> 2568** <tr><th> URI filenames <th> Results 2569** <tr><td> file:data.db <td> 2570** Open the file "data.db" in the current directory. 2571** <tr><td> file:/home/fred/data.db<br> 2572** file:///home/fred/data.db <br> 2573** file://localhost/home/fred/data.db <br> <td> 2574** Open the database file "/home/fred/data.db". 2575** <tr><td> file://darkstar/home/fred/data.db <td> 2576** An error. "darkstar" is not a recognized authority. 2577** <tr><td style="white-space:nowrap"> 2578** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2579** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2580** C:. Note that the %20 escaping in this example is not strictly 2581** necessary - space characters can be used literally 2582** in URI filenames. 2583** <tr><td> file:data.db?mode=ro&cache=private <td> 2584** Open file "data.db" in the current directory for read-only access. 2585** Regardless of whether or not shared-cache mode is enabled by 2586** default, use a private cache. 2587** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2588** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2589** <tr><td> file:data.db?mode=readonly <td> 2590** An error. "readonly" is not a valid option for the "mode" parameter. 2591** </table> 2592** 2593** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2594** query components of a URI. A hexadecimal escape sequence consists of a 2595** percent sign - "%" - followed by exactly two hexadecimal digits 2596** specifying an octet value. ^Before the path or query components of a 2597** URI filename are interpreted, they are encoded using UTF-8 and all 2598** hexadecimal escape sequences replaced by a single byte containing the 2599** corresponding octet. If this process generates an invalid UTF-8 encoding, 2600** the results are undefined. 2601** 2602** <b>Note to Windows users:</b> The encoding used for the filename argument 2603** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2604** codepage is currently defined. Filenames containing international 2605** characters must be converted to UTF-8 prior to passing them into 2606** sqlite3_open() or sqlite3_open_v2(). 2607*/ 2608int sqlite3_open( 2609 const char *filename, /* Database filename (UTF-8) */ 2610 sqlite3 **ppDb /* OUT: SQLite db handle */ 2611); 2612int sqlite3_open16( 2613 const void *filename, /* Database filename (UTF-16) */ 2614 sqlite3 **ppDb /* OUT: SQLite db handle */ 2615); 2616int sqlite3_open_v2( 2617 const char *filename, /* Database filename (UTF-8) */ 2618 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2619 int flags, /* Flags */ 2620 const char *zVfs /* Name of VFS module to use */ 2621); 2622 2623/* 2624** CAPI3REF: Obtain Values For URI Parameters 2625** 2626** These are utility routines, useful to VFS implementations, that check 2627** to see if a database file was a URI that contained a specific query 2628** parameter, and if so obtains the value of that query parameter. 2629** 2630** If F is the database filename pointer passed into the xOpen() method of 2631** a VFS implementation when the flags parameter to xOpen() has one or 2632** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2633** P is the name of the query parameter, then 2634** sqlite3_uri_parameter(F,P) returns the value of the P 2635** parameter if it exists or a NULL pointer if P does not appear as a 2636** query parameter on F. If P is a query parameter of F 2637** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2638** a pointer to an empty string. 2639** 2640** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2641** parameter and returns true (1) or false (0) according to the value 2642** of P. The value of P is true if it is "yes" or "true" or "on" or 2643** a non-zero number and is false otherwise. If P is not a query parameter 2644** on F then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2645** 2646** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2647** 64-bit signed integer and returns that integer, or D if P does not 2648** exist. If the value of P is something other than an integer, then 2649** zero is returned. 2650** 2651** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2652** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2653** is not a database file pathname pointer that SQLite passed into the xOpen 2654** VFS method, then the behavior of this routine is undefined and probably 2655** undesirable. 2656*/ 2657const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2658int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2659sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2660 2661 2662/* 2663** CAPI3REF: Error Codes And Messages 2664** 2665** ^The sqlite3_errcode() interface returns the numeric [result code] or 2666** [extended result code] for the most recent failed sqlite3_* API call 2667** associated with a [database connection]. If a prior API call failed 2668** but the most recent API call succeeded, the return value from 2669** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2670** interface is the same except that it always returns the 2671** [extended result code] even when extended result codes are 2672** disabled. 2673** 2674** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2675** text that describes the error, as either UTF-8 or UTF-16 respectively. 2676** ^(Memory to hold the error message string is managed internally. 2677** The application does not need to worry about freeing the result. 2678** However, the error string might be overwritten or deallocated by 2679** subsequent calls to other SQLite interface functions.)^ 2680** 2681** When the serialized [threading mode] is in use, it might be the 2682** case that a second error occurs on a separate thread in between 2683** the time of the first error and the call to these interfaces. 2684** When that happens, the second error will be reported since these 2685** interfaces always report the most recent result. To avoid 2686** this, each thread can obtain exclusive use of the [database connection] D 2687** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2688** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2689** all calls to the interfaces listed here are completed. 2690** 2691** If an interface fails with SQLITE_MISUSE, that means the interface 2692** was invoked incorrectly by the application. In that case, the 2693** error code and message may or may not be set. 2694*/ 2695int sqlite3_errcode(sqlite3 *db); 2696int sqlite3_extended_errcode(sqlite3 *db); 2697const char *sqlite3_errmsg(sqlite3*); 2698const void *sqlite3_errmsg16(sqlite3*); 2699 2700/* 2701** CAPI3REF: SQL Statement Object 2702** KEYWORDS: {prepared statement} {prepared statements} 2703** 2704** An instance of this object represents a single SQL statement. 2705** This object is variously known as a "prepared statement" or a 2706** "compiled SQL statement" or simply as a "statement". 2707** 2708** The life of a statement object goes something like this: 2709** 2710** <ol> 2711** <li> Create the object using [sqlite3_prepare_v2()] or a related 2712** function. 2713** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2714** interfaces. 2715** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2716** <li> Reset the statement using [sqlite3_reset()] then go back 2717** to step 2. Do this zero or more times. 2718** <li> Destroy the object using [sqlite3_finalize()]. 2719** </ol> 2720** 2721** Refer to documentation on individual methods above for additional 2722** information. 2723*/ 2724typedef struct sqlite3_stmt sqlite3_stmt; 2725 2726/* 2727** CAPI3REF: Run-time Limits 2728** 2729** ^(This interface allows the size of various constructs to be limited 2730** on a connection by connection basis. The first parameter is the 2731** [database connection] whose limit is to be set or queried. The 2732** second parameter is one of the [limit categories] that define a 2733** class of constructs to be size limited. The third parameter is the 2734** new limit for that construct.)^ 2735** 2736** ^If the new limit is a negative number, the limit is unchanged. 2737** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2738** [limits | hard upper bound] 2739** set at compile-time by a C preprocessor macro called 2740** [limits | SQLITE_MAX_<i>NAME</i>]. 2741** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2742** ^Attempts to increase a limit above its hard upper bound are 2743** silently truncated to the hard upper bound. 2744** 2745** ^Regardless of whether or not the limit was changed, the 2746** [sqlite3_limit()] interface returns the prior value of the limit. 2747** ^Hence, to find the current value of a limit without changing it, 2748** simply invoke this interface with the third parameter set to -1. 2749** 2750** Run-time limits are intended for use in applications that manage 2751** both their own internal database and also databases that are controlled 2752** by untrusted external sources. An example application might be a 2753** web browser that has its own databases for storing history and 2754** separate databases controlled by JavaScript applications downloaded 2755** off the Internet. The internal databases can be given the 2756** large, default limits. Databases managed by external sources can 2757** be given much smaller limits designed to prevent a denial of service 2758** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2759** interface to further control untrusted SQL. The size of the database 2760** created by an untrusted script can be contained using the 2761** [max_page_count] [PRAGMA]. 2762** 2763** New run-time limit categories may be added in future releases. 2764*/ 2765int sqlite3_limit(sqlite3*, int id, int newVal); 2766 2767/* 2768** CAPI3REF: Run-Time Limit Categories 2769** KEYWORDS: {limit category} {*limit categories} 2770** 2771** These constants define various performance limits 2772** that can be lowered at run-time using [sqlite3_limit()]. 2773** The synopsis of the meanings of the various limits is shown below. 2774** Additional information is available at [limits | Limits in SQLite]. 2775** 2776** <dl> 2777** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2778** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2779** 2780** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2781** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2782** 2783** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2784** <dd>The maximum number of columns in a table definition or in the 2785** result set of a [SELECT] or the maximum number of columns in an index 2786** or in an ORDER BY or GROUP BY clause.</dd>)^ 2787** 2788** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2789** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2790** 2791** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2792** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2793** 2794** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2795** <dd>The maximum number of instructions in a virtual machine program 2796** used to implement an SQL statement. This limit is not currently 2797** enforced, though that might be added in some future release of 2798** SQLite.</dd>)^ 2799** 2800** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2801** <dd>The maximum number of arguments on a function.</dd>)^ 2802** 2803** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2804** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2805** 2806** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2807** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2808** <dd>The maximum length of the pattern argument to the [LIKE] or 2809** [GLOB] operators.</dd>)^ 2810** 2811** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2812** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2813** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2814** 2815** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2816** <dd>The maximum depth of recursion for triggers.</dd>)^ 2817** </dl> 2818*/ 2819#define SQLITE_LIMIT_LENGTH 0 2820#define SQLITE_LIMIT_SQL_LENGTH 1 2821#define SQLITE_LIMIT_COLUMN 2 2822#define SQLITE_LIMIT_EXPR_DEPTH 3 2823#define SQLITE_LIMIT_COMPOUND_SELECT 4 2824#define SQLITE_LIMIT_VDBE_OP 5 2825#define SQLITE_LIMIT_FUNCTION_ARG 6 2826#define SQLITE_LIMIT_ATTACHED 7 2827#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2828#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2829#define SQLITE_LIMIT_TRIGGER_DEPTH 10 2830 2831/* 2832** CAPI3REF: Compiling An SQL Statement 2833** KEYWORDS: {SQL statement compiler} 2834** 2835** To execute an SQL query, it must first be compiled into a byte-code 2836** program using one of these routines. 2837** 2838** The first argument, "db", is a [database connection] obtained from a 2839** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2840** [sqlite3_open16()]. The database connection must not have been closed. 2841** 2842** The second argument, "zSql", is the statement to be compiled, encoded 2843** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2844** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2845** use UTF-16. 2846** 2847** ^If the nByte argument is less than zero, then zSql is read up to the 2848** first zero terminator. ^If nByte is non-negative, then it is the maximum 2849** number of bytes read from zSql. ^When nByte is non-negative, the 2850** zSql string ends at either the first '\000' or '\u0000' character or 2851** the nByte-th byte, whichever comes first. If the caller knows 2852** that the supplied string is nul-terminated, then there is a small 2853** performance advantage to be gained by passing an nByte parameter that 2854** is equal to the number of bytes in the input string <i>including</i> 2855** the nul-terminator bytes as this saves SQLite from having to 2856** make a copy of the input string. 2857** 2858** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2859** past the end of the first SQL statement in zSql. These routines only 2860** compile the first statement in zSql, so *pzTail is left pointing to 2861** what remains uncompiled. 2862** 2863** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2864** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2865** to NULL. ^If the input text contains no SQL (if the input is an empty 2866** string or a comment) then *ppStmt is set to NULL. 2867** The calling procedure is responsible for deleting the compiled 2868** SQL statement using [sqlite3_finalize()] after it has finished with it. 2869** ppStmt may not be NULL. 2870** 2871** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2872** otherwise an [error code] is returned. 2873** 2874** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2875** recommended for all new programs. The two older interfaces are retained 2876** for backwards compatibility, but their use is discouraged. 2877** ^In the "v2" interfaces, the prepared statement 2878** that is returned (the [sqlite3_stmt] object) contains a copy of the 2879** original SQL text. This causes the [sqlite3_step()] interface to 2880** behave differently in three ways: 2881** 2882** <ol> 2883** <li> 2884** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2885** always used to do, [sqlite3_step()] will automatically recompile the SQL 2886** statement and try to run it again. 2887** </li> 2888** 2889** <li> 2890** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2891** [error codes] or [extended error codes]. ^The legacy behavior was that 2892** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2893** and the application would have to make a second call to [sqlite3_reset()] 2894** in order to find the underlying cause of the problem. With the "v2" prepare 2895** interfaces, the underlying reason for the error is returned immediately. 2896** </li> 2897** 2898** <li> 2899** ^If the specific value bound to [parameter | host parameter] in the 2900** WHERE clause might influence the choice of query plan for a statement, 2901** then the statement will be automatically recompiled, as if there had been 2902** a schema change, on the first [sqlite3_step()] call following any change 2903** to the [sqlite3_bind_text | bindings] of that [parameter]. 2904** ^The specific value of WHERE-clause [parameter] might influence the 2905** choice of query plan if the parameter is the left-hand side of a [LIKE] 2906** or [GLOB] operator or if the parameter is compared to an indexed column 2907** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 2908** the 2909** </li> 2910** </ol> 2911*/ 2912int sqlite3_prepare( 2913 sqlite3 *db, /* Database handle */ 2914 const char *zSql, /* SQL statement, UTF-8 encoded */ 2915 int nByte, /* Maximum length of zSql in bytes. */ 2916 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2917 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2918); 2919int sqlite3_prepare_v2( 2920 sqlite3 *db, /* Database handle */ 2921 const char *zSql, /* SQL statement, UTF-8 encoded */ 2922 int nByte, /* Maximum length of zSql in bytes. */ 2923 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2924 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2925); 2926int sqlite3_prepare16( 2927 sqlite3 *db, /* Database handle */ 2928 const void *zSql, /* SQL statement, UTF-16 encoded */ 2929 int nByte, /* Maximum length of zSql in bytes. */ 2930 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2931 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2932); 2933int sqlite3_prepare16_v2( 2934 sqlite3 *db, /* Database handle */ 2935 const void *zSql, /* SQL statement, UTF-16 encoded */ 2936 int nByte, /* Maximum length of zSql in bytes. */ 2937 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2938 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2939); 2940 2941/* 2942** CAPI3REF: Retrieving Statement SQL 2943** 2944** ^This interface can be used to retrieve a saved copy of the original 2945** SQL text used to create a [prepared statement] if that statement was 2946** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2947*/ 2948const char *sqlite3_sql(sqlite3_stmt *pStmt); 2949 2950/* 2951** CAPI3REF: Determine If An SQL Statement Writes The Database 2952** 2953** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 2954** and only if the [prepared statement] X makes no direct changes to 2955** the content of the database file. 2956** 2957** Note that [application-defined SQL functions] or 2958** [virtual tables] might change the database indirectly as a side effect. 2959** ^(For example, if an application defines a function "eval()" that 2960** calls [sqlite3_exec()], then the following SQL statement would 2961** change the database file through side-effects: 2962** 2963** <blockquote><pre> 2964** SELECT eval('DELETE FROM t1') FROM t2; 2965** </pre></blockquote> 2966** 2967** But because the [SELECT] statement does not change the database file 2968** directly, sqlite3_stmt_readonly() would still return true.)^ 2969** 2970** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 2971** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 2972** since the statements themselves do not actually modify the database but 2973** rather they control the timing of when other statements modify the 2974** database. ^The [ATTACH] and [DETACH] statements also cause 2975** sqlite3_stmt_readonly() to return true since, while those statements 2976** change the configuration of a database connection, they do not make 2977** changes to the content of the database files on disk. 2978*/ 2979int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 2980 2981/* 2982** CAPI3REF: Determine If A Prepared Statement Has Been Reset 2983** 2984** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 2985** [prepared statement] S has been stepped at least once using 2986** [sqlite3_step(S)] but has not run to completion and/or has not 2987** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 2988** interface returns false if S is a NULL pointer. If S is not a 2989** NULL pointer and is not a pointer to a valid [prepared statement] 2990** object, then the behavior is undefined and probably undesirable. 2991** 2992** This interface can be used in combination [sqlite3_next_stmt()] 2993** to locate all prepared statements associated with a database 2994** connection that are in need of being reset. This can be used, 2995** for example, in diagnostic routines to search for prepared 2996** statements that are holding a transaction open. 2997*/ 2998int sqlite3_stmt_busy(sqlite3_stmt*); 2999 3000/* 3001** CAPI3REF: Dynamically Typed Value Object 3002** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3003** 3004** SQLite uses the sqlite3_value object to represent all values 3005** that can be stored in a database table. SQLite uses dynamic typing 3006** for the values it stores. ^Values stored in sqlite3_value objects 3007** can be integers, floating point values, strings, BLOBs, or NULL. 3008** 3009** An sqlite3_value object may be either "protected" or "unprotected". 3010** Some interfaces require a protected sqlite3_value. Other interfaces 3011** will accept either a protected or an unprotected sqlite3_value. 3012** Every interface that accepts sqlite3_value arguments specifies 3013** whether or not it requires a protected sqlite3_value. 3014** 3015** The terms "protected" and "unprotected" refer to whether or not 3016** a mutex is held. An internal mutex is held for a protected 3017** sqlite3_value object but no mutex is held for an unprotected 3018** sqlite3_value object. If SQLite is compiled to be single-threaded 3019** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3020** or if SQLite is run in one of reduced mutex modes 3021** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3022** then there is no distinction between protected and unprotected 3023** sqlite3_value objects and they can be used interchangeably. However, 3024** for maximum code portability it is recommended that applications 3025** still make the distinction between protected and unprotected 3026** sqlite3_value objects even when not strictly required. 3027** 3028** ^The sqlite3_value objects that are passed as parameters into the 3029** implementation of [application-defined SQL functions] are protected. 3030** ^The sqlite3_value object returned by 3031** [sqlite3_column_value()] is unprotected. 3032** Unprotected sqlite3_value objects may only be used with 3033** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3034** The [sqlite3_value_blob | sqlite3_value_type()] family of 3035** interfaces require protected sqlite3_value objects. 3036*/ 3037typedef struct Mem sqlite3_value; 3038 3039/* 3040** CAPI3REF: SQL Function Context Object 3041** 3042** The context in which an SQL function executes is stored in an 3043** sqlite3_context object. ^A pointer to an sqlite3_context object 3044** is always first parameter to [application-defined SQL functions]. 3045** The application-defined SQL function implementation will pass this 3046** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3047** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3048** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3049** and/or [sqlite3_set_auxdata()]. 3050*/ 3051typedef struct sqlite3_context sqlite3_context; 3052 3053/* 3054** CAPI3REF: Binding Values To Prepared Statements 3055** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3056** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3057** 3058** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3059** literals may be replaced by a [parameter] that matches one of following 3060** templates: 3061** 3062** <ul> 3063** <li> ? 3064** <li> ?NNN 3065** <li> :VVV 3066** <li> @VVV 3067** <li> $VVV 3068** </ul> 3069** 3070** In the templates above, NNN represents an integer literal, 3071** and VVV represents an alphanumeric identifier.)^ ^The values of these 3072** parameters (also called "host parameter names" or "SQL parameters") 3073** can be set using the sqlite3_bind_*() routines defined here. 3074** 3075** ^The first argument to the sqlite3_bind_*() routines is always 3076** a pointer to the [sqlite3_stmt] object returned from 3077** [sqlite3_prepare_v2()] or its variants. 3078** 3079** ^The second argument is the index of the SQL parameter to be set. 3080** ^The leftmost SQL parameter has an index of 1. ^When the same named 3081** SQL parameter is used more than once, second and subsequent 3082** occurrences have the same index as the first occurrence. 3083** ^The index for named parameters can be looked up using the 3084** [sqlite3_bind_parameter_index()] API if desired. ^The index 3085** for "?NNN" parameters is the value of NNN. 3086** ^The NNN value must be between 1 and the [sqlite3_limit()] 3087** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3088** 3089** ^The third argument is the value to bind to the parameter. 3090** 3091** ^(In those routines that have a fourth argument, its value is the 3092** number of bytes in the parameter. To be clear: the value is the 3093** number of <u>bytes</u> in the value, not the number of characters.)^ 3094** ^If the fourth parameter is negative, the length of the string is 3095** the number of bytes up to the first zero terminator. 3096** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3097** or sqlite3_bind_text16() then that parameter must be the byte offset 3098** where the NUL terminator would occur assuming the string were NUL 3099** terminated. If any NUL characters occur at byte offsets less than 3100** the value of the fourth parameter then the resulting string value will 3101** contain embedded NULs. The result of expressions involving strings 3102** with embedded NULs is undefined. 3103** 3104** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3105** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3106** string after SQLite has finished with it. ^The destructor is called 3107** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3108** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3109** ^If the fifth argument is 3110** the special value [SQLITE_STATIC], then SQLite assumes that the 3111** information is in static, unmanaged space and does not need to be freed. 3112** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3113** SQLite makes its own private copy of the data immediately, before 3114** the sqlite3_bind_*() routine returns. 3115** 3116** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3117** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3118** (just an integer to hold its size) while it is being processed. 3119** Zeroblobs are intended to serve as placeholders for BLOBs whose 3120** content is later written using 3121** [sqlite3_blob_open | incremental BLOB I/O] routines. 3122** ^A negative value for the zeroblob results in a zero-length BLOB. 3123** 3124** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3125** for the [prepared statement] or with a prepared statement for which 3126** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3127** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3128** routine is passed a [prepared statement] that has been finalized, the 3129** result is undefined and probably harmful. 3130** 3131** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3132** ^Unbound parameters are interpreted as NULL. 3133** 3134** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3135** [error code] if anything goes wrong. 3136** ^[SQLITE_RANGE] is returned if the parameter 3137** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3138** 3139** See also: [sqlite3_bind_parameter_count()], 3140** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3141*/ 3142int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3143int sqlite3_bind_double(sqlite3_stmt*, int, double); 3144int sqlite3_bind_int(sqlite3_stmt*, int, int); 3145int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3146int sqlite3_bind_null(sqlite3_stmt*, int); 3147int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3148int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3149int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3150int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3151 3152/* 3153** CAPI3REF: Number Of SQL Parameters 3154** 3155** ^This routine can be used to find the number of [SQL parameters] 3156** in a [prepared statement]. SQL parameters are tokens of the 3157** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3158** placeholders for values that are [sqlite3_bind_blob | bound] 3159** to the parameters at a later time. 3160** 3161** ^(This routine actually returns the index of the largest (rightmost) 3162** parameter. For all forms except ?NNN, this will correspond to the 3163** number of unique parameters. If parameters of the ?NNN form are used, 3164** there may be gaps in the list.)^ 3165** 3166** See also: [sqlite3_bind_blob|sqlite3_bind()], 3167** [sqlite3_bind_parameter_name()], and 3168** [sqlite3_bind_parameter_index()]. 3169*/ 3170int sqlite3_bind_parameter_count(sqlite3_stmt*); 3171 3172/* 3173** CAPI3REF: Name Of A Host Parameter 3174** 3175** ^The sqlite3_bind_parameter_name(P,N) interface returns 3176** the name of the N-th [SQL parameter] in the [prepared statement] P. 3177** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3178** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3179** respectively. 3180** In other words, the initial ":" or "$" or "@" or "?" 3181** is included as part of the name.)^ 3182** ^Parameters of the form "?" without a following integer have no name 3183** and are referred to as "nameless" or "anonymous parameters". 3184** 3185** ^The first host parameter has an index of 1, not 0. 3186** 3187** ^If the value N is out of range or if the N-th parameter is 3188** nameless, then NULL is returned. ^The returned string is 3189** always in UTF-8 encoding even if the named parameter was 3190** originally specified as UTF-16 in [sqlite3_prepare16()] or 3191** [sqlite3_prepare16_v2()]. 3192** 3193** See also: [sqlite3_bind_blob|sqlite3_bind()], 3194** [sqlite3_bind_parameter_count()], and 3195** [sqlite3_bind_parameter_index()]. 3196*/ 3197const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3198 3199/* 3200** CAPI3REF: Index Of A Parameter With A Given Name 3201** 3202** ^Return the index of an SQL parameter given its name. ^The 3203** index value returned is suitable for use as the second 3204** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3205** is returned if no matching parameter is found. ^The parameter 3206** name must be given in UTF-8 even if the original statement 3207** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3208** 3209** See also: [sqlite3_bind_blob|sqlite3_bind()], 3210** [sqlite3_bind_parameter_count()], and 3211** [sqlite3_bind_parameter_index()]. 3212*/ 3213int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3214 3215/* 3216** CAPI3REF: Reset All Bindings On A Prepared Statement 3217** 3218** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3219** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3220** ^Use this routine to reset all host parameters to NULL. 3221*/ 3222int sqlite3_clear_bindings(sqlite3_stmt*); 3223 3224/* 3225** CAPI3REF: Number Of Columns In A Result Set 3226** 3227** ^Return the number of columns in the result set returned by the 3228** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3229** statement that does not return data (for example an [UPDATE]). 3230** 3231** See also: [sqlite3_data_count()] 3232*/ 3233int sqlite3_column_count(sqlite3_stmt *pStmt); 3234 3235/* 3236** CAPI3REF: Column Names In A Result Set 3237** 3238** ^These routines return the name assigned to a particular column 3239** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3240** interface returns a pointer to a zero-terminated UTF-8 string 3241** and sqlite3_column_name16() returns a pointer to a zero-terminated 3242** UTF-16 string. ^The first parameter is the [prepared statement] 3243** that implements the [SELECT] statement. ^The second parameter is the 3244** column number. ^The leftmost column is number 0. 3245** 3246** ^The returned string pointer is valid until either the [prepared statement] 3247** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3248** reprepared by the first call to [sqlite3_step()] for a particular run 3249** or until the next call to 3250** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3251** 3252** ^If sqlite3_malloc() fails during the processing of either routine 3253** (for example during a conversion from UTF-8 to UTF-16) then a 3254** NULL pointer is returned. 3255** 3256** ^The name of a result column is the value of the "AS" clause for 3257** that column, if there is an AS clause. If there is no AS clause 3258** then the name of the column is unspecified and may change from 3259** one release of SQLite to the next. 3260*/ 3261const char *sqlite3_column_name(sqlite3_stmt*, int N); 3262const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3263 3264/* 3265** CAPI3REF: Source Of Data In A Query Result 3266** 3267** ^These routines provide a means to determine the database, table, and 3268** table column that is the origin of a particular result column in 3269** [SELECT] statement. 3270** ^The name of the database or table or column can be returned as 3271** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3272** the database name, the _table_ routines return the table name, and 3273** the origin_ routines return the column name. 3274** ^The returned string is valid until the [prepared statement] is destroyed 3275** using [sqlite3_finalize()] or until the statement is automatically 3276** reprepared by the first call to [sqlite3_step()] for a particular run 3277** or until the same information is requested 3278** again in a different encoding. 3279** 3280** ^The names returned are the original un-aliased names of the 3281** database, table, and column. 3282** 3283** ^The first argument to these interfaces is a [prepared statement]. 3284** ^These functions return information about the Nth result column returned by 3285** the statement, where N is the second function argument. 3286** ^The left-most column is column 0 for these routines. 3287** 3288** ^If the Nth column returned by the statement is an expression or 3289** subquery and is not a column value, then all of these functions return 3290** NULL. ^These routine might also return NULL if a memory allocation error 3291** occurs. ^Otherwise, they return the name of the attached database, table, 3292** or column that query result column was extracted from. 3293** 3294** ^As with all other SQLite APIs, those whose names end with "16" return 3295** UTF-16 encoded strings and the other functions return UTF-8. 3296** 3297** ^These APIs are only available if the library was compiled with the 3298** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3299** 3300** If two or more threads call one or more of these routines against the same 3301** prepared statement and column at the same time then the results are 3302** undefined. 3303** 3304** If two or more threads call one or more 3305** [sqlite3_column_database_name | column metadata interfaces] 3306** for the same [prepared statement] and result column 3307** at the same time then the results are undefined. 3308*/ 3309const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3310const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3311const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3312const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3313const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3314const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3315 3316/* 3317** CAPI3REF: Declared Datatype Of A Query Result 3318** 3319** ^(The first parameter is a [prepared statement]. 3320** If this statement is a [SELECT] statement and the Nth column of the 3321** returned result set of that [SELECT] is a table column (not an 3322** expression or subquery) then the declared type of the table 3323** column is returned.)^ ^If the Nth column of the result set is an 3324** expression or subquery, then a NULL pointer is returned. 3325** ^The returned string is always UTF-8 encoded. 3326** 3327** ^(For example, given the database schema: 3328** 3329** CREATE TABLE t1(c1 VARIANT); 3330** 3331** and the following statement to be compiled: 3332** 3333** SELECT c1 + 1, c1 FROM t1; 3334** 3335** this routine would return the string "VARIANT" for the second result 3336** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3337** 3338** ^SQLite uses dynamic run-time typing. ^So just because a column 3339** is declared to contain a particular type does not mean that the 3340** data stored in that column is of the declared type. SQLite is 3341** strongly typed, but the typing is dynamic not static. ^Type 3342** is associated with individual values, not with the containers 3343** used to hold those values. 3344*/ 3345const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3346const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3347 3348/* 3349** CAPI3REF: Evaluate An SQL Statement 3350** 3351** After a [prepared statement] has been prepared using either 3352** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3353** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3354** must be called one or more times to evaluate the statement. 3355** 3356** The details of the behavior of the sqlite3_step() interface depend 3357** on whether the statement was prepared using the newer "v2" interface 3358** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3359** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3360** new "v2" interface is recommended for new applications but the legacy 3361** interface will continue to be supported. 3362** 3363** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3364** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3365** ^With the "v2" interface, any of the other [result codes] or 3366** [extended result codes] might be returned as well. 3367** 3368** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3369** database locks it needs to do its job. ^If the statement is a [COMMIT] 3370** or occurs outside of an explicit transaction, then you can retry the 3371** statement. If the statement is not a [COMMIT] and occurs within an 3372** explicit transaction then you should rollback the transaction before 3373** continuing. 3374** 3375** ^[SQLITE_DONE] means that the statement has finished executing 3376** successfully. sqlite3_step() should not be called again on this virtual 3377** machine without first calling [sqlite3_reset()] to reset the virtual 3378** machine back to its initial state. 3379** 3380** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3381** is returned each time a new row of data is ready for processing by the 3382** caller. The values may be accessed using the [column access functions]. 3383** sqlite3_step() is called again to retrieve the next row of data. 3384** 3385** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3386** violation) has occurred. sqlite3_step() should not be called again on 3387** the VM. More information may be found by calling [sqlite3_errmsg()]. 3388** ^With the legacy interface, a more specific error code (for example, 3389** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3390** can be obtained by calling [sqlite3_reset()] on the 3391** [prepared statement]. ^In the "v2" interface, 3392** the more specific error code is returned directly by sqlite3_step(). 3393** 3394** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3395** Perhaps it was called on a [prepared statement] that has 3396** already been [sqlite3_finalize | finalized] or on one that had 3397** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3398** be the case that the same database connection is being used by two or 3399** more threads at the same moment in time. 3400** 3401** For all versions of SQLite up to and including 3.6.23.1, a call to 3402** [sqlite3_reset()] was required after sqlite3_step() returned anything 3403** other than [SQLITE_ROW] before any subsequent invocation of 3404** sqlite3_step(). Failure to reset the prepared statement using 3405** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3406** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3407** calling [sqlite3_reset()] automatically in this circumstance rather 3408** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3409** break because any application that ever receives an SQLITE_MISUSE error 3410** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3411** can be used to restore the legacy behavior. 3412** 3413** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3414** API always returns a generic error code, [SQLITE_ERROR], following any 3415** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3416** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3417** specific [error codes] that better describes the error. 3418** We admit that this is a goofy design. The problem has been fixed 3419** with the "v2" interface. If you prepare all of your SQL statements 3420** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3421** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3422** then the more specific [error codes] are returned directly 3423** by sqlite3_step(). The use of the "v2" interface is recommended. 3424*/ 3425int sqlite3_step(sqlite3_stmt*); 3426 3427/* 3428** CAPI3REF: Number of columns in a result set 3429** 3430** ^The sqlite3_data_count(P) interface returns the number of columns in the 3431** current row of the result set of [prepared statement] P. 3432** ^If prepared statement P does not have results ready to return 3433** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3434** interfaces) then sqlite3_data_count(P) returns 0. 3435** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3436** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3437** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3438** will return non-zero if previous call to [sqlite3_step](P) returned 3439** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3440** where it always returns zero since each step of that multi-step 3441** pragma returns 0 columns of data. 3442** 3443** See also: [sqlite3_column_count()] 3444*/ 3445int sqlite3_data_count(sqlite3_stmt *pStmt); 3446 3447/* 3448** CAPI3REF: Fundamental Datatypes 3449** KEYWORDS: SQLITE_TEXT 3450** 3451** ^(Every value in SQLite has one of five fundamental datatypes: 3452** 3453** <ul> 3454** <li> 64-bit signed integer 3455** <li> 64-bit IEEE floating point number 3456** <li> string 3457** <li> BLOB 3458** <li> NULL 3459** </ul>)^ 3460** 3461** These constants are codes for each of those types. 3462** 3463** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3464** for a completely different meaning. Software that links against both 3465** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3466** SQLITE_TEXT. 3467*/ 3468#define SQLITE_INTEGER 1 3469#define SQLITE_FLOAT 2 3470#define SQLITE_BLOB 4 3471#define SQLITE_NULL 5 3472#ifdef SQLITE_TEXT 3473# undef SQLITE_TEXT 3474#else 3475# define SQLITE_TEXT 3 3476#endif 3477#define SQLITE3_TEXT 3 3478 3479/* 3480** CAPI3REF: Result Values From A Query 3481** KEYWORDS: {column access functions} 3482** 3483** These routines form the "result set" interface. 3484** 3485** ^These routines return information about a single column of the current 3486** result row of a query. ^In every case the first argument is a pointer 3487** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3488** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3489** and the second argument is the index of the column for which information 3490** should be returned. ^The leftmost column of the result set has the index 0. 3491** ^The number of columns in the result can be determined using 3492** [sqlite3_column_count()]. 3493** 3494** If the SQL statement does not currently point to a valid row, or if the 3495** column index is out of range, the result is undefined. 3496** These routines may only be called when the most recent call to 3497** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3498** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3499** If any of these routines are called after [sqlite3_reset()] or 3500** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3501** something other than [SQLITE_ROW], the results are undefined. 3502** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3503** are called from a different thread while any of these routines 3504** are pending, then the results are undefined. 3505** 3506** ^The sqlite3_column_type() routine returns the 3507** [SQLITE_INTEGER | datatype code] for the initial data type 3508** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3509** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3510** returned by sqlite3_column_type() is only meaningful if no type 3511** conversions have occurred as described below. After a type conversion, 3512** the value returned by sqlite3_column_type() is undefined. Future 3513** versions of SQLite may change the behavior of sqlite3_column_type() 3514** following a type conversion. 3515** 3516** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3517** routine returns the number of bytes in that BLOB or string. 3518** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3519** the string to UTF-8 and then returns the number of bytes. 3520** ^If the result is a numeric value then sqlite3_column_bytes() uses 3521** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3522** the number of bytes in that string. 3523** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3524** 3525** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3526** routine returns the number of bytes in that BLOB or string. 3527** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3528** the string to UTF-16 and then returns the number of bytes. 3529** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3530** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3531** the number of bytes in that string. 3532** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3533** 3534** ^The values returned by [sqlite3_column_bytes()] and 3535** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3536** of the string. ^For clarity: the values returned by 3537** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3538** bytes in the string, not the number of characters. 3539** 3540** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3541** even empty strings, are always zero-terminated. ^The return 3542** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3543** 3544** ^The object returned by [sqlite3_column_value()] is an 3545** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3546** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3547** If the [unprotected sqlite3_value] object returned by 3548** [sqlite3_column_value()] is used in any other way, including calls 3549** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3550** or [sqlite3_value_bytes()], then the behavior is undefined. 3551** 3552** These routines attempt to convert the value where appropriate. ^For 3553** example, if the internal representation is FLOAT and a text result 3554** is requested, [sqlite3_snprintf()] is used internally to perform the 3555** conversion automatically. ^(The following table details the conversions 3556** that are applied: 3557** 3558** <blockquote> 3559** <table border="1"> 3560** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3561** 3562** <tr><td> NULL <td> INTEGER <td> Result is 0 3563** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3564** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3565** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3566** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3567** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3568** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3569** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3570** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3571** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3572** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3573** <tr><td> TEXT <td> FLOAT <td> Use atof() 3574** <tr><td> TEXT <td> BLOB <td> No change 3575** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3576** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3577** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3578** </table> 3579** </blockquote>)^ 3580** 3581** The table above makes reference to standard C library functions atoi() 3582** and atof(). SQLite does not really use these functions. It has its 3583** own equivalent internal routines. The atoi() and atof() names are 3584** used in the table for brevity and because they are familiar to most 3585** C programmers. 3586** 3587** Note that when type conversions occur, pointers returned by prior 3588** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3589** sqlite3_column_text16() may be invalidated. 3590** Type conversions and pointer invalidations might occur 3591** in the following cases: 3592** 3593** <ul> 3594** <li> The initial content is a BLOB and sqlite3_column_text() or 3595** sqlite3_column_text16() is called. A zero-terminator might 3596** need to be added to the string.</li> 3597** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3598** sqlite3_column_text16() is called. The content must be converted 3599** to UTF-16.</li> 3600** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3601** sqlite3_column_text() is called. The content must be converted 3602** to UTF-8.</li> 3603** </ul> 3604** 3605** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3606** not invalidate a prior pointer, though of course the content of the buffer 3607** that the prior pointer references will have been modified. Other kinds 3608** of conversion are done in place when it is possible, but sometimes they 3609** are not possible and in those cases prior pointers are invalidated. 3610** 3611** The safest and easiest to remember policy is to invoke these routines 3612** in one of the following ways: 3613** 3614** <ul> 3615** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3616** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3617** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3618** </ul> 3619** 3620** In other words, you should call sqlite3_column_text(), 3621** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3622** into the desired format, then invoke sqlite3_column_bytes() or 3623** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3624** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3625** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3626** with calls to sqlite3_column_bytes(). 3627** 3628** ^The pointers returned are valid until a type conversion occurs as 3629** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3630** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3631** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3632** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3633** [sqlite3_free()]. 3634** 3635** ^(If a memory allocation error occurs during the evaluation of any 3636** of these routines, a default value is returned. The default value 3637** is either the integer 0, the floating point number 0.0, or a NULL 3638** pointer. Subsequent calls to [sqlite3_errcode()] will return 3639** [SQLITE_NOMEM].)^ 3640*/ 3641const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3642int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3643int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3644double sqlite3_column_double(sqlite3_stmt*, int iCol); 3645int sqlite3_column_int(sqlite3_stmt*, int iCol); 3646sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3647const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3648const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3649int sqlite3_column_type(sqlite3_stmt*, int iCol); 3650sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3651 3652/* 3653** CAPI3REF: Destroy A Prepared Statement Object 3654** 3655** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3656** ^If the most recent evaluation of the statement encountered no errors 3657** or if the statement is never been evaluated, then sqlite3_finalize() returns 3658** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3659** sqlite3_finalize(S) returns the appropriate [error code] or 3660** [extended error code]. 3661** 3662** ^The sqlite3_finalize(S) routine can be called at any point during 3663** the life cycle of [prepared statement] S: 3664** before statement S is ever evaluated, after 3665** one or more calls to [sqlite3_reset()], or after any call 3666** to [sqlite3_step()] regardless of whether or not the statement has 3667** completed execution. 3668** 3669** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3670** 3671** The application must finalize every [prepared statement] in order to avoid 3672** resource leaks. It is a grievous error for the application to try to use 3673** a prepared statement after it has been finalized. Any use of a prepared 3674** statement after it has been finalized can result in undefined and 3675** undesirable behavior such as segfaults and heap corruption. 3676*/ 3677int sqlite3_finalize(sqlite3_stmt *pStmt); 3678 3679/* 3680** CAPI3REF: Reset A Prepared Statement Object 3681** 3682** The sqlite3_reset() function is called to reset a [prepared statement] 3683** object back to its initial state, ready to be re-executed. 3684** ^Any SQL statement variables that had values bound to them using 3685** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3686** Use [sqlite3_clear_bindings()] to reset the bindings. 3687** 3688** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3689** back to the beginning of its program. 3690** 3691** ^If the most recent call to [sqlite3_step(S)] for the 3692** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3693** or if [sqlite3_step(S)] has never before been called on S, 3694** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3695** 3696** ^If the most recent call to [sqlite3_step(S)] for the 3697** [prepared statement] S indicated an error, then 3698** [sqlite3_reset(S)] returns an appropriate [error code]. 3699** 3700** ^The [sqlite3_reset(S)] interface does not change the values 3701** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3702*/ 3703int sqlite3_reset(sqlite3_stmt *pStmt); 3704 3705/* 3706** CAPI3REF: Create Or Redefine SQL Functions 3707** KEYWORDS: {function creation routines} 3708** KEYWORDS: {application-defined SQL function} 3709** KEYWORDS: {application-defined SQL functions} 3710** 3711** ^These functions (collectively known as "function creation routines") 3712** are used to add SQL functions or aggregates or to redefine the behavior 3713** of existing SQL functions or aggregates. The only differences between 3714** these routines are the text encoding expected for 3715** the second parameter (the name of the function being created) 3716** and the presence or absence of a destructor callback for 3717** the application data pointer. 3718** 3719** ^The first parameter is the [database connection] to which the SQL 3720** function is to be added. ^If an application uses more than one database 3721** connection then application-defined SQL functions must be added 3722** to each database connection separately. 3723** 3724** ^The second parameter is the name of the SQL function to be created or 3725** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3726** representation, exclusive of the zero-terminator. ^Note that the name 3727** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3728** ^Any attempt to create a function with a longer name 3729** will result in [SQLITE_MISUSE] being returned. 3730** 3731** ^The third parameter (nArg) 3732** is the number of arguments that the SQL function or 3733** aggregate takes. ^If this parameter is -1, then the SQL function or 3734** aggregate may take any number of arguments between 0 and the limit 3735** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3736** parameter is less than -1 or greater than 127 then the behavior is 3737** undefined. 3738** 3739** ^The fourth parameter, eTextRep, specifies what 3740** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3741** its parameters. Every SQL function implementation must be able to work 3742** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3743** more efficient with one encoding than another. ^An application may 3744** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3745** times with the same function but with different values of eTextRep. 3746** ^When multiple implementations of the same function are available, SQLite 3747** will pick the one that involves the least amount of data conversion. 3748** If there is only a single implementation which does not care what text 3749** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3750** 3751** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3752** function can gain access to this pointer using [sqlite3_user_data()].)^ 3753** 3754** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3755** pointers to C-language functions that implement the SQL function or 3756** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3757** callback only; NULL pointers must be passed as the xStep and xFinal 3758** parameters. ^An aggregate SQL function requires an implementation of xStep 3759** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3760** SQL function or aggregate, pass NULL pointers for all three function 3761** callbacks. 3762** 3763** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3764** then it is destructor for the application data pointer. 3765** The destructor is invoked when the function is deleted, either by being 3766** overloaded or when the database connection closes.)^ 3767** ^The destructor is also invoked if the call to 3768** sqlite3_create_function_v2() fails. 3769** ^When the destructor callback of the tenth parameter is invoked, it 3770** is passed a single argument which is a copy of the application data 3771** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3772** 3773** ^It is permitted to register multiple implementations of the same 3774** functions with the same name but with either differing numbers of 3775** arguments or differing preferred text encodings. ^SQLite will use 3776** the implementation that most closely matches the way in which the 3777** SQL function is used. ^A function implementation with a non-negative 3778** nArg parameter is a better match than a function implementation with 3779** a negative nArg. ^A function where the preferred text encoding 3780** matches the database encoding is a better 3781** match than a function where the encoding is different. 3782** ^A function where the encoding difference is between UTF16le and UTF16be 3783** is a closer match than a function where the encoding difference is 3784** between UTF8 and UTF16. 3785** 3786** ^Built-in functions may be overloaded by new application-defined functions. 3787** 3788** ^An application-defined function is permitted to call other 3789** SQLite interfaces. However, such calls must not 3790** close the database connection nor finalize or reset the prepared 3791** statement in which the function is running. 3792*/ 3793int sqlite3_create_function( 3794 sqlite3 *db, 3795 const char *zFunctionName, 3796 int nArg, 3797 int eTextRep, 3798 void *pApp, 3799 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3800 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3801 void (*xFinal)(sqlite3_context*) 3802); 3803int sqlite3_create_function16( 3804 sqlite3 *db, 3805 const void *zFunctionName, 3806 int nArg, 3807 int eTextRep, 3808 void *pApp, 3809 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3810 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3811 void (*xFinal)(sqlite3_context*) 3812); 3813int sqlite3_create_function_v2( 3814 sqlite3 *db, 3815 const char *zFunctionName, 3816 int nArg, 3817 int eTextRep, 3818 void *pApp, 3819 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3820 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3821 void (*xFinal)(sqlite3_context*), 3822 void(*xDestroy)(void*) 3823); 3824 3825/* 3826** CAPI3REF: Text Encodings 3827** 3828** These constant define integer codes that represent the various 3829** text encodings supported by SQLite. 3830*/ 3831#define SQLITE_UTF8 1 3832#define SQLITE_UTF16LE 2 3833#define SQLITE_UTF16BE 3 3834#define SQLITE_UTF16 4 /* Use native byte order */ 3835#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3836#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3837 3838/* 3839** CAPI3REF: Deprecated Functions 3840** DEPRECATED 3841** 3842** These functions are [deprecated]. In order to maintain 3843** backwards compatibility with older code, these functions continue 3844** to be supported. However, new applications should avoid 3845** the use of these functions. To help encourage people to avoid 3846** using these functions, we are not going to tell you what they do. 3847*/ 3848#ifndef SQLITE_OMIT_DEPRECATED 3849SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3850SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3851SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3852SQLITE_DEPRECATED int sqlite3_global_recover(void); 3853SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3854SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3855#endif 3856 3857/* 3858** CAPI3REF: Obtaining SQL Function Parameter Values 3859** 3860** The C-language implementation of SQL functions and aggregates uses 3861** this set of interface routines to access the parameter values on 3862** the function or aggregate. 3863** 3864** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3865** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3866** define callbacks that implement the SQL functions and aggregates. 3867** The 3rd parameter to these callbacks is an array of pointers to 3868** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3869** each parameter to the SQL function. These routines are used to 3870** extract values from the [sqlite3_value] objects. 3871** 3872** These routines work only with [protected sqlite3_value] objects. 3873** Any attempt to use these routines on an [unprotected sqlite3_value] 3874** object results in undefined behavior. 3875** 3876** ^These routines work just like the corresponding [column access functions] 3877** except that these routines take a single [protected sqlite3_value] object 3878** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3879** 3880** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3881** in the native byte-order of the host machine. ^The 3882** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3883** extract UTF-16 strings as big-endian and little-endian respectively. 3884** 3885** ^(The sqlite3_value_numeric_type() interface attempts to apply 3886** numeric affinity to the value. This means that an attempt is 3887** made to convert the value to an integer or floating point. If 3888** such a conversion is possible without loss of information (in other 3889** words, if the value is a string that looks like a number) 3890** then the conversion is performed. Otherwise no conversion occurs. 3891** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3892** 3893** Please pay particular attention to the fact that the pointer returned 3894** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3895** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3896** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3897** or [sqlite3_value_text16()]. 3898** 3899** These routines must be called from the same thread as 3900** the SQL function that supplied the [sqlite3_value*] parameters. 3901*/ 3902const void *sqlite3_value_blob(sqlite3_value*); 3903int sqlite3_value_bytes(sqlite3_value*); 3904int sqlite3_value_bytes16(sqlite3_value*); 3905double sqlite3_value_double(sqlite3_value*); 3906int sqlite3_value_int(sqlite3_value*); 3907sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3908const unsigned char *sqlite3_value_text(sqlite3_value*); 3909const void *sqlite3_value_text16(sqlite3_value*); 3910const void *sqlite3_value_text16le(sqlite3_value*); 3911const void *sqlite3_value_text16be(sqlite3_value*); 3912int sqlite3_value_type(sqlite3_value*); 3913int sqlite3_value_numeric_type(sqlite3_value*); 3914 3915/* 3916** CAPI3REF: Obtain Aggregate Function Context 3917** 3918** Implementations of aggregate SQL functions use this 3919** routine to allocate memory for storing their state. 3920** 3921** ^The first time the sqlite3_aggregate_context(C,N) routine is called 3922** for a particular aggregate function, SQLite 3923** allocates N of memory, zeroes out that memory, and returns a pointer 3924** to the new memory. ^On second and subsequent calls to 3925** sqlite3_aggregate_context() for the same aggregate function instance, 3926** the same buffer is returned. Sqlite3_aggregate_context() is normally 3927** called once for each invocation of the xStep callback and then one 3928** last time when the xFinal callback is invoked. ^(When no rows match 3929** an aggregate query, the xStep() callback of the aggregate function 3930** implementation is never called and xFinal() is called exactly once. 3931** In those cases, sqlite3_aggregate_context() might be called for the 3932** first time from within xFinal().)^ 3933** 3934** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 3935** less than or equal to zero or if a memory allocate error occurs. 3936** 3937** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 3938** determined by the N parameter on first successful call. Changing the 3939** value of N in subsequent call to sqlite3_aggregate_context() within 3940** the same aggregate function instance will not resize the memory 3941** allocation.)^ 3942** 3943** ^SQLite automatically frees the memory allocated by 3944** sqlite3_aggregate_context() when the aggregate query concludes. 3945** 3946** The first parameter must be a copy of the 3947** [sqlite3_context | SQL function context] that is the first parameter 3948** to the xStep or xFinal callback routine that implements the aggregate 3949** function. 3950** 3951** This routine must be called from the same thread in which 3952** the aggregate SQL function is running. 3953*/ 3954void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3955 3956/* 3957** CAPI3REF: User Data For Functions 3958** 3959** ^The sqlite3_user_data() interface returns a copy of 3960** the pointer that was the pUserData parameter (the 5th parameter) 3961** of the [sqlite3_create_function()] 3962** and [sqlite3_create_function16()] routines that originally 3963** registered the application defined function. 3964** 3965** This routine must be called from the same thread in which 3966** the application-defined function is running. 3967*/ 3968void *sqlite3_user_data(sqlite3_context*); 3969 3970/* 3971** CAPI3REF: Database Connection For Functions 3972** 3973** ^The sqlite3_context_db_handle() interface returns a copy of 3974** the pointer to the [database connection] (the 1st parameter) 3975** of the [sqlite3_create_function()] 3976** and [sqlite3_create_function16()] routines that originally 3977** registered the application defined function. 3978*/ 3979sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3980 3981/* 3982** CAPI3REF: Function Auxiliary Data 3983** 3984** The following two functions may be used by scalar SQL functions to 3985** associate metadata with argument values. If the same value is passed to 3986** multiple invocations of the same SQL function during query execution, under 3987** some circumstances the associated metadata may be preserved. This may 3988** be used, for example, to add a regular-expression matching scalar 3989** function. The compiled version of the regular expression is stored as 3990** metadata associated with the SQL value passed as the regular expression 3991** pattern. The compiled regular expression can be reused on multiple 3992** invocations of the same function so that the original pattern string 3993** does not need to be recompiled on each invocation. 3994** 3995** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 3996** associated by the sqlite3_set_auxdata() function with the Nth argument 3997** value to the application-defined function. ^If no metadata has been ever 3998** been set for the Nth argument of the function, or if the corresponding 3999** function parameter has changed since the meta-data was set, 4000** then sqlite3_get_auxdata() returns a NULL pointer. 4001** 4002** ^The sqlite3_set_auxdata() interface saves the metadata 4003** pointed to by its 3rd parameter as the metadata for the N-th 4004** argument of the application-defined function. Subsequent 4005** calls to sqlite3_get_auxdata() might return this data, if it has 4006** not been destroyed. 4007** ^If it is not NULL, SQLite will invoke the destructor 4008** function given by the 4th parameter to sqlite3_set_auxdata() on 4009** the metadata when the corresponding function parameter changes 4010** or when the SQL statement completes, whichever comes first. 4011** 4012** SQLite is free to call the destructor and drop metadata on any 4013** parameter of any function at any time. ^The only guarantee is that 4014** the destructor will be called before the metadata is dropped. 4015** 4016** ^(In practice, metadata is preserved between function calls for 4017** expressions that are constant at compile time. This includes literal 4018** values and [parameters].)^ 4019** 4020** These routines must be called from the same thread in which 4021** the SQL function is running. 4022*/ 4023void *sqlite3_get_auxdata(sqlite3_context*, int N); 4024void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4025 4026 4027/* 4028** CAPI3REF: Constants Defining Special Destructor Behavior 4029** 4030** These are special values for the destructor that is passed in as the 4031** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4032** argument is SQLITE_STATIC, it means that the content pointer is constant 4033** and will never change. It does not need to be destroyed. ^The 4034** SQLITE_TRANSIENT value means that the content will likely change in 4035** the near future and that SQLite should make its own private copy of 4036** the content before returning. 4037** 4038** The typedef is necessary to work around problems in certain 4039** C++ compilers. See ticket #2191. 4040*/ 4041typedef void (*sqlite3_destructor_type)(void*); 4042#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4043#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4044 4045/* 4046** CAPI3REF: Setting The Result Of An SQL Function 4047** 4048** These routines are used by the xFunc or xFinal callbacks that 4049** implement SQL functions and aggregates. See 4050** [sqlite3_create_function()] and [sqlite3_create_function16()] 4051** for additional information. 4052** 4053** These functions work very much like the [parameter binding] family of 4054** functions used to bind values to host parameters in prepared statements. 4055** Refer to the [SQL parameter] documentation for additional information. 4056** 4057** ^The sqlite3_result_blob() interface sets the result from 4058** an application-defined function to be the BLOB whose content is pointed 4059** to by the second parameter and which is N bytes long where N is the 4060** third parameter. 4061** 4062** ^The sqlite3_result_zeroblob() interfaces set the result of 4063** the application-defined function to be a BLOB containing all zero 4064** bytes and N bytes in size, where N is the value of the 2nd parameter. 4065** 4066** ^The sqlite3_result_double() interface sets the result from 4067** an application-defined function to be a floating point value specified 4068** by its 2nd argument. 4069** 4070** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4071** cause the implemented SQL function to throw an exception. 4072** ^SQLite uses the string pointed to by the 4073** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4074** as the text of an error message. ^SQLite interprets the error 4075** message string from sqlite3_result_error() as UTF-8. ^SQLite 4076** interprets the string from sqlite3_result_error16() as UTF-16 in native 4077** byte order. ^If the third parameter to sqlite3_result_error() 4078** or sqlite3_result_error16() is negative then SQLite takes as the error 4079** message all text up through the first zero character. 4080** ^If the third parameter to sqlite3_result_error() or 4081** sqlite3_result_error16() is non-negative then SQLite takes that many 4082** bytes (not characters) from the 2nd parameter as the error message. 4083** ^The sqlite3_result_error() and sqlite3_result_error16() 4084** routines make a private copy of the error message text before 4085** they return. Hence, the calling function can deallocate or 4086** modify the text after they return without harm. 4087** ^The sqlite3_result_error_code() function changes the error code 4088** returned by SQLite as a result of an error in a function. ^By default, 4089** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4090** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4091** 4092** ^The sqlite3_result_toobig() interface causes SQLite to throw an error 4093** indicating that a string or BLOB is too long to represent. 4094** 4095** ^The sqlite3_result_nomem() interface causes SQLite to throw an error 4096** indicating that a memory allocation failed. 4097** 4098** ^The sqlite3_result_int() interface sets the return value 4099** of the application-defined function to be the 32-bit signed integer 4100** value given in the 2nd argument. 4101** ^The sqlite3_result_int64() interface sets the return value 4102** of the application-defined function to be the 64-bit signed integer 4103** value given in the 2nd argument. 4104** 4105** ^The sqlite3_result_null() interface sets the return value 4106** of the application-defined function to be NULL. 4107** 4108** ^The sqlite3_result_text(), sqlite3_result_text16(), 4109** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4110** set the return value of the application-defined function to be 4111** a text string which is represented as UTF-8, UTF-16 native byte order, 4112** UTF-16 little endian, or UTF-16 big endian, respectively. 4113** ^SQLite takes the text result from the application from 4114** the 2nd parameter of the sqlite3_result_text* interfaces. 4115** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4116** is negative, then SQLite takes result text from the 2nd parameter 4117** through the first zero character. 4118** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4119** is non-negative, then as many bytes (not characters) of the text 4120** pointed to by the 2nd parameter are taken as the application-defined 4121** function result. If the 3rd parameter is non-negative, then it 4122** must be the byte offset into the string where the NUL terminator would 4123** appear if the string where NUL terminated. If any NUL characters occur 4124** in the string at a byte offset that is less than the value of the 3rd 4125** parameter, then the resulting string will contain embedded NULs and the 4126** result of expressions operating on strings with embedded NULs is undefined. 4127** ^If the 4th parameter to the sqlite3_result_text* interfaces 4128** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4129** function as the destructor on the text or BLOB result when it has 4130** finished using that result. 4131** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4132** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4133** assumes that the text or BLOB result is in constant space and does not 4134** copy the content of the parameter nor call a destructor on the content 4135** when it has finished using that result. 4136** ^If the 4th parameter to the sqlite3_result_text* interfaces 4137** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4138** then SQLite makes a copy of the result into space obtained from 4139** from [sqlite3_malloc()] before it returns. 4140** 4141** ^The sqlite3_result_value() interface sets the result of 4142** the application-defined function to be a copy the 4143** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4144** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4145** so that the [sqlite3_value] specified in the parameter may change or 4146** be deallocated after sqlite3_result_value() returns without harm. 4147** ^A [protected sqlite3_value] object may always be used where an 4148** [unprotected sqlite3_value] object is required, so either 4149** kind of [sqlite3_value] object can be used with this interface. 4150** 4151** If these routines are called from within the different thread 4152** than the one containing the application-defined function that received 4153** the [sqlite3_context] pointer, the results are undefined. 4154*/ 4155void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4156void sqlite3_result_double(sqlite3_context*, double); 4157void sqlite3_result_error(sqlite3_context*, const char*, int); 4158void sqlite3_result_error16(sqlite3_context*, const void*, int); 4159void sqlite3_result_error_toobig(sqlite3_context*); 4160void sqlite3_result_error_nomem(sqlite3_context*); 4161void sqlite3_result_error_code(sqlite3_context*, int); 4162void sqlite3_result_int(sqlite3_context*, int); 4163void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4164void sqlite3_result_null(sqlite3_context*); 4165void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4166void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4167void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4168void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4169void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4170void sqlite3_result_zeroblob(sqlite3_context*, int n); 4171 4172/* 4173** CAPI3REF: Define New Collating Sequences 4174** 4175** ^These functions add, remove, or modify a [collation] associated 4176** with the [database connection] specified as the first argument. 4177** 4178** ^The name of the collation is a UTF-8 string 4179** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4180** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4181** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4182** considered to be the same name. 4183** 4184** ^(The third argument (eTextRep) must be one of the constants: 4185** <ul> 4186** <li> [SQLITE_UTF8], 4187** <li> [SQLITE_UTF16LE], 4188** <li> [SQLITE_UTF16BE], 4189** <li> [SQLITE_UTF16], or 4190** <li> [SQLITE_UTF16_ALIGNED]. 4191** </ul>)^ 4192** ^The eTextRep argument determines the encoding of strings passed 4193** to the collating function callback, xCallback. 4194** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4195** force strings to be UTF16 with native byte order. 4196** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4197** on an even byte address. 4198** 4199** ^The fourth argument, pArg, is an application data pointer that is passed 4200** through as the first argument to the collating function callback. 4201** 4202** ^The fifth argument, xCallback, is a pointer to the collating function. 4203** ^Multiple collating functions can be registered using the same name but 4204** with different eTextRep parameters and SQLite will use whichever 4205** function requires the least amount of data transformation. 4206** ^If the xCallback argument is NULL then the collating function is 4207** deleted. ^When all collating functions having the same name are deleted, 4208** that collation is no longer usable. 4209** 4210** ^The collating function callback is invoked with a copy of the pArg 4211** application data pointer and with two strings in the encoding specified 4212** by the eTextRep argument. The collating function must return an 4213** integer that is negative, zero, or positive 4214** if the first string is less than, equal to, or greater than the second, 4215** respectively. A collating function must always return the same answer 4216** given the same inputs. If two or more collating functions are registered 4217** to the same collation name (using different eTextRep values) then all 4218** must give an equivalent answer when invoked with equivalent strings. 4219** The collating function must obey the following properties for all 4220** strings A, B, and C: 4221** 4222** <ol> 4223** <li> If A==B then B==A. 4224** <li> If A==B and B==C then A==C. 4225** <li> If A<B THEN B>A. 4226** <li> If A<B and B<C then A<C. 4227** </ol> 4228** 4229** If a collating function fails any of the above constraints and that 4230** collating function is registered and used, then the behavior of SQLite 4231** is undefined. 4232** 4233** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4234** with the addition that the xDestroy callback is invoked on pArg when 4235** the collating function is deleted. 4236** ^Collating functions are deleted when they are overridden by later 4237** calls to the collation creation functions or when the 4238** [database connection] is closed using [sqlite3_close()]. 4239** 4240** ^The xDestroy callback is <u>not</u> called if the 4241** sqlite3_create_collation_v2() function fails. Applications that invoke 4242** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4243** check the return code and dispose of the application data pointer 4244** themselves rather than expecting SQLite to deal with it for them. 4245** This is different from every other SQLite interface. The inconsistency 4246** is unfortunate but cannot be changed without breaking backwards 4247** compatibility. 4248** 4249** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4250*/ 4251int sqlite3_create_collation( 4252 sqlite3*, 4253 const char *zName, 4254 int eTextRep, 4255 void *pArg, 4256 int(*xCompare)(void*,int,const void*,int,const void*) 4257); 4258int sqlite3_create_collation_v2( 4259 sqlite3*, 4260 const char *zName, 4261 int eTextRep, 4262 void *pArg, 4263 int(*xCompare)(void*,int,const void*,int,const void*), 4264 void(*xDestroy)(void*) 4265); 4266int sqlite3_create_collation16( 4267 sqlite3*, 4268 const void *zName, 4269 int eTextRep, 4270 void *pArg, 4271 int(*xCompare)(void*,int,const void*,int,const void*) 4272); 4273 4274/* 4275** CAPI3REF: Collation Needed Callbacks 4276** 4277** ^To avoid having to register all collation sequences before a database 4278** can be used, a single callback function may be registered with the 4279** [database connection] to be invoked whenever an undefined collation 4280** sequence is required. 4281** 4282** ^If the function is registered using the sqlite3_collation_needed() API, 4283** then it is passed the names of undefined collation sequences as strings 4284** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4285** the names are passed as UTF-16 in machine native byte order. 4286** ^A call to either function replaces the existing collation-needed callback. 4287** 4288** ^(When the callback is invoked, the first argument passed is a copy 4289** of the second argument to sqlite3_collation_needed() or 4290** sqlite3_collation_needed16(). The second argument is the database 4291** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4292** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4293** sequence function required. The fourth parameter is the name of the 4294** required collation sequence.)^ 4295** 4296** The callback function should register the desired collation using 4297** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4298** [sqlite3_create_collation_v2()]. 4299*/ 4300int sqlite3_collation_needed( 4301 sqlite3*, 4302 void*, 4303 void(*)(void*,sqlite3*,int eTextRep,const char*) 4304); 4305int sqlite3_collation_needed16( 4306 sqlite3*, 4307 void*, 4308 void(*)(void*,sqlite3*,int eTextRep,const void*) 4309); 4310 4311#ifdef SQLITE_HAS_CODEC 4312/* 4313** Specify the key for an encrypted database. This routine should be 4314** called right after sqlite3_open(). 4315** 4316** The code to implement this API is not available in the public release 4317** of SQLite. 4318*/ 4319int sqlite3_key( 4320 sqlite3 *db, /* Database to be rekeyed */ 4321 const void *pKey, int nKey /* The key */ 4322); 4323 4324/* 4325** Change the key on an open database. If the current database is not 4326** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4327** database is decrypted. 4328** 4329** The code to implement this API is not available in the public release 4330** of SQLite. 4331*/ 4332int sqlite3_rekey( 4333 sqlite3 *db, /* Database to be rekeyed */ 4334 const void *pKey, int nKey /* The new key */ 4335); 4336 4337/* 4338** Specify the activation key for a SEE database. Unless 4339** activated, none of the SEE routines will work. 4340*/ 4341void sqlite3_activate_see( 4342 const char *zPassPhrase /* Activation phrase */ 4343); 4344#endif 4345 4346#ifdef SQLITE_ENABLE_CEROD 4347/* 4348** Specify the activation key for a CEROD database. Unless 4349** activated, none of the CEROD routines will work. 4350*/ 4351void sqlite3_activate_cerod( 4352 const char *zPassPhrase /* Activation phrase */ 4353); 4354#endif 4355 4356/* 4357** CAPI3REF: Suspend Execution For A Short Time 4358** 4359** The sqlite3_sleep() function causes the current thread to suspend execution 4360** for at least a number of milliseconds specified in its parameter. 4361** 4362** If the operating system does not support sleep requests with 4363** millisecond time resolution, then the time will be rounded up to 4364** the nearest second. The number of milliseconds of sleep actually 4365** requested from the operating system is returned. 4366** 4367** ^SQLite implements this interface by calling the xSleep() 4368** method of the default [sqlite3_vfs] object. If the xSleep() method 4369** of the default VFS is not implemented correctly, or not implemented at 4370** all, then the behavior of sqlite3_sleep() may deviate from the description 4371** in the previous paragraphs. 4372*/ 4373int sqlite3_sleep(int); 4374 4375/* 4376** CAPI3REF: Name Of The Folder Holding Temporary Files 4377** 4378** ^(If this global variable is made to point to a string which is 4379** the name of a folder (a.k.a. directory), then all temporary files 4380** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4381** will be placed in that directory.)^ ^If this variable 4382** is a NULL pointer, then SQLite performs a search for an appropriate 4383** temporary file directory. 4384** 4385** It is not safe to read or modify this variable in more than one 4386** thread at a time. It is not safe to read or modify this variable 4387** if a [database connection] is being used at the same time in a separate 4388** thread. 4389** It is intended that this variable be set once 4390** as part of process initialization and before any SQLite interface 4391** routines have been called and that this variable remain unchanged 4392** thereafter. 4393** 4394** ^The [temp_store_directory pragma] may modify this variable and cause 4395** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4396** the [temp_store_directory pragma] always assumes that any string 4397** that this variable points to is held in memory obtained from 4398** [sqlite3_malloc] and the pragma may attempt to free that memory 4399** using [sqlite3_free]. 4400** Hence, if this variable is modified directly, either it should be 4401** made NULL or made to point to memory obtained from [sqlite3_malloc] 4402** or else the use of the [temp_store_directory pragma] should be avoided. 4403*/ 4404SQLITE_EXTERN char *sqlite3_temp_directory; 4405 4406/* 4407** CAPI3REF: Test For Auto-Commit Mode 4408** KEYWORDS: {autocommit mode} 4409** 4410** ^The sqlite3_get_autocommit() interface returns non-zero or 4411** zero if the given database connection is or is not in autocommit mode, 4412** respectively. ^Autocommit mode is on by default. 4413** ^Autocommit mode is disabled by a [BEGIN] statement. 4414** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4415** 4416** If certain kinds of errors occur on a statement within a multi-statement 4417** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4418** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4419** transaction might be rolled back automatically. The only way to 4420** find out whether SQLite automatically rolled back the transaction after 4421** an error is to use this function. 4422** 4423** If another thread changes the autocommit status of the database 4424** connection while this routine is running, then the return value 4425** is undefined. 4426*/ 4427int sqlite3_get_autocommit(sqlite3*); 4428 4429/* 4430** CAPI3REF: Find The Database Handle Of A Prepared Statement 4431** 4432** ^The sqlite3_db_handle interface returns the [database connection] handle 4433** to which a [prepared statement] belongs. ^The [database connection] 4434** returned by sqlite3_db_handle is the same [database connection] 4435** that was the first argument 4436** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4437** create the statement in the first place. 4438*/ 4439sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4440 4441/* 4442** CAPI3REF: Return The Filename For A Database Connection 4443** 4444** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4445** associated with database N of connection D. ^The main database file 4446** has the name "main". If there is no attached database N on the database 4447** connection D, or if database N is a temporary or in-memory database, then 4448** a NULL pointer is returned. 4449** 4450** ^The filename returned by this function is the output of the 4451** xFullPathname method of the [VFS]. ^In other words, the filename 4452** will be an absolute pathname, even if the filename used 4453** to open the database originally was a URI or relative pathname. 4454*/ 4455const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4456 4457/* 4458** CAPI3REF: Find the next prepared statement 4459** 4460** ^This interface returns a pointer to the next [prepared statement] after 4461** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4462** then this interface returns a pointer to the first prepared statement 4463** associated with the database connection pDb. ^If no prepared statement 4464** satisfies the conditions of this routine, it returns NULL. 4465** 4466** The [database connection] pointer D in a call to 4467** [sqlite3_next_stmt(D,S)] must refer to an open database 4468** connection and in particular must not be a NULL pointer. 4469*/ 4470sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4471 4472/* 4473** CAPI3REF: Commit And Rollback Notification Callbacks 4474** 4475** ^The sqlite3_commit_hook() interface registers a callback 4476** function to be invoked whenever a transaction is [COMMIT | committed]. 4477** ^Any callback set by a previous call to sqlite3_commit_hook() 4478** for the same database connection is overridden. 4479** ^The sqlite3_rollback_hook() interface registers a callback 4480** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4481** ^Any callback set by a previous call to sqlite3_rollback_hook() 4482** for the same database connection is overridden. 4483** ^The pArg argument is passed through to the callback. 4484** ^If the callback on a commit hook function returns non-zero, 4485** then the commit is converted into a rollback. 4486** 4487** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4488** return the P argument from the previous call of the same function 4489** on the same [database connection] D, or NULL for 4490** the first call for each function on D. 4491** 4492** The commit and rollback hook callbacks are not reentrant. 4493** The callback implementation must not do anything that will modify 4494** the database connection that invoked the callback. Any actions 4495** to modify the database connection must be deferred until after the 4496** completion of the [sqlite3_step()] call that triggered the commit 4497** or rollback hook in the first place. 4498** Note that running any other SQL statements, including SELECT statements, 4499** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4500** the database connections for the meaning of "modify" in this paragraph. 4501** 4502** ^Registering a NULL function disables the callback. 4503** 4504** ^When the commit hook callback routine returns zero, the [COMMIT] 4505** operation is allowed to continue normally. ^If the commit hook 4506** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4507** ^The rollback hook is invoked on a rollback that results from a commit 4508** hook returning non-zero, just as it would be with any other rollback. 4509** 4510** ^For the purposes of this API, a transaction is said to have been 4511** rolled back if an explicit "ROLLBACK" statement is executed, or 4512** an error or constraint causes an implicit rollback to occur. 4513** ^The rollback callback is not invoked if a transaction is 4514** automatically rolled back because the database connection is closed. 4515** 4516** See also the [sqlite3_update_hook()] interface. 4517*/ 4518void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4519void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4520 4521/* 4522** CAPI3REF: Data Change Notification Callbacks 4523** 4524** ^The sqlite3_update_hook() interface registers a callback function 4525** with the [database connection] identified by the first argument 4526** to be invoked whenever a row is updated, inserted or deleted. 4527** ^Any callback set by a previous call to this function 4528** for the same database connection is overridden. 4529** 4530** ^The second argument is a pointer to the function to invoke when a 4531** row is updated, inserted or deleted. 4532** ^The first argument to the callback is a copy of the third argument 4533** to sqlite3_update_hook(). 4534** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4535** or [SQLITE_UPDATE], depending on the operation that caused the callback 4536** to be invoked. 4537** ^The third and fourth arguments to the callback contain pointers to the 4538** database and table name containing the affected row. 4539** ^The final callback parameter is the [rowid] of the row. 4540** ^In the case of an update, this is the [rowid] after the update takes place. 4541** 4542** ^(The update hook is not invoked when internal system tables are 4543** modified (i.e. sqlite_master and sqlite_sequence).)^ 4544** 4545** ^In the current implementation, the update hook 4546** is not invoked when duplication rows are deleted because of an 4547** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4548** invoked when rows are deleted using the [truncate optimization]. 4549** The exceptions defined in this paragraph might change in a future 4550** release of SQLite. 4551** 4552** The update hook implementation must not do anything that will modify 4553** the database connection that invoked the update hook. Any actions 4554** to modify the database connection must be deferred until after the 4555** completion of the [sqlite3_step()] call that triggered the update hook. 4556** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4557** database connections for the meaning of "modify" in this paragraph. 4558** 4559** ^The sqlite3_update_hook(D,C,P) function 4560** returns the P argument from the previous call 4561** on the same [database connection] D, or NULL for 4562** the first call on D. 4563** 4564** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4565** interfaces. 4566*/ 4567void *sqlite3_update_hook( 4568 sqlite3*, 4569 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4570 void* 4571); 4572 4573/* 4574** CAPI3REF: Enable Or Disable Shared Pager Cache 4575** KEYWORDS: {shared cache} 4576** 4577** ^(This routine enables or disables the sharing of the database cache 4578** and schema data structures between [database connection | connections] 4579** to the same database. Sharing is enabled if the argument is true 4580** and disabled if the argument is false.)^ 4581** 4582** ^Cache sharing is enabled and disabled for an entire process. 4583** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4584** sharing was enabled or disabled for each thread separately. 4585** 4586** ^(The cache sharing mode set by this interface effects all subsequent 4587** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4588** Existing database connections continue use the sharing mode 4589** that was in effect at the time they were opened.)^ 4590** 4591** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4592** successfully. An [error code] is returned otherwise.)^ 4593** 4594** ^Shared cache is disabled by default. But this might change in 4595** future releases of SQLite. Applications that care about shared 4596** cache setting should set it explicitly. 4597** 4598** See Also: [SQLite Shared-Cache Mode] 4599*/ 4600int sqlite3_enable_shared_cache(int); 4601 4602/* 4603** CAPI3REF: Attempt To Free Heap Memory 4604** 4605** ^The sqlite3_release_memory() interface attempts to free N bytes 4606** of heap memory by deallocating non-essential memory allocations 4607** held by the database library. Memory used to cache database 4608** pages to improve performance is an example of non-essential memory. 4609** ^sqlite3_release_memory() returns the number of bytes actually freed, 4610** which might be more or less than the amount requested. 4611** ^The sqlite3_release_memory() routine is a no-op returning zero 4612** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4613** 4614** See also: [sqlite3_db_release_memory()] 4615*/ 4616int sqlite3_release_memory(int); 4617 4618/* 4619** CAPI3REF: Free Memory Used By A Database Connection 4620** 4621** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4622** memory as possible from database connection D. Unlike the 4623** [sqlite3_release_memory()] interface, this interface is effect even 4624** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4625** omitted. 4626** 4627** See also: [sqlite3_release_memory()] 4628*/ 4629int sqlite3_db_release_memory(sqlite3*); 4630 4631/* 4632** CAPI3REF: Impose A Limit On Heap Size 4633** 4634** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4635** soft limit on the amount of heap memory that may be allocated by SQLite. 4636** ^SQLite strives to keep heap memory utilization below the soft heap 4637** limit by reducing the number of pages held in the page cache 4638** as heap memory usages approaches the limit. 4639** ^The soft heap limit is "soft" because even though SQLite strives to stay 4640** below the limit, it will exceed the limit rather than generate 4641** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4642** is advisory only. 4643** 4644** ^The return value from sqlite3_soft_heap_limit64() is the size of 4645** the soft heap limit prior to the call, or negative in the case of an 4646** error. ^If the argument N is negative 4647** then no change is made to the soft heap limit. Hence, the current 4648** size of the soft heap limit can be determined by invoking 4649** sqlite3_soft_heap_limit64() with a negative argument. 4650** 4651** ^If the argument N is zero then the soft heap limit is disabled. 4652** 4653** ^(The soft heap limit is not enforced in the current implementation 4654** if one or more of following conditions are true: 4655** 4656** <ul> 4657** <li> The soft heap limit is set to zero. 4658** <li> Memory accounting is disabled using a combination of the 4659** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4660** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4661** <li> An alternative page cache implementation is specified using 4662** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 4663** <li> The page cache allocates from its own memory pool supplied 4664** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4665** from the heap. 4666** </ul>)^ 4667** 4668** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4669** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4670** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4671** the soft heap limit is enforced on every memory allocation. Without 4672** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4673** when memory is allocated by the page cache. Testing suggests that because 4674** the page cache is the predominate memory user in SQLite, most 4675** applications will achieve adequate soft heap limit enforcement without 4676** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4677** 4678** The circumstances under which SQLite will enforce the soft heap limit may 4679** changes in future releases of SQLite. 4680*/ 4681sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4682 4683/* 4684** CAPI3REF: Deprecated Soft Heap Limit Interface 4685** DEPRECATED 4686** 4687** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4688** interface. This routine is provided for historical compatibility 4689** only. All new applications should use the 4690** [sqlite3_soft_heap_limit64()] interface rather than this one. 4691*/ 4692SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4693 4694 4695/* 4696** CAPI3REF: Extract Metadata About A Column Of A Table 4697** 4698** ^This routine returns metadata about a specific column of a specific 4699** database table accessible using the [database connection] handle 4700** passed as the first function argument. 4701** 4702** ^The column is identified by the second, third and fourth parameters to 4703** this function. ^The second parameter is either the name of the database 4704** (i.e. "main", "temp", or an attached database) containing the specified 4705** table or NULL. ^If it is NULL, then all attached databases are searched 4706** for the table using the same algorithm used by the database engine to 4707** resolve unqualified table references. 4708** 4709** ^The third and fourth parameters to this function are the table and column 4710** name of the desired column, respectively. Neither of these parameters 4711** may be NULL. 4712** 4713** ^Metadata is returned by writing to the memory locations passed as the 5th 4714** and subsequent parameters to this function. ^Any of these arguments may be 4715** NULL, in which case the corresponding element of metadata is omitted. 4716** 4717** ^(<blockquote> 4718** <table border="1"> 4719** <tr><th> Parameter <th> Output<br>Type <th> Description 4720** 4721** <tr><td> 5th <td> const char* <td> Data type 4722** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4723** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4724** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4725** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4726** </table> 4727** </blockquote>)^ 4728** 4729** ^The memory pointed to by the character pointers returned for the 4730** declaration type and collation sequence is valid only until the next 4731** call to any SQLite API function. 4732** 4733** ^If the specified table is actually a view, an [error code] is returned. 4734** 4735** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4736** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4737** parameters are set for the explicitly declared column. ^(If there is no 4738** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4739** parameters are set as follows: 4740** 4741** <pre> 4742** data type: "INTEGER" 4743** collation sequence: "BINARY" 4744** not null: 0 4745** primary key: 1 4746** auto increment: 0 4747** </pre>)^ 4748** 4749** ^(This function may load one or more schemas from database files. If an 4750** error occurs during this process, or if the requested table or column 4751** cannot be found, an [error code] is returned and an error message left 4752** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4753** 4754** ^This API is only available if the library was compiled with the 4755** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4756*/ 4757int sqlite3_table_column_metadata( 4758 sqlite3 *db, /* Connection handle */ 4759 const char *zDbName, /* Database name or NULL */ 4760 const char *zTableName, /* Table name */ 4761 const char *zColumnName, /* Column name */ 4762 char const **pzDataType, /* OUTPUT: Declared data type */ 4763 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4764 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4765 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4766 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4767); 4768 4769/* 4770** CAPI3REF: Load An Extension 4771** 4772** ^This interface loads an SQLite extension library from the named file. 4773** 4774** ^The sqlite3_load_extension() interface attempts to load an 4775** SQLite extension library contained in the file zFile. 4776** 4777** ^The entry point is zProc. 4778** ^zProc may be 0, in which case the name of the entry point 4779** defaults to "sqlite3_extension_init". 4780** ^The sqlite3_load_extension() interface returns 4781** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4782** ^If an error occurs and pzErrMsg is not 0, then the 4783** [sqlite3_load_extension()] interface shall attempt to 4784** fill *pzErrMsg with error message text stored in memory 4785** obtained from [sqlite3_malloc()]. The calling function 4786** should free this memory by calling [sqlite3_free()]. 4787** 4788** ^Extension loading must be enabled using 4789** [sqlite3_enable_load_extension()] prior to calling this API, 4790** otherwise an error will be returned. 4791** 4792** See also the [load_extension() SQL function]. 4793*/ 4794int sqlite3_load_extension( 4795 sqlite3 *db, /* Load the extension into this database connection */ 4796 const char *zFile, /* Name of the shared library containing extension */ 4797 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4798 char **pzErrMsg /* Put error message here if not 0 */ 4799); 4800 4801/* 4802** CAPI3REF: Enable Or Disable Extension Loading 4803** 4804** ^So as not to open security holes in older applications that are 4805** unprepared to deal with extension loading, and as a means of disabling 4806** extension loading while evaluating user-entered SQL, the following API 4807** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4808** 4809** ^Extension loading is off by default. See ticket #1863. 4810** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4811** to turn extension loading on and call it with onoff==0 to turn 4812** it back off again. 4813*/ 4814int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4815 4816/* 4817** CAPI3REF: Automatically Load Statically Linked Extensions 4818** 4819** ^This interface causes the xEntryPoint() function to be invoked for 4820** each new [database connection] that is created. The idea here is that 4821** xEntryPoint() is the entry point for a statically linked SQLite extension 4822** that is to be automatically loaded into all new database connections. 4823** 4824** ^(Even though the function prototype shows that xEntryPoint() takes 4825** no arguments and returns void, SQLite invokes xEntryPoint() with three 4826** arguments and expects and integer result as if the signature of the 4827** entry point where as follows: 4828** 4829** <blockquote><pre> 4830** int xEntryPoint( 4831** sqlite3 *db, 4832** const char **pzErrMsg, 4833** const struct sqlite3_api_routines *pThunk 4834** ); 4835** </pre></blockquote>)^ 4836** 4837** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 4838** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 4839** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 4840** is NULL before calling the xEntryPoint(). ^SQLite will invoke 4841** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 4842** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 4843** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 4844** 4845** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 4846** on the list of automatic extensions is a harmless no-op. ^No entry point 4847** will be called more than once for each database connection that is opened. 4848** 4849** See also: [sqlite3_reset_auto_extension()]. 4850*/ 4851int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4852 4853/* 4854** CAPI3REF: Reset Automatic Extension Loading 4855** 4856** ^This interface disables all automatic extensions previously 4857** registered using [sqlite3_auto_extension()]. 4858*/ 4859void sqlite3_reset_auto_extension(void); 4860 4861/* 4862** The interface to the virtual-table mechanism is currently considered 4863** to be experimental. The interface might change in incompatible ways. 4864** If this is a problem for you, do not use the interface at this time. 4865** 4866** When the virtual-table mechanism stabilizes, we will declare the 4867** interface fixed, support it indefinitely, and remove this comment. 4868*/ 4869 4870/* 4871** Structures used by the virtual table interface 4872*/ 4873typedef struct sqlite3_vtab sqlite3_vtab; 4874typedef struct sqlite3_index_info sqlite3_index_info; 4875typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4876typedef struct sqlite3_module sqlite3_module; 4877 4878/* 4879** CAPI3REF: Virtual Table Object 4880** KEYWORDS: sqlite3_module {virtual table module} 4881** 4882** This structure, sometimes called a "virtual table module", 4883** defines the implementation of a [virtual tables]. 4884** This structure consists mostly of methods for the module. 4885** 4886** ^A virtual table module is created by filling in a persistent 4887** instance of this structure and passing a pointer to that instance 4888** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4889** ^The registration remains valid until it is replaced by a different 4890** module or until the [database connection] closes. The content 4891** of this structure must not change while it is registered with 4892** any database connection. 4893*/ 4894struct sqlite3_module { 4895 int iVersion; 4896 int (*xCreate)(sqlite3*, void *pAux, 4897 int argc, const char *const*argv, 4898 sqlite3_vtab **ppVTab, char**); 4899 int (*xConnect)(sqlite3*, void *pAux, 4900 int argc, const char *const*argv, 4901 sqlite3_vtab **ppVTab, char**); 4902 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4903 int (*xDisconnect)(sqlite3_vtab *pVTab); 4904 int (*xDestroy)(sqlite3_vtab *pVTab); 4905 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4906 int (*xClose)(sqlite3_vtab_cursor*); 4907 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4908 int argc, sqlite3_value **argv); 4909 int (*xNext)(sqlite3_vtab_cursor*); 4910 int (*xEof)(sqlite3_vtab_cursor*); 4911 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4912 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4913 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4914 int (*xBegin)(sqlite3_vtab *pVTab); 4915 int (*xSync)(sqlite3_vtab *pVTab); 4916 int (*xCommit)(sqlite3_vtab *pVTab); 4917 int (*xRollback)(sqlite3_vtab *pVTab); 4918 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4919 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4920 void **ppArg); 4921 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4922 /* The methods above are in version 1 of the sqlite_module object. Those 4923 ** below are for version 2 and greater. */ 4924 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 4925 int (*xRelease)(sqlite3_vtab *pVTab, int); 4926 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 4927}; 4928 4929/* 4930** CAPI3REF: Virtual Table Indexing Information 4931** KEYWORDS: sqlite3_index_info 4932** 4933** The sqlite3_index_info structure and its substructures is used as part 4934** of the [virtual table] interface to 4935** pass information into and receive the reply from the [xBestIndex] 4936** method of a [virtual table module]. The fields under **Inputs** are the 4937** inputs to xBestIndex and are read-only. xBestIndex inserts its 4938** results into the **Outputs** fields. 4939** 4940** ^(The aConstraint[] array records WHERE clause constraints of the form: 4941** 4942** <blockquote>column OP expr</blockquote> 4943** 4944** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 4945** stored in aConstraint[].op using one of the 4946** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 4947** ^(The index of the column is stored in 4948** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 4949** expr on the right-hand side can be evaluated (and thus the constraint 4950** is usable) and false if it cannot.)^ 4951** 4952** ^The optimizer automatically inverts terms of the form "expr OP column" 4953** and makes other simplifications to the WHERE clause in an attempt to 4954** get as many WHERE clause terms into the form shown above as possible. 4955** ^The aConstraint[] array only reports WHERE clause terms that are 4956** relevant to the particular virtual table being queried. 4957** 4958** ^Information about the ORDER BY clause is stored in aOrderBy[]. 4959** ^Each term of aOrderBy records a column of the ORDER BY clause. 4960** 4961** The [xBestIndex] method must fill aConstraintUsage[] with information 4962** about what parameters to pass to xFilter. ^If argvIndex>0 then 4963** the right-hand side of the corresponding aConstraint[] is evaluated 4964** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 4965** is true, then the constraint is assumed to be fully handled by the 4966** virtual table and is not checked again by SQLite.)^ 4967** 4968** ^The idxNum and idxPtr values are recorded and passed into the 4969** [xFilter] method. 4970** ^[sqlite3_free()] is used to free idxPtr if and only if 4971** needToFreeIdxPtr is true. 4972** 4973** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4974** the correct order to satisfy the ORDER BY clause so that no separate 4975** sorting step is required. 4976** 4977** ^The estimatedCost value is an estimate of the cost of doing the 4978** particular lookup. A full scan of a table with N entries should have 4979** a cost of N. A binary search of a table of N entries should have a 4980** cost of approximately log(N). 4981*/ 4982struct sqlite3_index_info { 4983 /* Inputs */ 4984 int nConstraint; /* Number of entries in aConstraint */ 4985 struct sqlite3_index_constraint { 4986 int iColumn; /* Column on left-hand side of constraint */ 4987 unsigned char op; /* Constraint operator */ 4988 unsigned char usable; /* True if this constraint is usable */ 4989 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4990 } *aConstraint; /* Table of WHERE clause constraints */ 4991 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4992 struct sqlite3_index_orderby { 4993 int iColumn; /* Column number */ 4994 unsigned char desc; /* True for DESC. False for ASC. */ 4995 } *aOrderBy; /* The ORDER BY clause */ 4996 /* Outputs */ 4997 struct sqlite3_index_constraint_usage { 4998 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4999 unsigned char omit; /* Do not code a test for this constraint */ 5000 } *aConstraintUsage; 5001 int idxNum; /* Number used to identify the index */ 5002 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5003 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5004 int orderByConsumed; /* True if output is already ordered */ 5005 double estimatedCost; /* Estimated cost of using this index */ 5006}; 5007 5008/* 5009** CAPI3REF: Virtual Table Constraint Operator Codes 5010** 5011** These macros defined the allowed values for the 5012** [sqlite3_index_info].aConstraint[].op field. Each value represents 5013** an operator that is part of a constraint term in the wHERE clause of 5014** a query that uses a [virtual table]. 5015*/ 5016#define SQLITE_INDEX_CONSTRAINT_EQ 2 5017#define SQLITE_INDEX_CONSTRAINT_GT 4 5018#define SQLITE_INDEX_CONSTRAINT_LE 8 5019#define SQLITE_INDEX_CONSTRAINT_LT 16 5020#define SQLITE_INDEX_CONSTRAINT_GE 32 5021#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5022 5023/* 5024** CAPI3REF: Register A Virtual Table Implementation 5025** 5026** ^These routines are used to register a new [virtual table module] name. 5027** ^Module names must be registered before 5028** creating a new [virtual table] using the module and before using a 5029** preexisting [virtual table] for the module. 5030** 5031** ^The module name is registered on the [database connection] specified 5032** by the first parameter. ^The name of the module is given by the 5033** second parameter. ^The third parameter is a pointer to 5034** the implementation of the [virtual table module]. ^The fourth 5035** parameter is an arbitrary client data pointer that is passed through 5036** into the [xCreate] and [xConnect] methods of the virtual table module 5037** when a new virtual table is be being created or reinitialized. 5038** 5039** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5040** is a pointer to a destructor for the pClientData. ^SQLite will 5041** invoke the destructor function (if it is not NULL) when SQLite 5042** no longer needs the pClientData pointer. ^The destructor will also 5043** be invoked if the call to sqlite3_create_module_v2() fails. 5044** ^The sqlite3_create_module() 5045** interface is equivalent to sqlite3_create_module_v2() with a NULL 5046** destructor. 5047*/ 5048int sqlite3_create_module( 5049 sqlite3 *db, /* SQLite connection to register module with */ 5050 const char *zName, /* Name of the module */ 5051 const sqlite3_module *p, /* Methods for the module */ 5052 void *pClientData /* Client data for xCreate/xConnect */ 5053); 5054int sqlite3_create_module_v2( 5055 sqlite3 *db, /* SQLite connection to register module with */ 5056 const char *zName, /* Name of the module */ 5057 const sqlite3_module *p, /* Methods for the module */ 5058 void *pClientData, /* Client data for xCreate/xConnect */ 5059 void(*xDestroy)(void*) /* Module destructor function */ 5060); 5061 5062/* 5063** CAPI3REF: Virtual Table Instance Object 5064** KEYWORDS: sqlite3_vtab 5065** 5066** Every [virtual table module] implementation uses a subclass 5067** of this object to describe a particular instance 5068** of the [virtual table]. Each subclass will 5069** be tailored to the specific needs of the module implementation. 5070** The purpose of this superclass is to define certain fields that are 5071** common to all module implementations. 5072** 5073** ^Virtual tables methods can set an error message by assigning a 5074** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5075** take care that any prior string is freed by a call to [sqlite3_free()] 5076** prior to assigning a new string to zErrMsg. ^After the error message 5077** is delivered up to the client application, the string will be automatically 5078** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5079*/ 5080struct sqlite3_vtab { 5081 const sqlite3_module *pModule; /* The module for this virtual table */ 5082 int nRef; /* NO LONGER USED */ 5083 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5084 /* Virtual table implementations will typically add additional fields */ 5085}; 5086 5087/* 5088** CAPI3REF: Virtual Table Cursor Object 5089** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5090** 5091** Every [virtual table module] implementation uses a subclass of the 5092** following structure to describe cursors that point into the 5093** [virtual table] and are used 5094** to loop through the virtual table. Cursors are created using the 5095** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5096** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5097** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5098** of the module. Each module implementation will define 5099** the content of a cursor structure to suit its own needs. 5100** 5101** This superclass exists in order to define fields of the cursor that 5102** are common to all implementations. 5103*/ 5104struct sqlite3_vtab_cursor { 5105 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5106 /* Virtual table implementations will typically add additional fields */ 5107}; 5108 5109/* 5110** CAPI3REF: Declare The Schema Of A Virtual Table 5111** 5112** ^The [xCreate] and [xConnect] methods of a 5113** [virtual table module] call this interface 5114** to declare the format (the names and datatypes of the columns) of 5115** the virtual tables they implement. 5116*/ 5117int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5118 5119/* 5120** CAPI3REF: Overload A Function For A Virtual Table 5121** 5122** ^(Virtual tables can provide alternative implementations of functions 5123** using the [xFindFunction] method of the [virtual table module]. 5124** But global versions of those functions 5125** must exist in order to be overloaded.)^ 5126** 5127** ^(This API makes sure a global version of a function with a particular 5128** name and number of parameters exists. If no such function exists 5129** before this API is called, a new function is created.)^ ^The implementation 5130** of the new function always causes an exception to be thrown. So 5131** the new function is not good for anything by itself. Its only 5132** purpose is to be a placeholder function that can be overloaded 5133** by a [virtual table]. 5134*/ 5135int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5136 5137/* 5138** The interface to the virtual-table mechanism defined above (back up 5139** to a comment remarkably similar to this one) is currently considered 5140** to be experimental. The interface might change in incompatible ways. 5141** If this is a problem for you, do not use the interface at this time. 5142** 5143** When the virtual-table mechanism stabilizes, we will declare the 5144** interface fixed, support it indefinitely, and remove this comment. 5145*/ 5146 5147/* 5148** CAPI3REF: A Handle To An Open BLOB 5149** KEYWORDS: {BLOB handle} {BLOB handles} 5150** 5151** An instance of this object represents an open BLOB on which 5152** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5153** ^Objects of this type are created by [sqlite3_blob_open()] 5154** and destroyed by [sqlite3_blob_close()]. 5155** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5156** can be used to read or write small subsections of the BLOB. 5157** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5158*/ 5159typedef struct sqlite3_blob sqlite3_blob; 5160 5161/* 5162** CAPI3REF: Open A BLOB For Incremental I/O 5163** 5164** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5165** in row iRow, column zColumn, table zTable in database zDb; 5166** in other words, the same BLOB that would be selected by: 5167** 5168** <pre> 5169** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5170** </pre>)^ 5171** 5172** ^If the flags parameter is non-zero, then the BLOB is opened for read 5173** and write access. ^If it is zero, the BLOB is opened for read access. 5174** ^It is not possible to open a column that is part of an index or primary 5175** key for writing. ^If [foreign key constraints] are enabled, it is 5176** not possible to open a column that is part of a [child key] for writing. 5177** 5178** ^Note that the database name is not the filename that contains 5179** the database but rather the symbolic name of the database that 5180** appears after the AS keyword when the database is connected using [ATTACH]. 5181** ^For the main database file, the database name is "main". 5182** ^For TEMP tables, the database name is "temp". 5183** 5184** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5185** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5186** to be a null pointer.)^ 5187** ^This function sets the [database connection] error code and message 5188** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5189** functions. ^Note that the *ppBlob variable is always initialized in a 5190** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5191** regardless of the success or failure of this routine. 5192** 5193** ^(If the row that a BLOB handle points to is modified by an 5194** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5195** then the BLOB handle is marked as "expired". 5196** This is true if any column of the row is changed, even a column 5197** other than the one the BLOB handle is open on.)^ 5198** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5199** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5200** ^(Changes written into a BLOB prior to the BLOB expiring are not 5201** rolled back by the expiration of the BLOB. Such changes will eventually 5202** commit if the transaction continues to completion.)^ 5203** 5204** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5205** the opened blob. ^The size of a blob may not be changed by this 5206** interface. Use the [UPDATE] SQL command to change the size of a 5207** blob. 5208** 5209** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5210** and the built-in [zeroblob] SQL function can be used, if desired, 5211** to create an empty, zero-filled blob in which to read or write using 5212** this interface. 5213** 5214** To avoid a resource leak, every open [BLOB handle] should eventually 5215** be released by a call to [sqlite3_blob_close()]. 5216*/ 5217int sqlite3_blob_open( 5218 sqlite3*, 5219 const char *zDb, 5220 const char *zTable, 5221 const char *zColumn, 5222 sqlite3_int64 iRow, 5223 int flags, 5224 sqlite3_blob **ppBlob 5225); 5226 5227/* 5228** CAPI3REF: Move a BLOB Handle to a New Row 5229** 5230** ^This function is used to move an existing blob handle so that it points 5231** to a different row of the same database table. ^The new row is identified 5232** by the rowid value passed as the second argument. Only the row can be 5233** changed. ^The database, table and column on which the blob handle is open 5234** remain the same. Moving an existing blob handle to a new row can be 5235** faster than closing the existing handle and opening a new one. 5236** 5237** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5238** it must exist and there must be either a blob or text value stored in 5239** the nominated column.)^ ^If the new row is not present in the table, or if 5240** it does not contain a blob or text value, or if another error occurs, an 5241** SQLite error code is returned and the blob handle is considered aborted. 5242** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5243** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5244** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5245** always returns zero. 5246** 5247** ^This function sets the database handle error code and message. 5248*/ 5249SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5250 5251/* 5252** CAPI3REF: Close A BLOB Handle 5253** 5254** ^Closes an open [BLOB handle]. 5255** 5256** ^Closing a BLOB shall cause the current transaction to commit 5257** if there are no other BLOBs, no pending prepared statements, and the 5258** database connection is in [autocommit mode]. 5259** ^If any writes were made to the BLOB, they might be held in cache 5260** until the close operation if they will fit. 5261** 5262** ^(Closing the BLOB often forces the changes 5263** out to disk and so if any I/O errors occur, they will likely occur 5264** at the time when the BLOB is closed. Any errors that occur during 5265** closing are reported as a non-zero return value.)^ 5266** 5267** ^(The BLOB is closed unconditionally. Even if this routine returns 5268** an error code, the BLOB is still closed.)^ 5269** 5270** ^Calling this routine with a null pointer (such as would be returned 5271** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5272*/ 5273int sqlite3_blob_close(sqlite3_blob *); 5274 5275/* 5276** CAPI3REF: Return The Size Of An Open BLOB 5277** 5278** ^Returns the size in bytes of the BLOB accessible via the 5279** successfully opened [BLOB handle] in its only argument. ^The 5280** incremental blob I/O routines can only read or overwriting existing 5281** blob content; they cannot change the size of a blob. 5282** 5283** This routine only works on a [BLOB handle] which has been created 5284** by a prior successful call to [sqlite3_blob_open()] and which has not 5285** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5286** to this routine results in undefined and probably undesirable behavior. 5287*/ 5288int sqlite3_blob_bytes(sqlite3_blob *); 5289 5290/* 5291** CAPI3REF: Read Data From A BLOB Incrementally 5292** 5293** ^(This function is used to read data from an open [BLOB handle] into a 5294** caller-supplied buffer. N bytes of data are copied into buffer Z 5295** from the open BLOB, starting at offset iOffset.)^ 5296** 5297** ^If offset iOffset is less than N bytes from the end of the BLOB, 5298** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5299** less than zero, [SQLITE_ERROR] is returned and no data is read. 5300** ^The size of the blob (and hence the maximum value of N+iOffset) 5301** can be determined using the [sqlite3_blob_bytes()] interface. 5302** 5303** ^An attempt to read from an expired [BLOB handle] fails with an 5304** error code of [SQLITE_ABORT]. 5305** 5306** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5307** Otherwise, an [error code] or an [extended error code] is returned.)^ 5308** 5309** This routine only works on a [BLOB handle] which has been created 5310** by a prior successful call to [sqlite3_blob_open()] and which has not 5311** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5312** to this routine results in undefined and probably undesirable behavior. 5313** 5314** See also: [sqlite3_blob_write()]. 5315*/ 5316int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5317 5318/* 5319** CAPI3REF: Write Data Into A BLOB Incrementally 5320** 5321** ^This function is used to write data into an open [BLOB handle] from a 5322** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5323** into the open BLOB, starting at offset iOffset. 5324** 5325** ^If the [BLOB handle] passed as the first argument was not opened for 5326** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5327** this function returns [SQLITE_READONLY]. 5328** 5329** ^This function may only modify the contents of the BLOB; it is 5330** not possible to increase the size of a BLOB using this API. 5331** ^If offset iOffset is less than N bytes from the end of the BLOB, 5332** [SQLITE_ERROR] is returned and no data is written. ^If N is 5333** less than zero [SQLITE_ERROR] is returned and no data is written. 5334** The size of the BLOB (and hence the maximum value of N+iOffset) 5335** can be determined using the [sqlite3_blob_bytes()] interface. 5336** 5337** ^An attempt to write to an expired [BLOB handle] fails with an 5338** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5339** before the [BLOB handle] expired are not rolled back by the 5340** expiration of the handle, though of course those changes might 5341** have been overwritten by the statement that expired the BLOB handle 5342** or by other independent statements. 5343** 5344** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5345** Otherwise, an [error code] or an [extended error code] is returned.)^ 5346** 5347** This routine only works on a [BLOB handle] which has been created 5348** by a prior successful call to [sqlite3_blob_open()] and which has not 5349** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5350** to this routine results in undefined and probably undesirable behavior. 5351** 5352** See also: [sqlite3_blob_read()]. 5353*/ 5354int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5355 5356/* 5357** CAPI3REF: Virtual File System Objects 5358** 5359** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5360** that SQLite uses to interact 5361** with the underlying operating system. Most SQLite builds come with a 5362** single default VFS that is appropriate for the host computer. 5363** New VFSes can be registered and existing VFSes can be unregistered. 5364** The following interfaces are provided. 5365** 5366** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5367** ^Names are case sensitive. 5368** ^Names are zero-terminated UTF-8 strings. 5369** ^If there is no match, a NULL pointer is returned. 5370** ^If zVfsName is NULL then the default VFS is returned. 5371** 5372** ^New VFSes are registered with sqlite3_vfs_register(). 5373** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5374** ^The same VFS can be registered multiple times without injury. 5375** ^To make an existing VFS into the default VFS, register it again 5376** with the makeDflt flag set. If two different VFSes with the 5377** same name are registered, the behavior is undefined. If a 5378** VFS is registered with a name that is NULL or an empty string, 5379** then the behavior is undefined. 5380** 5381** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5382** ^(If the default VFS is unregistered, another VFS is chosen as 5383** the default. The choice for the new VFS is arbitrary.)^ 5384*/ 5385sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5386int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5387int sqlite3_vfs_unregister(sqlite3_vfs*); 5388 5389/* 5390** CAPI3REF: Mutexes 5391** 5392** The SQLite core uses these routines for thread 5393** synchronization. Though they are intended for internal 5394** use by SQLite, code that links against SQLite is 5395** permitted to use any of these routines. 5396** 5397** The SQLite source code contains multiple implementations 5398** of these mutex routines. An appropriate implementation 5399** is selected automatically at compile-time. ^(The following 5400** implementations are available in the SQLite core: 5401** 5402** <ul> 5403** <li> SQLITE_MUTEX_OS2 5404** <li> SQLITE_MUTEX_PTHREADS 5405** <li> SQLITE_MUTEX_W32 5406** <li> SQLITE_MUTEX_NOOP 5407** </ul>)^ 5408** 5409** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5410** that does no real locking and is appropriate for use in 5411** a single-threaded application. ^The SQLITE_MUTEX_OS2, 5412** SQLITE_MUTEX_PTHREADS, and SQLITE_MUTEX_W32 implementations 5413** are appropriate for use on OS/2, Unix, and Windows. 5414** 5415** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5416** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5417** implementation is included with the library. In this case the 5418** application must supply a custom mutex implementation using the 5419** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5420** before calling sqlite3_initialize() or any other public sqlite3_ 5421** function that calls sqlite3_initialize().)^ 5422** 5423** ^The sqlite3_mutex_alloc() routine allocates a new 5424** mutex and returns a pointer to it. ^If it returns NULL 5425** that means that a mutex could not be allocated. ^SQLite 5426** will unwind its stack and return an error. ^(The argument 5427** to sqlite3_mutex_alloc() is one of these integer constants: 5428** 5429** <ul> 5430** <li> SQLITE_MUTEX_FAST 5431** <li> SQLITE_MUTEX_RECURSIVE 5432** <li> SQLITE_MUTEX_STATIC_MASTER 5433** <li> SQLITE_MUTEX_STATIC_MEM 5434** <li> SQLITE_MUTEX_STATIC_MEM2 5435** <li> SQLITE_MUTEX_STATIC_PRNG 5436** <li> SQLITE_MUTEX_STATIC_LRU 5437** <li> SQLITE_MUTEX_STATIC_LRU2 5438** </ul>)^ 5439** 5440** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5441** cause sqlite3_mutex_alloc() to create 5442** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5443** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5444** The mutex implementation does not need to make a distinction 5445** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5446** not want to. ^SQLite will only request a recursive mutex in 5447** cases where it really needs one. ^If a faster non-recursive mutex 5448** implementation is available on the host platform, the mutex subsystem 5449** might return such a mutex in response to SQLITE_MUTEX_FAST. 5450** 5451** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5452** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5453** a pointer to a static preexisting mutex. ^Six static mutexes are 5454** used by the current version of SQLite. Future versions of SQLite 5455** may add additional static mutexes. Static mutexes are for internal 5456** use by SQLite only. Applications that use SQLite mutexes should 5457** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5458** SQLITE_MUTEX_RECURSIVE. 5459** 5460** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5461** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5462** returns a different mutex on every call. ^But for the static 5463** mutex types, the same mutex is returned on every call that has 5464** the same type number. 5465** 5466** ^The sqlite3_mutex_free() routine deallocates a previously 5467** allocated dynamic mutex. ^SQLite is careful to deallocate every 5468** dynamic mutex that it allocates. The dynamic mutexes must not be in 5469** use when they are deallocated. Attempting to deallocate a static 5470** mutex results in undefined behavior. ^SQLite never deallocates 5471** a static mutex. 5472** 5473** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5474** to enter a mutex. ^If another thread is already within the mutex, 5475** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5476** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5477** upon successful entry. ^(Mutexes created using 5478** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5479** In such cases the, 5480** mutex must be exited an equal number of times before another thread 5481** can enter.)^ ^(If the same thread tries to enter any other 5482** kind of mutex more than once, the behavior is undefined. 5483** SQLite will never exhibit 5484** such behavior in its own use of mutexes.)^ 5485** 5486** ^(Some systems (for example, Windows 95) do not support the operation 5487** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5488** will always return SQLITE_BUSY. The SQLite core only ever uses 5489** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5490** 5491** ^The sqlite3_mutex_leave() routine exits a mutex that was 5492** previously entered by the same thread. ^(The behavior 5493** is undefined if the mutex is not currently entered by the 5494** calling thread or is not currently allocated. SQLite will 5495** never do either.)^ 5496** 5497** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5498** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5499** behave as no-ops. 5500** 5501** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5502*/ 5503sqlite3_mutex *sqlite3_mutex_alloc(int); 5504void sqlite3_mutex_free(sqlite3_mutex*); 5505void sqlite3_mutex_enter(sqlite3_mutex*); 5506int sqlite3_mutex_try(sqlite3_mutex*); 5507void sqlite3_mutex_leave(sqlite3_mutex*); 5508 5509/* 5510** CAPI3REF: Mutex Methods Object 5511** 5512** An instance of this structure defines the low-level routines 5513** used to allocate and use mutexes. 5514** 5515** Usually, the default mutex implementations provided by SQLite are 5516** sufficient, however the user has the option of substituting a custom 5517** implementation for specialized deployments or systems for which SQLite 5518** does not provide a suitable implementation. In this case, the user 5519** creates and populates an instance of this structure to pass 5520** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5521** Additionally, an instance of this structure can be used as an 5522** output variable when querying the system for the current mutex 5523** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5524** 5525** ^The xMutexInit method defined by this structure is invoked as 5526** part of system initialization by the sqlite3_initialize() function. 5527** ^The xMutexInit routine is called by SQLite exactly once for each 5528** effective call to [sqlite3_initialize()]. 5529** 5530** ^The xMutexEnd method defined by this structure is invoked as 5531** part of system shutdown by the sqlite3_shutdown() function. The 5532** implementation of this method is expected to release all outstanding 5533** resources obtained by the mutex methods implementation, especially 5534** those obtained by the xMutexInit method. ^The xMutexEnd() 5535** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5536** 5537** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5538** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5539** xMutexNotheld) implement the following interfaces (respectively): 5540** 5541** <ul> 5542** <li> [sqlite3_mutex_alloc()] </li> 5543** <li> [sqlite3_mutex_free()] </li> 5544** <li> [sqlite3_mutex_enter()] </li> 5545** <li> [sqlite3_mutex_try()] </li> 5546** <li> [sqlite3_mutex_leave()] </li> 5547** <li> [sqlite3_mutex_held()] </li> 5548** <li> [sqlite3_mutex_notheld()] </li> 5549** </ul>)^ 5550** 5551** The only difference is that the public sqlite3_XXX functions enumerated 5552** above silently ignore any invocations that pass a NULL pointer instead 5553** of a valid mutex handle. The implementations of the methods defined 5554** by this structure are not required to handle this case, the results 5555** of passing a NULL pointer instead of a valid mutex handle are undefined 5556** (i.e. it is acceptable to provide an implementation that segfaults if 5557** it is passed a NULL pointer). 5558** 5559** The xMutexInit() method must be threadsafe. ^It must be harmless to 5560** invoke xMutexInit() multiple times within the same process and without 5561** intervening calls to xMutexEnd(). Second and subsequent calls to 5562** xMutexInit() must be no-ops. 5563** 5564** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5565** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5566** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5567** memory allocation for a fast or recursive mutex. 5568** 5569** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5570** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5571** If xMutexInit fails in any way, it is expected to clean up after itself 5572** prior to returning. 5573*/ 5574typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5575struct sqlite3_mutex_methods { 5576 int (*xMutexInit)(void); 5577 int (*xMutexEnd)(void); 5578 sqlite3_mutex *(*xMutexAlloc)(int); 5579 void (*xMutexFree)(sqlite3_mutex *); 5580 void (*xMutexEnter)(sqlite3_mutex *); 5581 int (*xMutexTry)(sqlite3_mutex *); 5582 void (*xMutexLeave)(sqlite3_mutex *); 5583 int (*xMutexHeld)(sqlite3_mutex *); 5584 int (*xMutexNotheld)(sqlite3_mutex *); 5585}; 5586 5587/* 5588** CAPI3REF: Mutex Verification Routines 5589** 5590** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5591** are intended for use inside assert() statements. ^The SQLite core 5592** never uses these routines except inside an assert() and applications 5593** are advised to follow the lead of the core. ^The SQLite core only 5594** provides implementations for these routines when it is compiled 5595** with the SQLITE_DEBUG flag. ^External mutex implementations 5596** are only required to provide these routines if SQLITE_DEBUG is 5597** defined and if NDEBUG is not defined. 5598** 5599** ^These routines should return true if the mutex in their argument 5600** is held or not held, respectively, by the calling thread. 5601** 5602** ^The implementation is not required to provide versions of these 5603** routines that actually work. If the implementation does not provide working 5604** versions of these routines, it should at least provide stubs that always 5605** return true so that one does not get spurious assertion failures. 5606** 5607** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5608** the routine should return 1. This seems counter-intuitive since 5609** clearly the mutex cannot be held if it does not exist. But 5610** the reason the mutex does not exist is because the build is not 5611** using mutexes. And we do not want the assert() containing the 5612** call to sqlite3_mutex_held() to fail, so a non-zero return is 5613** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5614** interface should also return 1 when given a NULL pointer. 5615*/ 5616#ifndef NDEBUG 5617int sqlite3_mutex_held(sqlite3_mutex*); 5618int sqlite3_mutex_notheld(sqlite3_mutex*); 5619#endif 5620 5621/* 5622** CAPI3REF: Mutex Types 5623** 5624** The [sqlite3_mutex_alloc()] interface takes a single argument 5625** which is one of these integer constants. 5626** 5627** The set of static mutexes may change from one SQLite release to the 5628** next. Applications that override the built-in mutex logic must be 5629** prepared to accommodate additional static mutexes. 5630*/ 5631#define SQLITE_MUTEX_FAST 0 5632#define SQLITE_MUTEX_RECURSIVE 1 5633#define SQLITE_MUTEX_STATIC_MASTER 2 5634#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5635#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5636#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5637#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5638#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5639#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5640#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5641 5642/* 5643** CAPI3REF: Retrieve the mutex for a database connection 5644** 5645** ^This interface returns a pointer the [sqlite3_mutex] object that 5646** serializes access to the [database connection] given in the argument 5647** when the [threading mode] is Serialized. 5648** ^If the [threading mode] is Single-thread or Multi-thread then this 5649** routine returns a NULL pointer. 5650*/ 5651sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5652 5653/* 5654** CAPI3REF: Low-Level Control Of Database Files 5655** 5656** ^The [sqlite3_file_control()] interface makes a direct call to the 5657** xFileControl method for the [sqlite3_io_methods] object associated 5658** with a particular database identified by the second argument. ^The 5659** name of the database is "main" for the main database or "temp" for the 5660** TEMP database, or the name that appears after the AS keyword for 5661** databases that are added using the [ATTACH] SQL command. 5662** ^A NULL pointer can be used in place of "main" to refer to the 5663** main database file. 5664** ^The third and fourth parameters to this routine 5665** are passed directly through to the second and third parameters of 5666** the xFileControl method. ^The return value of the xFileControl 5667** method becomes the return value of this routine. 5668** 5669** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5670** a pointer to the underlying [sqlite3_file] object to be written into 5671** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5672** case is a short-circuit path which does not actually invoke the 5673** underlying sqlite3_io_methods.xFileControl method. 5674** 5675** ^If the second parameter (zDbName) does not match the name of any 5676** open database file, then SQLITE_ERROR is returned. ^This error 5677** code is not remembered and will not be recalled by [sqlite3_errcode()] 5678** or [sqlite3_errmsg()]. The underlying xFileControl method might 5679** also return SQLITE_ERROR. There is no way to distinguish between 5680** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5681** xFileControl method. 5682** 5683** See also: [SQLITE_FCNTL_LOCKSTATE] 5684*/ 5685int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5686 5687/* 5688** CAPI3REF: Testing Interface 5689** 5690** ^The sqlite3_test_control() interface is used to read out internal 5691** state of SQLite and to inject faults into SQLite for testing 5692** purposes. ^The first parameter is an operation code that determines 5693** the number, meaning, and operation of all subsequent parameters. 5694** 5695** This interface is not for use by applications. It exists solely 5696** for verifying the correct operation of the SQLite library. Depending 5697** on how the SQLite library is compiled, this interface might not exist. 5698** 5699** The details of the operation codes, their meanings, the parameters 5700** they take, and what they do are all subject to change without notice. 5701** Unlike most of the SQLite API, this function is not guaranteed to 5702** operate consistently from one release to the next. 5703*/ 5704int sqlite3_test_control(int op, ...); 5705 5706/* 5707** CAPI3REF: Testing Interface Operation Codes 5708** 5709** These constants are the valid operation code parameters used 5710** as the first argument to [sqlite3_test_control()]. 5711** 5712** These parameters and their meanings are subject to change 5713** without notice. These values are for testing purposes only. 5714** Applications should not use any of these parameters or the 5715** [sqlite3_test_control()] interface. 5716*/ 5717#define SQLITE_TESTCTRL_FIRST 5 5718#define SQLITE_TESTCTRL_PRNG_SAVE 5 5719#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5720#define SQLITE_TESTCTRL_PRNG_RESET 7 5721#define SQLITE_TESTCTRL_BITVEC_TEST 8 5722#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5723#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5724#define SQLITE_TESTCTRL_PENDING_BYTE 11 5725#define SQLITE_TESTCTRL_ASSERT 12 5726#define SQLITE_TESTCTRL_ALWAYS 13 5727#define SQLITE_TESTCTRL_RESERVE 14 5728#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5729#define SQLITE_TESTCTRL_ISKEYWORD 16 5730#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 5731#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 5732#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 5733#define SQLITE_TESTCTRL_LAST 19 5734 5735/* 5736** CAPI3REF: SQLite Runtime Status 5737** 5738** ^This interface is used to retrieve runtime status information 5739** about the performance of SQLite, and optionally to reset various 5740** highwater marks. ^The first argument is an integer code for 5741** the specific parameter to measure. ^(Recognized integer codes 5742** are of the form [status parameters | SQLITE_STATUS_...].)^ 5743** ^The current value of the parameter is returned into *pCurrent. 5744** ^The highest recorded value is returned in *pHighwater. ^If the 5745** resetFlag is true, then the highest record value is reset after 5746** *pHighwater is written. ^(Some parameters do not record the highest 5747** value. For those parameters 5748** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5749** ^(Other parameters record only the highwater mark and not the current 5750** value. For these latter parameters nothing is written into *pCurrent.)^ 5751** 5752** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5753** non-zero [error code] on failure. 5754** 5755** This routine is threadsafe but is not atomic. This routine can be 5756** called while other threads are running the same or different SQLite 5757** interfaces. However the values returned in *pCurrent and 5758** *pHighwater reflect the status of SQLite at different points in time 5759** and it is possible that another thread might change the parameter 5760** in between the times when *pCurrent and *pHighwater are written. 5761** 5762** See also: [sqlite3_db_status()] 5763*/ 5764int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5765 5766 5767/* 5768** CAPI3REF: Status Parameters 5769** KEYWORDS: {status parameters} 5770** 5771** These integer constants designate various run-time status parameters 5772** that can be returned by [sqlite3_status()]. 5773** 5774** <dl> 5775** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5776** <dd>This parameter is the current amount of memory checked out 5777** using [sqlite3_malloc()], either directly or indirectly. The 5778** figure includes calls made to [sqlite3_malloc()] by the application 5779** and internal memory usage by the SQLite library. Scratch memory 5780** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5781** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5782** this parameter. The amount returned is the sum of the allocation 5783** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5784** 5785** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5786** <dd>This parameter records the largest memory allocation request 5787** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5788** internal equivalents). Only the value returned in the 5789** *pHighwater parameter to [sqlite3_status()] is of interest. 5790** The value written into the *pCurrent parameter is undefined.</dd>)^ 5791** 5792** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5793** <dd>This parameter records the number of separate memory allocations 5794** currently checked out.</dd>)^ 5795** 5796** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5797** <dd>This parameter returns the number of pages used out of the 5798** [pagecache memory allocator] that was configured using 5799** [SQLITE_CONFIG_PAGECACHE]. The 5800** value returned is in pages, not in bytes.</dd>)^ 5801** 5802** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 5803** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5804** <dd>This parameter returns the number of bytes of page cache 5805** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5806** buffer and where forced to overflow to [sqlite3_malloc()]. The 5807** returned value includes allocations that overflowed because they 5808** where too large (they were larger than the "sz" parameter to 5809** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5810** no space was left in the page cache.</dd>)^ 5811** 5812** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5813** <dd>This parameter records the largest memory allocation request 5814** handed to [pagecache memory allocator]. Only the value returned in the 5815** *pHighwater parameter to [sqlite3_status()] is of interest. 5816** The value written into the *pCurrent parameter is undefined.</dd>)^ 5817** 5818** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5819** <dd>This parameter returns the number of allocations used out of the 5820** [scratch memory allocator] configured using 5821** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5822** in bytes. Since a single thread may only have one scratch allocation 5823** outstanding at time, this parameter also reports the number of threads 5824** using scratch memory at the same time.</dd>)^ 5825** 5826** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5827** <dd>This parameter returns the number of bytes of scratch memory 5828** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5829** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5830** returned include overflows because the requested allocation was too 5831** larger (that is, because the requested allocation was larger than the 5832** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5833** slots were available. 5834** </dd>)^ 5835** 5836** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5837** <dd>This parameter records the largest memory allocation request 5838** handed to [scratch memory allocator]. Only the value returned in the 5839** *pHighwater parameter to [sqlite3_status()] is of interest. 5840** The value written into the *pCurrent parameter is undefined.</dd>)^ 5841** 5842** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 5843** <dd>This parameter records the deepest parser stack. It is only 5844** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 5845** </dl> 5846** 5847** New status parameters may be added from time to time. 5848*/ 5849#define SQLITE_STATUS_MEMORY_USED 0 5850#define SQLITE_STATUS_PAGECACHE_USED 1 5851#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5852#define SQLITE_STATUS_SCRATCH_USED 3 5853#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5854#define SQLITE_STATUS_MALLOC_SIZE 5 5855#define SQLITE_STATUS_PARSER_STACK 6 5856#define SQLITE_STATUS_PAGECACHE_SIZE 7 5857#define SQLITE_STATUS_SCRATCH_SIZE 8 5858#define SQLITE_STATUS_MALLOC_COUNT 9 5859 5860/* 5861** CAPI3REF: Database Connection Status 5862** 5863** ^This interface is used to retrieve runtime status information 5864** about a single [database connection]. ^The first argument is the 5865** database connection object to be interrogated. ^The second argument 5866** is an integer constant, taken from the set of 5867** [SQLITE_DBSTATUS options], that 5868** determines the parameter to interrogate. The set of 5869** [SQLITE_DBSTATUS options] is likely 5870** to grow in future releases of SQLite. 5871** 5872** ^The current value of the requested parameter is written into *pCur 5873** and the highest instantaneous value is written into *pHiwtr. ^If 5874** the resetFlg is true, then the highest instantaneous value is 5875** reset back down to the current value. 5876** 5877** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 5878** non-zero [error code] on failure. 5879** 5880** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5881*/ 5882int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5883 5884/* 5885** CAPI3REF: Status Parameters for database connections 5886** KEYWORDS: {SQLITE_DBSTATUS options} 5887** 5888** These constants are the available integer "verbs" that can be passed as 5889** the second argument to the [sqlite3_db_status()] interface. 5890** 5891** New verbs may be added in future releases of SQLite. Existing verbs 5892** might be discontinued. Applications should check the return code from 5893** [sqlite3_db_status()] to make sure that the call worked. 5894** The [sqlite3_db_status()] interface will return a non-zero error code 5895** if a discontinued or unsupported verb is invoked. 5896** 5897** <dl> 5898** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 5899** <dd>This parameter returns the number of lookaside memory slots currently 5900** checked out.</dd>)^ 5901** 5902** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 5903** <dd>This parameter returns the number malloc attempts that were 5904** satisfied using lookaside memory. Only the high-water value is meaningful; 5905** the current value is always zero.)^ 5906** 5907** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 5908** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 5909** <dd>This parameter returns the number malloc attempts that might have 5910** been satisfied using lookaside memory but failed due to the amount of 5911** memory requested being larger than the lookaside slot size. 5912** Only the high-water value is meaningful; 5913** the current value is always zero.)^ 5914** 5915** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 5916** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 5917** <dd>This parameter returns the number malloc attempts that might have 5918** been satisfied using lookaside memory but failed due to all lookaside 5919** memory already being in use. 5920** Only the high-water value is meaningful; 5921** the current value is always zero.)^ 5922** 5923** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 5924** <dd>This parameter returns the approximate number of of bytes of heap 5925** memory used by all pager caches associated with the database connection.)^ 5926** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 5927** 5928** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 5929** <dd>This parameter returns the approximate number of of bytes of heap 5930** memory used to store the schema for all databases associated 5931** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 5932** ^The full amount of memory used by the schemas is reported, even if the 5933** schema memory is shared with other database connections due to 5934** [shared cache mode] being enabled. 5935** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 5936** 5937** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 5938** <dd>This parameter returns the approximate number of of bytes of heap 5939** and lookaside memory used by all prepared statements associated with 5940** the database connection.)^ 5941** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 5942** </dd> 5943** 5944** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 5945** <dd>This parameter returns the number of pager cache hits that have 5946** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 5947** is always 0. 5948** </dd> 5949** 5950** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 5951** <dd>This parameter returns the number of pager cache misses that have 5952** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 5953** is always 0. 5954** </dd> 5955** </dl> 5956*/ 5957#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 5958#define SQLITE_DBSTATUS_CACHE_USED 1 5959#define SQLITE_DBSTATUS_SCHEMA_USED 2 5960#define SQLITE_DBSTATUS_STMT_USED 3 5961#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 5962#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 5963#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 5964#define SQLITE_DBSTATUS_CACHE_HIT 7 5965#define SQLITE_DBSTATUS_CACHE_MISS 8 5966#define SQLITE_DBSTATUS_MAX 8 /* Largest defined DBSTATUS */ 5967 5968 5969/* 5970** CAPI3REF: Prepared Statement Status 5971** 5972** ^(Each prepared statement maintains various 5973** [SQLITE_STMTSTATUS counters] that measure the number 5974** of times it has performed specific operations.)^ These counters can 5975** be used to monitor the performance characteristics of the prepared 5976** statements. For example, if the number of table steps greatly exceeds 5977** the number of table searches or result rows, that would tend to indicate 5978** that the prepared statement is using a full table scan rather than 5979** an index. 5980** 5981** ^(This interface is used to retrieve and reset counter values from 5982** a [prepared statement]. The first argument is the prepared statement 5983** object to be interrogated. The second argument 5984** is an integer code for a specific [SQLITE_STMTSTATUS counter] 5985** to be interrogated.)^ 5986** ^The current value of the requested counter is returned. 5987** ^If the resetFlg is true, then the counter is reset to zero after this 5988** interface call returns. 5989** 5990** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5991*/ 5992int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5993 5994/* 5995** CAPI3REF: Status Parameters for prepared statements 5996** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 5997** 5998** These preprocessor macros define integer codes that name counter 5999** values associated with the [sqlite3_stmt_status()] interface. 6000** The meanings of the various counters are as follows: 6001** 6002** <dl> 6003** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6004** <dd>^This is the number of times that SQLite has stepped forward in 6005** a table as part of a full table scan. Large numbers for this counter 6006** may indicate opportunities for performance improvement through 6007** careful use of indices.</dd> 6008** 6009** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6010** <dd>^This is the number of sort operations that have occurred. 6011** A non-zero value in this counter may indicate an opportunity to 6012** improvement performance through careful use of indices.</dd> 6013** 6014** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6015** <dd>^This is the number of rows inserted into transient indices that 6016** were created automatically in order to help joins run faster. 6017** A non-zero value in this counter may indicate an opportunity to 6018** improvement performance by adding permanent indices that do not 6019** need to be reinitialized each time the statement is run.</dd> 6020** </dl> 6021*/ 6022#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6023#define SQLITE_STMTSTATUS_SORT 2 6024#define SQLITE_STMTSTATUS_AUTOINDEX 3 6025 6026/* 6027** CAPI3REF: Custom Page Cache Object 6028** 6029** The sqlite3_pcache type is opaque. It is implemented by 6030** the pluggable module. The SQLite core has no knowledge of 6031** its size or internal structure and never deals with the 6032** sqlite3_pcache object except by holding and passing pointers 6033** to the object. 6034** 6035** See [sqlite3_pcache_methods2] for additional information. 6036*/ 6037typedef struct sqlite3_pcache sqlite3_pcache; 6038 6039/* 6040** CAPI3REF: Custom Page Cache Object 6041** 6042** The sqlite3_pcache_page object represents a single page in the 6043** page cache. The page cache will allocate instances of this 6044** object. Various methods of the page cache use pointers to instances 6045** of this object as parameters or as their return value. 6046** 6047** See [sqlite3_pcache_methods2] for additional information. 6048*/ 6049typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6050struct sqlite3_pcache_page { 6051 void *pBuf; /* The content of the page */ 6052 void *pExtra; /* Extra information associated with the page */ 6053}; 6054 6055/* 6056** CAPI3REF: Application Defined Page Cache. 6057** KEYWORDS: {page cache} 6058** 6059** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6060** register an alternative page cache implementation by passing in an 6061** instance of the sqlite3_pcache_methods2 structure.)^ 6062** In many applications, most of the heap memory allocated by 6063** SQLite is used for the page cache. 6064** By implementing a 6065** custom page cache using this API, an application can better control 6066** the amount of memory consumed by SQLite, the way in which 6067** that memory is allocated and released, and the policies used to 6068** determine exactly which parts of a database file are cached and for 6069** how long. 6070** 6071** The alternative page cache mechanism is an 6072** extreme measure that is only needed by the most demanding applications. 6073** The built-in page cache is recommended for most uses. 6074** 6075** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6076** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6077** the application may discard the parameter after the call to 6078** [sqlite3_config()] returns.)^ 6079** 6080** [[the xInit() page cache method]] 6081** ^(The xInit() method is called once for each effective 6082** call to [sqlite3_initialize()])^ 6083** (usually only once during the lifetime of the process). ^(The xInit() 6084** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6085** The intent of the xInit() method is to set up global data structures 6086** required by the custom page cache implementation. 6087** ^(If the xInit() method is NULL, then the 6088** built-in default page cache is used instead of the application defined 6089** page cache.)^ 6090** 6091** [[the xShutdown() page cache method]] 6092** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6093** It can be used to clean up 6094** any outstanding resources before process shutdown, if required. 6095** ^The xShutdown() method may be NULL. 6096** 6097** ^SQLite automatically serializes calls to the xInit method, 6098** so the xInit method need not be threadsafe. ^The 6099** xShutdown method is only called from [sqlite3_shutdown()] so it does 6100** not need to be threadsafe either. All other methods must be threadsafe 6101** in multithreaded applications. 6102** 6103** ^SQLite will never invoke xInit() more than once without an intervening 6104** call to xShutdown(). 6105** 6106** [[the xCreate() page cache methods]] 6107** ^SQLite invokes the xCreate() method to construct a new cache instance. 6108** SQLite will typically create one cache instance for each open database file, 6109** though this is not guaranteed. ^The 6110** first parameter, szPage, is the size in bytes of the pages that must 6111** be allocated by the cache. ^szPage will always a power of two. ^The 6112** second parameter szExtra is a number of bytes of extra storage 6113** associated with each page cache entry. ^The szExtra parameter will 6114** a number less than 250. SQLite will use the 6115** extra szExtra bytes on each page to store metadata about the underlying 6116** database page on disk. The value passed into szExtra depends 6117** on the SQLite version, the target platform, and how SQLite was compiled. 6118** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6119** created will be used to cache database pages of a file stored on disk, or 6120** false if it is used for an in-memory database. The cache implementation 6121** does not have to do anything special based with the value of bPurgeable; 6122** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6123** never invoke xUnpin() except to deliberately delete a page. 6124** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6125** false will always have the "discard" flag set to true. 6126** ^Hence, a cache created with bPurgeable false will 6127** never contain any unpinned pages. 6128** 6129** [[the xCachesize() page cache method]] 6130** ^(The xCachesize() method may be called at any time by SQLite to set the 6131** suggested maximum cache-size (number of pages stored by) the cache 6132** instance passed as the first argument. This is the value configured using 6133** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6134** parameter, the implementation is not required to do anything with this 6135** value; it is advisory only. 6136** 6137** [[the xPagecount() page cache methods]] 6138** The xPagecount() method must return the number of pages currently 6139** stored in the cache, both pinned and unpinned. 6140** 6141** [[the xFetch() page cache methods]] 6142** The xFetch() method locates a page in the cache and returns a pointer to 6143** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6144** The pBuf element of the returned sqlite3_pcache_page object will be a 6145** pointer to a buffer of szPage bytes used to store the content of a 6146** single database page. The pExtra element of sqlite3_pcache_page will be 6147** a pointer to the szExtra bytes of extra storage that SQLite has requested 6148** for each entry in the page cache. 6149** 6150** The page to be fetched is determined by the key. ^The minimum key value 6151** is 1. After it has been retrieved using xFetch, the page is considered 6152** to be "pinned". 6153** 6154** If the requested page is already in the page cache, then the page cache 6155** implementation must return a pointer to the page buffer with its content 6156** intact. If the requested page is not already in the cache, then the 6157** cache implementation should use the value of the createFlag 6158** parameter to help it determined what action to take: 6159** 6160** <table border=1 width=85% align=center> 6161** <tr><th> createFlag <th> Behaviour when page is not already in cache 6162** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6163** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6164** Otherwise return NULL. 6165** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6166** NULL if allocating a new page is effectively impossible. 6167** </table> 6168** 6169** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6170** will only use a createFlag of 2 after a prior call with a createFlag of 1 6171** failed.)^ In between the to xFetch() calls, SQLite may 6172** attempt to unpin one or more cache pages by spilling the content of 6173** pinned pages to disk and synching the operating system disk cache. 6174** 6175** [[the xUnpin() page cache method]] 6176** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6177** as its second argument. If the third parameter, discard, is non-zero, 6178** then the page must be evicted from the cache. 6179** ^If the discard parameter is 6180** zero, then the page may be discarded or retained at the discretion of 6181** page cache implementation. ^The page cache implementation 6182** may choose to evict unpinned pages at any time. 6183** 6184** The cache must not perform any reference counting. A single 6185** call to xUnpin() unpins the page regardless of the number of prior calls 6186** to xFetch(). 6187** 6188** [[the xRekey() page cache methods]] 6189** The xRekey() method is used to change the key value associated with the 6190** page passed as the second argument. If the cache 6191** previously contains an entry associated with newKey, it must be 6192** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6193** to be pinned. 6194** 6195** When SQLite calls the xTruncate() method, the cache must discard all 6196** existing cache entries with page numbers (keys) greater than or equal 6197** to the value of the iLimit parameter passed to xTruncate(). If any 6198** of these pages are pinned, they are implicitly unpinned, meaning that 6199** they can be safely discarded. 6200** 6201** [[the xDestroy() page cache method]] 6202** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6203** All resources associated with the specified cache should be freed. ^After 6204** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6205** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6206** functions. 6207** 6208** [[the xShrink() page cache method]] 6209** ^SQLite invokes the xShrink() method when it wants the page cache to 6210** free up as much of heap memory as possible. The page cache implementation 6211** is not obligated to free any memory, but well-behaved implementations should 6212** do their best. 6213*/ 6214typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6215struct sqlite3_pcache_methods2 { 6216 int iVersion; 6217 void *pArg; 6218 int (*xInit)(void*); 6219 void (*xShutdown)(void*); 6220 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6221 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6222 int (*xPagecount)(sqlite3_pcache*); 6223 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6224 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6225 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6226 unsigned oldKey, unsigned newKey); 6227 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6228 void (*xDestroy)(sqlite3_pcache*); 6229 void (*xShrink)(sqlite3_pcache*); 6230}; 6231 6232/* 6233** This is the obsolete pcache_methods object that has now been replaced 6234** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6235** retained in the header file for backwards compatibility only. 6236*/ 6237typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6238struct sqlite3_pcache_methods { 6239 void *pArg; 6240 int (*xInit)(void*); 6241 void (*xShutdown)(void*); 6242 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6243 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6244 int (*xPagecount)(sqlite3_pcache*); 6245 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6246 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6247 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6248 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6249 void (*xDestroy)(sqlite3_pcache*); 6250}; 6251 6252 6253/* 6254** CAPI3REF: Online Backup Object 6255** 6256** The sqlite3_backup object records state information about an ongoing 6257** online backup operation. ^The sqlite3_backup object is created by 6258** a call to [sqlite3_backup_init()] and is destroyed by a call to 6259** [sqlite3_backup_finish()]. 6260** 6261** See Also: [Using the SQLite Online Backup API] 6262*/ 6263typedef struct sqlite3_backup sqlite3_backup; 6264 6265/* 6266** CAPI3REF: Online Backup API. 6267** 6268** The backup API copies the content of one database into another. 6269** It is useful either for creating backups of databases or 6270** for copying in-memory databases to or from persistent files. 6271** 6272** See Also: [Using the SQLite Online Backup API] 6273** 6274** ^SQLite holds a write transaction open on the destination database file 6275** for the duration of the backup operation. 6276** ^The source database is read-locked only while it is being read; 6277** it is not locked continuously for the entire backup operation. 6278** ^Thus, the backup may be performed on a live source database without 6279** preventing other database connections from 6280** reading or writing to the source database while the backup is underway. 6281** 6282** ^(To perform a backup operation: 6283** <ol> 6284** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6285** backup, 6286** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6287** the data between the two databases, and finally 6288** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6289** associated with the backup operation. 6290** </ol>)^ 6291** There should be exactly one call to sqlite3_backup_finish() for each 6292** successful call to sqlite3_backup_init(). 6293** 6294** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6295** 6296** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6297** [database connection] associated with the destination database 6298** and the database name, respectively. 6299** ^The database name is "main" for the main database, "temp" for the 6300** temporary database, or the name specified after the AS keyword in 6301** an [ATTACH] statement for an attached database. 6302** ^The S and M arguments passed to 6303** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6304** and database name of the source database, respectively. 6305** ^The source and destination [database connections] (parameters S and D) 6306** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6307** an error. 6308** 6309** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6310** returned and an error code and error message are stored in the 6311** destination [database connection] D. 6312** ^The error code and message for the failed call to sqlite3_backup_init() 6313** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6314** [sqlite3_errmsg16()] functions. 6315** ^A successful call to sqlite3_backup_init() returns a pointer to an 6316** [sqlite3_backup] object. 6317** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6318** sqlite3_backup_finish() functions to perform the specified backup 6319** operation. 6320** 6321** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6322** 6323** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6324** the source and destination databases specified by [sqlite3_backup] object B. 6325** ^If N is negative, all remaining source pages are copied. 6326** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6327** are still more pages to be copied, then the function returns [SQLITE_OK]. 6328** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6329** from source to destination, then it returns [SQLITE_DONE]. 6330** ^If an error occurs while running sqlite3_backup_step(B,N), 6331** then an [error code] is returned. ^As well as [SQLITE_OK] and 6332** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6333** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6334** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6335** 6336** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6337** <ol> 6338** <li> the destination database was opened read-only, or 6339** <li> the destination database is using write-ahead-log journaling 6340** and the destination and source page sizes differ, or 6341** <li> the destination database is an in-memory database and the 6342** destination and source page sizes differ. 6343** </ol>)^ 6344** 6345** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6346** the [sqlite3_busy_handler | busy-handler function] 6347** is invoked (if one is specified). ^If the 6348** busy-handler returns non-zero before the lock is available, then 6349** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6350** sqlite3_backup_step() can be retried later. ^If the source 6351** [database connection] 6352** is being used to write to the source database when sqlite3_backup_step() 6353** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6354** case the call to sqlite3_backup_step() can be retried later on. ^(If 6355** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6356** [SQLITE_READONLY] is returned, then 6357** there is no point in retrying the call to sqlite3_backup_step(). These 6358** errors are considered fatal.)^ The application must accept 6359** that the backup operation has failed and pass the backup operation handle 6360** to the sqlite3_backup_finish() to release associated resources. 6361** 6362** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6363** on the destination file. ^The exclusive lock is not released until either 6364** sqlite3_backup_finish() is called or the backup operation is complete 6365** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6366** sqlite3_backup_step() obtains a [shared lock] on the source database that 6367** lasts for the duration of the sqlite3_backup_step() call. 6368** ^Because the source database is not locked between calls to 6369** sqlite3_backup_step(), the source database may be modified mid-way 6370** through the backup process. ^If the source database is modified by an 6371** external process or via a database connection other than the one being 6372** used by the backup operation, then the backup will be automatically 6373** restarted by the next call to sqlite3_backup_step(). ^If the source 6374** database is modified by the using the same database connection as is used 6375** by the backup operation, then the backup database is automatically 6376** updated at the same time. 6377** 6378** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6379** 6380** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6381** application wishes to abandon the backup operation, the application 6382** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6383** ^The sqlite3_backup_finish() interfaces releases all 6384** resources associated with the [sqlite3_backup] object. 6385** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6386** active write-transaction on the destination database is rolled back. 6387** The [sqlite3_backup] object is invalid 6388** and may not be used following a call to sqlite3_backup_finish(). 6389** 6390** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6391** sqlite3_backup_step() errors occurred, regardless or whether or not 6392** sqlite3_backup_step() completed. 6393** ^If an out-of-memory condition or IO error occurred during any prior 6394** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6395** sqlite3_backup_finish() returns the corresponding [error code]. 6396** 6397** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6398** is not a permanent error and does not affect the return value of 6399** sqlite3_backup_finish(). 6400** 6401** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6402** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6403** 6404** ^Each call to sqlite3_backup_step() sets two values inside 6405** the [sqlite3_backup] object: the number of pages still to be backed 6406** up and the total number of pages in the source database file. 6407** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6408** retrieve these two values, respectively. 6409** 6410** ^The values returned by these functions are only updated by 6411** sqlite3_backup_step(). ^If the source database is modified during a backup 6412** operation, then the values are not updated to account for any extra 6413** pages that need to be updated or the size of the source database file 6414** changing. 6415** 6416** <b>Concurrent Usage of Database Handles</b> 6417** 6418** ^The source [database connection] may be used by the application for other 6419** purposes while a backup operation is underway or being initialized. 6420** ^If SQLite is compiled and configured to support threadsafe database 6421** connections, then the source database connection may be used concurrently 6422** from within other threads. 6423** 6424** However, the application must guarantee that the destination 6425** [database connection] is not passed to any other API (by any thread) after 6426** sqlite3_backup_init() is called and before the corresponding call to 6427** sqlite3_backup_finish(). SQLite does not currently check to see 6428** if the application incorrectly accesses the destination [database connection] 6429** and so no error code is reported, but the operations may malfunction 6430** nevertheless. Use of the destination database connection while a 6431** backup is in progress might also also cause a mutex deadlock. 6432** 6433** If running in [shared cache mode], the application must 6434** guarantee that the shared cache used by the destination database 6435** is not accessed while the backup is running. In practice this means 6436** that the application must guarantee that the disk file being 6437** backed up to is not accessed by any connection within the process, 6438** not just the specific connection that was passed to sqlite3_backup_init(). 6439** 6440** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6441** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6442** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6443** APIs are not strictly speaking threadsafe. If they are invoked at the 6444** same time as another thread is invoking sqlite3_backup_step() it is 6445** possible that they return invalid values. 6446*/ 6447sqlite3_backup *sqlite3_backup_init( 6448 sqlite3 *pDest, /* Destination database handle */ 6449 const char *zDestName, /* Destination database name */ 6450 sqlite3 *pSource, /* Source database handle */ 6451 const char *zSourceName /* Source database name */ 6452); 6453int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6454int sqlite3_backup_finish(sqlite3_backup *p); 6455int sqlite3_backup_remaining(sqlite3_backup *p); 6456int sqlite3_backup_pagecount(sqlite3_backup *p); 6457 6458/* 6459** CAPI3REF: Unlock Notification 6460** 6461** ^When running in shared-cache mode, a database operation may fail with 6462** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6463** individual tables within the shared-cache cannot be obtained. See 6464** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6465** ^This API may be used to register a callback that SQLite will invoke 6466** when the connection currently holding the required lock relinquishes it. 6467** ^This API is only available if the library was compiled with the 6468** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6469** 6470** See Also: [Using the SQLite Unlock Notification Feature]. 6471** 6472** ^Shared-cache locks are released when a database connection concludes 6473** its current transaction, either by committing it or rolling it back. 6474** 6475** ^When a connection (known as the blocked connection) fails to obtain a 6476** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6477** identity of the database connection (the blocking connection) that 6478** has locked the required resource is stored internally. ^After an 6479** application receives an SQLITE_LOCKED error, it may call the 6480** sqlite3_unlock_notify() method with the blocked connection handle as 6481** the first argument to register for a callback that will be invoked 6482** when the blocking connections current transaction is concluded. ^The 6483** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6484** call that concludes the blocking connections transaction. 6485** 6486** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6487** there is a chance that the blocking connection will have already 6488** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6489** If this happens, then the specified callback is invoked immediately, 6490** from within the call to sqlite3_unlock_notify().)^ 6491** 6492** ^If the blocked connection is attempting to obtain a write-lock on a 6493** shared-cache table, and more than one other connection currently holds 6494** a read-lock on the same table, then SQLite arbitrarily selects one of 6495** the other connections to use as the blocking connection. 6496** 6497** ^(There may be at most one unlock-notify callback registered by a 6498** blocked connection. If sqlite3_unlock_notify() is called when the 6499** blocked connection already has a registered unlock-notify callback, 6500** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6501** called with a NULL pointer as its second argument, then any existing 6502** unlock-notify callback is canceled. ^The blocked connections 6503** unlock-notify callback may also be canceled by closing the blocked 6504** connection using [sqlite3_close()]. 6505** 6506** The unlock-notify callback is not reentrant. If an application invokes 6507** any sqlite3_xxx API functions from within an unlock-notify callback, a 6508** crash or deadlock may be the result. 6509** 6510** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6511** returns SQLITE_OK. 6512** 6513** <b>Callback Invocation Details</b> 6514** 6515** When an unlock-notify callback is registered, the application provides a 6516** single void* pointer that is passed to the callback when it is invoked. 6517** However, the signature of the callback function allows SQLite to pass 6518** it an array of void* context pointers. The first argument passed to 6519** an unlock-notify callback is a pointer to an array of void* pointers, 6520** and the second is the number of entries in the array. 6521** 6522** When a blocking connections transaction is concluded, there may be 6523** more than one blocked connection that has registered for an unlock-notify 6524** callback. ^If two or more such blocked connections have specified the 6525** same callback function, then instead of invoking the callback function 6526** multiple times, it is invoked once with the set of void* context pointers 6527** specified by the blocked connections bundled together into an array. 6528** This gives the application an opportunity to prioritize any actions 6529** related to the set of unblocked database connections. 6530** 6531** <b>Deadlock Detection</b> 6532** 6533** Assuming that after registering for an unlock-notify callback a 6534** database waits for the callback to be issued before taking any further 6535** action (a reasonable assumption), then using this API may cause the 6536** application to deadlock. For example, if connection X is waiting for 6537** connection Y's transaction to be concluded, and similarly connection 6538** Y is waiting on connection X's transaction, then neither connection 6539** will proceed and the system may remain deadlocked indefinitely. 6540** 6541** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6542** detection. ^If a given call to sqlite3_unlock_notify() would put the 6543** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6544** unlock-notify callback is registered. The system is said to be in 6545** a deadlocked state if connection A has registered for an unlock-notify 6546** callback on the conclusion of connection B's transaction, and connection 6547** B has itself registered for an unlock-notify callback when connection 6548** A's transaction is concluded. ^Indirect deadlock is also detected, so 6549** the system is also considered to be deadlocked if connection B has 6550** registered for an unlock-notify callback on the conclusion of connection 6551** C's transaction, where connection C is waiting on connection A. ^Any 6552** number of levels of indirection are allowed. 6553** 6554** <b>The "DROP TABLE" Exception</b> 6555** 6556** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6557** always appropriate to call sqlite3_unlock_notify(). There is however, 6558** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6559** SQLite checks if there are any currently executing SELECT statements 6560** that belong to the same connection. If there are, SQLITE_LOCKED is 6561** returned. In this case there is no "blocking connection", so invoking 6562** sqlite3_unlock_notify() results in the unlock-notify callback being 6563** invoked immediately. If the application then re-attempts the "DROP TABLE" 6564** or "DROP INDEX" query, an infinite loop might be the result. 6565** 6566** One way around this problem is to check the extended error code returned 6567** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6568** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6569** the special "DROP TABLE/INDEX" case, the extended error code is just 6570** SQLITE_LOCKED.)^ 6571*/ 6572int sqlite3_unlock_notify( 6573 sqlite3 *pBlocked, /* Waiting connection */ 6574 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6575 void *pNotifyArg /* Argument to pass to xNotify */ 6576); 6577 6578 6579/* 6580** CAPI3REF: String Comparison 6581** 6582** ^The [sqlite3_strnicmp()] API allows applications and extensions to 6583** compare the contents of two buffers containing UTF-8 strings in a 6584** case-independent fashion, using the same definition of case independence 6585** that SQLite uses internally when comparing identifiers. 6586*/ 6587int sqlite3_strnicmp(const char *, const char *, int); 6588 6589/* 6590** CAPI3REF: Error Logging Interface 6591** 6592** ^The [sqlite3_log()] interface writes a message into the error log 6593** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6594** ^If logging is enabled, the zFormat string and subsequent arguments are 6595** used with [sqlite3_snprintf()] to generate the final output string. 6596** 6597** The sqlite3_log() interface is intended for use by extensions such as 6598** virtual tables, collating functions, and SQL functions. While there is 6599** nothing to prevent an application from calling sqlite3_log(), doing so 6600** is considered bad form. 6601** 6602** The zFormat string must not be NULL. 6603** 6604** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6605** will not use dynamically allocated memory. The log message is stored in 6606** a fixed-length buffer on the stack. If the log message is longer than 6607** a few hundred characters, it will be truncated to the length of the 6608** buffer. 6609*/ 6610void sqlite3_log(int iErrCode, const char *zFormat, ...); 6611 6612/* 6613** CAPI3REF: Write-Ahead Log Commit Hook 6614** 6615** ^The [sqlite3_wal_hook()] function is used to register a callback that 6616** will be invoked each time a database connection commits data to a 6617** [write-ahead log] (i.e. whenever a transaction is committed in 6618** [journal_mode | journal_mode=WAL mode]). 6619** 6620** ^The callback is invoked by SQLite after the commit has taken place and 6621** the associated write-lock on the database released, so the implementation 6622** may read, write or [checkpoint] the database as required. 6623** 6624** ^The first parameter passed to the callback function when it is invoked 6625** is a copy of the third parameter passed to sqlite3_wal_hook() when 6626** registering the callback. ^The second is a copy of the database handle. 6627** ^The third parameter is the name of the database that was written to - 6628** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6629** is the number of pages currently in the write-ahead log file, 6630** including those that were just committed. 6631** 6632** The callback function should normally return [SQLITE_OK]. ^If an error 6633** code is returned, that error will propagate back up through the 6634** SQLite code base to cause the statement that provoked the callback 6635** to report an error, though the commit will have still occurred. If the 6636** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6637** that does not correspond to any valid SQLite error code, the results 6638** are undefined. 6639** 6640** A single database handle may have at most a single write-ahead log callback 6641** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6642** previously registered write-ahead log callback. ^Note that the 6643** [sqlite3_wal_autocheckpoint()] interface and the 6644** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6645** those overwrite any prior [sqlite3_wal_hook()] settings. 6646*/ 6647void *sqlite3_wal_hook( 6648 sqlite3*, 6649 int(*)(void *,sqlite3*,const char*,int), 6650 void* 6651); 6652 6653/* 6654** CAPI3REF: Configure an auto-checkpoint 6655** 6656** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6657** [sqlite3_wal_hook()] that causes any database on [database connection] D 6658** to automatically [checkpoint] 6659** after committing a transaction if there are N or 6660** more frames in the [write-ahead log] file. ^Passing zero or 6661** a negative value as the nFrame parameter disables automatic 6662** checkpoints entirely. 6663** 6664** ^The callback registered by this function replaces any existing callback 6665** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6666** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6667** configured by this function. 6668** 6669** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6670** from SQL. 6671** 6672** ^Every new [database connection] defaults to having the auto-checkpoint 6673** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6674** pages. The use of this interface 6675** is only necessary if the default setting is found to be suboptimal 6676** for a particular application. 6677*/ 6678int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6679 6680/* 6681** CAPI3REF: Checkpoint a database 6682** 6683** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6684** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6685** empty string, then a checkpoint is run on all databases of 6686** connection D. ^If the database connection D is not in 6687** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6688** 6689** ^The [wal_checkpoint pragma] can be used to invoke this interface 6690** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6691** [wal_autocheckpoint pragma] can be used to cause this interface to be 6692** run whenever the WAL reaches a certain size threshold. 6693** 6694** See also: [sqlite3_wal_checkpoint_v2()] 6695*/ 6696int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6697 6698/* 6699** CAPI3REF: Checkpoint a database 6700** 6701** Run a checkpoint operation on WAL database zDb attached to database 6702** handle db. The specific operation is determined by the value of the 6703** eMode parameter: 6704** 6705** <dl> 6706** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6707** Checkpoint as many frames as possible without waiting for any database 6708** readers or writers to finish. Sync the db file if all frames in the log 6709** are checkpointed. This mode is the same as calling 6710** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6711** 6712** <dt>SQLITE_CHECKPOINT_FULL<dd> 6713** This mode blocks (calls the busy-handler callback) until there is no 6714** database writer and all readers are reading from the most recent database 6715** snapshot. It then checkpoints all frames in the log file and syncs the 6716** database file. This call blocks database writers while it is running, 6717** but not database readers. 6718** 6719** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6720** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6721** checkpointing the log file it blocks (calls the busy-handler callback) 6722** until all readers are reading from the database file only. This ensures 6723** that the next client to write to the database file restarts the log file 6724** from the beginning. This call blocks database writers while it is running, 6725** but not database readers. 6726** </dl> 6727** 6728** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6729** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6730** the total number of checkpointed frames (including any that were already 6731** checkpointed when this function is called). *pnLog and *pnCkpt may be 6732** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6733** If no values are available because of an error, they are both set to -1 6734** before returning to communicate this to the caller. 6735** 6736** All calls obtain an exclusive "checkpoint" lock on the database file. If 6737** any other process is running a checkpoint operation at the same time, the 6738** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6739** busy-handler configured, it will not be invoked in this case. 6740** 6741** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6742** "writer" lock on the database file. If the writer lock cannot be obtained 6743** immediately, and a busy-handler is configured, it is invoked and the writer 6744** lock retried until either the busy-handler returns 0 or the lock is 6745** successfully obtained. The busy-handler is also invoked while waiting for 6746** database readers as described above. If the busy-handler returns 0 before 6747** the writer lock is obtained or while waiting for database readers, the 6748** checkpoint operation proceeds from that point in the same way as 6749** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6750** without blocking any further. SQLITE_BUSY is returned in this case. 6751** 6752** If parameter zDb is NULL or points to a zero length string, then the 6753** specified operation is attempted on all WAL databases. In this case the 6754** values written to output parameters *pnLog and *pnCkpt are undefined. If 6755** an SQLITE_BUSY error is encountered when processing one or more of the 6756** attached WAL databases, the operation is still attempted on any remaining 6757** attached databases and SQLITE_BUSY is returned to the caller. If any other 6758** error occurs while processing an attached database, processing is abandoned 6759** and the error code returned to the caller immediately. If no error 6760** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6761** databases, SQLITE_OK is returned. 6762** 6763** If database zDb is the name of an attached database that is not in WAL 6764** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6765** zDb is not NULL (or a zero length string) and is not the name of any 6766** attached database, SQLITE_ERROR is returned to the caller. 6767*/ 6768int sqlite3_wal_checkpoint_v2( 6769 sqlite3 *db, /* Database handle */ 6770 const char *zDb, /* Name of attached database (or NULL) */ 6771 int eMode, /* SQLITE_CHECKPOINT_* value */ 6772 int *pnLog, /* OUT: Size of WAL log in frames */ 6773 int *pnCkpt /* OUT: Total number of frames checkpointed */ 6774); 6775 6776/* 6777** CAPI3REF: Checkpoint operation parameters 6778** 6779** These constants can be used as the 3rd parameter to 6780** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6781** documentation for additional information about the meaning and use of 6782** each of these values. 6783*/ 6784#define SQLITE_CHECKPOINT_PASSIVE 0 6785#define SQLITE_CHECKPOINT_FULL 1 6786#define SQLITE_CHECKPOINT_RESTART 2 6787 6788/* 6789** CAPI3REF: Virtual Table Interface Configuration 6790** 6791** This function may be called by either the [xConnect] or [xCreate] method 6792** of a [virtual table] implementation to configure 6793** various facets of the virtual table interface. 6794** 6795** If this interface is invoked outside the context of an xConnect or 6796** xCreate virtual table method then the behavior is undefined. 6797** 6798** At present, there is only one option that may be configured using 6799** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 6800** may be added in the future. 6801*/ 6802int sqlite3_vtab_config(sqlite3*, int op, ...); 6803 6804/* 6805** CAPI3REF: Virtual Table Configuration Options 6806** 6807** These macros define the various options to the 6808** [sqlite3_vtab_config()] interface that [virtual table] implementations 6809** can use to customize and optimize their behavior. 6810** 6811** <dl> 6812** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 6813** <dd>Calls of the form 6814** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 6815** where X is an integer. If X is zero, then the [virtual table] whose 6816** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 6817** support constraints. In this configuration (which is the default) if 6818** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 6819** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 6820** specified as part of the users SQL statement, regardless of the actual 6821** ON CONFLICT mode specified. 6822** 6823** If X is non-zero, then the virtual table implementation guarantees 6824** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 6825** any modifications to internal or persistent data structures have been made. 6826** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 6827** is able to roll back a statement or database transaction, and abandon 6828** or continue processing the current SQL statement as appropriate. 6829** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 6830** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 6831** had been ABORT. 6832** 6833** Virtual table implementations that are required to handle OR REPLACE 6834** must do so within the [xUpdate] method. If a call to the 6835** [sqlite3_vtab_on_conflict()] function indicates that the current ON 6836** CONFLICT policy is REPLACE, the virtual table implementation should 6837** silently replace the appropriate rows within the xUpdate callback and 6838** return SQLITE_OK. Or, if this is not possible, it may return 6839** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 6840** constraint handling. 6841** </dl> 6842*/ 6843#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 6844 6845/* 6846** CAPI3REF: Determine The Virtual Table Conflict Policy 6847** 6848** This function may only be called from within a call to the [xUpdate] method 6849** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 6850** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 6851** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 6852** of the SQL statement that triggered the call to the [xUpdate] method of the 6853** [virtual table]. 6854*/ 6855int sqlite3_vtab_on_conflict(sqlite3 *); 6856 6857/* 6858** CAPI3REF: Conflict resolution modes 6859** 6860** These constants are returned by [sqlite3_vtab_on_conflict()] to 6861** inform a [virtual table] implementation what the [ON CONFLICT] mode 6862** is for the SQL statement being evaluated. 6863** 6864** Note that the [SQLITE_IGNORE] constant is also used as a potential 6865** return value from the [sqlite3_set_authorizer()] callback and that 6866** [SQLITE_ABORT] is also a [result code]. 6867*/ 6868#define SQLITE_ROLLBACK 1 6869/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 6870#define SQLITE_FAIL 3 6871/* #define SQLITE_ABORT 4 // Also an error code */ 6872#define SQLITE_REPLACE 5 6873 6874 6875 6876/* 6877** Undo the hack that converts floating point types to integer for 6878** builds on processors without floating point support. 6879*/ 6880#ifdef SQLITE_OMIT_FLOATING_POINT 6881# undef double 6882#endif 6883 6884#ifdef __cplusplus 6885} /* End of the 'extern "C"' block */ 6886#endif 6887#endif 6888