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 to make minor changes if 22** 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** @(#) $Id: sqlite.h.in,v 1.443 2009/04/20 12:31:46 drh Exp $ 34*/ 35#ifndef _SQLITE3_H_ 36#define _SQLITE3_H_ 37#include <stdarg.h> /* Needed for the definition of va_list */ 38 39/* 40** Make sure we can call this stuff from C++. 41*/ 42#ifdef __cplusplus 43extern "C" { 44#endif 45 46 47/* 48** Add the ability to override 'extern' 49*/ 50#ifndef SQLITE_EXTERN 51# define SQLITE_EXTERN extern 52#endif 53 54/* 55** These no-op macros are used in front of interfaces to mark those 56** interfaces as either deprecated or experimental. New applications 57** should not use deprecated intrfaces - they are support for backwards 58** compatibility only. Application writers should be aware that 59** experimental interfaces are subject to change in point releases. 60** 61** These macros used to resolve to various kinds of compiler magic that 62** would generate warning messages when they were used. But that 63** compiler magic ended up generating such a flurry of bug reports 64** that we have taken it all out and gone back to using simple 65** noop macros. 66*/ 67#define SQLITE_DEPRECATED 68#define SQLITE_EXPERIMENTAL 69 70/* 71** Ensure these symbols were not defined by some previous header file. 72*/ 73#ifdef SQLITE_VERSION 74# undef SQLITE_VERSION 75#endif 76#ifdef SQLITE_VERSION_NUMBER 77# undef SQLITE_VERSION_NUMBER 78#endif 79 80/* 81** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> 82** 83** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 84** the sqlite3.h file specify the version of SQLite with which 85** that header file is associated. 86** 87** The "version" of SQLite is a string of the form "X.Y.Z". 88** The phrase "alpha" or "beta" might be appended after the Z. 89** The X value is major version number always 3 in SQLite3. 90** The X value only changes when backwards compatibility is 91** broken and we intend to never break backwards compatibility. 92** The Y value is the minor version number and only changes when 93** there are major feature enhancements that are forwards compatible 94** but not backwards compatible. 95** The Z value is the release number and is incremented with 96** each release but resets back to 0 whenever Y is incremented. 97** 98** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 99** 100** Requirements: [H10011] [H10014] 101*/ 102#define SQLITE_VERSION "--VERS--" 103#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 104 105/* 106** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> 107** KEYWORDS: sqlite3_version 108** 109** These features provide the same information as the [SQLITE_VERSION] 110** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated 111** with the library instead of the header file. Cautious programmers might 112** include a check in their application to verify that 113** sqlite3_libversion_number() always returns the value 114** [SQLITE_VERSION_NUMBER]. 115** 116** The sqlite3_libversion() function returns the same information as is 117** in the sqlite3_version[] string constant. The function is provided 118** for use in DLLs since DLL users usually do not have direct access to string 119** constants within the DLL. 120** 121** Requirements: [H10021] [H10022] [H10023] 122*/ 123SQLITE_EXTERN const char sqlite3_version[]; 124const char *sqlite3_libversion(void); 125int sqlite3_libversion_number(void); 126 127/* 128** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> 129** 130** SQLite can be compiled with or without mutexes. When 131** the [SQLITE_THREADSAFE] C preprocessor macro 1 or 2, mutexes 132** are enabled and SQLite is threadsafe. When the 133** [SQLITE_THREADSAFE] macro is 0, 134** the mutexes are omitted. Without the mutexes, it is not safe 135** to use SQLite concurrently from more than one thread. 136** 137** Enabling mutexes incurs a measurable performance penalty. 138** So if speed is of utmost importance, it makes sense to disable 139** the mutexes. But for maximum safety, mutexes should be enabled. 140** The default behavior is for mutexes to be enabled. 141** 142** This interface can be used by a program to make sure that the 143** version of SQLite that it is linking against was compiled with 144** the desired setting of the [SQLITE_THREADSAFE] macro. 145** 146** This interface only reports on the compile-time mutex setting 147** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 148** SQLITE_THREADSAFE=1 then mutexes are enabled by default but 149** can be fully or partially disabled using a call to [sqlite3_config()] 150** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 151** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows 152** only the default compile-time setting, not any run-time changes 153** to that setting. 154** 155** See the [threading mode] documentation for additional information. 156** 157** Requirements: [H10101] [H10102] 158*/ 159int sqlite3_threadsafe(void); 160 161/* 162** CAPI3REF: Database Connection Handle {H12000} <S40200> 163** KEYWORDS: {database connection} {database connections} 164** 165** Each open SQLite database is represented by a pointer to an instance of 166** the opaque structure named "sqlite3". It is useful to think of an sqlite3 167** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 168** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 169** is its destructor. There are many other interfaces (such as 170** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 171** [sqlite3_busy_timeout()] to name but three) that are methods on an 172** sqlite3 object. 173*/ 174typedef struct sqlite3 sqlite3; 175 176/* 177** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> 178** KEYWORDS: sqlite_int64 sqlite_uint64 179** 180** Because there is no cross-platform way to specify 64-bit integer types 181** SQLite includes typedefs for 64-bit signed and unsigned integers. 182** 183** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 184** The sqlite_int64 and sqlite_uint64 types are supported for backwards 185** compatibility only. 186** 187** Requirements: [H10201] [H10202] 188*/ 189#ifdef SQLITE_INT64_TYPE 190 typedef SQLITE_INT64_TYPE sqlite_int64; 191 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 192#elif defined(_MSC_VER) || defined(__BORLANDC__) 193 typedef __int64 sqlite_int64; 194 typedef unsigned __int64 sqlite_uint64; 195#else 196 typedef long long int sqlite_int64; 197 typedef unsigned long long int sqlite_uint64; 198#endif 199typedef sqlite_int64 sqlite3_int64; 200typedef sqlite_uint64 sqlite3_uint64; 201 202/* 203** If compiling for a processor that lacks floating point support, 204** substitute integer for floating-point. 205*/ 206#ifdef SQLITE_OMIT_FLOATING_POINT 207# define double sqlite3_int64 208#endif 209 210/* 211** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> 212** 213** This routine is the destructor for the [sqlite3] object. 214** 215** Applications should [sqlite3_finalize | finalize] all [prepared statements] 216** and [sqlite3_blob_close | close] all [BLOB handles] associated with 217** the [sqlite3] object prior to attempting to close the object. 218** The [sqlite3_next_stmt()] interface can be used to locate all 219** [prepared statements] associated with a [database connection] if desired. 220** Typical code might look like this: 221** 222** <blockquote><pre> 223** sqlite3_stmt *pStmt; 224** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ 225** sqlite3_finalize(pStmt); 226** } 227** </pre></blockquote> 228** 229** If [sqlite3_close()] is invoked while a transaction is open, 230** the transaction is automatically rolled back. 231** 232** The C parameter to [sqlite3_close(C)] must be either a NULL 233** pointer or an [sqlite3] object pointer obtained 234** from [sqlite3_open()], [sqlite3_open16()], or 235** [sqlite3_open_v2()], and not previously closed. 236** 237** Requirements: 238** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] 239*/ 240int sqlite3_close(sqlite3 *); 241 242/* 243** The type for a callback function. 244** This is legacy and deprecated. It is included for historical 245** compatibility and is not documented. 246*/ 247typedef int (*sqlite3_callback)(void*,int,char**, char**); 248 249/* 250** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> 251** 252** The sqlite3_exec() interface is a convenient way of running one or more 253** SQL statements without having to write a lot of C code. The UTF-8 encoded 254** SQL statements are passed in as the second parameter to sqlite3_exec(). 255** The statements are evaluated one by one until either an error or 256** an interrupt is encountered, or until they are all done. The 3rd parameter 257** is an optional callback that is invoked once for each row of any query 258** results produced by the SQL statements. The 5th parameter tells where 259** to write any error messages. 260** 261** The error message passed back through the 5th parameter is held 262** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, 263** the calling application should call [sqlite3_free()] on any error 264** message returned through the 5th parameter when it has finished using 265** the error message. 266** 267** If the SQL statement in the 2nd parameter is NULL or an empty string 268** or a string containing only whitespace and comments, then no SQL 269** statements are evaluated and the database is not changed. 270** 271** The sqlite3_exec() interface is implemented in terms of 272** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 273** The sqlite3_exec() routine does nothing to the database that cannot be done 274** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 275** 276** The first parameter to [sqlite3_exec()] must be an valid and open 277** [database connection]. 278** 279** The database connection must not be closed while 280** [sqlite3_exec()] is running. 281** 282** The calling function should use [sqlite3_free()] to free 283** the memory that *errmsg is left pointing at once the error 284** message is no longer needed. 285** 286** The SQL statement text in the 2nd parameter to [sqlite3_exec()] 287** must remain unchanged while [sqlite3_exec()] is running. 288** 289** Requirements: 290** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] 291** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] 292*/ 293int sqlite3_exec( 294 sqlite3*, /* An open database */ 295 const char *sql, /* SQL to be evaluated */ 296 int (*callback)(void*,int,char**,char**), /* Callback function */ 297 void *, /* 1st argument to callback */ 298 char **errmsg /* Error msg written here */ 299); 300 301/* 302** CAPI3REF: Result Codes {H10210} <S10700> 303** KEYWORDS: SQLITE_OK {error code} {error codes} 304** KEYWORDS: {result code} {result codes} 305** 306** Many SQLite functions return an integer result code from the set shown 307** here in order to indicates success or failure. 308** 309** New error codes may be added in future versions of SQLite. 310** 311** See also: [SQLITE_IOERR_READ | extended result codes] 312*/ 313#define SQLITE_OK 0 /* Successful result */ 314/* beginning-of-error-codes */ 315#define SQLITE_ERROR 1 /* SQL error or missing database */ 316#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 317#define SQLITE_PERM 3 /* Access permission denied */ 318#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 319#define SQLITE_BUSY 5 /* The database file is locked */ 320#define SQLITE_LOCKED 6 /* A table in the database is locked */ 321#define SQLITE_NOMEM 7 /* A malloc() failed */ 322#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 323#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 324#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 325#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 326#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 327#define SQLITE_FULL 13 /* Insertion failed because database is full */ 328#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 329#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 330#define SQLITE_EMPTY 16 /* Database is empty */ 331#define SQLITE_SCHEMA 17 /* The database schema changed */ 332#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 333#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 334#define SQLITE_MISMATCH 20 /* Data type mismatch */ 335#define SQLITE_MISUSE 21 /* Library used incorrectly */ 336#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 337#define SQLITE_AUTH 23 /* Authorization denied */ 338#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 339#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 340#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 341#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 342#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 343/* end-of-error-codes */ 344 345/* 346** CAPI3REF: Extended Result Codes {H10220} <S10700> 347** KEYWORDS: {extended error code} {extended error codes} 348** KEYWORDS: {extended result code} {extended result codes} 349** 350** In its default configuration, SQLite API routines return one of 26 integer 351** [SQLITE_OK | result codes]. However, experience has shown that many of 352** these result codes are too coarse-grained. They do not provide as 353** much information about problems as programmers might like. In an effort to 354** address this, newer versions of SQLite (version 3.3.8 and later) include 355** support for additional result codes that provide more detailed information 356** about errors. The extended result codes are enabled or disabled 357** on a per database connection basis using the 358** [sqlite3_extended_result_codes()] API. 359** 360** Some of the available extended result codes are listed here. 361** One may expect the number of extended result codes will be expand 362** over time. Software that uses extended result codes should expect 363** to see new result codes in future releases of SQLite. 364** 365** The SQLITE_OK result code will never be extended. It will always 366** be exactly zero. 367*/ 368#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 369#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 370#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 371#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 372#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 373#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 374#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 375#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 376#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 377#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 378#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 379#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 380#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 381#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 382#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 383#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 384#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 385#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) 386 387/* 388** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> 389** 390** These bit values are intended for use in the 391** 3rd parameter to the [sqlite3_open_v2()] interface and 392** in the 4th parameter to the xOpen method of the 393** [sqlite3_vfs] object. 394*/ 395#define SQLITE_OPEN_READONLY 0x00000001 396#define SQLITE_OPEN_READWRITE 0x00000002 397#define SQLITE_OPEN_CREATE 0x00000004 398#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 399#define SQLITE_OPEN_EXCLUSIVE 0x00000010 400#define SQLITE_OPEN_MAIN_DB 0x00000100 401#define SQLITE_OPEN_TEMP_DB 0x00000200 402#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 403#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 404#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 405#define SQLITE_OPEN_SUBJOURNAL 0x00002000 406#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 407#define SQLITE_OPEN_NOMUTEX 0x00008000 408#define SQLITE_OPEN_FULLMUTEX 0x00010000 409 410/* 411** CAPI3REF: Device Characteristics {H10240} <H11120> 412** 413** The xDeviceCapabilities method of the [sqlite3_io_methods] 414** object returns an integer which is a vector of the these 415** bit values expressing I/O characteristics of the mass storage 416** device that holds the file that the [sqlite3_io_methods] 417** refers to. 418** 419** The SQLITE_IOCAP_ATOMIC property means that all writes of 420** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 421** mean that writes of blocks that are nnn bytes in size and 422** are aligned to an address which is an integer multiple of 423** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 424** that when data is appended to a file, the data is appended 425** first then the size of the file is extended, never the other 426** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 427** information is written to disk in the same order as calls 428** to xWrite(). 429*/ 430#define SQLITE_IOCAP_ATOMIC 0x00000001 431#define SQLITE_IOCAP_ATOMIC512 0x00000002 432#define SQLITE_IOCAP_ATOMIC1K 0x00000004 433#define SQLITE_IOCAP_ATOMIC2K 0x00000008 434#define SQLITE_IOCAP_ATOMIC4K 0x00000010 435#define SQLITE_IOCAP_ATOMIC8K 0x00000020 436#define SQLITE_IOCAP_ATOMIC16K 0x00000040 437#define SQLITE_IOCAP_ATOMIC32K 0x00000080 438#define SQLITE_IOCAP_ATOMIC64K 0x00000100 439#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 440#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 441 442/* 443** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> 444** 445** SQLite uses one of these integer values as the second 446** argument to calls it makes to the xLock() and xUnlock() methods 447** of an [sqlite3_io_methods] object. 448*/ 449#define SQLITE_LOCK_NONE 0 450#define SQLITE_LOCK_SHARED 1 451#define SQLITE_LOCK_RESERVED 2 452#define SQLITE_LOCK_PENDING 3 453#define SQLITE_LOCK_EXCLUSIVE 4 454 455/* 456** CAPI3REF: Synchronization Type Flags {H10260} <H11120> 457** 458** When SQLite invokes the xSync() method of an 459** [sqlite3_io_methods] object it uses a combination of 460** these integer values as the second argument. 461** 462** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 463** sync operation only needs to flush data to mass storage. Inode 464** information need not be flushed. If the lower four bits of the flag 465** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 466** If the lower four bits equal SQLITE_SYNC_FULL, that means 467** to use Mac OS X style fullsync instead of fsync(). 468*/ 469#define SQLITE_SYNC_NORMAL 0x00002 470#define SQLITE_SYNC_FULL 0x00003 471#define SQLITE_SYNC_DATAONLY 0x00010 472 473/* 474** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> 475** 476** An [sqlite3_file] object represents an open file in the OS 477** interface layer. Individual OS interface implementations will 478** want to subclass this object by appending additional fields 479** for their own use. The pMethods entry is a pointer to an 480** [sqlite3_io_methods] object that defines methods for performing 481** I/O operations on the open file. 482*/ 483typedef struct sqlite3_file sqlite3_file; 484struct sqlite3_file { 485 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 486}; 487 488/* 489** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> 490** 491** Every file opened by the [sqlite3_vfs] xOpen method populates an 492** [sqlite3_file] object (or, more commonly, a subclass of the 493** [sqlite3_file] object) with a pointer to an instance of this object. 494** This object defines the methods used to perform various operations 495** against the open file represented by the [sqlite3_file] object. 496** 497** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 498** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 499** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 500** flag may be ORed in to indicate that only the data of the file 501** and not its inode needs to be synced. 502** 503** The integer values to xLock() and xUnlock() are one of 504** <ul> 505** <li> [SQLITE_LOCK_NONE], 506** <li> [SQLITE_LOCK_SHARED], 507** <li> [SQLITE_LOCK_RESERVED], 508** <li> [SQLITE_LOCK_PENDING], or 509** <li> [SQLITE_LOCK_EXCLUSIVE]. 510** </ul> 511** xLock() increases the lock. xUnlock() decreases the lock. 512** The xCheckReservedLock() method checks whether any database connection, 513** either in this process or in some other process, is holding a RESERVED, 514** PENDING, or EXCLUSIVE lock on the file. It returns true 515** if such a lock exists and false otherwise. 516** 517** The xFileControl() method is a generic interface that allows custom 518** VFS implementations to directly control an open file using the 519** [sqlite3_file_control()] interface. The second "op" argument is an 520** integer opcode. The third argument is a generic pointer intended to 521** point to a structure that may contain arguments or space in which to 522** write return values. Potential uses for xFileControl() might be 523** functions to enable blocking locks with timeouts, to change the 524** locking strategy (for example to use dot-file locks), to inquire 525** about the status of a lock, or to break stale locks. The SQLite 526** core reserves all opcodes less than 100 for its own use. 527** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 528** Applications that define a custom xFileControl method should use opcodes 529** greater than 100 to avoid conflicts. 530** 531** The xSectorSize() method returns the sector size of the 532** device that underlies the file. The sector size is the 533** minimum write that can be performed without disturbing 534** other bytes in the file. The xDeviceCharacteristics() 535** method returns a bit vector describing behaviors of the 536** underlying device: 537** 538** <ul> 539** <li> [SQLITE_IOCAP_ATOMIC] 540** <li> [SQLITE_IOCAP_ATOMIC512] 541** <li> [SQLITE_IOCAP_ATOMIC1K] 542** <li> [SQLITE_IOCAP_ATOMIC2K] 543** <li> [SQLITE_IOCAP_ATOMIC4K] 544** <li> [SQLITE_IOCAP_ATOMIC8K] 545** <li> [SQLITE_IOCAP_ATOMIC16K] 546** <li> [SQLITE_IOCAP_ATOMIC32K] 547** <li> [SQLITE_IOCAP_ATOMIC64K] 548** <li> [SQLITE_IOCAP_SAFE_APPEND] 549** <li> [SQLITE_IOCAP_SEQUENTIAL] 550** </ul> 551** 552** The SQLITE_IOCAP_ATOMIC property means that all writes of 553** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 554** mean that writes of blocks that are nnn bytes in size and 555** are aligned to an address which is an integer multiple of 556** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 557** that when data is appended to a file, the data is appended 558** first then the size of the file is extended, never the other 559** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 560** information is written to disk in the same order as calls 561** to xWrite(). 562** 563** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 564** in the unread portions of the buffer with zeros. A VFS that 565** fails to zero-fill short reads might seem to work. However, 566** failure to zero-fill short reads will eventually lead to 567** database corruption. 568*/ 569typedef struct sqlite3_io_methods sqlite3_io_methods; 570struct sqlite3_io_methods { 571 int iVersion; 572 int (*xClose)(sqlite3_file*); 573 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 574 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 575 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 576 int (*xSync)(sqlite3_file*, int flags); 577 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 578 int (*xLock)(sqlite3_file*, int); 579 int (*xUnlock)(sqlite3_file*, int); 580 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 581 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 582 int (*xSectorSize)(sqlite3_file*); 583 int (*xDeviceCharacteristics)(sqlite3_file*); 584 /* Additional methods may be added in future releases */ 585}; 586 587/* 588** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> 589** 590** These integer constants are opcodes for the xFileControl method 591** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 592** interface. 593** 594** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 595** opcode causes the xFileControl method to write the current state of 596** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 597** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 598** into an integer that the pArg argument points to. This capability 599** is used during testing and only needs to be supported when SQLITE_TEST 600** is defined. 601*/ 602#define SQLITE_FCNTL_LOCKSTATE 1 603#define SQLITE_GET_LOCKPROXYFILE 2 604#define SQLITE_SET_LOCKPROXYFILE 3 605#define SQLITE_LAST_ERRNO 4 606 607/* 608** CAPI3REF: Mutex Handle {H17110} <S20130> 609** 610** The mutex module within SQLite defines [sqlite3_mutex] to be an 611** abstract type for a mutex object. The SQLite core never looks 612** at the internal representation of an [sqlite3_mutex]. It only 613** deals with pointers to the [sqlite3_mutex] object. 614** 615** Mutexes are created using [sqlite3_mutex_alloc()]. 616*/ 617typedef struct sqlite3_mutex sqlite3_mutex; 618 619/* 620** CAPI3REF: OS Interface Object {H11140} <S20100> 621** 622** An instance of the sqlite3_vfs object defines the interface between 623** the SQLite core and the underlying operating system. The "vfs" 624** in the name of the object stands for "virtual file system". 625** 626** The value of the iVersion field is initially 1 but may be larger in 627** future versions of SQLite. Additional fields may be appended to this 628** object when the iVersion value is increased. Note that the structure 629** of the sqlite3_vfs object changes in the transaction between 630** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 631** modified. 632** 633** The szOsFile field is the size of the subclassed [sqlite3_file] 634** structure used by this VFS. mxPathname is the maximum length of 635** a pathname in this VFS. 636** 637** Registered sqlite3_vfs objects are kept on a linked list formed by 638** the pNext pointer. The [sqlite3_vfs_register()] 639** and [sqlite3_vfs_unregister()] interfaces manage this list 640** in a thread-safe way. The [sqlite3_vfs_find()] interface 641** searches the list. Neither the application code nor the VFS 642** implementation should use the pNext pointer. 643** 644** The pNext field is the only field in the sqlite3_vfs 645** structure that SQLite will ever modify. SQLite will only access 646** or modify this field while holding a particular static mutex. 647** The application should never modify anything within the sqlite3_vfs 648** object once the object has been registered. 649** 650** The zName field holds the name of the VFS module. The name must 651** be unique across all VFS modules. 652** 653** SQLite will guarantee that the zFilename parameter to xOpen 654** is either a NULL pointer or string obtained 655** from xFullPathname(). SQLite further guarantees that 656** the string will be valid and unchanged until xClose() is 657** called. Because of the previous sentense, 658** the [sqlite3_file] can safely store a pointer to the 659** filename if it needs to remember the filename for some reason. 660** If the zFilename parameter is xOpen is a NULL pointer then xOpen 661** must invite its own temporary name for the file. Whenever the 662** xFilename parameter is NULL it will also be the case that the 663** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 664** 665** The flags argument to xOpen() includes all bits set in 666** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 667** or [sqlite3_open16()] is used, then flags includes at least 668** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 669** If xOpen() opens a file read-only then it sets *pOutFlags to 670** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 671** 672** SQLite will also add one of the following flags to the xOpen() 673** call, depending on the object being opened: 674** 675** <ul> 676** <li> [SQLITE_OPEN_MAIN_DB] 677** <li> [SQLITE_OPEN_MAIN_JOURNAL] 678** <li> [SQLITE_OPEN_TEMP_DB] 679** <li> [SQLITE_OPEN_TEMP_JOURNAL] 680** <li> [SQLITE_OPEN_TRANSIENT_DB] 681** <li> [SQLITE_OPEN_SUBJOURNAL] 682** <li> [SQLITE_OPEN_MASTER_JOURNAL] 683** </ul> 684** 685** The file I/O implementation can use the object type flags to 686** change the way it deals with files. For example, an application 687** that does not care about crash recovery or rollback might make 688** the open of a journal file a no-op. Writes to this journal would 689** also be no-ops, and any attempt to read the journal would return 690** SQLITE_IOERR. Or the implementation might recognize that a database 691** file will be doing page-aligned sector reads and writes in a random 692** order and set up its I/O subsystem accordingly. 693** 694** SQLite might also add one of the following flags to the xOpen method: 695** 696** <ul> 697** <li> [SQLITE_OPEN_DELETEONCLOSE] 698** <li> [SQLITE_OPEN_EXCLUSIVE] 699** </ul> 700** 701** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 702** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] 703** will be set for TEMP databases, journals and for subjournals. 704** 705** The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 706** for exclusive access. This flag is set for all files except 707** for the main database file. 708** 709** At least szOsFile bytes of memory are allocated by SQLite 710** to hold the [sqlite3_file] structure passed as the third 711** argument to xOpen. The xOpen method does not have to 712** allocate the structure; it should just fill it in. 713** 714** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 715** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 716** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 717** to test whether a file is at least readable. The file can be a 718** directory. 719** 720** SQLite will always allocate at least mxPathname+1 bytes for the 721** output buffer xFullPathname. The exact size of the output buffer 722** is also passed as a parameter to both methods. If the output buffer 723** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 724** handled as a fatal error by SQLite, vfs implementations should endeavor 725** to prevent this by setting mxPathname to a sufficiently large value. 726** 727** The xRandomness(), xSleep(), and xCurrentTime() interfaces 728** are not strictly a part of the filesystem, but they are 729** included in the VFS structure for completeness. 730** The xRandomness() function attempts to return nBytes bytes 731** of good-quality randomness into zOut. The return value is 732** the actual number of bytes of randomness obtained. 733** The xSleep() method causes the calling thread to sleep for at 734** least the number of microseconds given. The xCurrentTime() 735** method returns a Julian Day Number for the current date and time. 736** 737*/ 738typedef struct sqlite3_vfs sqlite3_vfs; 739struct sqlite3_vfs { 740 int iVersion; /* Structure version number */ 741 int szOsFile; /* Size of subclassed sqlite3_file */ 742 int mxPathname; /* Maximum file pathname length */ 743 sqlite3_vfs *pNext; /* Next registered VFS */ 744 const char *zName; /* Name of this virtual file system */ 745 void *pAppData; /* Pointer to application-specific data */ 746 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 747 int flags, int *pOutFlags); 748 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 749 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 750 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 751 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 752 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 753 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 754 void (*xDlClose)(sqlite3_vfs*, void*); 755 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 756 int (*xSleep)(sqlite3_vfs*, int microseconds); 757 int (*xCurrentTime)(sqlite3_vfs*, double*); 758 int (*xGetLastError)(sqlite3_vfs*, int, char *); 759 /* New fields may be appended in figure versions. The iVersion 760 ** value will increment whenever this happens. */ 761}; 762 763/* 764** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> 765** 766** These integer constants can be used as the third parameter to 767** the xAccess method of an [sqlite3_vfs] object. {END} They determine 768** what kind of permissions the xAccess method is looking for. 769** With SQLITE_ACCESS_EXISTS, the xAccess method 770** simply checks whether the file exists. 771** With SQLITE_ACCESS_READWRITE, the xAccess method 772** checks whether the file is both readable and writable. 773** With SQLITE_ACCESS_READ, the xAccess method 774** checks whether the file is readable. 775*/ 776#define SQLITE_ACCESS_EXISTS 0 777#define SQLITE_ACCESS_READWRITE 1 778#define SQLITE_ACCESS_READ 2 779 780/* 781** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> 782** 783** The sqlite3_initialize() routine initializes the 784** SQLite library. The sqlite3_shutdown() routine 785** deallocates any resources that were allocated by sqlite3_initialize(). 786** 787** A call to sqlite3_initialize() is an "effective" call if it is 788** the first time sqlite3_initialize() is invoked during the lifetime of 789** the process, or if it is the first time sqlite3_initialize() is invoked 790** following a call to sqlite3_shutdown(). Only an effective call 791** of sqlite3_initialize() does any initialization. All other calls 792** are harmless no-ops. 793** 794** A call to sqlite3_shutdown() is an "effective" call if it is the first 795** call to sqlite3_shutdown() since the last sqlite3_initialize(). Only 796** an effective call to sqlite3_shutdown() does any deinitialization. 797** All other calls to sqlite3_shutdown() are harmless no-ops. 798** 799** Among other things, sqlite3_initialize() shall invoke 800** sqlite3_os_init(). Similarly, sqlite3_shutdown() 801** shall invoke sqlite3_os_end(). 802** 803** The sqlite3_initialize() routine returns [SQLITE_OK] on success. 804** If for some reason, sqlite3_initialize() is unable to initialize 805** the library (perhaps it is unable to allocate a needed resource such 806** as a mutex) it returns an [error code] other than [SQLITE_OK]. 807** 808** The sqlite3_initialize() routine is called internally by many other 809** SQLite interfaces so that an application usually does not need to 810** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 811** calls sqlite3_initialize() so the SQLite library will be automatically 812** initialized when [sqlite3_open()] is called if it has not be initialized 813** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 814** compile-time option, then the automatic calls to sqlite3_initialize() 815** are omitted and the application must call sqlite3_initialize() directly 816** prior to using any other SQLite interface. For maximum portability, 817** it is recommended that applications always invoke sqlite3_initialize() 818** directly prior to using any other SQLite interface. Future releases 819** of SQLite may require this. In other words, the behavior exhibited 820** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 821** default behavior in some future release of SQLite. 822** 823** The sqlite3_os_init() routine does operating-system specific 824** initialization of the SQLite library. The sqlite3_os_end() 825** routine undoes the effect of sqlite3_os_init(). Typical tasks 826** performed by these routines include allocation or deallocation 827** of static resources, initialization of global variables, 828** setting up a default [sqlite3_vfs] module, or setting up 829** a default configuration using [sqlite3_config()]. 830** 831** The application should never invoke either sqlite3_os_init() 832** or sqlite3_os_end() directly. The application should only invoke 833** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 834** interface is called automatically by sqlite3_initialize() and 835** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 836** implementations for sqlite3_os_init() and sqlite3_os_end() 837** are built into SQLite when it is compiled for unix, windows, or os/2. 838** When built for other platforms (using the [SQLITE_OS_OTHER=1] compile-time 839** option) the application must supply a suitable implementation for 840** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 841** implementation of sqlite3_os_init() or sqlite3_os_end() 842** must return [SQLITE_OK] on success and some other [error code] upon 843** failure. 844*/ 845int sqlite3_initialize(void); 846int sqlite3_shutdown(void); 847int sqlite3_os_init(void); 848int sqlite3_os_end(void); 849 850/* 851** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> 852** EXPERIMENTAL 853** 854** The sqlite3_config() interface is used to make global configuration 855** changes to SQLite in order to tune SQLite to the specific needs of 856** the application. The default configuration is recommended for most 857** applications and so this routine is usually not necessary. It is 858** provided to support rare applications with unusual needs. 859** 860** The sqlite3_config() interface is not threadsafe. The application 861** must insure that no other SQLite interfaces are invoked by other 862** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 863** may only be invoked prior to library initialization using 864** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 865** Note, however, that sqlite3_config() can be called as part of the 866** implementation of an application-defined [sqlite3_os_init()]. 867** 868** The first argument to sqlite3_config() is an integer 869** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 870** what property of SQLite is to be configured. Subsequent arguments 871** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 872** in the first argument. 873** 874** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 875** If the option is unknown or SQLite is unable to set the option 876** then this routine returns a non-zero [error code]. 877** 878** Requirements: 879** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] 880** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] 881** [H14162] [H14165] [H14168] 882*/ 883SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); 884 885/* 886** CAPI3REF: Configure database connections {H14200} <S20000> 887** EXPERIMENTAL 888** 889** The sqlite3_db_config() interface is used to make configuration 890** changes to a [database connection]. The interface is similar to 891** [sqlite3_config()] except that the changes apply to a single 892** [database connection] (specified in the first argument). The 893** sqlite3_db_config() interface can only be used immediately after 894** the database connection is created using [sqlite3_open()], 895** [sqlite3_open16()], or [sqlite3_open_v2()]. 896** 897** The second argument to sqlite3_db_config(D,V,...) is the 898** configuration verb - an integer code that indicates what 899** aspect of the [database connection] is being configured. 900** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. 901** New verbs are likely to be added in future releases of SQLite. 902** Additional arguments depend on the verb. 903** 904** Requirements: 905** [H14203] [H14206] [H14209] [H14212] [H14215] 906*/ 907SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); 908 909/* 910** CAPI3REF: Memory Allocation Routines {H10155} <S20120> 911** EXPERIMENTAL 912** 913** An instance of this object defines the interface between SQLite 914** and low-level memory allocation routines. 915** 916** This object is used in only one place in the SQLite interface. 917** A pointer to an instance of this object is the argument to 918** [sqlite3_config()] when the configuration option is 919** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object 920** and passing it to [sqlite3_config()] during configuration, an 921** application can specify an alternative memory allocation subsystem 922** for SQLite to use for all of its dynamic memory needs. 923** 924** Note that SQLite comes with a built-in memory allocator that is 925** perfectly adequate for the overwhelming majority of applications 926** and that this object is only useful to a tiny minority of applications 927** with specialized memory allocation requirements. This object is 928** also used during testing of SQLite in order to specify an alternative 929** memory allocator that simulates memory out-of-memory conditions in 930** order to verify that SQLite recovers gracefully from such 931** conditions. 932** 933** The xMalloc, xFree, and xRealloc methods must work like the 934** malloc(), free(), and realloc() functions from the standard library. 935** 936** xSize should return the allocated size of a memory allocation 937** previously obtained from xMalloc or xRealloc. The allocated size 938** is always at least as big as the requested size but may be larger. 939** 940** The xRoundup method returns what would be the allocated size of 941** a memory allocation given a particular requested size. Most memory 942** allocators round up memory allocations at least to the next multiple 943** of 8. Some allocators round up to a larger multiple or to a power of 2. 944** 945** The xInit method initializes the memory allocator. (For example, 946** it might allocate any require mutexes or initialize internal data 947** structures. The xShutdown method is invoked (indirectly) by 948** [sqlite3_shutdown()] and should deallocate any resources acquired 949** by xInit. The pAppData pointer is used as the only parameter to 950** xInit and xShutdown. 951*/ 952typedef struct sqlite3_mem_methods sqlite3_mem_methods; 953struct sqlite3_mem_methods { 954 void *(*xMalloc)(int); /* Memory allocation function */ 955 void (*xFree)(void*); /* Free a prior allocation */ 956 void *(*xRealloc)(void*,int); /* Resize an allocation */ 957 int (*xSize)(void*); /* Return the size of an allocation */ 958 int (*xRoundup)(int); /* Round up request size to allocation size */ 959 int (*xInit)(void*); /* Initialize the memory allocator */ 960 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 961 void *pAppData; /* Argument to xInit() and xShutdown() */ 962}; 963 964/* 965** CAPI3REF: Configuration Options {H10160} <S20000> 966** EXPERIMENTAL 967** 968** These constants are the available integer configuration options that 969** can be passed as the first argument to the [sqlite3_config()] interface. 970** 971** New configuration options may be added in future releases of SQLite. 972** Existing configuration options might be discontinued. Applications 973** should check the return code from [sqlite3_config()] to make sure that 974** the call worked. The [sqlite3_config()] interface will return a 975** non-zero [error code] if a discontinued or unsupported configuration option 976** is invoked. 977** 978** <dl> 979** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 980** <dd>There are no arguments to this option. This option disables 981** all mutexing and puts SQLite into a mode where it can only be used 982** by a single thread.</dd> 983** 984** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 985** <dd>There are no arguments to this option. This option disables 986** mutexing on [database connection] and [prepared statement] objects. 987** The application is responsible for serializing access to 988** [database connections] and [prepared statements]. But other mutexes 989** are enabled so that SQLite will be safe to use in a multi-threaded 990** environment as long as no two threads attempt to use the same 991** [database connection] at the same time. See the [threading mode] 992** documentation for additional information.</dd> 993** 994** <dt>SQLITE_CONFIG_SERIALIZED</dt> 995** <dd>There are no arguments to this option. This option enables 996** all mutexes including the recursive 997** mutexes on [database connection] and [prepared statement] objects. 998** In this mode (which is the default when SQLite is compiled with 999** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1000** to [database connections] and [prepared statements] so that the 1001** application is free to use the same [database connection] or the 1002** same [prepared statement] in different threads at the same time. 1003** See the [threading mode] documentation for additional information.</dd> 1004** 1005** <dt>SQLITE_CONFIG_MALLOC</dt> 1006** <dd>This option takes a single argument which is a pointer to an 1007** instance of the [sqlite3_mem_methods] structure. The argument specifies 1008** alternative low-level memory allocation routines to be used in place of 1009** the memory allocation routines built into SQLite.</dd> 1010** 1011** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1012** <dd>This option takes a single argument which is a pointer to an 1013** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1014** structure is filled with the currently defined memory allocation routines. 1015** This option can be used to overload the default memory allocation 1016** routines with a wrapper that simulations memory allocation failure or 1017** tracks memory usage, for example.</dd> 1018** 1019** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1020** <dd>This option takes single argument of type int, interpreted as a 1021** boolean, which enables or disables the collection of memory allocation 1022** statistics. When disabled, the following SQLite interfaces become 1023** non-operational: 1024** <ul> 1025** <li> [sqlite3_memory_used()] 1026** <li> [sqlite3_memory_highwater()] 1027** <li> [sqlite3_soft_heap_limit()] 1028** <li> [sqlite3_status()] 1029** </ul> 1030** </dd> 1031** 1032** <dt>SQLITE_CONFIG_SCRATCH</dt> 1033** <dd>This option specifies a static memory buffer that SQLite can use for 1034** scratch memory. There are three arguments: A pointer to the memory, the 1035** size of each scratch buffer (sz), and the number of buffers (N). The sz 1036** argument must be a multiple of 16. The sz parameter should be a few bytes 1037** larger than the actual scratch space required due internal overhead. 1038** The first 1039** argument should point to an allocation of at least sz*N bytes of memory. 1040** SQLite will use no more than one scratch buffer at once per thread, so 1041** N should be set to the expected maximum number of threads. The sz 1042** parameter should be 6 times the size of the largest database page size. 1043** Scratch buffers are used as part of the btree balance operation. If 1044** The btree balancer needs additional memory beyond what is provided by 1045** scratch buffers or if no scratch buffer space is specified, then SQLite 1046** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> 1047** 1048** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1049** <dd>This option specifies a static memory buffer that SQLite can use for 1050** the database page cache with the default page cache implemenation. 1051** This configuration should not be used if an application-define page 1052** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1053** There are three arguments to this option: A pointer to the 1054** memory, the size of each page buffer (sz), and the number of pages (N). 1055** The sz argument must be a power of two between 512 and 32768. The first 1056** argument should point to an allocation of at least sz*N bytes of memory. 1057** SQLite will use the memory provided by the first argument to satisfy its 1058** memory needs for the first N pages that it adds to cache. If additional 1059** page cache memory is needed beyond what is provided by this option, then 1060** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1061** The implementation might use one or more of the N buffers to hold 1062** memory accounting information. </dd> 1063** 1064** <dt>SQLITE_CONFIG_HEAP</dt> 1065** <dd>This option specifies a static memory buffer that SQLite will use 1066** for all of its dynamic memory allocation needs beyond those provided 1067** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1068** There are three arguments: A pointer to the memory, the number of 1069** bytes in the memory buffer, and the minimum allocation size. If 1070** the first pointer (the memory pointer) is NULL, then SQLite reverts 1071** to using its default memory allocator (the system malloc() implementation), 1072** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the 1073** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1074** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1075** allocator is engaged to handle all of SQLites memory allocation needs.</dd> 1076** 1077** <dt>SQLITE_CONFIG_MUTEX</dt> 1078** <dd>This option takes a single argument which is a pointer to an 1079** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1080** alternative low-level mutex routines to be used in place 1081** the mutex routines built into SQLite.</dd> 1082** 1083** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1084** <dd>This option takes a single argument which is a pointer to an 1085** instance of the [sqlite3_mutex_methods] structure. The 1086** [sqlite3_mutex_methods] 1087** structure is filled with the currently defined mutex routines. 1088** This option can be used to overload the default mutex allocation 1089** routines with a wrapper used to track mutex usage for performance 1090** profiling or testing, for example.</dd> 1091** 1092** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1093** <dd>This option takes two arguments that determine the default 1094** memory allcation lookaside optimization. The first argument is the 1095** size of each lookaside buffer slot and the second is the number of 1096** slots allocated to each database connection.</dd> 1097** 1098** <dt>SQLITE_CONFIG_PCACHE</dt> 1099** <dd>This option takes a single argument which is a pointer to 1100** an [sqlite3_pcache_methods] object. This object specifies the interface 1101** to a custom page cache implementation. SQLite makes a copy of the 1102** object and uses it for page cache memory allocations.</dd> 1103** 1104** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1105** <dd>This option takes a single argument which is a pointer to an 1106** [sqlite3_pcache_methods] object. SQLite copies of the current 1107** page cache implementation into that object.</dd> 1108** 1109** </dl> 1110*/ 1111#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1112#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1113#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1114#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1115#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1116#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1117#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1118#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1119#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1120#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1121#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1122/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1123#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1124#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1125#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1126 1127/* 1128** CAPI3REF: Configuration Options {H10170} <S20000> 1129** EXPERIMENTAL 1130** 1131** These constants are the available integer configuration options that 1132** can be passed as the second argument to the [sqlite3_db_config()] interface. 1133** 1134** New configuration options may be added in future releases of SQLite. 1135** Existing configuration options might be discontinued. Applications 1136** should check the return code from [sqlite3_db_config()] to make sure that 1137** the call worked. The [sqlite3_db_config()] interface will return a 1138** non-zero [error code] if a discontinued or unsupported configuration option 1139** is invoked. 1140** 1141** <dl> 1142** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1143** <dd>This option takes three additional arguments that determine the 1144** [lookaside memory allocator] configuration for the [database connection]. 1145** The first argument (the third parameter to [sqlite3_db_config()] is a 1146** pointer to a memory buffer to use for lookaside memory. The first 1147** argument may be NULL in which case SQLite will allocate the lookaside 1148** buffer itself using [sqlite3_malloc()]. The second argument is the 1149** size of each lookaside buffer slot and the third argument is the number of 1150** slots. The size of the buffer in the first argument must be greater than 1151** or equal to the product of the second and third arguments.</dd> 1152** 1153** </dl> 1154*/ 1155#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1156 1157 1158/* 1159** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> 1160** 1161** The sqlite3_extended_result_codes() routine enables or disables the 1162** [extended result codes] feature of SQLite. The extended result 1163** codes are disabled by default for historical compatibility considerations. 1164** 1165** Requirements: 1166** [H12201] [H12202] 1167*/ 1168int sqlite3_extended_result_codes(sqlite3*, int onoff); 1169 1170/* 1171** CAPI3REF: Last Insert Rowid {H12220} <S10700> 1172** 1173** Each entry in an SQLite table has a unique 64-bit signed 1174** integer key called the [ROWID | "rowid"]. The rowid is always available 1175** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1176** names are not also used by explicitly declared columns. If 1177** the table has a column of type [INTEGER PRIMARY KEY] then that column 1178** is another alias for the rowid. 1179** 1180** This routine returns the [rowid] of the most recent 1181** successful [INSERT] into the database from the [database connection] 1182** in the first argument. If no successful [INSERT]s 1183** have ever occurred on that database connection, zero is returned. 1184** 1185** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1186** row is returned by this routine as long as the trigger is running. 1187** But once the trigger terminates, the value returned by this routine 1188** reverts to the last value inserted before the trigger fired. 1189** 1190** An [INSERT] that fails due to a constraint violation is not a 1191** successful [INSERT] and does not change the value returned by this 1192** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1193** and INSERT OR ABORT make no changes to the return value of this 1194** routine when their insertion fails. When INSERT OR REPLACE 1195** encounters a constraint violation, it does not fail. The 1196** INSERT continues to completion after deleting rows that caused 1197** the constraint problem so INSERT OR REPLACE will always change 1198** the return value of this interface. 1199** 1200** For the purposes of this routine, an [INSERT] is considered to 1201** be successful even if it is subsequently rolled back. 1202** 1203** Requirements: 1204** [H12221] [H12223] 1205** 1206** If a separate thread performs a new [INSERT] on the same 1207** database connection while the [sqlite3_last_insert_rowid()] 1208** function is running and thus changes the last insert [rowid], 1209** then the value returned by [sqlite3_last_insert_rowid()] is 1210** unpredictable and might not equal either the old or the new 1211** last insert [rowid]. 1212*/ 1213sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1214 1215/* 1216** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> 1217** 1218** This function returns the number of database rows that were changed 1219** or inserted or deleted by the most recently completed SQL statement 1220** on the [database connection] specified by the first parameter. 1221** Only changes that are directly specified by the [INSERT], [UPDATE], 1222** or [DELETE] statement are counted. Auxiliary changes caused by 1223** triggers are not counted. Use the [sqlite3_total_changes()] function 1224** to find the total number of changes including changes caused by triggers. 1225** 1226** A "row change" is a change to a single row of a single table 1227** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1228** are changed as side effects of REPLACE constraint resolution, 1229** rollback, ABORT processing, DROP TABLE, or by any other 1230** mechanisms do not count as direct row changes. 1231** 1232** A "trigger context" is a scope of execution that begins and 1233** ends with the script of a trigger. Most SQL statements are 1234** evaluated outside of any trigger. This is the "top level" 1235** trigger context. If a trigger fires from the top level, a 1236** new trigger context is entered for the duration of that one 1237** trigger. Subtriggers create subcontexts for their duration. 1238** 1239** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1240** not create a new trigger context. 1241** 1242** This function returns the number of direct row changes in the 1243** most recent INSERT, UPDATE, or DELETE statement within the same 1244** trigger context. 1245** 1246** Thus, when called from the top level, this function returns the 1247** number of changes in the most recent INSERT, UPDATE, or DELETE 1248** that also occurred at the top level. Within the body of a trigger, 1249** the sqlite3_changes() interface can be called to find the number of 1250** changes in the most recently completed INSERT, UPDATE, or DELETE 1251** statement within the body of the same trigger. 1252** However, the number returned does not include changes 1253** caused by subtriggers since those have their own context. 1254** 1255** SQLite implements the command "DELETE FROM table" without a WHERE clause 1256** by dropping and recreating the table. Doing so is much faster than going 1257** through and deleting individual elements from the table. Because of this 1258** optimization, the deletions in "DELETE FROM table" are not row changes and 1259** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1260** functions, regardless of the number of elements that were originally 1261** in the table. To get an accurate count of the number of rows deleted, use 1262** "DELETE FROM table WHERE 1" instead. Or recompile using the 1263** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1264** optimization on all queries. 1265** 1266** Requirements: 1267** [H12241] [H12243] 1268** 1269** If a separate thread makes changes on the same database connection 1270** while [sqlite3_changes()] is running then the value returned 1271** is unpredictable and not meaningful. 1272*/ 1273int sqlite3_changes(sqlite3*); 1274 1275/* 1276** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> 1277** 1278** This function returns the number of row changes caused by INSERT, 1279** UPDATE or DELETE statements since the [database connection] was opened. 1280** The count includes all changes from all trigger contexts. However, 1281** the count does not include changes used to implement REPLACE constraints, 1282** do rollbacks or ABORT processing, or DROP table processing. 1283** The changes are counted as soon as the statement that makes them is 1284** completed (when the statement handle is passed to [sqlite3_reset()] or 1285** [sqlite3_finalize()]). 1286** 1287** SQLite implements the command "DELETE FROM table" without a WHERE clause 1288** by dropping and recreating the table. (This is much faster than going 1289** through and deleting individual elements from the table.) Because of this 1290** optimization, the deletions in "DELETE FROM table" are not row changes and 1291** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1292** functions, regardless of the number of elements that were originally 1293** in the table. To get an accurate count of the number of rows deleted, use 1294** "DELETE FROM table WHERE 1" instead. Or recompile using the 1295** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1296** optimization on all queries. 1297** 1298** See also the [sqlite3_changes()] interface. 1299** 1300** Requirements: 1301** [H12261] [H12263] 1302** 1303** If a separate thread makes changes on the same database connection 1304** while [sqlite3_total_changes()] is running then the value 1305** returned is unpredictable and not meaningful. 1306*/ 1307int sqlite3_total_changes(sqlite3*); 1308 1309/* 1310** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> 1311** 1312** This function causes any pending database operation to abort and 1313** return at its earliest opportunity. This routine is typically 1314** called in response to a user action such as pressing "Cancel" 1315** or Ctrl-C where the user wants a long query operation to halt 1316** immediately. 1317** 1318** It is safe to call this routine from a thread different from the 1319** thread that is currently running the database operation. But it 1320** is not safe to call this routine with a [database connection] that 1321** is closed or might close before sqlite3_interrupt() returns. 1322** 1323** If an SQL operation is very nearly finished at the time when 1324** sqlite3_interrupt() is called, then it might not have an opportunity 1325** to be interrupted and might continue to completion. 1326** 1327** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1328** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1329** that is inside an explicit transaction, then the entire transaction 1330** will be rolled back automatically. 1331** 1332** The sqlite3_interrupt(D) call is in effect until all currently running 1333** SQL statements on [database connection] D complete. Any new SQL statements 1334** that are started after the sqlite3_interrupt() call and before the 1335** running statements reaches zero are interrupted as if they had been 1336** running prior to the sqlite3_interrupt() call. New SQL statements 1337** that are started after the running statement count reaches zero are 1338** not effected by the sqlite3_interrupt(). 1339** A call to sqlite3_interrupt(D) that occurs when there are no running 1340** SQL statements is a no-op and has no effect on SQL statements 1341** that are started after the sqlite3_interrupt() call returns. 1342** 1343** Requirements: 1344** [H12271] [H12272] 1345** 1346** If the database connection closes while [sqlite3_interrupt()] 1347** is running then bad things will likely happen. 1348*/ 1349void sqlite3_interrupt(sqlite3*); 1350 1351/* 1352** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> 1353** 1354** These routines are useful for command-line input to determine if the 1355** currently entered text seems to form complete a SQL statement or 1356** if additional input is needed before sending the text into 1357** SQLite for parsing. These routines return true if the input string 1358** appears to be a complete SQL statement. A statement is judged to be 1359** complete if it ends with a semicolon token and is not a fragment of a 1360** CREATE TRIGGER statement. Semicolons that are embedded within 1361** string literals or quoted identifier names or comments are not 1362** independent tokens (they are part of the token in which they are 1363** embedded) and thus do not count as a statement terminator. 1364** 1365** These routines do not parse the SQL statements thus 1366** will not detect syntactically incorrect SQL. 1367** 1368** Requirements: [H10511] [H10512] 1369** 1370** The input to [sqlite3_complete()] must be a zero-terminated 1371** UTF-8 string. 1372** 1373** The input to [sqlite3_complete16()] must be a zero-terminated 1374** UTF-16 string in native byte order. 1375*/ 1376int sqlite3_complete(const char *sql); 1377int sqlite3_complete16(const void *sql); 1378 1379/* 1380** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> 1381** 1382** This routine sets a callback function that might be invoked whenever 1383** an attempt is made to open a database table that another thread 1384** or process has locked. 1385** 1386** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1387** is returned immediately upon encountering the lock. If the busy callback 1388** is not NULL, then the callback will be invoked with two arguments. 1389** 1390** The first argument to the handler is a copy of the void* pointer which 1391** is the third argument to sqlite3_busy_handler(). The second argument to 1392** the handler callback is the number of times that the busy handler has 1393** been invoked for this locking event. If the 1394** busy callback returns 0, then no additional attempts are made to 1395** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1396** If the callback returns non-zero, then another attempt 1397** is made to open the database for reading and the cycle repeats. 1398** 1399** The presence of a busy handler does not guarantee that it will be invoked 1400** when there is lock contention. If SQLite determines that invoking the busy 1401** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1402** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1403** Consider a scenario where one process is holding a read lock that 1404** it is trying to promote to a reserved lock and 1405** a second process is holding a reserved lock that it is trying 1406** to promote to an exclusive lock. The first process cannot proceed 1407** because it is blocked by the second and the second process cannot 1408** proceed because it is blocked by the first. If both processes 1409** invoke the busy handlers, neither will make any progress. Therefore, 1410** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1411** will induce the first process to release its read lock and allow 1412** the second process to proceed. 1413** 1414** The default busy callback is NULL. 1415** 1416** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1417** when SQLite is in the middle of a large transaction where all the 1418** changes will not fit into the in-memory cache. SQLite will 1419** already hold a RESERVED lock on the database file, but it needs 1420** to promote this lock to EXCLUSIVE so that it can spill cache 1421** pages into the database file without harm to concurrent 1422** readers. If it is unable to promote the lock, then the in-memory 1423** cache will be left in an inconsistent state and so the error 1424** code is promoted from the relatively benign [SQLITE_BUSY] to 1425** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1426** forces an automatic rollback of the changes. See the 1427** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1428** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1429** this is important. 1430** 1431** There can only be a single busy handler defined for each 1432** [database connection]. Setting a new busy handler clears any 1433** previously set handler. Note that calling [sqlite3_busy_timeout()] 1434** will also set or clear the busy handler. 1435** 1436** The busy callback should not take any actions which modify the 1437** database connection that invoked the busy handler. Any such actions 1438** result in undefined behavior. 1439** 1440** Requirements: 1441** [H12311] [H12312] [H12314] [H12316] [H12318] 1442** 1443** A busy handler must not close the database connection 1444** or [prepared statement] that invoked the busy handler. 1445*/ 1446int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1447 1448/* 1449** CAPI3REF: Set A Busy Timeout {H12340} <S40410> 1450** 1451** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1452** for a specified amount of time when a table is locked. The handler 1453** will sleep multiple times until at least "ms" milliseconds of sleeping 1454** have accumulated. {H12343} After "ms" milliseconds of sleeping, 1455** the handler returns 0 which causes [sqlite3_step()] to return 1456** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1457** 1458** Calling this routine with an argument less than or equal to zero 1459** turns off all busy handlers. 1460** 1461** There can only be a single busy handler for a particular 1462** [database connection] any any given moment. If another busy handler 1463** was defined (using [sqlite3_busy_handler()]) prior to calling 1464** this routine, that other busy handler is cleared. 1465** 1466** Requirements: 1467** [H12341] [H12343] [H12344] 1468*/ 1469int sqlite3_busy_timeout(sqlite3*, int ms); 1470 1471/* 1472** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> 1473** 1474** Definition: A <b>result table</b> is memory data structure created by the 1475** [sqlite3_get_table()] interface. A result table records the 1476** complete query results from one or more queries. 1477** 1478** The table conceptually has a number of rows and columns. But 1479** these numbers are not part of the result table itself. These 1480** numbers are obtained separately. Let N be the number of rows 1481** and M be the number of columns. 1482** 1483** A result table is an array of pointers to zero-terminated UTF-8 strings. 1484** There are (N+1)*M elements in the array. The first M pointers point 1485** to zero-terminated strings that contain the names of the columns. 1486** The remaining entries all point to query results. NULL values result 1487** in NULL pointers. All other values are in their UTF-8 zero-terminated 1488** string representation as returned by [sqlite3_column_text()]. 1489** 1490** A result table might consist of one or more memory allocations. 1491** It is not safe to pass a result table directly to [sqlite3_free()]. 1492** A result table should be deallocated using [sqlite3_free_table()]. 1493** 1494** As an example of the result table format, suppose a query result 1495** is as follows: 1496** 1497** <blockquote><pre> 1498** Name | Age 1499** ----------------------- 1500** Alice | 43 1501** Bob | 28 1502** Cindy | 21 1503** </pre></blockquote> 1504** 1505** There are two column (M==2) and three rows (N==3). Thus the 1506** result table has 8 entries. Suppose the result table is stored 1507** in an array names azResult. Then azResult holds this content: 1508** 1509** <blockquote><pre> 1510** azResult[0] = "Name"; 1511** azResult[1] = "Age"; 1512** azResult[2] = "Alice"; 1513** azResult[3] = "43"; 1514** azResult[4] = "Bob"; 1515** azResult[5] = "28"; 1516** azResult[6] = "Cindy"; 1517** azResult[7] = "21"; 1518** </pre></blockquote> 1519** 1520** The sqlite3_get_table() function evaluates one or more 1521** semicolon-separated SQL statements in the zero-terminated UTF-8 1522** string of its 2nd parameter. It returns a result table to the 1523** pointer given in its 3rd parameter. 1524** 1525** After the calling function has finished using the result, it should 1526** pass the pointer to the result table to sqlite3_free_table() in order to 1527** release the memory that was malloced. Because of the way the 1528** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1529** function must not try to call [sqlite3_free()] directly. Only 1530** [sqlite3_free_table()] is able to release the memory properly and safely. 1531** 1532** The sqlite3_get_table() interface is implemented as a wrapper around 1533** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1534** to any internal data structures of SQLite. It uses only the public 1535** interface defined here. As a consequence, errors that occur in the 1536** wrapper layer outside of the internal [sqlite3_exec()] call are not 1537** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. 1538** 1539** Requirements: 1540** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] 1541*/ 1542int sqlite3_get_table( 1543 sqlite3 *db, /* An open database */ 1544 const char *zSql, /* SQL to be evaluated */ 1545 char ***pazResult, /* Results of the query */ 1546 int *pnRow, /* Number of result rows written here */ 1547 int *pnColumn, /* Number of result columns written here */ 1548 char **pzErrmsg /* Error msg written here */ 1549); 1550void sqlite3_free_table(char **result); 1551 1552/* 1553** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> 1554** 1555** These routines are workalikes of the "printf()" family of functions 1556** from the standard C library. 1557** 1558** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1559** results into memory obtained from [sqlite3_malloc()]. 1560** The strings returned by these two routines should be 1561** released by [sqlite3_free()]. Both routines return a 1562** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1563** memory to hold the resulting string. 1564** 1565** In sqlite3_snprintf() routine is similar to "snprintf()" from 1566** the standard C library. The result is written into the 1567** buffer supplied as the second parameter whose size is given by 1568** the first parameter. Note that the order of the 1569** first two parameters is reversed from snprintf(). This is an 1570** historical accident that cannot be fixed without breaking 1571** backwards compatibility. Note also that sqlite3_snprintf() 1572** returns a pointer to its buffer instead of the number of 1573** characters actually written into the buffer. We admit that 1574** the number of characters written would be a more useful return 1575** value but we cannot change the implementation of sqlite3_snprintf() 1576** now without breaking compatibility. 1577** 1578** As long as the buffer size is greater than zero, sqlite3_snprintf() 1579** guarantees that the buffer is always zero-terminated. The first 1580** parameter "n" is the total size of the buffer, including space for 1581** the zero terminator. So the longest string that can be completely 1582** written will be n-1 characters. 1583** 1584** These routines all implement some additional formatting 1585** options that are useful for constructing SQL statements. 1586** All of the usual printf() formatting options apply. In addition, there 1587** is are "%q", "%Q", and "%z" options. 1588** 1589** The %q option works like %s in that it substitutes a null-terminated 1590** string from the argument list. But %q also doubles every '\'' character. 1591** %q is designed for use inside a string literal. By doubling each '\'' 1592** character it escapes that character and allows it to be inserted into 1593** the string. 1594** 1595** For example, assume the string variable zText contains text as follows: 1596** 1597** <blockquote><pre> 1598** char *zText = "It's a happy day!"; 1599** </pre></blockquote> 1600** 1601** One can use this text in an SQL statement as follows: 1602** 1603** <blockquote><pre> 1604** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1605** sqlite3_exec(db, zSQL, 0, 0, 0); 1606** sqlite3_free(zSQL); 1607** </pre></blockquote> 1608** 1609** Because the %q format string is used, the '\'' character in zText 1610** is escaped and the SQL generated is as follows: 1611** 1612** <blockquote><pre> 1613** INSERT INTO table1 VALUES('It''s a happy day!') 1614** </pre></blockquote> 1615** 1616** This is correct. Had we used %s instead of %q, the generated SQL 1617** would have looked like this: 1618** 1619** <blockquote><pre> 1620** INSERT INTO table1 VALUES('It's a happy day!'); 1621** </pre></blockquote> 1622** 1623** This second example is an SQL syntax error. As a general rule you should 1624** always use %q instead of %s when inserting text into a string literal. 1625** 1626** The %Q option works like %q except it also adds single quotes around 1627** the outside of the total string. Additionally, if the parameter in the 1628** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1629** single quotes) in place of the %Q option. So, for example, one could say: 1630** 1631** <blockquote><pre> 1632** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1633** sqlite3_exec(db, zSQL, 0, 0, 0); 1634** sqlite3_free(zSQL); 1635** </pre></blockquote> 1636** 1637** The code above will render a correct SQL statement in the zSQL 1638** variable even if the zText variable is a NULL pointer. 1639** 1640** The "%z" formatting option works exactly like "%s" with the 1641** addition that after the string has been read and copied into 1642** the result, [sqlite3_free()] is called on the input string. {END} 1643** 1644** Requirements: 1645** [H17403] [H17406] [H17407] 1646*/ 1647char *sqlite3_mprintf(const char*,...); 1648char *sqlite3_vmprintf(const char*, va_list); 1649char *sqlite3_snprintf(int,char*,const char*, ...); 1650 1651/* 1652** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> 1653** 1654** The SQLite core uses these three routines for all of its own 1655** internal memory allocation needs. "Core" in the previous sentence 1656** does not include operating-system specific VFS implementation. The 1657** Windows VFS uses native malloc() and free() for some operations. 1658** 1659** The sqlite3_malloc() routine returns a pointer to a block 1660** of memory at least N bytes in length, where N is the parameter. 1661** If sqlite3_malloc() is unable to obtain sufficient free 1662** memory, it returns a NULL pointer. If the parameter N to 1663** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1664** a NULL pointer. 1665** 1666** Calling sqlite3_free() with a pointer previously returned 1667** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1668** that it might be reused. The sqlite3_free() routine is 1669** a no-op if is called with a NULL pointer. Passing a NULL pointer 1670** to sqlite3_free() is harmless. After being freed, memory 1671** should neither be read nor written. Even reading previously freed 1672** memory might result in a segmentation fault or other severe error. 1673** Memory corruption, a segmentation fault, or other severe error 1674** might result if sqlite3_free() is called with a non-NULL pointer that 1675** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 1676** 1677** The sqlite3_realloc() interface attempts to resize a 1678** prior memory allocation to be at least N bytes, where N is the 1679** second parameter. The memory allocation to be resized is the first 1680** parameter. If the first parameter to sqlite3_realloc() 1681** is a NULL pointer then its behavior is identical to calling 1682** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1683** If the second parameter to sqlite3_realloc() is zero or 1684** negative then the behavior is exactly the same as calling 1685** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1686** sqlite3_realloc() returns a pointer to a memory allocation 1687** of at least N bytes in size or NULL if sufficient memory is unavailable. 1688** If M is the size of the prior allocation, then min(N,M) bytes 1689** of the prior allocation are copied into the beginning of buffer returned 1690** by sqlite3_realloc() and the prior allocation is freed. 1691** If sqlite3_realloc() returns NULL, then the prior allocation 1692** is not freed. 1693** 1694** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1695** is always aligned to at least an 8 byte boundary. {END} 1696** 1697** The default implementation of the memory allocation subsystem uses 1698** the malloc(), realloc() and free() provided by the standard C library. 1699** {H17382} However, if SQLite is compiled with the 1700** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> 1701** is an integer), then SQLite create a static array of at least 1702** <i>NNN</i> bytes in size and uses that array for all of its dynamic 1703** memory allocation needs. {END} Additional memory allocator options 1704** may be added in future releases. 1705** 1706** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1707** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1708** implementation of these routines to be omitted. That capability 1709** is no longer provided. Only built-in memory allocators can be used. 1710** 1711** The Windows OS interface layer calls 1712** the system malloc() and free() directly when converting 1713** filenames between the UTF-8 encoding used by SQLite 1714** and whatever filename encoding is used by the particular Windows 1715** installation. Memory allocation errors are detected, but 1716** they are reported back as [SQLITE_CANTOPEN] or 1717** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1718** 1719** Requirements: 1720** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] 1721** [H17321] [H17322] [H17323] 1722** 1723** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1724** must be either NULL or else pointers obtained from a prior 1725** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 1726** not yet been released. 1727** 1728** The application must not read or write any part of 1729** a block of memory after it has been released using 1730** [sqlite3_free()] or [sqlite3_realloc()]. 1731*/ 1732void *sqlite3_malloc(int); 1733void *sqlite3_realloc(void*, int); 1734void sqlite3_free(void*); 1735 1736/* 1737** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> 1738** 1739** SQLite provides these two interfaces for reporting on the status 1740** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1741** routines, which form the built-in memory allocation subsystem. 1742** 1743** Requirements: 1744** [H17371] [H17373] [H17374] [H17375] 1745*/ 1746sqlite3_int64 sqlite3_memory_used(void); 1747sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1748 1749/* 1750** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> 1751** 1752** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1753** select random [ROWID | ROWIDs] when inserting new records into a table that 1754** already uses the largest possible [ROWID]. The PRNG is also used for 1755** the build-in random() and randomblob() SQL functions. This interface allows 1756** applications to access the same PRNG for other purposes. 1757** 1758** A call to this routine stores N bytes of randomness into buffer P. 1759** 1760** The first time this routine is invoked (either internally or by 1761** the application) the PRNG is seeded using randomness obtained 1762** from the xRandomness method of the default [sqlite3_vfs] object. 1763** On all subsequent invocations, the pseudo-randomness is generated 1764** internally and without recourse to the [sqlite3_vfs] xRandomness 1765** method. 1766** 1767** Requirements: 1768** [H17392] 1769*/ 1770void sqlite3_randomness(int N, void *P); 1771 1772/* 1773** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> 1774** 1775** This routine registers a authorizer callback with a particular 1776** [database connection], supplied in the first argument. 1777** The authorizer callback is invoked as SQL statements are being compiled 1778** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1779** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1780** points during the compilation process, as logic is being created 1781** to perform various actions, the authorizer callback is invoked to 1782** see if those actions are allowed. The authorizer callback should 1783** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1784** specific action but allow the SQL statement to continue to be 1785** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1786** rejected with an error. If the authorizer callback returns 1787** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1788** then the [sqlite3_prepare_v2()] or equivalent call that triggered 1789** the authorizer will fail with an error message. 1790** 1791** When the callback returns [SQLITE_OK], that means the operation 1792** requested is ok. When the callback returns [SQLITE_DENY], the 1793** [sqlite3_prepare_v2()] or equivalent call that triggered the 1794** authorizer will fail with an error message explaining that 1795** access is denied. If the authorizer code is [SQLITE_READ] 1796** and the callback returns [SQLITE_IGNORE] then the 1797** [prepared statement] statement is constructed to substitute 1798** a NULL value in place of the table column that would have 1799** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1800** return can be used to deny an untrusted user access to individual 1801** columns of a table. 1802** 1803** The first parameter to the authorizer callback is a copy of the third 1804** parameter to the sqlite3_set_authorizer() interface. The second parameter 1805** to the callback is an integer [SQLITE_COPY | action code] that specifies 1806** the particular action to be authorized. The third through sixth parameters 1807** to the callback are zero-terminated strings that contain additional 1808** details about the action to be authorized. 1809** 1810** An authorizer is used when [sqlite3_prepare | preparing] 1811** SQL statements from an untrusted source, to ensure that the SQL statements 1812** do not try to access data they are not allowed to see, or that they do not 1813** try to execute malicious statements that damage the database. For 1814** example, an application may allow a user to enter arbitrary 1815** SQL queries for evaluation by a database. But the application does 1816** not want the user to be able to make arbitrary changes to the 1817** database. An authorizer could then be put in place while the 1818** user-entered SQL is being [sqlite3_prepare | prepared] that 1819** disallows everything except [SELECT] statements. 1820** 1821** Applications that need to process SQL from untrusted sources 1822** might also consider lowering resource limits using [sqlite3_limit()] 1823** and limiting database size using the [max_page_count] [PRAGMA] 1824** in addition to using an authorizer. 1825** 1826** Only a single authorizer can be in place on a database connection 1827** at a time. Each call to sqlite3_set_authorizer overrides the 1828** previous call. Disable the authorizer by installing a NULL callback. 1829** The authorizer is disabled by default. 1830** 1831** The authorizer callback must not do anything that will modify 1832** the database connection that invoked the authorizer callback. 1833** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1834** database connections for the meaning of "modify" in this paragraph. 1835** 1836** When [sqlite3_prepare_v2()] is used to prepare a statement, the 1837** statement might be reprepared during [sqlite3_step()] due to a 1838** schema change. Hence, the application should ensure that the 1839** correct authorizer callback remains in place during the [sqlite3_step()]. 1840** 1841** Note that the authorizer callback is invoked only during 1842** [sqlite3_prepare()] or its variants. Authorization is not 1843** performed during statement evaluation in [sqlite3_step()]. 1844** 1845** Requirements: 1846** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] 1847** [H12511] [H12512] [H12520] [H12521] [H12522] 1848*/ 1849int sqlite3_set_authorizer( 1850 sqlite3*, 1851 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1852 void *pUserData 1853); 1854 1855/* 1856** CAPI3REF: Authorizer Return Codes {H12590} <H12500> 1857** 1858** The [sqlite3_set_authorizer | authorizer callback function] must 1859** return either [SQLITE_OK] or one of these two constants in order 1860** to signal SQLite whether or not the action is permitted. See the 1861** [sqlite3_set_authorizer | authorizer documentation] for additional 1862** information. 1863*/ 1864#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1865#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1866 1867/* 1868** CAPI3REF: Authorizer Action Codes {H12550} <H12500> 1869** 1870** The [sqlite3_set_authorizer()] interface registers a callback function 1871** that is invoked to authorize certain SQL statement actions. The 1872** second parameter to the callback is an integer code that specifies 1873** what action is being authorized. These are the integer action codes that 1874** the authorizer callback may be passed. 1875** 1876** These action code values signify what kind of operation is to be 1877** authorized. The 3rd and 4th parameters to the authorization 1878** callback function will be parameters or NULL depending on which of these 1879** codes is used as the second parameter. The 5th parameter to the 1880** authorizer callback is the name of the database ("main", "temp", 1881** etc.) if applicable. The 6th parameter to the authorizer callback 1882** is the name of the inner-most trigger or view that is responsible for 1883** the access attempt or NULL if this access attempt is directly from 1884** top-level SQL code. 1885** 1886** Requirements: 1887** [H12551] [H12552] [H12553] [H12554] 1888*/ 1889/******************************************* 3rd ************ 4th ***********/ 1890#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1891#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1892#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1893#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1894#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1895#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1896#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1897#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1898#define SQLITE_DELETE 9 /* Table Name NULL */ 1899#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1900#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1901#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1902#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1903#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1904#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1905#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1906#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1907#define SQLITE_INSERT 18 /* Table Name NULL */ 1908#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1909#define SQLITE_READ 20 /* Table Name Column Name */ 1910#define SQLITE_SELECT 21 /* NULL NULL */ 1911#define SQLITE_TRANSACTION 22 /* Operation NULL */ 1912#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1913#define SQLITE_ATTACH 24 /* Filename NULL */ 1914#define SQLITE_DETACH 25 /* Database Name NULL */ 1915#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1916#define SQLITE_REINDEX 27 /* Index Name NULL */ 1917#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1918#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1919#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1920#define SQLITE_FUNCTION 31 /* NULL Function Name */ 1921#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 1922#define SQLITE_COPY 0 /* No longer used */ 1923 1924/* 1925** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> 1926** EXPERIMENTAL 1927** 1928** These routines register callback functions that can be used for 1929** tracing and profiling the execution of SQL statements. 1930** 1931** The callback function registered by sqlite3_trace() is invoked at 1932** various times when an SQL statement is being run by [sqlite3_step()]. 1933** The callback returns a UTF-8 rendering of the SQL statement text 1934** as the statement first begins executing. Additional callbacks occur 1935** as each triggered subprogram is entered. The callbacks for triggers 1936** contain a UTF-8 SQL comment that identifies the trigger. 1937** 1938** The callback function registered by sqlite3_profile() is invoked 1939** as each SQL statement finishes. The profile callback contains 1940** the original statement text and an estimate of wall-clock time 1941** of how long that statement took to run. 1942** 1943** Requirements: 1944** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] 1945** [H12290] 1946*/ 1947SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1948SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 1949 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1950 1951/* 1952** CAPI3REF: Query Progress Callbacks {H12910} <S60400> 1953** 1954** This routine configures a callback function - the 1955** progress callback - that is invoked periodically during long 1956** running calls to [sqlite3_exec()], [sqlite3_step()] and 1957** [sqlite3_get_table()]. An example use for this 1958** interface is to keep a GUI updated during a large query. 1959** 1960** If the progress callback returns non-zero, the operation is 1961** interrupted. This feature can be used to implement a 1962** "Cancel" button on a GUI progress dialog box. 1963** 1964** The progress handler must not do anything that will modify 1965** the database connection that invoked the progress handler. 1966** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1967** database connections for the meaning of "modify" in this paragraph. 1968** 1969** Requirements: 1970** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] 1971** 1972*/ 1973void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1974 1975/* 1976** CAPI3REF: Opening A New Database Connection {H12700} <S40200> 1977** 1978** These routines open an SQLite database file whose name is given by the 1979** filename argument. The filename argument is interpreted as UTF-8 for 1980** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 1981** order for sqlite3_open16(). A [database connection] handle is usually 1982** returned in *ppDb, even if an error occurs. The only exception is that 1983** if SQLite is unable to allocate memory to hold the [sqlite3] object, 1984** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 1985** object. If the database is opened (and/or created) successfully, then 1986** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The 1987** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1988** an English language description of the error. 1989** 1990** The default encoding for the database will be UTF-8 if 1991** sqlite3_open() or sqlite3_open_v2() is called and 1992** UTF-16 in the native byte order if sqlite3_open16() is used. 1993** 1994** Whether or not an error occurs when it is opened, resources 1995** associated with the [database connection] handle should be released by 1996** passing it to [sqlite3_close()] when it is no longer required. 1997** 1998** The sqlite3_open_v2() interface works like sqlite3_open() 1999** except that it accepts two additional parameters for additional control 2000** over the new database connection. The flags parameter can take one of 2001** the following three values, optionally combined with the 2002** [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags: 2003** 2004** <dl> 2005** <dt>[SQLITE_OPEN_READONLY]</dt> 2006** <dd>The database is opened in read-only mode. If the database does not 2007** already exist, an error is returned.</dd> 2008** 2009** <dt>[SQLITE_OPEN_READWRITE]</dt> 2010** <dd>The database is opened for reading and writing if possible, or reading 2011** only if the file is write protected by the operating system. In either 2012** case the database must already exist, otherwise an error is returned.</dd> 2013** 2014** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2015** <dd>The database is opened for reading and writing, and is creates it if 2016** it does not already exist. This is the behavior that is always used for 2017** sqlite3_open() and sqlite3_open16().</dd> 2018** </dl> 2019** 2020** If the 3rd parameter to sqlite3_open_v2() is not one of the 2021** combinations shown above or one of the combinations shown above combined 2022** with the [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags, 2023** then the behavior is undefined. 2024** 2025** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2026** opens in the multi-thread [threading mode] as long as the single-thread 2027** mode has not been set at compile-time or start-time. If the 2028** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2029** in the serialized [threading mode] unless single-thread was 2030** previously selected at compile-time or start-time. 2031** 2032** If the filename is ":memory:", then a private, temporary in-memory database 2033** is created for the connection. This in-memory database will vanish when 2034** the database connection is closed. Future versions of SQLite might 2035** make use of additional special filenames that begin with the ":" character. 2036** It is recommended that when a database filename actually does begin with 2037** a ":" character you should prefix the filename with a pathname such as 2038** "./" to avoid ambiguity. 2039** 2040** If the filename is an empty string, then a private, temporary 2041** on-disk database will be created. This private database will be 2042** automatically deleted as soon as the database connection is closed. 2043** 2044** The fourth parameter to sqlite3_open_v2() is the name of the 2045** [sqlite3_vfs] object that defines the operating system interface that 2046** the new database connection should use. If the fourth parameter is 2047** a NULL pointer then the default [sqlite3_vfs] object is used. 2048** 2049** <b>Note to Windows users:</b> The encoding used for the filename argument 2050** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2051** codepage is currently defined. Filenames containing international 2052** characters must be converted to UTF-8 prior to passing them into 2053** sqlite3_open() or sqlite3_open_v2(). 2054** 2055** Requirements: 2056** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] 2057** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] 2058*/ 2059int sqlite3_open( 2060 const char *filename, /* Database filename (UTF-8) */ 2061 sqlite3 **ppDb /* OUT: SQLite db handle */ 2062); 2063int sqlite3_open16( 2064 const void *filename, /* Database filename (UTF-16) */ 2065 sqlite3 **ppDb /* OUT: SQLite db handle */ 2066); 2067int sqlite3_open_v2( 2068 const char *filename, /* Database filename (UTF-8) */ 2069 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2070 int flags, /* Flags */ 2071 const char *zVfs /* Name of VFS module to use */ 2072); 2073 2074/* 2075** CAPI3REF: Error Codes And Messages {H12800} <S60200> 2076** 2077** The sqlite3_errcode() interface returns the numeric [result code] or 2078** [extended result code] for the most recent failed sqlite3_* API call 2079** associated with a [database connection]. If a prior API call failed 2080** but the most recent API call succeeded, the return value from 2081** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() 2082** interface is the same except that it always returns the 2083** [extended result code] even when extended result codes are 2084** disabled. 2085** 2086** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2087** text that describes the error, as either UTF-8 or UTF-16 respectively. 2088** Memory to hold the error message string is managed internally. 2089** The application does not need to worry about freeing the result. 2090** However, the error string might be overwritten or deallocated by 2091** subsequent calls to other SQLite interface functions. 2092** 2093** When the serialized [threading mode] is in use, it might be the 2094** case that a second error occurs on a separate thread in between 2095** the time of the first error and the call to these interfaces. 2096** When that happens, the second error will be reported since these 2097** interfaces always report the most recent result. To avoid 2098** this, each thread can obtain exclusive use of the [database connection] D 2099** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2100** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2101** all calls to the interfaces listed here are completed. 2102** 2103** If an interface fails with SQLITE_MISUSE, that means the interface 2104** was invoked incorrectly by the application. In that case, the 2105** error code and message may or may not be set. 2106** 2107** Requirements: 2108** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] 2109*/ 2110int sqlite3_errcode(sqlite3 *db); 2111int sqlite3_extended_errcode(sqlite3 *db); 2112const char *sqlite3_errmsg(sqlite3*); 2113const void *sqlite3_errmsg16(sqlite3*); 2114 2115/* 2116** CAPI3REF: SQL Statement Object {H13000} <H13010> 2117** KEYWORDS: {prepared statement} {prepared statements} 2118** 2119** An instance of this object represents a single SQL statement. 2120** This object is variously known as a "prepared statement" or a 2121** "compiled SQL statement" or simply as a "statement". 2122** 2123** The life of a statement object goes something like this: 2124** 2125** <ol> 2126** <li> Create the object using [sqlite3_prepare_v2()] or a related 2127** function. 2128** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2129** interfaces. 2130** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2131** <li> Reset the statement using [sqlite3_reset()] then go back 2132** to step 2. Do this zero or more times. 2133** <li> Destroy the object using [sqlite3_finalize()]. 2134** </ol> 2135** 2136** Refer to documentation on individual methods above for additional 2137** information. 2138*/ 2139typedef struct sqlite3_stmt sqlite3_stmt; 2140 2141/* 2142** CAPI3REF: Run-time Limits {H12760} <S20600> 2143** 2144** This interface allows the size of various constructs to be limited 2145** on a connection by connection basis. The first parameter is the 2146** [database connection] whose limit is to be set or queried. The 2147** second parameter is one of the [limit categories] that define a 2148** class of constructs to be size limited. The third parameter is the 2149** new limit for that construct. The function returns the old limit. 2150** 2151** If the new limit is a negative number, the limit is unchanged. 2152** For the limit category of SQLITE_LIMIT_XYZ there is a 2153** [limits | hard upper bound] 2154** set by a compile-time C preprocessor macro named 2155** [limits | SQLITE_MAX_XYZ]. 2156** (The "_LIMIT_" in the name is changed to "_MAX_".) 2157** Attempts to increase a limit above its hard upper bound are 2158** silently truncated to the hard upper limit. 2159** 2160** Run time limits are intended for use in applications that manage 2161** both their own internal database and also databases that are controlled 2162** by untrusted external sources. An example application might be a 2163** web browser that has its own databases for storing history and 2164** separate databases controlled by JavaScript applications downloaded 2165** off the Internet. The internal databases can be given the 2166** large, default limits. Databases managed by external sources can 2167** be given much smaller limits designed to prevent a denial of service 2168** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2169** interface to further control untrusted SQL. The size of the database 2170** created by an untrusted script can be contained using the 2171** [max_page_count] [PRAGMA]. 2172** 2173** New run-time limit categories may be added in future releases. 2174** 2175** Requirements: 2176** [H12762] [H12766] [H12769] 2177*/ 2178int sqlite3_limit(sqlite3*, int id, int newVal); 2179 2180/* 2181** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> 2182** KEYWORDS: {limit category} {limit categories} 2183** 2184** These constants define various performance limits 2185** that can be lowered at run-time using [sqlite3_limit()]. 2186** The synopsis of the meanings of the various limits is shown below. 2187** Additional information is available at [limits | Limits in SQLite]. 2188** 2189** <dl> 2190** <dt>SQLITE_LIMIT_LENGTH</dt> 2191** <dd>The maximum size of any string or BLOB or table row.<dd> 2192** 2193** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2194** <dd>The maximum length of an SQL statement.</dd> 2195** 2196** <dt>SQLITE_LIMIT_COLUMN</dt> 2197** <dd>The maximum number of columns in a table definition or in the 2198** result set of a [SELECT] or the maximum number of columns in an index 2199** or in an ORDER BY or GROUP BY clause.</dd> 2200** 2201** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2202** <dd>The maximum depth of the parse tree on any expression.</dd> 2203** 2204** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2205** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2206** 2207** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2208** <dd>The maximum number of instructions in a virtual machine program 2209** used to implement an SQL statement.</dd> 2210** 2211** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2212** <dd>The maximum number of arguments on a function.</dd> 2213** 2214** <dt>SQLITE_LIMIT_ATTACHED</dt> 2215** <dd>The maximum number of [ATTACH | attached databases].</dd> 2216** 2217** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2218** <dd>The maximum length of the pattern argument to the [LIKE] or 2219** [GLOB] operators.</dd> 2220** 2221** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2222** <dd>The maximum number of variables in an SQL statement that can 2223** be bound.</dd> 2224** </dl> 2225*/ 2226#define SQLITE_LIMIT_LENGTH 0 2227#define SQLITE_LIMIT_SQL_LENGTH 1 2228#define SQLITE_LIMIT_COLUMN 2 2229#define SQLITE_LIMIT_EXPR_DEPTH 3 2230#define SQLITE_LIMIT_COMPOUND_SELECT 4 2231#define SQLITE_LIMIT_VDBE_OP 5 2232#define SQLITE_LIMIT_FUNCTION_ARG 6 2233#define SQLITE_LIMIT_ATTACHED 7 2234#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2235#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2236 2237/* 2238** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> 2239** KEYWORDS: {SQL statement compiler} 2240** 2241** To execute an SQL query, it must first be compiled into a byte-code 2242** program using one of these routines. 2243** 2244** The first argument, "db", is a [database connection] obtained from a 2245** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2246** [sqlite3_open16()]. The database connection must not have been closed. 2247** 2248** The second argument, "zSql", is the statement to be compiled, encoded 2249** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2250** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2251** use UTF-16. 2252** 2253** If the nByte argument is less than zero, then zSql is read up to the 2254** first zero terminator. If nByte is non-negative, then it is the maximum 2255** number of bytes read from zSql. When nByte is non-negative, the 2256** zSql string ends at either the first '\000' or '\u0000' character or 2257** the nByte-th byte, whichever comes first. If the caller knows 2258** that the supplied string is nul-terminated, then there is a small 2259** performance advantage to be gained by passing an nByte parameter that 2260** is equal to the number of bytes in the input string <i>including</i> 2261** the nul-terminator bytes. 2262** 2263** If pzTail is not NULL then *pzTail is made to point to the first byte 2264** past the end of the first SQL statement in zSql. These routines only 2265** compile the first statement in zSql, so *pzTail is left pointing to 2266** what remains uncompiled. 2267** 2268** *ppStmt is left pointing to a compiled [prepared statement] that can be 2269** executed using [sqlite3_step()]. If there is an error, *ppStmt is set 2270** to NULL. If the input text contains no SQL (if the input is an empty 2271** string or a comment) then *ppStmt is set to NULL. 2272** The calling procedure is responsible for deleting the compiled 2273** SQL statement using [sqlite3_finalize()] after it has finished with it. 2274** ppStmt may not be NULL. 2275** 2276** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. 2277** 2278** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2279** recommended for all new programs. The two older interfaces are retained 2280** for backwards compatibility, but their use is discouraged. 2281** In the "v2" interfaces, the prepared statement 2282** that is returned (the [sqlite3_stmt] object) contains a copy of the 2283** original SQL text. This causes the [sqlite3_step()] interface to 2284** behave a differently in two ways: 2285** 2286** <ol> 2287** <li> 2288** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2289** always used to do, [sqlite3_step()] will automatically recompile the SQL 2290** statement and try to run it again. If the schema has changed in 2291** a way that makes the statement no longer valid, [sqlite3_step()] will still 2292** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is 2293** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the 2294** error go away. Note: use [sqlite3_errmsg()] to find the text 2295** of the parsing error that results in an [SQLITE_SCHEMA] return. 2296** </li> 2297** 2298** <li> 2299** When an error occurs, [sqlite3_step()] will return one of the detailed 2300** [error codes] or [extended error codes]. The legacy behavior was that 2301** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2302** and you would have to make a second call to [sqlite3_reset()] in order 2303** to find the underlying cause of the problem. With the "v2" prepare 2304** interfaces, the underlying reason for the error is returned immediately. 2305** </li> 2306** </ol> 2307** 2308** Requirements: 2309** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] 2310** 2311*/ 2312int sqlite3_prepare( 2313 sqlite3 *db, /* Database handle */ 2314 const char *zSql, /* SQL statement, UTF-8 encoded */ 2315 int nByte, /* Maximum length of zSql in bytes. */ 2316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2317 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2318); 2319int sqlite3_prepare_v2( 2320 sqlite3 *db, /* Database handle */ 2321 const char *zSql, /* SQL statement, UTF-8 encoded */ 2322 int nByte, /* Maximum length of zSql in bytes. */ 2323 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2324 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2325); 2326int sqlite3_prepare16( 2327 sqlite3 *db, /* Database handle */ 2328 const void *zSql, /* SQL statement, UTF-16 encoded */ 2329 int nByte, /* Maximum length of zSql in bytes. */ 2330 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2331 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2332); 2333int sqlite3_prepare16_v2( 2334 sqlite3 *db, /* Database handle */ 2335 const void *zSql, /* SQL statement, UTF-16 encoded */ 2336 int nByte, /* Maximum length of zSql in bytes. */ 2337 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2338 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2339); 2340 2341/* 2342** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> 2343** 2344** This interface can be used to retrieve a saved copy of the original 2345** SQL text used to create a [prepared statement] if that statement was 2346** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2347** 2348** Requirements: 2349** [H13101] [H13102] [H13103] 2350*/ 2351const char *sqlite3_sql(sqlite3_stmt *pStmt); 2352 2353/* 2354** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> 2355** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2356** 2357** SQLite uses the sqlite3_value object to represent all values 2358** that can be stored in a database table. SQLite uses dynamic typing 2359** for the values it stores. Values stored in sqlite3_value objects 2360** can be integers, floating point values, strings, BLOBs, or NULL. 2361** 2362** An sqlite3_value object may be either "protected" or "unprotected". 2363** Some interfaces require a protected sqlite3_value. Other interfaces 2364** will accept either a protected or an unprotected sqlite3_value. 2365** Every interface that accepts sqlite3_value arguments specifies 2366** whether or not it requires a protected sqlite3_value. 2367** 2368** The terms "protected" and "unprotected" refer to whether or not 2369** a mutex is held. A internal mutex is held for a protected 2370** sqlite3_value object but no mutex is held for an unprotected 2371** sqlite3_value object. If SQLite is compiled to be single-threaded 2372** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2373** or if SQLite is run in one of reduced mutex modes 2374** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2375** then there is no distinction between protected and unprotected 2376** sqlite3_value objects and they can be used interchangeably. However, 2377** for maximum code portability it is recommended that applications 2378** still make the distinction between between protected and unprotected 2379** sqlite3_value objects even when not strictly required. 2380** 2381** The sqlite3_value objects that are passed as parameters into the 2382** implementation of [application-defined SQL functions] are protected. 2383** The sqlite3_value object returned by 2384** [sqlite3_column_value()] is unprotected. 2385** Unprotected sqlite3_value objects may only be used with 2386** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2387** The [sqlite3_value_blob | sqlite3_value_type()] family of 2388** interfaces require protected sqlite3_value objects. 2389*/ 2390typedef struct Mem sqlite3_value; 2391 2392/* 2393** CAPI3REF: SQL Function Context Object {H16001} <S20200> 2394** 2395** The context in which an SQL function executes is stored in an 2396** sqlite3_context object. A pointer to an sqlite3_context object 2397** is always first parameter to [application-defined SQL functions]. 2398** The application-defined SQL function implementation will pass this 2399** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2400** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2401** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2402** and/or [sqlite3_set_auxdata()]. 2403*/ 2404typedef struct sqlite3_context sqlite3_context; 2405 2406/* 2407** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> 2408** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2409** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2410** 2411** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, 2412** literals may be replaced by a [parameter] in one of these forms: 2413** 2414** <ul> 2415** <li> ? 2416** <li> ?NNN 2417** <li> :VVV 2418** <li> @VVV 2419** <li> $VVV 2420** </ul> 2421** 2422** In the parameter forms shown above NNN is an integer literal, 2423** and VVV is an alpha-numeric parameter name. The values of these 2424** parameters (also called "host parameter names" or "SQL parameters") 2425** can be set using the sqlite3_bind_*() routines defined here. 2426** 2427** The first argument to the sqlite3_bind_*() routines is always 2428** a pointer to the [sqlite3_stmt] object returned from 2429** [sqlite3_prepare_v2()] or its variants. 2430** 2431** The second argument is the index of the SQL parameter to be set. 2432** The leftmost SQL parameter has an index of 1. When the same named 2433** SQL parameter is used more than once, second and subsequent 2434** occurrences have the same index as the first occurrence. 2435** The index for named parameters can be looked up using the 2436** [sqlite3_bind_parameter_index()] API if desired. The index 2437** for "?NNN" parameters is the value of NNN. 2438** The NNN value must be between 1 and the [sqlite3_limit()] 2439** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2440** 2441** The third argument is the value to bind to the parameter. 2442** 2443** In those routines that have a fourth argument, its value is the 2444** number of bytes in the parameter. To be clear: the value is the 2445** number of <u>bytes</u> in the value, not the number of characters. 2446** If the fourth parameter is negative, the length of the string is 2447** the number of bytes up to the first zero terminator. 2448** 2449** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2450** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2451** string after SQLite has finished with it. If the fifth argument is 2452** the special value [SQLITE_STATIC], then SQLite assumes that the 2453** information is in static, unmanaged space and does not need to be freed. 2454** If the fifth argument has the value [SQLITE_TRANSIENT], then 2455** SQLite makes its own private copy of the data immediately, before 2456** the sqlite3_bind_*() routine returns. 2457** 2458** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2459** is filled with zeroes. A zeroblob uses a fixed amount of memory 2460** (just an integer to hold its size) while it is being processed. 2461** Zeroblobs are intended to serve as placeholders for BLOBs whose 2462** content is later written using 2463** [sqlite3_blob_open | incremental BLOB I/O] routines. 2464** A negative value for the zeroblob results in a zero-length BLOB. 2465** 2466** The sqlite3_bind_*() routines must be called after 2467** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2468** before [sqlite3_step()]. 2469** Bindings are not cleared by the [sqlite3_reset()] routine. 2470** Unbound parameters are interpreted as NULL. 2471** 2472** These routines return [SQLITE_OK] on success or an error code if 2473** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2474** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. 2475** [SQLITE_MISUSE] might be returned if these routines are called on a 2476** virtual machine that is the wrong state or which has already been finalized. 2477** Detection of misuse is unreliable. Applications should not depend 2478** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2479** a logic error in the application. Future versions of SQLite might 2480** panic rather than return SQLITE_MISUSE. 2481** 2482** See also: [sqlite3_bind_parameter_count()], 2483** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2484** 2485** Requirements: 2486** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] 2487** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] 2488** 2489*/ 2490int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2491int sqlite3_bind_double(sqlite3_stmt*, int, double); 2492int sqlite3_bind_int(sqlite3_stmt*, int, int); 2493int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2494int sqlite3_bind_null(sqlite3_stmt*, int); 2495int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2496int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2497int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2498int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2499 2500/* 2501** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> 2502** 2503** This routine can be used to find the number of [SQL parameters] 2504** in a [prepared statement]. SQL parameters are tokens of the 2505** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2506** placeholders for values that are [sqlite3_bind_blob | bound] 2507** to the parameters at a later time. 2508** 2509** This routine actually returns the index of the largest (rightmost) 2510** parameter. For all forms except ?NNN, this will correspond to the 2511** number of unique parameters. If parameters of the ?NNN are used, 2512** there may be gaps in the list. 2513** 2514** See also: [sqlite3_bind_blob|sqlite3_bind()], 2515** [sqlite3_bind_parameter_name()], and 2516** [sqlite3_bind_parameter_index()]. 2517** 2518** Requirements: 2519** [H13601] 2520*/ 2521int sqlite3_bind_parameter_count(sqlite3_stmt*); 2522 2523/* 2524** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> 2525** 2526** This routine returns a pointer to the name of the n-th 2527** [SQL parameter] in a [prepared statement]. 2528** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2529** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2530** respectively. 2531** In other words, the initial ":" or "$" or "@" or "?" 2532** is included as part of the name. 2533** Parameters of the form "?" without a following integer have no name 2534** and are also referred to as "anonymous parameters". 2535** 2536** The first host parameter has an index of 1, not 0. 2537** 2538** If the value n is out of range or if the n-th parameter is 2539** nameless, then NULL is returned. The returned string is 2540** always in UTF-8 encoding even if the named parameter was 2541** originally specified as UTF-16 in [sqlite3_prepare16()] or 2542** [sqlite3_prepare16_v2()]. 2543** 2544** See also: [sqlite3_bind_blob|sqlite3_bind()], 2545** [sqlite3_bind_parameter_count()], and 2546** [sqlite3_bind_parameter_index()]. 2547** 2548** Requirements: 2549** [H13621] 2550*/ 2551const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2552 2553/* 2554** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> 2555** 2556** Return the index of an SQL parameter given its name. The 2557** index value returned is suitable for use as the second 2558** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2559** is returned if no matching parameter is found. The parameter 2560** name must be given in UTF-8 even if the original statement 2561** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2562** 2563** See also: [sqlite3_bind_blob|sqlite3_bind()], 2564** [sqlite3_bind_parameter_count()], and 2565** [sqlite3_bind_parameter_index()]. 2566** 2567** Requirements: 2568** [H13641] 2569*/ 2570int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2571 2572/* 2573** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> 2574** 2575** Contrary to the intuition of many, [sqlite3_reset()] does not reset 2576** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2577** Use this routine to reset all host parameters to NULL. 2578** 2579** Requirements: 2580** [H13661] 2581*/ 2582int sqlite3_clear_bindings(sqlite3_stmt*); 2583 2584/* 2585** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> 2586** 2587** Return the number of columns in the result set returned by the 2588** [prepared statement]. This routine returns 0 if pStmt is an SQL 2589** statement that does not return data (for example an [UPDATE]). 2590** 2591** Requirements: 2592** [H13711] 2593*/ 2594int sqlite3_column_count(sqlite3_stmt *pStmt); 2595 2596/* 2597** CAPI3REF: Column Names In A Result Set {H13720} <S10700> 2598** 2599** These routines return the name assigned to a particular column 2600** in the result set of a [SELECT] statement. The sqlite3_column_name() 2601** interface returns a pointer to a zero-terminated UTF-8 string 2602** and sqlite3_column_name16() returns a pointer to a zero-terminated 2603** UTF-16 string. The first parameter is the [prepared statement] 2604** that implements the [SELECT] statement. The second parameter is the 2605** column number. The leftmost column is number 0. 2606** 2607** The returned string pointer is valid until either the [prepared statement] 2608** is destroyed by [sqlite3_finalize()] or until the next call to 2609** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2610** 2611** If sqlite3_malloc() fails during the processing of either routine 2612** (for example during a conversion from UTF-8 to UTF-16) then a 2613** NULL pointer is returned. 2614** 2615** The name of a result column is the value of the "AS" clause for 2616** that column, if there is an AS clause. If there is no AS clause 2617** then the name of the column is unspecified and may change from 2618** one release of SQLite to the next. 2619** 2620** Requirements: 2621** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] 2622*/ 2623const char *sqlite3_column_name(sqlite3_stmt*, int N); 2624const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2625 2626/* 2627** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> 2628** 2629** These routines provide a means to determine what column of what 2630** table in which database a result of a [SELECT] statement comes from. 2631** The name of the database or table or column can be returned as 2632** either a UTF-8 or UTF-16 string. The _database_ routines return 2633** the database name, the _table_ routines return the table name, and 2634** the origin_ routines return the column name. 2635** The returned string is valid until the [prepared statement] is destroyed 2636** using [sqlite3_finalize()] or until the same information is requested 2637** again in a different encoding. 2638** 2639** The names returned are the original un-aliased names of the 2640** database, table, and column. 2641** 2642** The first argument to the following calls is a [prepared statement]. 2643** These functions return information about the Nth column returned by 2644** the statement, where N is the second function argument. 2645** 2646** If the Nth column returned by the statement is an expression or 2647** subquery and is not a column value, then all of these functions return 2648** NULL. These routine might also return NULL if a memory allocation error 2649** occurs. Otherwise, they return the name of the attached database, table 2650** and column that query result column was extracted from. 2651** 2652** As with all other SQLite APIs, those postfixed with "16" return 2653** UTF-16 encoded strings, the other functions return UTF-8. {END} 2654** 2655** These APIs are only available if the library was compiled with the 2656** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 2657** 2658** {A13751} 2659** If two or more threads call one or more of these routines against the same 2660** prepared statement and column at the same time then the results are 2661** undefined. 2662** 2663** Requirements: 2664** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] 2665** 2666** If two or more threads call one or more 2667** [sqlite3_column_database_name | column metadata interfaces] 2668** for the same [prepared statement] and result column 2669** at the same time then the results are undefined. 2670*/ 2671const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2672const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2673const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2674const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2675const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2676const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2677 2678/* 2679** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> 2680** 2681** The first parameter is a [prepared statement]. 2682** If this statement is a [SELECT] statement and the Nth column of the 2683** returned result set of that [SELECT] is a table column (not an 2684** expression or subquery) then the declared type of the table 2685** column is returned. If the Nth column of the result set is an 2686** expression or subquery, then a NULL pointer is returned. 2687** The returned string is always UTF-8 encoded. {END} 2688** 2689** For example, given the database schema: 2690** 2691** CREATE TABLE t1(c1 VARIANT); 2692** 2693** and the following statement to be compiled: 2694** 2695** SELECT c1 + 1, c1 FROM t1; 2696** 2697** this routine would return the string "VARIANT" for the second result 2698** column (i==1), and a NULL pointer for the first result column (i==0). 2699** 2700** SQLite uses dynamic run-time typing. So just because a column 2701** is declared to contain a particular type does not mean that the 2702** data stored in that column is of the declared type. SQLite is 2703** strongly typed, but the typing is dynamic not static. Type 2704** is associated with individual values, not with the containers 2705** used to hold those values. 2706** 2707** Requirements: 2708** [H13761] [H13762] [H13763] 2709*/ 2710const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2711const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2712 2713/* 2714** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> 2715** 2716** After a [prepared statement] has been prepared using either 2717** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 2718** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 2719** must be called one or more times to evaluate the statement. 2720** 2721** The details of the behavior of the sqlite3_step() interface depend 2722** on whether the statement was prepared using the newer "v2" interface 2723** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 2724** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 2725** new "v2" interface is recommended for new applications but the legacy 2726** interface will continue to be supported. 2727** 2728** In the legacy interface, the return value will be either [SQLITE_BUSY], 2729** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 2730** With the "v2" interface, any of the other [result codes] or 2731** [extended result codes] might be returned as well. 2732** 2733** [SQLITE_BUSY] means that the database engine was unable to acquire the 2734** database locks it needs to do its job. If the statement is a [COMMIT] 2735** or occurs outside of an explicit transaction, then you can retry the 2736** statement. If the statement is not a [COMMIT] and occurs within a 2737** explicit transaction then you should rollback the transaction before 2738** continuing. 2739** 2740** [SQLITE_DONE] means that the statement has finished executing 2741** successfully. sqlite3_step() should not be called again on this virtual 2742** machine without first calling [sqlite3_reset()] to reset the virtual 2743** machine back to its initial state. 2744** 2745** If the SQL statement being executed returns any data, then [SQLITE_ROW] 2746** is returned each time a new row of data is ready for processing by the 2747** caller. The values may be accessed using the [column access functions]. 2748** sqlite3_step() is called again to retrieve the next row of data. 2749** 2750** [SQLITE_ERROR] means that a run-time error (such as a constraint 2751** violation) has occurred. sqlite3_step() should not be called again on 2752** the VM. More information may be found by calling [sqlite3_errmsg()]. 2753** With the legacy interface, a more specific error code (for example, 2754** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 2755** can be obtained by calling [sqlite3_reset()] on the 2756** [prepared statement]. In the "v2" interface, 2757** the more specific error code is returned directly by sqlite3_step(). 2758** 2759** [SQLITE_MISUSE] means that the this routine was called inappropriately. 2760** Perhaps it was called on a [prepared statement] that has 2761** already been [sqlite3_finalize | finalized] or on one that had 2762** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 2763** be the case that the same database connection is being used by two or 2764** more threads at the same moment in time. 2765** 2766** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 2767** API always returns a generic error code, [SQLITE_ERROR], following any 2768** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 2769** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 2770** specific [error codes] that better describes the error. 2771** We admit that this is a goofy design. The problem has been fixed 2772** with the "v2" interface. If you prepare all of your SQL statements 2773** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 2774** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 2775** then the more specific [error codes] are returned directly 2776** by sqlite3_step(). The use of the "v2" interface is recommended. 2777** 2778** Requirements: 2779** [H13202] [H15304] [H15306] [H15308] [H15310] 2780*/ 2781int sqlite3_step(sqlite3_stmt*); 2782 2783/* 2784** CAPI3REF: Number of columns in a result set {H13770} <S10700> 2785** 2786** Returns the number of values in the current row of the result set. 2787** 2788** Requirements: 2789** [H13771] [H13772] 2790*/ 2791int sqlite3_data_count(sqlite3_stmt *pStmt); 2792 2793/* 2794** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> 2795** KEYWORDS: SQLITE_TEXT 2796** 2797** {H10266} Every value in SQLite has one of five fundamental datatypes: 2798** 2799** <ul> 2800** <li> 64-bit signed integer 2801** <li> 64-bit IEEE floating point number 2802** <li> string 2803** <li> BLOB 2804** <li> NULL 2805** </ul> {END} 2806** 2807** These constants are codes for each of those types. 2808** 2809** Note that the SQLITE_TEXT constant was also used in SQLite version 2 2810** for a completely different meaning. Software that links against both 2811** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 2812** SQLITE_TEXT. 2813*/ 2814#define SQLITE_INTEGER 1 2815#define SQLITE_FLOAT 2 2816#define SQLITE_BLOB 4 2817#define SQLITE_NULL 5 2818#ifdef SQLITE_TEXT 2819# undef SQLITE_TEXT 2820#else 2821# define SQLITE_TEXT 3 2822#endif 2823#define SQLITE3_TEXT 3 2824 2825/* 2826** CAPI3REF: Result Values From A Query {H13800} <S10700> 2827** KEYWORDS: {column access functions} 2828** 2829** These routines form the "result set query" interface. 2830** 2831** These routines return information about a single column of the current 2832** result row of a query. In every case the first argument is a pointer 2833** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 2834** that was returned from [sqlite3_prepare_v2()] or one of its variants) 2835** and the second argument is the index of the column for which information 2836** should be returned. The leftmost column of the result set has the index 0. 2837** 2838** If the SQL statement does not currently point to a valid row, or if the 2839** column index is out of range, the result is undefined. 2840** These routines may only be called when the most recent call to 2841** [sqlite3_step()] has returned [SQLITE_ROW] and neither 2842** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 2843** If any of these routines are called after [sqlite3_reset()] or 2844** [sqlite3_finalize()] or after [sqlite3_step()] has returned 2845** something other than [SQLITE_ROW], the results are undefined. 2846** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 2847** are called from a different thread while any of these routines 2848** are pending, then the results are undefined. 2849** 2850** The sqlite3_column_type() routine returns the 2851** [SQLITE_INTEGER | datatype code] for the initial data type 2852** of the result column. The returned value is one of [SQLITE_INTEGER], 2853** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 2854** returned by sqlite3_column_type() is only meaningful if no type 2855** conversions have occurred as described below. After a type conversion, 2856** the value returned by sqlite3_column_type() is undefined. Future 2857** versions of SQLite may change the behavior of sqlite3_column_type() 2858** following a type conversion. 2859** 2860** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 2861** routine returns the number of bytes in that BLOB or string. 2862** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 2863** the string to UTF-8 and then returns the number of bytes. 2864** If the result is a numeric value then sqlite3_column_bytes() uses 2865** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 2866** the number of bytes in that string. 2867** The value returned does not include the zero terminator at the end 2868** of the string. For clarity: the value returned is the number of 2869** bytes in the string, not the number of characters. 2870** 2871** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 2872** even empty strings, are always zero terminated. The return 2873** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary 2874** pointer, possibly even a NULL pointer. 2875** 2876** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 2877** but leaves the result in UTF-16 in native byte order instead of UTF-8. 2878** The zero terminator is not included in this count. 2879** 2880** The object returned by [sqlite3_column_value()] is an 2881** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 2882** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 2883** If the [unprotected sqlite3_value] object returned by 2884** [sqlite3_column_value()] is used in any other way, including calls 2885** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 2886** or [sqlite3_value_bytes()], then the behavior is undefined. 2887** 2888** These routines attempt to convert the value where appropriate. For 2889** example, if the internal representation is FLOAT and a text result 2890** is requested, [sqlite3_snprintf()] is used internally to perform the 2891** conversion automatically. The following table details the conversions 2892** that are applied: 2893** 2894** <blockquote> 2895** <table border="1"> 2896** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 2897** 2898** <tr><td> NULL <td> INTEGER <td> Result is 0 2899** <tr><td> NULL <td> FLOAT <td> Result is 0.0 2900** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 2901** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 2902** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 2903** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 2904** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 2905** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 2906** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 2907** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 2908** <tr><td> TEXT <td> INTEGER <td> Use atoi() 2909** <tr><td> TEXT <td> FLOAT <td> Use atof() 2910** <tr><td> TEXT <td> BLOB <td> No change 2911** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 2912** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 2913** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 2914** </table> 2915** </blockquote> 2916** 2917** The table above makes reference to standard C library functions atoi() 2918** and atof(). SQLite does not really use these functions. It has its 2919** own equivalent internal routines. The atoi() and atof() names are 2920** used in the table for brevity and because they are familiar to most 2921** C programmers. 2922** 2923** Note that when type conversions occur, pointers returned by prior 2924** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 2925** sqlite3_column_text16() may be invalidated. 2926** Type conversions and pointer invalidations might occur 2927** in the following cases: 2928** 2929** <ul> 2930** <li> The initial content is a BLOB and sqlite3_column_text() or 2931** sqlite3_column_text16() is called. A zero-terminator might 2932** need to be added to the string.</li> 2933** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 2934** sqlite3_column_text16() is called. The content must be converted 2935** to UTF-16.</li> 2936** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 2937** sqlite3_column_text() is called. The content must be converted 2938** to UTF-8.</li> 2939** </ul> 2940** 2941** Conversions between UTF-16be and UTF-16le are always done in place and do 2942** not invalidate a prior pointer, though of course the content of the buffer 2943** that the prior pointer points to will have been modified. Other kinds 2944** of conversion are done in place when it is possible, but sometimes they 2945** are not possible and in those cases prior pointers are invalidated. 2946** 2947** The safest and easiest to remember policy is to invoke these routines 2948** in one of the following ways: 2949** 2950** <ul> 2951** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 2952** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 2953** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 2954** </ul> 2955** 2956** In other words, you should call sqlite3_column_text(), 2957** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 2958** into the desired format, then invoke sqlite3_column_bytes() or 2959** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 2960** to sqlite3_column_text() or sqlite3_column_blob() with calls to 2961** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 2962** with calls to sqlite3_column_bytes(). 2963** 2964** The pointers returned are valid until a type conversion occurs as 2965** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 2966** [sqlite3_finalize()] is called. The memory space used to hold strings 2967** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 2968** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 2969** [sqlite3_free()]. 2970** 2971** If a memory allocation error occurs during the evaluation of any 2972** of these routines, a default value is returned. The default value 2973** is either the integer 0, the floating point number 0.0, or a NULL 2974** pointer. Subsequent calls to [sqlite3_errcode()] will return 2975** [SQLITE_NOMEM]. 2976** 2977** Requirements: 2978** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] 2979** [H13827] [H13830] 2980*/ 2981const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 2982int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 2983int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 2984double sqlite3_column_double(sqlite3_stmt*, int iCol); 2985int sqlite3_column_int(sqlite3_stmt*, int iCol); 2986sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 2987const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 2988const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 2989int sqlite3_column_type(sqlite3_stmt*, int iCol); 2990sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 2991 2992/* 2993** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> 2994** 2995** The sqlite3_finalize() function is called to delete a [prepared statement]. 2996** If the statement was executed successfully or not executed at all, then 2997** SQLITE_OK is returned. If execution of the statement failed then an 2998** [error code] or [extended error code] is returned. 2999** 3000** This routine can be called at any point during the execution of the 3001** [prepared statement]. If the virtual machine has not 3002** completed execution when this routine is called, that is like 3003** encountering an error or an [sqlite3_interrupt | interrupt]. 3004** Incomplete updates may be rolled back and transactions canceled, 3005** depending on the circumstances, and the 3006** [error code] returned will be [SQLITE_ABORT]. 3007** 3008** Requirements: 3009** [H11302] [H11304] 3010*/ 3011int sqlite3_finalize(sqlite3_stmt *pStmt); 3012 3013/* 3014** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> 3015** 3016** The sqlite3_reset() function is called to reset a [prepared statement] 3017** object back to its initial state, ready to be re-executed. 3018** Any SQL statement variables that had values bound to them using 3019** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3020** Use [sqlite3_clear_bindings()] to reset the bindings. 3021** 3022** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3023** back to the beginning of its program. 3024** 3025** {H11334} If the most recent call to [sqlite3_step(S)] for the 3026** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3027** or if [sqlite3_step(S)] has never before been called on S, 3028** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3029** 3030** {H11336} If the most recent call to [sqlite3_step(S)] for the 3031** [prepared statement] S indicated an error, then 3032** [sqlite3_reset(S)] returns an appropriate [error code]. 3033** 3034** {H11338} The [sqlite3_reset(S)] interface does not change the values 3035** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3036*/ 3037int sqlite3_reset(sqlite3_stmt *pStmt); 3038 3039/* 3040** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> 3041** KEYWORDS: {function creation routines} 3042** KEYWORDS: {application-defined SQL function} 3043** KEYWORDS: {application-defined SQL functions} 3044** 3045** These two functions (collectively known as "function creation routines") 3046** are used to add SQL functions or aggregates or to redefine the behavior 3047** of existing SQL functions or aggregates. The only difference between the 3048** two is that the second parameter, the name of the (scalar) function or 3049** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 3050** for sqlite3_create_function16(). 3051** 3052** The first parameter is the [database connection] to which the SQL 3053** function is to be added. If a single program uses more than one database 3054** connection internally, then SQL functions must be added individually to 3055** each database connection. 3056** 3057** The second parameter is the name of the SQL function to be created or 3058** redefined. The length of the name is limited to 255 bytes, exclusive of 3059** the zero-terminator. Note that the name length limit is in bytes, not 3060** characters. Any attempt to create a function with a longer name 3061** will result in [SQLITE_ERROR] being returned. 3062** 3063** The third parameter (nArg) 3064** is the number of arguments that the SQL function or 3065** aggregate takes. If this parameter is negative, then the SQL function or 3066** aggregate may take any number of arguments. 3067** 3068** The fourth parameter, eTextRep, specifies what 3069** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3070** its parameters. Any SQL function implementation should be able to work 3071** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3072** more efficient with one encoding than another. It is allowed to 3073** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3074** times with the same function but with different values of eTextRep. 3075** When multiple implementations of the same function are available, SQLite 3076** will pick the one that involves the least amount of data conversion. 3077** If there is only a single implementation which does not care what text 3078** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3079** 3080** The fifth parameter is an arbitrary pointer. The implementation of the 3081** function can gain access to this pointer using [sqlite3_user_data()]. 3082** 3083** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3084** pointers to C-language functions that implement the SQL function or 3085** aggregate. A scalar SQL function requires an implementation of the xFunc 3086** callback only, NULL pointers should be passed as the xStep and xFinal 3087** parameters. An aggregate SQL function requires an implementation of xStep 3088** and xFinal and NULL should be passed for xFunc. To delete an existing 3089** SQL function or aggregate, pass NULL for all three function callbacks. 3090** 3091** It is permitted to register multiple implementations of the same 3092** functions with the same name but with either differing numbers of 3093** arguments or differing preferred text encodings. SQLite will use 3094** the implementation most closely matches the way in which the 3095** SQL function is used. A function implementation with a non-negative 3096** nArg parameter is a better match than a function implementation with 3097** a negative nArg. A function where the preferred text encoding 3098** matches the database encoding is a better 3099** match than a function where the encoding is different. 3100** A function where the encoding difference is between UTF16le and UTF16be 3101** is a closer match than a function where the encoding difference is 3102** between UTF8 and UTF16. 3103** 3104** Built-in functions may be overloaded by new application-defined functions. 3105** The first application-defined function with a given name overrides all 3106** built-in functions in the same [database connection] with the same name. 3107** Subsequent application-defined functions of the same name only override 3108** prior application-defined functions that are an exact match for the 3109** number of parameters and preferred encoding. 3110** 3111** An application-defined function is permitted to call other 3112** SQLite interfaces. However, such calls must not 3113** close the database connection nor finalize or reset the prepared 3114** statement in which the function is running. 3115** 3116** Requirements: 3117** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16124] [H16127] 3118** [H16130] [H16133] [H16136] [H16139] [H16142] 3119*/ 3120int sqlite3_create_function( 3121 sqlite3 *db, 3122 const char *zFunctionName, 3123 int nArg, 3124 int eTextRep, 3125 void *pApp, 3126 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3127 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3128 void (*xFinal)(sqlite3_context*) 3129); 3130int sqlite3_create_function16( 3131 sqlite3 *db, 3132 const void *zFunctionName, 3133 int nArg, 3134 int eTextRep, 3135 void *pApp, 3136 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3137 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3138 void (*xFinal)(sqlite3_context*) 3139); 3140 3141/* 3142** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> 3143** 3144** These constant define integer codes that represent the various 3145** text encodings supported by SQLite. 3146*/ 3147#define SQLITE_UTF8 1 3148#define SQLITE_UTF16LE 2 3149#define SQLITE_UTF16BE 3 3150#define SQLITE_UTF16 4 /* Use native byte order */ 3151#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3152#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3153 3154/* 3155** CAPI3REF: Deprecated Functions 3156** DEPRECATED 3157** 3158** These functions are [deprecated]. In order to maintain 3159** backwards compatibility with older code, these functions continue 3160** to be supported. However, new applications should avoid 3161** the use of these functions. To help encourage people to avoid 3162** using these functions, we are not going to tell you what they do. 3163*/ 3164#ifndef SQLITE_OMIT_DEPRECATED 3165SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3166SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3167SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3168SQLITE_DEPRECATED int sqlite3_global_recover(void); 3169SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3170SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3171#endif 3172 3173/* 3174** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> 3175** 3176** The C-language implementation of SQL functions and aggregates uses 3177** this set of interface routines to access the parameter values on 3178** the function or aggregate. 3179** 3180** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3181** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3182** define callbacks that implement the SQL functions and aggregates. 3183** The 4th parameter to these callbacks is an array of pointers to 3184** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3185** each parameter to the SQL function. These routines are used to 3186** extract values from the [sqlite3_value] objects. 3187** 3188** These routines work only with [protected sqlite3_value] objects. 3189** Any attempt to use these routines on an [unprotected sqlite3_value] 3190** object results in undefined behavior. 3191** 3192** These routines work just like the corresponding [column access functions] 3193** except that these routines take a single [protected sqlite3_value] object 3194** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3195** 3196** The sqlite3_value_text16() interface extracts a UTF-16 string 3197** in the native byte-order of the host machine. The 3198** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3199** extract UTF-16 strings as big-endian and little-endian respectively. 3200** 3201** The sqlite3_value_numeric_type() interface attempts to apply 3202** numeric affinity to the value. This means that an attempt is 3203** made to convert the value to an integer or floating point. If 3204** such a conversion is possible without loss of information (in other 3205** words, if the value is a string that looks like a number) 3206** then the conversion is performed. Otherwise no conversion occurs. 3207** The [SQLITE_INTEGER | datatype] after conversion is returned. 3208** 3209** Please pay particular attention to the fact that the pointer returned 3210** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3211** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3212** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3213** or [sqlite3_value_text16()]. 3214** 3215** These routines must be called from the same thread as 3216** the SQL function that supplied the [sqlite3_value*] parameters. 3217** 3218** Requirements: 3219** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] 3220** [H15127] [H15130] [H15133] [H15136] 3221*/ 3222const void *sqlite3_value_blob(sqlite3_value*); 3223int sqlite3_value_bytes(sqlite3_value*); 3224int sqlite3_value_bytes16(sqlite3_value*); 3225double sqlite3_value_double(sqlite3_value*); 3226int sqlite3_value_int(sqlite3_value*); 3227sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3228const unsigned char *sqlite3_value_text(sqlite3_value*); 3229const void *sqlite3_value_text16(sqlite3_value*); 3230const void *sqlite3_value_text16le(sqlite3_value*); 3231const void *sqlite3_value_text16be(sqlite3_value*); 3232int sqlite3_value_type(sqlite3_value*); 3233int sqlite3_value_numeric_type(sqlite3_value*); 3234 3235/* 3236** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> 3237** 3238** The implementation of aggregate SQL functions use this routine to allocate 3239** a structure for storing their state. 3240** 3241** The first time the sqlite3_aggregate_context() routine is called for a 3242** particular aggregate, SQLite allocates nBytes of memory, zeroes out that 3243** memory, and returns a pointer to it. On second and subsequent calls to 3244** sqlite3_aggregate_context() for the same aggregate function index, 3245** the same buffer is returned. The implementation of the aggregate can use 3246** the returned buffer to accumulate data. 3247** 3248** SQLite automatically frees the allocated buffer when the aggregate 3249** query concludes. 3250** 3251** The first parameter should be a copy of the 3252** [sqlite3_context | SQL function context] that is the first parameter 3253** to the callback routine that implements the aggregate function. 3254** 3255** This routine must be called from the same thread in which 3256** the aggregate SQL function is running. 3257** 3258** Requirements: 3259** [H16211] [H16213] [H16215] [H16217] 3260*/ 3261void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3262 3263/* 3264** CAPI3REF: User Data For Functions {H16240} <S20200> 3265** 3266** The sqlite3_user_data() interface returns a copy of 3267** the pointer that was the pUserData parameter (the 5th parameter) 3268** of the [sqlite3_create_function()] 3269** and [sqlite3_create_function16()] routines that originally 3270** registered the application defined function. {END} 3271** 3272** This routine must be called from the same thread in which 3273** the application-defined function is running. 3274** 3275** Requirements: 3276** [H16243] 3277*/ 3278void *sqlite3_user_data(sqlite3_context*); 3279 3280/* 3281** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> 3282** 3283** The sqlite3_context_db_handle() interface returns a copy of 3284** the pointer to the [database connection] (the 1st parameter) 3285** of the [sqlite3_create_function()] 3286** and [sqlite3_create_function16()] routines that originally 3287** registered the application defined function. 3288** 3289** Requirements: 3290** [H16253] 3291*/ 3292sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3293 3294/* 3295** CAPI3REF: Function Auxiliary Data {H16270} <S20200> 3296** 3297** The following two functions may be used by scalar SQL functions to 3298** associate metadata with argument values. If the same value is passed to 3299** multiple invocations of the same SQL function during query execution, under 3300** some circumstances the associated metadata may be preserved. This may 3301** be used, for example, to add a regular-expression matching scalar 3302** function. The compiled version of the regular expression is stored as 3303** metadata associated with the SQL value passed as the regular expression 3304** pattern. The compiled regular expression can be reused on multiple 3305** invocations of the same function so that the original pattern string 3306** does not need to be recompiled on each invocation. 3307** 3308** The sqlite3_get_auxdata() interface returns a pointer to the metadata 3309** associated by the sqlite3_set_auxdata() function with the Nth argument 3310** value to the application-defined function. If no metadata has been ever 3311** been set for the Nth argument of the function, or if the corresponding 3312** function parameter has changed since the meta-data was set, 3313** then sqlite3_get_auxdata() returns a NULL pointer. 3314** 3315** The sqlite3_set_auxdata() interface saves the metadata 3316** pointed to by its 3rd parameter as the metadata for the N-th 3317** argument of the application-defined function. Subsequent 3318** calls to sqlite3_get_auxdata() might return this data, if it has 3319** not been destroyed. 3320** If it is not NULL, SQLite will invoke the destructor 3321** function given by the 4th parameter to sqlite3_set_auxdata() on 3322** the metadata when the corresponding function parameter changes 3323** or when the SQL statement completes, whichever comes first. 3324** 3325** SQLite is free to call the destructor and drop metadata on any 3326** parameter of any function at any time. The only guarantee is that 3327** the destructor will be called before the metadata is dropped. 3328** 3329** In practice, metadata is preserved between function calls for 3330** expressions that are constant at compile time. This includes literal 3331** values and SQL variables. 3332** 3333** These routines must be called from the same thread in which 3334** the SQL function is running. 3335** 3336** Requirements: 3337** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] 3338*/ 3339void *sqlite3_get_auxdata(sqlite3_context*, int N); 3340void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3341 3342 3343/* 3344** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> 3345** 3346** These are special values for the destructor that is passed in as the 3347** final argument to routines like [sqlite3_result_blob()]. If the destructor 3348** argument is SQLITE_STATIC, it means that the content pointer is constant 3349** and will never change. It does not need to be destroyed. The 3350** SQLITE_TRANSIENT value means that the content will likely change in 3351** the near future and that SQLite should make its own private copy of 3352** the content before returning. 3353** 3354** The typedef is necessary to work around problems in certain 3355** C++ compilers. See ticket #2191. 3356*/ 3357typedef void (*sqlite3_destructor_type)(void*); 3358#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3359#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3360 3361/* 3362** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> 3363** 3364** These routines are used by the xFunc or xFinal callbacks that 3365** implement SQL functions and aggregates. See 3366** [sqlite3_create_function()] and [sqlite3_create_function16()] 3367** for additional information. 3368** 3369** These functions work very much like the [parameter binding] family of 3370** functions used to bind values to host parameters in prepared statements. 3371** Refer to the [SQL parameter] documentation for additional information. 3372** 3373** The sqlite3_result_blob() interface sets the result from 3374** an application-defined function to be the BLOB whose content is pointed 3375** to by the second parameter and which is N bytes long where N is the 3376** third parameter. 3377** 3378** The sqlite3_result_zeroblob() interfaces set the result of 3379** the application-defined function to be a BLOB containing all zero 3380** bytes and N bytes in size, where N is the value of the 2nd parameter. 3381** 3382** The sqlite3_result_double() interface sets the result from 3383** an application-defined function to be a floating point value specified 3384** by its 2nd argument. 3385** 3386** The sqlite3_result_error() and sqlite3_result_error16() functions 3387** cause the implemented SQL function to throw an exception. 3388** SQLite uses the string pointed to by the 3389** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3390** as the text of an error message. SQLite interprets the error 3391** message string from sqlite3_result_error() as UTF-8. SQLite 3392** interprets the string from sqlite3_result_error16() as UTF-16 in native 3393** byte order. If the third parameter to sqlite3_result_error() 3394** or sqlite3_result_error16() is negative then SQLite takes as the error 3395** message all text up through the first zero character. 3396** If the third parameter to sqlite3_result_error() or 3397** sqlite3_result_error16() is non-negative then SQLite takes that many 3398** bytes (not characters) from the 2nd parameter as the error message. 3399** The sqlite3_result_error() and sqlite3_result_error16() 3400** routines make a private copy of the error message text before 3401** they return. Hence, the calling function can deallocate or 3402** modify the text after they return without harm. 3403** The sqlite3_result_error_code() function changes the error code 3404** returned by SQLite as a result of an error in a function. By default, 3405** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3406** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3407** 3408** The sqlite3_result_toobig() interface causes SQLite to throw an error 3409** indicating that a string or BLOB is to long to represent. 3410** 3411** The sqlite3_result_nomem() interface causes SQLite to throw an error 3412** indicating that a memory allocation failed. 3413** 3414** The sqlite3_result_int() interface sets the return value 3415** of the application-defined function to be the 32-bit signed integer 3416** value given in the 2nd argument. 3417** The sqlite3_result_int64() interface sets the return value 3418** of the application-defined function to be the 64-bit signed integer 3419** value given in the 2nd argument. 3420** 3421** The sqlite3_result_null() interface sets the return value 3422** of the application-defined function to be NULL. 3423** 3424** The sqlite3_result_text(), sqlite3_result_text16(), 3425** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3426** set the return value of the application-defined function to be 3427** a text string which is represented as UTF-8, UTF-16 native byte order, 3428** UTF-16 little endian, or UTF-16 big endian, respectively. 3429** SQLite takes the text result from the application from 3430** the 2nd parameter of the sqlite3_result_text* interfaces. 3431** If the 3rd parameter to the sqlite3_result_text* interfaces 3432** is negative, then SQLite takes result text from the 2nd parameter 3433** through the first zero character. 3434** If the 3rd parameter to the sqlite3_result_text* interfaces 3435** is non-negative, then as many bytes (not characters) of the text 3436** pointed to by the 2nd parameter are taken as the application-defined 3437** function result. 3438** If the 4th parameter to the sqlite3_result_text* interfaces 3439** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3440** function as the destructor on the text or BLOB result when it has 3441** finished using that result. 3442** If the 4th parameter to the sqlite3_result_text* interfaces or 3443** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3444** assumes that the text or BLOB result is in constant space and does not 3445** copy the it or call a destructor when it has finished using that result. 3446** If the 4th parameter to the sqlite3_result_text* interfaces 3447** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3448** then SQLite makes a copy of the result into space obtained from 3449** from [sqlite3_malloc()] before it returns. 3450** 3451** The sqlite3_result_value() interface sets the result of 3452** the application-defined function to be a copy the 3453** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3454** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3455** so that the [sqlite3_value] specified in the parameter may change or 3456** be deallocated after sqlite3_result_value() returns without harm. 3457** A [protected sqlite3_value] object may always be used where an 3458** [unprotected sqlite3_value] object is required, so either 3459** kind of [sqlite3_value] object can be used with this interface. 3460** 3461** If these routines are called from within the different thread 3462** than the one containing the application-defined function that received 3463** the [sqlite3_context] pointer, the results are undefined. 3464** 3465** Requirements: 3466** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] 3467** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] 3468** [H16451] [H16454] [H16457] [H16460] [H16463] 3469*/ 3470void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3471void sqlite3_result_double(sqlite3_context*, double); 3472void sqlite3_result_error(sqlite3_context*, const char*, int); 3473void sqlite3_result_error16(sqlite3_context*, const void*, int); 3474void sqlite3_result_error_toobig(sqlite3_context*); 3475void sqlite3_result_error_nomem(sqlite3_context*); 3476void sqlite3_result_error_code(sqlite3_context*, int); 3477void sqlite3_result_int(sqlite3_context*, int); 3478void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3479void sqlite3_result_null(sqlite3_context*); 3480void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3481void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3482void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3483void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3484void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3485void sqlite3_result_zeroblob(sqlite3_context*, int n); 3486 3487/* 3488** CAPI3REF: Define New Collating Sequences {H16600} <S20300> 3489** 3490** These functions are used to add new collation sequences to the 3491** [database connection] specified as the first argument. 3492** 3493** The name of the new collation sequence is specified as a UTF-8 string 3494** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3495** and a UTF-16 string for sqlite3_create_collation16(). In all cases 3496** the name is passed as the second function argument. 3497** 3498** The third argument may be one of the constants [SQLITE_UTF8], 3499** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 3500** routine expects to be passed pointers to strings encoded using UTF-8, 3501** UTF-16 little-endian, or UTF-16 big-endian, respectively. The 3502** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 3503** the routine expects pointers to 16-bit word aligned strings 3504** of UTF-16 in the native byte order of the host computer. 3505** 3506** A pointer to the user supplied routine must be passed as the fifth 3507** argument. If it is NULL, this is the same as deleting the collation 3508** sequence (so that SQLite cannot call it anymore). 3509** Each time the application supplied function is invoked, it is passed 3510** as its first parameter a copy of the void* passed as the fourth argument 3511** to sqlite3_create_collation() or sqlite3_create_collation16(). 3512** 3513** The remaining arguments to the application-supplied routine are two strings, 3514** each represented by a (length, data) pair and encoded in the encoding 3515** that was passed as the third argument when the collation sequence was 3516** registered. {END} The application defined collation routine should 3517** return negative, zero or positive if the first string is less than, 3518** equal to, or greater than the second string. i.e. (STRING1 - STRING2). 3519** 3520** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3521** except that it takes an extra argument which is a destructor for 3522** the collation. The destructor is called when the collation is 3523** destroyed and is passed a copy of the fourth parameter void* pointer 3524** of the sqlite3_create_collation_v2(). 3525** Collations are destroyed when they are overridden by later calls to the 3526** collation creation functions or when the [database connection] is closed 3527** using [sqlite3_close()]. 3528** 3529** Requirements: 3530** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] 3531** [H16624] [H16627] [H16630] 3532*/ 3533int sqlite3_create_collation( 3534 sqlite3*, 3535 const char *zName, 3536 int eTextRep, 3537 void*, 3538 int(*xCompare)(void*,int,const void*,int,const void*) 3539); 3540int sqlite3_create_collation_v2( 3541 sqlite3*, 3542 const char *zName, 3543 int eTextRep, 3544 void*, 3545 int(*xCompare)(void*,int,const void*,int,const void*), 3546 void(*xDestroy)(void*) 3547); 3548int sqlite3_create_collation16( 3549 sqlite3*, 3550 const void *zName, 3551 int eTextRep, 3552 void*, 3553 int(*xCompare)(void*,int,const void*,int,const void*) 3554); 3555 3556/* 3557** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> 3558** 3559** To avoid having to register all collation sequences before a database 3560** can be used, a single callback function may be registered with the 3561** [database connection] to be called whenever an undefined collation 3562** sequence is required. 3563** 3564** If the function is registered using the sqlite3_collation_needed() API, 3565** then it is passed the names of undefined collation sequences as strings 3566** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, 3567** the names are passed as UTF-16 in machine native byte order. 3568** A call to either function replaces any existing callback. 3569** 3570** When the callback is invoked, the first argument passed is a copy 3571** of the second argument to sqlite3_collation_needed() or 3572** sqlite3_collation_needed16(). The second argument is the database 3573** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 3574** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 3575** sequence function required. The fourth parameter is the name of the 3576** required collation sequence. 3577** 3578** The callback function should register the desired collation using 3579** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 3580** [sqlite3_create_collation_v2()]. 3581** 3582** Requirements: 3583** [H16702] [H16704] [H16706] 3584*/ 3585int sqlite3_collation_needed( 3586 sqlite3*, 3587 void*, 3588 void(*)(void*,sqlite3*,int eTextRep,const char*) 3589); 3590int sqlite3_collation_needed16( 3591 sqlite3*, 3592 void*, 3593 void(*)(void*,sqlite3*,int eTextRep,const void*) 3594); 3595 3596/* 3597** Specify the key for an encrypted database. This routine should be 3598** called right after sqlite3_open(). 3599** 3600** The code to implement this API is not available in the public release 3601** of SQLite. 3602*/ 3603int sqlite3_key( 3604 sqlite3 *db, /* Database to be rekeyed */ 3605 const void *pKey, int nKey /* The key */ 3606); 3607 3608/* 3609** Change the key on an open database. If the current database is not 3610** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 3611** database is decrypted. 3612** 3613** The code to implement this API is not available in the public release 3614** of SQLite. 3615*/ 3616int sqlite3_rekey( 3617 sqlite3 *db, /* Database to be rekeyed */ 3618 const void *pKey, int nKey /* The new key */ 3619); 3620 3621/* 3622** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> 3623** 3624** The sqlite3_sleep() function causes the current thread to suspend execution 3625** for at least a number of milliseconds specified in its parameter. 3626** 3627** If the operating system does not support sleep requests with 3628** millisecond time resolution, then the time will be rounded up to 3629** the nearest second. The number of milliseconds of sleep actually 3630** requested from the operating system is returned. 3631** 3632** SQLite implements this interface by calling the xSleep() 3633** method of the default [sqlite3_vfs] object. 3634** 3635** Requirements: [H10533] [H10536] 3636*/ 3637int sqlite3_sleep(int); 3638 3639/* 3640** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> 3641** 3642** If this global variable is made to point to a string which is 3643** the name of a folder (a.k.a. directory), then all temporary files 3644** created by SQLite will be placed in that directory. If this variable 3645** is a NULL pointer, then SQLite performs a search for an appropriate 3646** temporary file directory. 3647** 3648** It is not safe to read or modify this variable in more than one 3649** thread at a time. It is not safe to read or modify this variable 3650** if a [database connection] is being used at the same time in a separate 3651** thread. 3652** It is intended that this variable be set once 3653** as part of process initialization and before any SQLite interface 3654** routines have been called and that this variable remain unchanged 3655** thereafter. 3656** 3657** The [temp_store_directory pragma] may modify this variable and cause 3658** it to point to memory obtained from [sqlite3_malloc]. Furthermore, 3659** the [temp_store_directory pragma] always assumes that any string 3660** that this variable points to is held in memory obtained from 3661** [sqlite3_malloc] and the pragma may attempt to free that memory 3662** using [sqlite3_free]. 3663** Hence, if this variable is modified directly, either it should be 3664** made NULL or made to point to memory obtained from [sqlite3_malloc] 3665** or else the use of the [temp_store_directory pragma] should be avoided. 3666*/ 3667SQLITE_EXTERN char *sqlite3_temp_directory; 3668 3669/* 3670** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> 3671** KEYWORDS: {autocommit mode} 3672** 3673** The sqlite3_get_autocommit() interface returns non-zero or 3674** zero if the given database connection is or is not in autocommit mode, 3675** respectively. Autocommit mode is on by default. 3676** Autocommit mode is disabled by a [BEGIN] statement. 3677** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 3678** 3679** If certain kinds of errors occur on a statement within a multi-statement 3680** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 3681** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 3682** transaction might be rolled back automatically. The only way to 3683** find out whether SQLite automatically rolled back the transaction after 3684** an error is to use this function. 3685** 3686** If another thread changes the autocommit status of the database 3687** connection while this routine is running, then the return value 3688** is undefined. 3689** 3690** Requirements: [H12931] [H12932] [H12933] [H12934] 3691*/ 3692int sqlite3_get_autocommit(sqlite3*); 3693 3694/* 3695** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> 3696** 3697** The sqlite3_db_handle interface returns the [database connection] handle 3698** to which a [prepared statement] belongs. The [database connection] 3699** returned by sqlite3_db_handle is the same [database connection] that was the first argument 3700** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 3701** create the statement in the first place. 3702** 3703** Requirements: [H13123] 3704*/ 3705sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 3706 3707/* 3708** CAPI3REF: Find the next prepared statement {H13140} <S60600> 3709** 3710** This interface returns a pointer to the next [prepared statement] after 3711** pStmt associated with the [database connection] pDb. If pStmt is NULL 3712** then this interface returns a pointer to the first prepared statement 3713** associated with the database connection pDb. If no prepared statement 3714** satisfies the conditions of this routine, it returns NULL. 3715** 3716** The [database connection] pointer D in a call to 3717** [sqlite3_next_stmt(D,S)] must refer to an open database 3718** connection and in particular must not be a NULL pointer. 3719** 3720** Requirements: [H13143] [H13146] [H13149] [H13152] 3721*/ 3722sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 3723 3724/* 3725** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> 3726** 3727** The sqlite3_commit_hook() interface registers a callback 3728** function to be invoked whenever a transaction is committed. 3729** Any callback set by a previous call to sqlite3_commit_hook() 3730** for the same database connection is overridden. 3731** The sqlite3_rollback_hook() interface registers a callback 3732** function to be invoked whenever a transaction is committed. 3733** Any callback set by a previous call to sqlite3_commit_hook() 3734** for the same database connection is overridden. 3735** The pArg argument is passed through to the callback. 3736** If the callback on a commit hook function returns non-zero, 3737** then the commit is converted into a rollback. 3738** 3739** If another function was previously registered, its 3740** pArg value is returned. Otherwise NULL is returned. 3741** 3742** The callback implementation must not do anything that will modify 3743** the database connection that invoked the callback. Any actions 3744** to modify the database connection must be deferred until after the 3745** completion of the [sqlite3_step()] call that triggered the commit 3746** or rollback hook in the first place. 3747** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3748** database connections for the meaning of "modify" in this paragraph. 3749** 3750** Registering a NULL function disables the callback. 3751** 3752** For the purposes of this API, a transaction is said to have been 3753** rolled back if an explicit "ROLLBACK" statement is executed, or 3754** an error or constraint causes an implicit rollback to occur. 3755** The rollback callback is not invoked if a transaction is 3756** automatically rolled back because the database connection is closed. 3757** The rollback callback is not invoked if a transaction is 3758** rolled back because a commit callback returned non-zero. 3759** <todo> Check on this </todo> 3760** 3761** Requirements: 3762** [H12951] [H12952] [H12953] [H12954] [H12955] 3763** [H12961] [H12962] [H12963] [H12964] 3764*/ 3765void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 3766void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 3767 3768/* 3769** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> 3770** 3771** The sqlite3_update_hook() interface registers a callback function 3772** with the [database connection] identified by the first argument 3773** to be invoked whenever a row is updated, inserted or deleted. 3774** Any callback set by a previous call to this function 3775** for the same database connection is overridden. 3776** 3777** The second argument is a pointer to the function to invoke when a 3778** row is updated, inserted or deleted. 3779** The first argument to the callback is a copy of the third argument 3780** to sqlite3_update_hook(). 3781** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 3782** or [SQLITE_UPDATE], depending on the operation that caused the callback 3783** to be invoked. 3784** The third and fourth arguments to the callback contain pointers to the 3785** database and table name containing the affected row. 3786** The final callback parameter is the [rowid] of the row. 3787** In the case of an update, this is the [rowid] after the update takes place. 3788** 3789** The update hook is not invoked when internal system tables are 3790** modified (i.e. sqlite_master and sqlite_sequence). 3791** 3792** The update hook implementation must not do anything that will modify 3793** the database connection that invoked the update hook. Any actions 3794** to modify the database connection must be deferred until after the 3795** completion of the [sqlite3_step()] call that triggered the update hook. 3796** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3797** database connections for the meaning of "modify" in this paragraph. 3798** 3799** If another function was previously registered, its pArg value 3800** is returned. Otherwise NULL is returned. 3801** 3802** Requirements: 3803** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] 3804*/ 3805void *sqlite3_update_hook( 3806 sqlite3*, 3807 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 3808 void* 3809); 3810 3811/* 3812** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> 3813** KEYWORDS: {shared cache} {shared cache mode} 3814** 3815** This routine enables or disables the sharing of the database cache 3816** and schema data structures between [database connection | connections] 3817** to the same database. Sharing is enabled if the argument is true 3818** and disabled if the argument is false. 3819** 3820** Cache sharing is enabled and disabled for an entire process. 3821** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 3822** sharing was enabled or disabled for each thread separately. 3823** 3824** The cache sharing mode set by this interface effects all subsequent 3825** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 3826** Existing database connections continue use the sharing mode 3827** that was in effect at the time they were opened. 3828** 3829** Virtual tables cannot be used with a shared cache. When shared 3830** cache is enabled, the [sqlite3_create_module()] API used to register 3831** virtual tables will always return an error. 3832** 3833** This routine returns [SQLITE_OK] if shared cache was enabled or disabled 3834** successfully. An [error code] is returned otherwise. 3835** 3836** Shared cache is disabled by default. But this might change in 3837** future releases of SQLite. Applications that care about shared 3838** cache setting should set it explicitly. 3839** 3840** See Also: [SQLite Shared-Cache Mode] 3841** 3842** Requirements: [H10331] [H10336] [H10337] [H10339] 3843*/ 3844int sqlite3_enable_shared_cache(int); 3845 3846/* 3847** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> 3848** 3849** The sqlite3_release_memory() interface attempts to free N bytes 3850** of heap memory by deallocating non-essential memory allocations 3851** held by the database library. {END} Memory used to cache database 3852** pages to improve performance is an example of non-essential memory. 3853** sqlite3_release_memory() returns the number of bytes actually freed, 3854** which might be more or less than the amount requested. 3855** 3856** Requirements: [H17341] [H17342] 3857*/ 3858int sqlite3_release_memory(int); 3859 3860/* 3861** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> 3862** 3863** The sqlite3_soft_heap_limit() interface places a "soft" limit 3864** on the amount of heap memory that may be allocated by SQLite. 3865** If an internal allocation is requested that would exceed the 3866** soft heap limit, [sqlite3_release_memory()] is invoked one or 3867** more times to free up some space before the allocation is performed. 3868** 3869** The limit is called "soft", because if [sqlite3_release_memory()] 3870** cannot free sufficient memory to prevent the limit from being exceeded, 3871** the memory is allocated anyway and the current operation proceeds. 3872** 3873** A negative or zero value for N means that there is no soft heap limit and 3874** [sqlite3_release_memory()] will only be called when memory is exhausted. 3875** The default value for the soft heap limit is zero. 3876** 3877** SQLite makes a best effort to honor the soft heap limit. 3878** But if the soft heap limit cannot be honored, execution will 3879** continue without error or notification. This is why the limit is 3880** called a "soft" limit. It is advisory only. 3881** 3882** Prior to SQLite version 3.5.0, this routine only constrained the memory 3883** allocated by a single thread - the same thread in which this routine 3884** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 3885** applied to all threads. The value specified for the soft heap limit 3886** is an upper bound on the total memory allocation for all threads. In 3887** version 3.5.0 there is no mechanism for limiting the heap usage for 3888** individual threads. 3889** 3890** Requirements: 3891** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] 3892*/ 3893void sqlite3_soft_heap_limit(int); 3894 3895/* 3896** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> 3897** 3898** This routine returns metadata about a specific column of a specific 3899** database table accessible using the [database connection] handle 3900** passed as the first function argument. 3901** 3902** The column is identified by the second, third and fourth parameters to 3903** this function. The second parameter is either the name of the database 3904** (i.e. "main", "temp" or an attached database) containing the specified 3905** table or NULL. If it is NULL, then all attached databases are searched 3906** for the table using the same algorithm used by the database engine to 3907** resolve unqualified table references. 3908** 3909** The third and fourth parameters to this function are the table and column 3910** name of the desired column, respectively. Neither of these parameters 3911** may be NULL. 3912** 3913** Metadata is returned by writing to the memory locations passed as the 5th 3914** and subsequent parameters to this function. Any of these arguments may be 3915** NULL, in which case the corresponding element of metadata is omitted. 3916** 3917** <blockquote> 3918** <table border="1"> 3919** <tr><th> Parameter <th> Output<br>Type <th> Description 3920** 3921** <tr><td> 5th <td> const char* <td> Data type 3922** <tr><td> 6th <td> const char* <td> Name of default collation sequence 3923** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 3924** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 3925** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 3926** </table> 3927** </blockquote> 3928** 3929** The memory pointed to by the character pointers returned for the 3930** declaration type and collation sequence is valid only until the next 3931** call to any SQLite API function. 3932** 3933** If the specified table is actually a view, an [error code] is returned. 3934** 3935** If the specified column is "rowid", "oid" or "_rowid_" and an 3936** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 3937** parameters are set for the explicitly declared column. If there is no 3938** explicitly declared [INTEGER PRIMARY KEY] column, then the output 3939** parameters are set as follows: 3940** 3941** <pre> 3942** data type: "INTEGER" 3943** collation sequence: "BINARY" 3944** not null: 0 3945** primary key: 1 3946** auto increment: 0 3947** </pre> 3948** 3949** This function may load one or more schemas from database files. If an 3950** error occurs during this process, or if the requested table or column 3951** cannot be found, an [error code] is returned and an error message left 3952** in the [database connection] (to be retrieved using sqlite3_errmsg()). 3953** 3954** This API is only available if the library was compiled with the 3955** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 3956*/ 3957int sqlite3_table_column_metadata( 3958 sqlite3 *db, /* Connection handle */ 3959 const char *zDbName, /* Database name or NULL */ 3960 const char *zTableName, /* Table name */ 3961 const char *zColumnName, /* Column name */ 3962 char const **pzDataType, /* OUTPUT: Declared data type */ 3963 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 3964 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 3965 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 3966 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 3967); 3968 3969/* 3970** CAPI3REF: Load An Extension {H12600} <S20500> 3971** 3972** This interface loads an SQLite extension library from the named file. 3973** 3974** {H12601} The sqlite3_load_extension() interface attempts to load an 3975** SQLite extension library contained in the file zFile. 3976** 3977** {H12602} The entry point is zProc. 3978** 3979** {H12603} zProc may be 0, in which case the name of the entry point 3980** defaults to "sqlite3_extension_init". 3981** 3982** {H12604} The sqlite3_load_extension() interface shall return 3983** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 3984** 3985** {H12605} If an error occurs and pzErrMsg is not 0, then the 3986** [sqlite3_load_extension()] interface shall attempt to 3987** fill *pzErrMsg with error message text stored in memory 3988** obtained from [sqlite3_malloc()]. {END} The calling function 3989** should free this memory by calling [sqlite3_free()]. 3990** 3991** {H12606} Extension loading must be enabled using 3992** [sqlite3_enable_load_extension()] prior to calling this API, 3993** otherwise an error will be returned. 3994*/ 3995int sqlite3_load_extension( 3996 sqlite3 *db, /* Load the extension into this database connection */ 3997 const char *zFile, /* Name of the shared library containing extension */ 3998 const char *zProc, /* Entry point. Derived from zFile if 0 */ 3999 char **pzErrMsg /* Put error message here if not 0 */ 4000); 4001 4002/* 4003** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> 4004** 4005** So as not to open security holes in older applications that are 4006** unprepared to deal with extension loading, and as a means of disabling 4007** extension loading while evaluating user-entered SQL, the following API 4008** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4009** 4010** Extension loading is off by default. See ticket #1863. 4011** 4012** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 4013** to turn extension loading on and call it with onoff==0 to turn 4014** it back off again. 4015** 4016** {H12622} Extension loading is off by default. 4017*/ 4018int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4019 4020/* 4021** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> 4022** 4023** This API can be invoked at program startup in order to register 4024** one or more statically linked extensions that will be available 4025** to all new [database connections]. {END} 4026** 4027** This routine stores a pointer to the extension in an array that is 4028** obtained from [sqlite3_malloc()]. If you run a memory leak checker 4029** on your program and it reports a leak because of this array, invoke 4030** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. 4031** 4032** {H12641} This function registers an extension entry point that is 4033** automatically invoked whenever a new [database connection] 4034** is opened using [sqlite3_open()], [sqlite3_open16()], 4035** or [sqlite3_open_v2()]. 4036** 4037** {H12642} Duplicate extensions are detected so calling this routine 4038** multiple times with the same extension is harmless. 4039** 4040** {H12643} This routine stores a pointer to the extension in an array 4041** that is obtained from [sqlite3_malloc()]. 4042** 4043** {H12644} Automatic extensions apply across all threads. 4044*/ 4045int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4046 4047/* 4048** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> 4049** 4050** This function disables all previously registered automatic 4051** extensions. {END} It undoes the effect of all prior 4052** [sqlite3_auto_extension()] calls. 4053** 4054** {H12661} This function disables all previously registered 4055** automatic extensions. 4056** 4057** {H12662} This function disables automatic extensions in all threads. 4058*/ 4059void sqlite3_reset_auto_extension(void); 4060 4061/* 4062****** EXPERIMENTAL - subject to change without notice ************** 4063** 4064** The interface to the virtual-table mechanism is currently considered 4065** to be experimental. The interface might change in incompatible ways. 4066** If this is a problem for you, do not use the interface at this time. 4067** 4068** When the virtual-table mechanism stabilizes, we will declare the 4069** interface fixed, support it indefinitely, and remove this comment. 4070*/ 4071 4072/* 4073** Structures used by the virtual table interface 4074*/ 4075typedef struct sqlite3_vtab sqlite3_vtab; 4076typedef struct sqlite3_index_info sqlite3_index_info; 4077typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4078typedef struct sqlite3_module sqlite3_module; 4079 4080/* 4081** CAPI3REF: Virtual Table Object {H18000} <S20400> 4082** KEYWORDS: sqlite3_module {virtual table module} 4083** EXPERIMENTAL 4084** 4085** This structure, sometimes called a a "virtual table module", 4086** defines the implementation of a [virtual tables]. 4087** This structure consists mostly of methods for the module. 4088** 4089** A virtual table module is created by filling in a persistent 4090** instance of this structure and passing a pointer to that instance 4091** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4092** The registration remains valid until it is replaced by a different 4093** module or until the [database connection] closes. The content 4094** of this structure must not change while it is registered with 4095** any database connection. 4096*/ 4097struct sqlite3_module { 4098 int iVersion; 4099 int (*xCreate)(sqlite3*, void *pAux, 4100 int argc, const char *const*argv, 4101 sqlite3_vtab **ppVTab, char**); 4102 int (*xConnect)(sqlite3*, void *pAux, 4103 int argc, const char *const*argv, 4104 sqlite3_vtab **ppVTab, char**); 4105 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4106 int (*xDisconnect)(sqlite3_vtab *pVTab); 4107 int (*xDestroy)(sqlite3_vtab *pVTab); 4108 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4109 int (*xClose)(sqlite3_vtab_cursor*); 4110 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4111 int argc, sqlite3_value **argv); 4112 int (*xNext)(sqlite3_vtab_cursor*); 4113 int (*xEof)(sqlite3_vtab_cursor*); 4114 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4115 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4116 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4117 int (*xBegin)(sqlite3_vtab *pVTab); 4118 int (*xSync)(sqlite3_vtab *pVTab); 4119 int (*xCommit)(sqlite3_vtab *pVTab); 4120 int (*xRollback)(sqlite3_vtab *pVTab); 4121 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4122 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4123 void **ppArg); 4124 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4125}; 4126 4127/* 4128** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> 4129** KEYWORDS: sqlite3_index_info 4130** EXPERIMENTAL 4131** 4132** The sqlite3_index_info structure and its substructures is used to 4133** pass information into and receive the reply from the [xBestIndex] 4134** method of a [virtual table module]. The fields under **Inputs** are the 4135** inputs to xBestIndex and are read-only. xBestIndex inserts its 4136** results into the **Outputs** fields. 4137** 4138** The aConstraint[] array records WHERE clause constraints of the form: 4139** 4140** <pre>column OP expr</pre> 4141** 4142** where OP is =, <, <=, >, or >=. The particular operator is 4143** stored in aConstraint[].op. The index of the column is stored in 4144** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4145** expr on the right-hand side can be evaluated (and thus the constraint 4146** is usable) and false if it cannot. 4147** 4148** The optimizer automatically inverts terms of the form "expr OP column" 4149** and makes other simplifications to the WHERE clause in an attempt to 4150** get as many WHERE clause terms into the form shown above as possible. 4151** The aConstraint[] array only reports WHERE clause terms in the correct 4152** form that refer to the particular virtual table being queried. 4153** 4154** Information about the ORDER BY clause is stored in aOrderBy[]. 4155** Each term of aOrderBy records a column of the ORDER BY clause. 4156** 4157** The [xBestIndex] method must fill aConstraintUsage[] with information 4158** about what parameters to pass to xFilter. If argvIndex>0 then 4159** the right-hand side of the corresponding aConstraint[] is evaluated 4160** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4161** is true, then the constraint is assumed to be fully handled by the 4162** virtual table and is not checked again by SQLite. 4163** 4164** The idxNum and idxPtr values are recorded and passed into the 4165** [xFilter] method. 4166** [sqlite3_free()] is used to free idxPtr if and only iff 4167** needToFreeIdxPtr is true. 4168** 4169** The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4170** the correct order to satisfy the ORDER BY clause so that no separate 4171** sorting step is required. 4172** 4173** The estimatedCost value is an estimate of the cost of doing the 4174** particular lookup. A full scan of a table with N entries should have 4175** a cost of N. A binary search of a table of N entries should have a 4176** cost of approximately log(N). 4177*/ 4178struct sqlite3_index_info { 4179 /* Inputs */ 4180 int nConstraint; /* Number of entries in aConstraint */ 4181 struct sqlite3_index_constraint { 4182 int iColumn; /* Column on left-hand side of constraint */ 4183 unsigned char op; /* Constraint operator */ 4184 unsigned char usable; /* True if this constraint is usable */ 4185 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4186 } *aConstraint; /* Table of WHERE clause constraints */ 4187 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4188 struct sqlite3_index_orderby { 4189 int iColumn; /* Column number */ 4190 unsigned char desc; /* True for DESC. False for ASC. */ 4191 } *aOrderBy; /* The ORDER BY clause */ 4192 /* Outputs */ 4193 struct sqlite3_index_constraint_usage { 4194 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4195 unsigned char omit; /* Do not code a test for this constraint */ 4196 } *aConstraintUsage; 4197 int idxNum; /* Number used to identify the index */ 4198 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4199 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4200 int orderByConsumed; /* True if output is already ordered */ 4201 double estimatedCost; /* Estimated cost of using this index */ 4202}; 4203#define SQLITE_INDEX_CONSTRAINT_EQ 2 4204#define SQLITE_INDEX_CONSTRAINT_GT 4 4205#define SQLITE_INDEX_CONSTRAINT_LE 8 4206#define SQLITE_INDEX_CONSTRAINT_LT 16 4207#define SQLITE_INDEX_CONSTRAINT_GE 32 4208#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4209 4210/* 4211** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> 4212** EXPERIMENTAL 4213** 4214** This routine is used to register a new [virtual table module] name. 4215** Module names must be registered before 4216** creating a new [virtual table] using the module, or before using a 4217** preexisting [virtual table] for the module. 4218** 4219** The module name is registered on the [database connection] specified 4220** by the first parameter. The name of the module is given by the 4221** second parameter. The third parameter is a pointer to 4222** the implementation of the [virtual table module]. The fourth 4223** parameter is an arbitrary client data pointer that is passed through 4224** into the [xCreate] and [xConnect] methods of the virtual table module 4225** when a new virtual table is be being created or reinitialized. 4226** 4227** This interface has exactly the same effect as calling 4228** [sqlite3_create_module_v2()] with a NULL client data destructor. 4229*/ 4230SQLITE_EXPERIMENTAL int sqlite3_create_module( 4231 sqlite3 *db, /* SQLite connection to register module with */ 4232 const char *zName, /* Name of the module */ 4233 const sqlite3_module *p, /* Methods for the module */ 4234 void *pClientData /* Client data for xCreate/xConnect */ 4235); 4236 4237/* 4238** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> 4239** EXPERIMENTAL 4240** 4241** This routine is identical to the [sqlite3_create_module()] method, 4242** except that it has an extra parameter to specify 4243** a destructor function for the client data pointer. SQLite will 4244** invoke the destructor function (if it is not NULL) when SQLite 4245** no longer needs the pClientData pointer. 4246*/ 4247SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( 4248 sqlite3 *db, /* SQLite connection to register module with */ 4249 const char *zName, /* Name of the module */ 4250 const sqlite3_module *p, /* Methods for the module */ 4251 void *pClientData, /* Client data for xCreate/xConnect */ 4252 void(*xDestroy)(void*) /* Module destructor function */ 4253); 4254 4255/* 4256** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> 4257** KEYWORDS: sqlite3_vtab 4258** EXPERIMENTAL 4259** 4260** Every [virtual table module] implementation uses a subclass 4261** of the following structure to describe a particular instance 4262** of the [virtual table]. Each subclass will 4263** be tailored to the specific needs of the module implementation. 4264** The purpose of this superclass is to define certain fields that are 4265** common to all module implementations. 4266** 4267** Virtual tables methods can set an error message by assigning a 4268** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4269** take care that any prior string is freed by a call to [sqlite3_free()] 4270** prior to assigning a new string to zErrMsg. After the error message 4271** is delivered up to the client application, the string will be automatically 4272** freed by sqlite3_free() and the zErrMsg field will be zeroed. 4273*/ 4274struct sqlite3_vtab { 4275 const sqlite3_module *pModule; /* The module for this virtual table */ 4276 int nRef; /* Used internally */ 4277 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4278 /* Virtual table implementations will typically add additional fields */ 4279}; 4280 4281/* 4282** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> 4283** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 4284** EXPERIMENTAL 4285** 4286** Every [virtual table module] implementation uses a subclass of the 4287** following structure to describe cursors that point into the 4288** [virtual table] and are used 4289** to loop through the virtual table. Cursors are created using the 4290** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 4291** by the [sqlite3_module.xClose | xClose] method. Cussors are used 4292** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 4293** of the module. Each module implementation will define 4294** the content of a cursor structure to suit its own needs. 4295** 4296** This superclass exists in order to define fields of the cursor that 4297** are common to all implementations. 4298*/ 4299struct sqlite3_vtab_cursor { 4300 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4301 /* Virtual table implementations will typically add additional fields */ 4302}; 4303 4304/* 4305** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> 4306** EXPERIMENTAL 4307** 4308** The [xCreate] and [xConnect] methods of a 4309** [virtual table module] call this interface 4310** to declare the format (the names and datatypes of the columns) of 4311** the virtual tables they implement. 4312*/ 4313SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 4314 4315/* 4316** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> 4317** EXPERIMENTAL 4318** 4319** Virtual tables can provide alternative implementations of functions 4320** using the [xFindFunction] method of the [virtual table module]. 4321** But global versions of those functions 4322** must exist in order to be overloaded. 4323** 4324** This API makes sure a global version of a function with a particular 4325** name and number of parameters exists. If no such function exists 4326** before this API is called, a new function is created. The implementation 4327** of the new function always causes an exception to be thrown. So 4328** the new function is not good for anything by itself. Its only 4329** purpose is to be a placeholder function that can be overloaded 4330** by a [virtual table]. 4331*/ 4332SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4333 4334/* 4335** The interface to the virtual-table mechanism defined above (back up 4336** to a comment remarkably similar to this one) is currently considered 4337** to be experimental. The interface might change in incompatible ways. 4338** If this is a problem for you, do not use the interface at this time. 4339** 4340** When the virtual-table mechanism stabilizes, we will declare the 4341** interface fixed, support it indefinitely, and remove this comment. 4342** 4343****** EXPERIMENTAL - subject to change without notice ************** 4344*/ 4345 4346/* 4347** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> 4348** KEYWORDS: {BLOB handle} {BLOB handles} 4349** 4350** An instance of this object represents an open BLOB on which 4351** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4352** Objects of this type are created by [sqlite3_blob_open()] 4353** and destroyed by [sqlite3_blob_close()]. 4354** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4355** can be used to read or write small subsections of the BLOB. 4356** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4357*/ 4358typedef struct sqlite3_blob sqlite3_blob; 4359 4360/* 4361** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> 4362** 4363** This interfaces opens a [BLOB handle | handle] to the BLOB located 4364** in row iRow, column zColumn, table zTable in database zDb; 4365** in other words, the same BLOB that would be selected by: 4366** 4367** <pre> 4368** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4369** </pre> {END} 4370** 4371** If the flags parameter is non-zero, the the BLOB is opened for read 4372** and write access. If it is zero, the BLOB is opened for read access. 4373** 4374** Note that the database name is not the filename that contains 4375** the database but rather the symbolic name of the database that 4376** is assigned when the database is connected using [ATTACH]. 4377** For the main database file, the database name is "main". 4378** For TEMP tables, the database name is "temp". 4379** 4380** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4381** to *ppBlob. Otherwise an [error code] is returned and any value written 4382** to *ppBlob should not be used by the caller. 4383** This function sets the [database connection] error code and message 4384** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 4385** 4386** If the row that a BLOB handle points to is modified by an 4387** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4388** then the BLOB handle is marked as "expired". 4389** This is true if any column of the row is changed, even a column 4390** other than the one the BLOB handle is open on. 4391** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4392** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. 4393** Changes written into a BLOB prior to the BLOB expiring are not 4394** rollback by the expiration of the BLOB. Such changes will eventually 4395** commit if the transaction continues to completion. 4396** 4397** Requirements: 4398** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] 4399*/ 4400int sqlite3_blob_open( 4401 sqlite3*, 4402 const char *zDb, 4403 const char *zTable, 4404 const char *zColumn, 4405 sqlite3_int64 iRow, 4406 int flags, 4407 sqlite3_blob **ppBlob 4408); 4409 4410/* 4411** CAPI3REF: Close A BLOB Handle {H17830} <S30230> 4412** 4413** Closes an open [BLOB handle]. 4414** 4415** Closing a BLOB shall cause the current transaction to commit 4416** if there are no other BLOBs, no pending prepared statements, and the 4417** database connection is in [autocommit mode]. 4418** If any writes were made to the BLOB, they might be held in cache 4419** until the close operation if they will fit. {END} 4420** 4421** Closing the BLOB often forces the changes 4422** out to disk and so if any I/O errors occur, they will likely occur 4423** at the time when the BLOB is closed. {H17833} Any errors that occur during 4424** closing are reported as a non-zero return value. 4425** 4426** The BLOB is closed unconditionally. Even if this routine returns 4427** an error code, the BLOB is still closed. 4428** 4429** Requirements: 4430** [H17833] [H17836] [H17839] 4431*/ 4432int sqlite3_blob_close(sqlite3_blob *); 4433 4434/* 4435** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> 4436** 4437** Returns the size in bytes of the BLOB accessible via the open 4438** []BLOB handle] in its only argument. 4439** 4440** Requirements: 4441** [H17843] 4442*/ 4443int sqlite3_blob_bytes(sqlite3_blob *); 4444 4445/* 4446** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> 4447** 4448** This function is used to read data from an open [BLOB handle] into a 4449** caller-supplied buffer. N bytes of data are copied into buffer Z 4450** from the open BLOB, starting at offset iOffset. 4451** 4452** If offset iOffset is less than N bytes from the end of the BLOB, 4453** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 4454** less than zero, [SQLITE_ERROR] is returned and no data is read. 4455** 4456** An attempt to read from an expired [BLOB handle] fails with an 4457** error code of [SQLITE_ABORT]. 4458** 4459** On success, SQLITE_OK is returned. 4460** Otherwise, an [error code] or an [extended error code] is returned. 4461** 4462** Requirements: 4463** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] 4464*/ 4465int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 4466 4467/* 4468** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> 4469** 4470** This function is used to write data into an open [BLOB handle] from a 4471** caller-supplied buffer. N bytes of data are copied from the buffer Z 4472** into the open BLOB, starting at offset iOffset. 4473** 4474** If the [BLOB handle] passed as the first argument was not opened for 4475** writing (the flags parameter to [sqlite3_blob_open()] was zero), 4476** this function returns [SQLITE_READONLY]. 4477** 4478** This function may only modify the contents of the BLOB; it is 4479** not possible to increase the size of a BLOB using this API. 4480** If offset iOffset is less than N bytes from the end of the BLOB, 4481** [SQLITE_ERROR] is returned and no data is written. If N is 4482** less than zero [SQLITE_ERROR] is returned and no data is written. 4483** 4484** An attempt to write to an expired [BLOB handle] fails with an 4485** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred 4486** before the [BLOB handle] expired are not rolled back by the 4487** expiration of the handle, though of course those changes might 4488** have been overwritten by the statement that expired the BLOB handle 4489** or by other independent statements. 4490** 4491** On success, SQLITE_OK is returned. 4492** Otherwise, an [error code] or an [extended error code] is returned. 4493** 4494** Requirements: 4495** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] 4496** [H17888] 4497*/ 4498int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 4499 4500/* 4501** CAPI3REF: Virtual File System Objects {H11200} <S20100> 4502** 4503** A virtual filesystem (VFS) is an [sqlite3_vfs] object 4504** that SQLite uses to interact 4505** with the underlying operating system. Most SQLite builds come with a 4506** single default VFS that is appropriate for the host computer. 4507** New VFSes can be registered and existing VFSes can be unregistered. 4508** The following interfaces are provided. 4509** 4510** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 4511** Names are case sensitive. 4512** Names are zero-terminated UTF-8 strings. 4513** If there is no match, a NULL pointer is returned. 4514** If zVfsName is NULL then the default VFS is returned. 4515** 4516** New VFSes are registered with sqlite3_vfs_register(). 4517** Each new VFS becomes the default VFS if the makeDflt flag is set. 4518** The same VFS can be registered multiple times without injury. 4519** To make an existing VFS into the default VFS, register it again 4520** with the makeDflt flag set. If two different VFSes with the 4521** same name are registered, the behavior is undefined. If a 4522** VFS is registered with a name that is NULL or an empty string, 4523** then the behavior is undefined. 4524** 4525** Unregister a VFS with the sqlite3_vfs_unregister() interface. 4526** If the default VFS is unregistered, another VFS is chosen as 4527** the default. The choice for the new VFS is arbitrary. 4528** 4529** Requirements: 4530** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] 4531*/ 4532sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 4533int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 4534int sqlite3_vfs_unregister(sqlite3_vfs*); 4535 4536/* 4537** CAPI3REF: Mutexes {H17000} <S20000> 4538** 4539** The SQLite core uses these routines for thread 4540** synchronization. Though they are intended for internal 4541** use by SQLite, code that links against SQLite is 4542** permitted to use any of these routines. 4543** 4544** The SQLite source code contains multiple implementations 4545** of these mutex routines. An appropriate implementation 4546** is selected automatically at compile-time. The following 4547** implementations are available in the SQLite core: 4548** 4549** <ul> 4550** <li> SQLITE_MUTEX_OS2 4551** <li> SQLITE_MUTEX_PTHREAD 4552** <li> SQLITE_MUTEX_W32 4553** <li> SQLITE_MUTEX_NOOP 4554** </ul> 4555** 4556** The SQLITE_MUTEX_NOOP implementation is a set of routines 4557** that does no real locking and is appropriate for use in 4558** a single-threaded application. The SQLITE_MUTEX_OS2, 4559** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 4560** are appropriate for use on OS/2, Unix, and Windows. 4561** 4562** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 4563** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 4564** implementation is included with the library. In this case the 4565** application must supply a custom mutex implementation using the 4566** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 4567** before calling sqlite3_initialize() or any other public sqlite3_ 4568** function that calls sqlite3_initialize(). 4569** 4570** {H17011} The sqlite3_mutex_alloc() routine allocates a new 4571** mutex and returns a pointer to it. {H17012} If it returns NULL 4572** that means that a mutex could not be allocated. {H17013} SQLite 4573** will unwind its stack and return an error. {H17014} The argument 4574** to sqlite3_mutex_alloc() is one of these integer constants: 4575** 4576** <ul> 4577** <li> SQLITE_MUTEX_FAST 4578** <li> SQLITE_MUTEX_RECURSIVE 4579** <li> SQLITE_MUTEX_STATIC_MASTER 4580** <li> SQLITE_MUTEX_STATIC_MEM 4581** <li> SQLITE_MUTEX_STATIC_MEM2 4582** <li> SQLITE_MUTEX_STATIC_PRNG 4583** <li> SQLITE_MUTEX_STATIC_LRU 4584** <li> SQLITE_MUTEX_STATIC_LRU2 4585** </ul> 4586** 4587** {H17015} The first two constants cause sqlite3_mutex_alloc() to create 4588** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 4589** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 4590** The mutex implementation does not need to make a distinction 4591** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 4592** not want to. {H17016} But SQLite will only request a recursive mutex in 4593** cases where it really needs one. {END} If a faster non-recursive mutex 4594** implementation is available on the host platform, the mutex subsystem 4595** might return such a mutex in response to SQLITE_MUTEX_FAST. 4596** 4597** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return 4598** a pointer to a static preexisting mutex. {END} Four static mutexes are 4599** used by the current version of SQLite. Future versions of SQLite 4600** may add additional static mutexes. Static mutexes are for internal 4601** use by SQLite only. Applications that use SQLite mutexes should 4602** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 4603** SQLITE_MUTEX_RECURSIVE. 4604** 4605** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 4606** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 4607** returns a different mutex on every call. {H17034} But for the static 4608** mutex types, the same mutex is returned on every call that has 4609** the same type number. 4610** 4611** {H17019} The sqlite3_mutex_free() routine deallocates a previously 4612** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every 4613** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in 4614** use when they are deallocated. {A17022} Attempting to deallocate a static 4615** mutex results in undefined behavior. {H17023} SQLite never deallocates 4616** a static mutex. {END} 4617** 4618** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 4619** to enter a mutex. {H17024} If another thread is already within the mutex, 4620** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 4621** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] 4622** upon successful entry. {H17026} Mutexes created using 4623** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 4624** {H17027} In such cases the, 4625** mutex must be exited an equal number of times before another thread 4626** can enter. {A17028} If the same thread tries to enter any other 4627** kind of mutex more than once, the behavior is undefined. 4628** {H17029} SQLite will never exhibit 4629** such behavior in its own use of mutexes. 4630** 4631** Some systems (for example, Windows 95) do not support the operation 4632** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 4633** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses 4634** sqlite3_mutex_try() as an optimization so this is acceptable behavior. 4635** 4636** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was 4637** previously entered by the same thread. {A17032} The behavior 4638** is undefined if the mutex is not currently entered by the 4639** calling thread or is not currently allocated. {H17033} SQLite will 4640** never do either. {END} 4641** 4642** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 4643** sqlite3_mutex_leave() is a NULL pointer, then all three routines 4644** behave as no-ops. 4645** 4646** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 4647*/ 4648sqlite3_mutex *sqlite3_mutex_alloc(int); 4649void sqlite3_mutex_free(sqlite3_mutex*); 4650void sqlite3_mutex_enter(sqlite3_mutex*); 4651int sqlite3_mutex_try(sqlite3_mutex*); 4652void sqlite3_mutex_leave(sqlite3_mutex*); 4653 4654/* 4655** CAPI3REF: Mutex Methods Object {H17120} <S20130> 4656** EXPERIMENTAL 4657** 4658** An instance of this structure defines the low-level routines 4659** used to allocate and use mutexes. 4660** 4661** Usually, the default mutex implementations provided by SQLite are 4662** sufficient, however the user has the option of substituting a custom 4663** implementation for specialized deployments or systems for which SQLite 4664** does not provide a suitable implementation. In this case, the user 4665** creates and populates an instance of this structure to pass 4666** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 4667** Additionally, an instance of this structure can be used as an 4668** output variable when querying the system for the current mutex 4669** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 4670** 4671** The xMutexInit method defined by this structure is invoked as 4672** part of system initialization by the sqlite3_initialize() function. 4673** {H17001} The xMutexInit routine shall be called by SQLite once for each 4674** effective call to [sqlite3_initialize()]. 4675** 4676** The xMutexEnd method defined by this structure is invoked as 4677** part of system shutdown by the sqlite3_shutdown() function. The 4678** implementation of this method is expected to release all outstanding 4679** resources obtained by the mutex methods implementation, especially 4680** those obtained by the xMutexInit method. {H17003} The xMutexEnd() 4681** interface shall be invoked once for each call to [sqlite3_shutdown()]. 4682** 4683** The remaining seven methods defined by this structure (xMutexAlloc, 4684** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 4685** xMutexNotheld) implement the following interfaces (respectively): 4686** 4687** <ul> 4688** <li> [sqlite3_mutex_alloc()] </li> 4689** <li> [sqlite3_mutex_free()] </li> 4690** <li> [sqlite3_mutex_enter()] </li> 4691** <li> [sqlite3_mutex_try()] </li> 4692** <li> [sqlite3_mutex_leave()] </li> 4693** <li> [sqlite3_mutex_held()] </li> 4694** <li> [sqlite3_mutex_notheld()] </li> 4695** </ul> 4696** 4697** The only difference is that the public sqlite3_XXX functions enumerated 4698** above silently ignore any invocations that pass a NULL pointer instead 4699** of a valid mutex handle. The implementations of the methods defined 4700** by this structure are not required to handle this case, the results 4701** of passing a NULL pointer instead of a valid mutex handle are undefined 4702** (i.e. it is acceptable to provide an implementation that segfaults if 4703** it is passed a NULL pointer). 4704*/ 4705typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 4706struct sqlite3_mutex_methods { 4707 int (*xMutexInit)(void); 4708 int (*xMutexEnd)(void); 4709 sqlite3_mutex *(*xMutexAlloc)(int); 4710 void (*xMutexFree)(sqlite3_mutex *); 4711 void (*xMutexEnter)(sqlite3_mutex *); 4712 int (*xMutexTry)(sqlite3_mutex *); 4713 void (*xMutexLeave)(sqlite3_mutex *); 4714 int (*xMutexHeld)(sqlite3_mutex *); 4715 int (*xMutexNotheld)(sqlite3_mutex *); 4716}; 4717 4718/* 4719** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> 4720** 4721** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 4722** are intended for use inside assert() statements. {H17081} The SQLite core 4723** never uses these routines except inside an assert() and applications 4724** are advised to follow the lead of the core. {H17082} The core only 4725** provides implementations for these routines when it is compiled 4726** with the SQLITE_DEBUG flag. {A17087} External mutex implementations 4727** are only required to provide these routines if SQLITE_DEBUG is 4728** defined and if NDEBUG is not defined. 4729** 4730** {H17083} These routines should return true if the mutex in their argument 4731** is held or not held, respectively, by the calling thread. 4732** 4733** {X17084} The implementation is not required to provided versions of these 4734** routines that actually work. If the implementation does not provide working 4735** versions of these routines, it should at least provide stubs that always 4736** return true so that one does not get spurious assertion failures. 4737** 4738** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 4739** the routine should return 1. {END} This seems counter-intuitive since 4740** clearly the mutex cannot be held if it does not exist. But the 4741** the reason the mutex does not exist is because the build is not 4742** using mutexes. And we do not want the assert() containing the 4743** call to sqlite3_mutex_held() to fail, so a non-zero return is 4744** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() 4745** interface should also return 1 when given a NULL pointer. 4746*/ 4747int sqlite3_mutex_held(sqlite3_mutex*); 4748int sqlite3_mutex_notheld(sqlite3_mutex*); 4749 4750/* 4751** CAPI3REF: Mutex Types {H17001} <H17000> 4752** 4753** The [sqlite3_mutex_alloc()] interface takes a single argument 4754** which is one of these integer constants. 4755** 4756** The set of static mutexes may change from one SQLite release to the 4757** next. Applications that override the built-in mutex logic must be 4758** prepared to accommodate additional static mutexes. 4759*/ 4760#define SQLITE_MUTEX_FAST 0 4761#define SQLITE_MUTEX_RECURSIVE 1 4762#define SQLITE_MUTEX_STATIC_MASTER 2 4763#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 4764#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 4765#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 4766#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 4767#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 4768#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 4769 4770/* 4771** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> 4772** 4773** This interface returns a pointer the [sqlite3_mutex] object that 4774** serializes access to the [database connection] given in the argument 4775** when the [threading mode] is Serialized. 4776** If the [threading mode] is Single-thread or Multi-thread then this 4777** routine returns a NULL pointer. 4778*/ 4779sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 4780 4781/* 4782** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> 4783** 4784** {H11301} The [sqlite3_file_control()] interface makes a direct call to the 4785** xFileControl method for the [sqlite3_io_methods] object associated 4786** with a particular database identified by the second argument. {H11302} The 4787** name of the database is the name assigned to the database by the 4788** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 4789** database. {H11303} To control the main database file, use the name "main" 4790** or a NULL pointer. {H11304} The third and fourth parameters to this routine 4791** are passed directly through to the second and third parameters of 4792** the xFileControl method. {H11305} The return value of the xFileControl 4793** method becomes the return value of this routine. 4794** 4795** {H11306} If the second parameter (zDbName) does not match the name of any 4796** open database file, then SQLITE_ERROR is returned. {H11307} This error 4797** code is not remembered and will not be recalled by [sqlite3_errcode()] 4798** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might 4799** also return SQLITE_ERROR. {A11309} There is no way to distinguish between 4800** an incorrect zDbName and an SQLITE_ERROR return from the underlying 4801** xFileControl method. {END} 4802** 4803** See also: [SQLITE_FCNTL_LOCKSTATE] 4804*/ 4805int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 4806 4807/* 4808** CAPI3REF: Testing Interface {H11400} <S30800> 4809** 4810** The sqlite3_test_control() interface is used to read out internal 4811** state of SQLite and to inject faults into SQLite for testing 4812** purposes. The first parameter is an operation code that determines 4813** the number, meaning, and operation of all subsequent parameters. 4814** 4815** This interface is not for use by applications. It exists solely 4816** for verifying the correct operation of the SQLite library. Depending 4817** on how the SQLite library is compiled, this interface might not exist. 4818** 4819** The details of the operation codes, their meanings, the parameters 4820** they take, and what they do are all subject to change without notice. 4821** Unlike most of the SQLite API, this function is not guaranteed to 4822** operate consistently from one release to the next. 4823*/ 4824int sqlite3_test_control(int op, ...); 4825 4826/* 4827** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> 4828** 4829** These constants are the valid operation code parameters used 4830** as the first argument to [sqlite3_test_control()]. 4831** 4832** These parameters and their meanings are subject to change 4833** without notice. These values are for testing purposes only. 4834** Applications should not use any of these parameters or the 4835** [sqlite3_test_control()] interface. 4836*/ 4837#define SQLITE_TESTCTRL_PRNG_SAVE 5 4838#define SQLITE_TESTCTRL_PRNG_RESTORE 6 4839#define SQLITE_TESTCTRL_PRNG_RESET 7 4840#define SQLITE_TESTCTRL_BITVEC_TEST 8 4841#define SQLITE_TESTCTRL_FAULT_INSTALL 9 4842#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 4843#define SQLITE_TESTCTRL_PENDING_BYTE 11 4844 4845/* 4846** CAPI3REF: SQLite Runtime Status {H17200} <S60200> 4847** EXPERIMENTAL 4848** 4849** This interface is used to retrieve runtime status information 4850** about the preformance of SQLite, and optionally to reset various 4851** highwater marks. The first argument is an integer code for 4852** the specific parameter to measure. Recognized integer codes 4853** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. 4854** The current value of the parameter is returned into *pCurrent. 4855** The highest recorded value is returned in *pHighwater. If the 4856** resetFlag is true, then the highest record value is reset after 4857** *pHighwater is written. Some parameters do not record the highest 4858** value. For those parameters 4859** nothing is written into *pHighwater and the resetFlag is ignored. 4860** Other parameters record only the highwater mark and not the current 4861** value. For these latter parameters nothing is written into *pCurrent. 4862** 4863** This routine returns SQLITE_OK on success and a non-zero 4864** [error code] on failure. 4865** 4866** This routine is threadsafe but is not atomic. This routine can 4867** called while other threads are running the same or different SQLite 4868** interfaces. However the values returned in *pCurrent and 4869** *pHighwater reflect the status of SQLite at different points in time 4870** and it is possible that another thread might change the parameter 4871** in between the times when *pCurrent and *pHighwater are written. 4872** 4873** See also: [sqlite3_db_status()] 4874*/ 4875SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 4876 4877 4878/* 4879** CAPI3REF: Status Parameters {H17250} <H17200> 4880** EXPERIMENTAL 4881** 4882** These integer constants designate various run-time status parameters 4883** that can be returned by [sqlite3_status()]. 4884** 4885** <dl> 4886** <dt>SQLITE_STATUS_MEMORY_USED</dt> 4887** <dd>This parameter is the current amount of memory checked out 4888** using [sqlite3_malloc()], either directly or indirectly. The 4889** figure includes calls made to [sqlite3_malloc()] by the application 4890** and internal memory usage by the SQLite library. Scratch memory 4891** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 4892** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 4893** this parameter. The amount returned is the sum of the allocation 4894** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> 4895** 4896** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> 4897** <dd>This parameter records the largest memory allocation request 4898** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 4899** internal equivalents). Only the value returned in the 4900** *pHighwater parameter to [sqlite3_status()] is of interest. 4901** The value written into the *pCurrent parameter is undefined.</dd> 4902** 4903** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> 4904** <dd>This parameter returns the number of pages used out of the 4905** [pagecache memory allocator] that was configured using 4906** [SQLITE_CONFIG_PAGECACHE]. The 4907** value returned is in pages, not in bytes.</dd> 4908** 4909** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 4910** <dd>This parameter returns the number of bytes of page cache 4911** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] 4912** buffer and where forced to overflow to [sqlite3_malloc()]. The 4913** returned value includes allocations that overflowed because they 4914** where too large (they were larger than the "sz" parameter to 4915** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 4916** no space was left in the page cache.</dd> 4917** 4918** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 4919** <dd>This parameter records the largest memory allocation request 4920** handed to [pagecache memory allocator]. Only the value returned in the 4921** *pHighwater parameter to [sqlite3_status()] is of interest. 4922** The value written into the *pCurrent parameter is undefined.</dd> 4923** 4924** <dt>SQLITE_STATUS_SCRATCH_USED</dt> 4925** <dd>This parameter returns the number of allocations used out of the 4926** [scratch memory allocator] configured using 4927** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 4928** in bytes. Since a single thread may only have one scratch allocation 4929** outstanding at time, this parameter also reports the number of threads 4930** using scratch memory at the same time.</dd> 4931** 4932** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 4933** <dd>This parameter returns the number of bytes of scratch memory 4934** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] 4935** buffer and where forced to overflow to [sqlite3_malloc()]. The values 4936** returned include overflows because the requested allocation was too 4937** larger (that is, because the requested allocation was larger than the 4938** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 4939** slots were available. 4940** </dd> 4941** 4942** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 4943** <dd>This parameter records the largest memory allocation request 4944** handed to [scratch memory allocator]. Only the value returned in the 4945** *pHighwater parameter to [sqlite3_status()] is of interest. 4946** The value written into the *pCurrent parameter is undefined.</dd> 4947** 4948** <dt>SQLITE_STATUS_PARSER_STACK</dt> 4949** <dd>This parameter records the deepest parser stack. It is only 4950** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> 4951** </dl> 4952** 4953** New status parameters may be added from time to time. 4954*/ 4955#define SQLITE_STATUS_MEMORY_USED 0 4956#define SQLITE_STATUS_PAGECACHE_USED 1 4957#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 4958#define SQLITE_STATUS_SCRATCH_USED 3 4959#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 4960#define SQLITE_STATUS_MALLOC_SIZE 5 4961#define SQLITE_STATUS_PARSER_STACK 6 4962#define SQLITE_STATUS_PAGECACHE_SIZE 7 4963#define SQLITE_STATUS_SCRATCH_SIZE 8 4964 4965/* 4966** CAPI3REF: Database Connection Status {H17500} <S60200> 4967** EXPERIMENTAL 4968** 4969** This interface is used to retrieve runtime status information 4970** about a single [database connection]. The first argument is the 4971** database connection object to be interrogated. The second argument 4972** is the parameter to interrogate. Currently, the only allowed value 4973** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. 4974** Additional options will likely appear in future releases of SQLite. 4975** 4976** The current value of the requested parameter is written into *pCur 4977** and the highest instantaneous value is written into *pHiwtr. If 4978** the resetFlg is true, then the highest instantaneous value is 4979** reset back down to the current value. 4980** 4981** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 4982*/ 4983SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 4984 4985/* 4986** CAPI3REF: Status Parameters for database connections {H17520} <H17500> 4987** EXPERIMENTAL 4988** 4989** Status verbs for [sqlite3_db_status()]. 4990** 4991** <dl> 4992** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 4993** <dd>This parameter returns the number of lookaside memory slots currently 4994** checked out.</dd> 4995** </dl> 4996*/ 4997#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 4998 4999 5000/* 5001** CAPI3REF: Prepared Statement Status {H17550} <S60200> 5002** EXPERIMENTAL 5003** 5004** Each prepared statement maintains various 5005** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 5006** of times it has performed specific operations. These counters can 5007** be used to monitor the performance characteristics of the prepared 5008** statements. For example, if the number of table steps greatly exceeds 5009** the number of table searches or result rows, that would tend to indicate 5010** that the prepared statement is using a full table scan rather than 5011** an index. 5012** 5013** This interface is used to retrieve and reset counter values from 5014** a [prepared statement]. The first argument is the prepared statement 5015** object to be interrogated. The second argument 5016** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 5017** to be interrogated. 5018** The current value of the requested counter is returned. 5019** If the resetFlg is true, then the counter is reset to zero after this 5020** interface call returns. 5021** 5022** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5023*/ 5024SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5025 5026/* 5027** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> 5028** EXPERIMENTAL 5029** 5030** These preprocessor macros define integer codes that name counter 5031** values associated with the [sqlite3_stmt_status()] interface. 5032** The meanings of the various counters are as follows: 5033** 5034** <dl> 5035** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5036** <dd>This is the number of times that SQLite has stepped forward in 5037** a table as part of a full table scan. Large numbers for this counter 5038** may indicate opportunities for performance improvement through 5039** careful use of indices.</dd> 5040** 5041** <dt>SQLITE_STMTSTATUS_SORT</dt> 5042** <dd>This is the number of sort operations that have occurred. 5043** A non-zero value in this counter may indicate an opportunity to 5044** improvement performance through careful use of indices.</dd> 5045** 5046** </dl> 5047*/ 5048#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5049#define SQLITE_STMTSTATUS_SORT 2 5050 5051/* 5052** CAPI3REF: Custom Page Cache Object 5053** EXPERIMENTAL 5054** 5055** The sqlite3_pcache type is opaque. It is implemented by 5056** the pluggable module. The SQLite core has no knowledge of 5057** its size or internal structure and never deals with the 5058** sqlite3_pcache object except by holding and passing pointers 5059** to the object. 5060** 5061** See [sqlite3_pcache_methods] for additional information. 5062*/ 5063typedef struct sqlite3_pcache sqlite3_pcache; 5064 5065/* 5066** CAPI3REF: Application Defined Page Cache. 5067** EXPERIMENTAL 5068** 5069** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5070** register an alternative page cache implementation by passing in an 5071** instance of the sqlite3_pcache_methods structure. The majority of the 5072** heap memory used by sqlite is used by the page cache to cache data read 5073** from, or ready to be written to, the database file. By implementing a 5074** custom page cache using this API, an application can control more 5075** precisely the amount of memory consumed by sqlite, the way in which 5076** said memory is allocated and released, and the policies used to 5077** determine exactly which parts of a database file are cached and for 5078** how long. 5079** 5080** The contents of the structure are copied to an internal buffer by sqlite 5081** within the call to [sqlite3_config]. 5082** 5083** The xInit() method is called once for each call to [sqlite3_initialize()] 5084** (usually only once during the lifetime of the process). It is passed 5085** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set 5086** up global structures and mutexes required by the custom page cache 5087** implementation. The xShutdown() method is called from within 5088** [sqlite3_shutdown()], if the application invokes this API. It can be used 5089** to clean up any outstanding resources before process shutdown, if required. 5090** 5091** The xCreate() method is used to construct a new cache instance. The 5092** first parameter, szPage, is the size in bytes of the pages that must 5093** be allocated by the cache. szPage will not be a power of two. The 5094** second argument, bPurgeable, is true if the cache being created will 5095** be used to cache database pages read from a file stored on disk, or 5096** false if it is used for an in-memory database. The cache implementation 5097** does not have to do anything special based on the value of bPurgeable, 5098** it is purely advisory. 5099** 5100** The xCachesize() method may be called at any time by SQLite to set the 5101** suggested maximum cache-size (number of pages stored by) the cache 5102** instance passed as the first argument. This is the value configured using 5103** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, 5104** the implementation is not required to do anything special with this 5105** value, it is advisory only. 5106** 5107** The xPagecount() method should return the number of pages currently 5108** stored in the cache supplied as an argument. 5109** 5110** The xFetch() method is used to fetch a page and return a pointer to it. 5111** A 'page', in this context, is a buffer of szPage bytes aligned at an 5112** 8-byte boundary. The page to be fetched is determined by the key. The 5113** mimimum key value is 1. After it has been retrieved using xFetch, the page 5114** is considered to be pinned. 5115** 5116** If the requested page is already in the page cache, then a pointer to 5117** the cached buffer should be returned with its contents intact. If the 5118** page is not already in the cache, then the expected behaviour of the 5119** cache is determined by the value of the createFlag parameter passed 5120** to xFetch, according to the following table: 5121** 5122** <table border=1 width=85% align=center> 5123** <tr><th>createFlag<th>Expected Behaviour 5124** <tr><td>0<td>NULL should be returned. No new cache entry is created. 5125** <tr><td>1<td>If createFlag is set to 1, this indicates that 5126** SQLite is holding pinned pages that can be unpinned 5127** by writing their contents to the database file (a 5128** relatively expensive operation). In this situation the 5129** cache implementation has two choices: it can return NULL, 5130** in which case SQLite will attempt to unpin one or more 5131** pages before re-requesting the same page, or it can 5132** allocate a new page and return a pointer to it. If a new 5133** page is allocated, then the first sizeof(void*) bytes of 5134** it (at least) must be zeroed before it is returned. 5135** <tr><td>2<td>If createFlag is set to 2, then SQLite is not holding any 5136** pinned pages associated with the specific cache passed 5137** as the first argument to xFetch() that can be unpinned. The 5138** cache implementation should attempt to allocate a new 5139** cache entry and return a pointer to it. Again, the first 5140** sizeof(void*) bytes of the page should be zeroed before 5141** it is returned. If the xFetch() method returns NULL when 5142** createFlag==2, SQLite assumes that a memory allocation 5143** failed and returns SQLITE_NOMEM to the user. 5144** </table> 5145** 5146** xUnpin() is called by SQLite with a pointer to a currently pinned page 5147** as its second argument. If the third parameter, discard, is non-zero, 5148** then the page should be evicted from the cache. In this case SQLite 5149** assumes that the next time the page is retrieved from the cache using 5150** the xFetch() method, it will be zeroed. If the discard parameter is 5151** zero, then the page is considered to be unpinned. The cache implementation 5152** may choose to reclaim (free or recycle) unpinned pages at any time. 5153** SQLite assumes that next time the page is retrieved from the cache 5154** it will either be zeroed, or contain the same data that it did when it 5155** was unpinned. 5156** 5157** The cache is not required to perform any reference counting. A single 5158** call to xUnpin() unpins the page regardless of the number of prior calls 5159** to xFetch(). 5160** 5161** The xRekey() method is used to change the key value associated with the 5162** page passed as the second argument from oldKey to newKey. If the cache 5163** previously contains an entry associated with newKey, it should be 5164** discarded. Any prior cache entry associated with newKey is guaranteed not 5165** to be pinned. 5166** 5167** When SQLite calls the xTruncate() method, the cache must discard all 5168** existing cache entries with page numbers (keys) greater than or equal 5169** to the value of the iLimit parameter passed to xTruncate(). If any 5170** of these pages are pinned, they are implicitly unpinned, meaning that 5171** they can be safely discarded. 5172** 5173** The xDestroy() method is used to delete a cache allocated by xCreate(). 5174** All resources associated with the specified cache should be freed. After 5175** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5176** handle invalid, and will not use it with any other sqlite3_pcache_methods 5177** functions. 5178*/ 5179typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5180struct sqlite3_pcache_methods { 5181 void *pArg; 5182 int (*xInit)(void*); 5183 void (*xShutdown)(void*); 5184 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5185 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5186 int (*xPagecount)(sqlite3_pcache*); 5187 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5188 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5189 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5190 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5191 void (*xDestroy)(sqlite3_pcache*); 5192}; 5193 5194/* 5195** CAPI3REF: Online Backup Object 5196** EXPERIMENTAL 5197** 5198** The sqlite3_backup object records state information about an ongoing 5199** online backup operation. The sqlite3_backup object is created by 5200** a call to [sqlite3_backup_init()] and is destroyed by a call to 5201** [sqlite3_backup_finish()]. 5202** 5203** See Also: [Using the SQLite Online Backup API] 5204*/ 5205typedef struct sqlite3_backup sqlite3_backup; 5206 5207/* 5208** CAPI3REF: Online Backup API. 5209** EXPERIMENTAL 5210** 5211** This API is used to overwrite the contents of one database with that 5212** of another. It is useful either for creating backups of databases or 5213** for copying in-memory databases to or from persistent files. 5214** 5215** See Also: [Using the SQLite Online Backup API] 5216** 5217** Exclusive access is required to the destination database for the 5218** duration of the operation. However the source database is only 5219** read-locked while it is actually being read, it is not locked 5220** continuously for the entire operation. Thus, the backup may be 5221** performed on a live database without preventing other users from 5222** writing to the database for an extended period of time. 5223** 5224** To perform a backup operation: 5225** <ol> 5226** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5227** backup, 5228** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5229** the data between the two databases, and finally 5230** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5231** associated with the backup operation. 5232** </ol> 5233** There should be exactly one call to sqlite3_backup_finish() for each 5234** successful call to sqlite3_backup_init(). 5235** 5236** <b>sqlite3_backup_init()</b> 5237** 5238** The first two arguments passed to [sqlite3_backup_init()] are the database 5239** handle associated with the destination database and the database name 5240** used to attach the destination database to the handle. The database name 5241** is "main" for the main database, "temp" for the temporary database, or 5242** the name specified as part of the [ATTACH] statement if the destination is 5243** an attached database. The third and fourth arguments passed to 5244** sqlite3_backup_init() identify the [database connection] 5245** and database name used 5246** to access the source database. The values passed for the source and 5247** destination [database connection] parameters must not be the same. 5248** 5249** If an error occurs within sqlite3_backup_init(), then NULL is returned 5250** and an error code and error message written into the [database connection] 5251** passed as the first argument. They may be retrieved using the 5252** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. 5253** Otherwise, if successful, a pointer to an [sqlite3_backup] object is 5254** returned. This pointer may be used with the sqlite3_backup_step() and 5255** sqlite3_backup_finish() functions to perform the specified backup 5256** operation. 5257** 5258** <b>sqlite3_backup_step()</b> 5259** 5260** Function [sqlite3_backup_step()] is used to copy up to nPage pages between 5261** the source and destination databases, where nPage is the value of the 5262** second parameter passed to sqlite3_backup_step(). If nPage is a negative 5263** value, all remaining source pages are copied. If the required pages are 5264** succesfully copied, but there are still more pages to copy before the 5265** backup is complete, it returns [SQLITE_OK]. If no error occured and there 5266** are no more pages to copy, then [SQLITE_DONE] is returned. If an error 5267** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and 5268** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5269** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5270** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5271** 5272** As well as the case where the destination database file was opened for 5273** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if 5274** the destination is an in-memory database with a different page size 5275** from the source database. 5276** 5277** If sqlite3_backup_step() cannot obtain a required file-system lock, then 5278** the [sqlite3_busy_handler | busy-handler function] 5279** is invoked (if one is specified). If the 5280** busy-handler returns non-zero before the lock is available, then 5281** [SQLITE_BUSY] is returned to the caller. In this case the call to 5282** sqlite3_backup_step() can be retried later. If the source 5283** [database connection] 5284** is being used to write to the source database when sqlite3_backup_step() 5285** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this 5286** case the call to sqlite3_backup_step() can be retried later on. If 5287** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5288** [SQLITE_READONLY] is returned, then 5289** there is no point in retrying the call to sqlite3_backup_step(). These 5290** errors are considered fatal. At this point the application must accept 5291** that the backup operation has failed and pass the backup operation handle 5292** to the sqlite3_backup_finish() to release associated resources. 5293** 5294** Following the first call to sqlite3_backup_step(), an exclusive lock is 5295** obtained on the destination file. It is not released until either 5296** sqlite3_backup_finish() is called or the backup operation is complete 5297** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time 5298** a call to sqlite3_backup_step() is made a [shared lock] is obtained on 5299** the source database file. This lock is released before the 5300** sqlite3_backup_step() call returns. Because the source database is not 5301** locked between calls to sqlite3_backup_step(), it may be modified mid-way 5302** through the backup procedure. If the source database is modified by an 5303** external process or via a database connection other than the one being 5304** used by the backup operation, then the backup will be transparently 5305** restarted by the next call to sqlite3_backup_step(). If the source 5306** database is modified by the using the same database connection as is used 5307** by the backup operation, then the backup database is transparently 5308** updated at the same time. 5309** 5310** <b>sqlite3_backup_finish()</b> 5311** 5312** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5313** application wishes to abandon the backup operation, the [sqlite3_backup] 5314** object should be passed to sqlite3_backup_finish(). This releases all 5315** resources associated with the backup operation. If sqlite3_backup_step() 5316** has not yet returned [SQLITE_DONE], then any active write-transaction on the 5317** destination database is rolled back. The [sqlite3_backup] object is invalid 5318** and may not be used following a call to sqlite3_backup_finish(). 5319** 5320** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error 5321** occurred, regardless or whether or not sqlite3_backup_step() was called 5322** a sufficient number of times to complete the backup operation. Or, if 5323** an out-of-memory condition or IO error occured during a call to 5324** sqlite3_backup_step() then [SQLITE_NOMEM] or an 5325** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code 5326** is returned. In this case the error code and an error message are 5327** written to the destination [database connection]. 5328** 5329** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is 5330** not a permanent error and does not affect the return value of 5331** sqlite3_backup_finish(). 5332** 5333** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 5334** 5335** Each call to sqlite3_backup_step() sets two values stored internally 5336** by an [sqlite3_backup] object. The number of pages still to be backed 5337** up, which may be queried by sqlite3_backup_remaining(), and the total 5338** number of pages in the source database file, which may be queried by 5339** sqlite3_backup_pagecount(). 5340** 5341** The values returned by these functions are only updated by 5342** sqlite3_backup_step(). If the source database is modified during a backup 5343** operation, then the values are not updated to account for any extra 5344** pages that need to be updated or the size of the source database file 5345** changing. 5346** 5347** <b>Concurrent Usage of Database Handles</b> 5348** 5349** The source [database connection] may be used by the application for other 5350** purposes while a backup operation is underway or being initialized. 5351** If SQLite is compiled and configured to support threadsafe database 5352** connections, then the source database connection may be used concurrently 5353** from within other threads. 5354** 5355** However, the application must guarantee that the destination database 5356** connection handle is not passed to any other API (by any thread) after 5357** sqlite3_backup_init() is called and before the corresponding call to 5358** sqlite3_backup_finish(). Unfortunately SQLite does not currently check 5359** for this, if the application does use the destination [database connection] 5360** for some other purpose during a backup operation, things may appear to 5361** work correctly but in fact be subtly malfunctioning. Use of the 5362** destination database connection while a backup is in progress might 5363** also cause a mutex deadlock. 5364** 5365** Furthermore, if running in [shared cache mode], the application must 5366** guarantee that the shared cache used by the destination database 5367** is not accessed while the backup is running. In practice this means 5368** that the application must guarantee that the file-system file being 5369** backed up to is not accessed by any connection within the process, 5370** not just the specific connection that was passed to sqlite3_backup_init(). 5371** 5372** The [sqlite3_backup] object itself is partially threadsafe. Multiple 5373** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 5374** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 5375** APIs are not strictly speaking threadsafe. If they are invoked at the 5376** same time as another thread is invoking sqlite3_backup_step() it is 5377** possible that they return invalid values. 5378*/ 5379sqlite3_backup *sqlite3_backup_init( 5380 sqlite3 *pDest, /* Destination database handle */ 5381 const char *zDestName, /* Destination database name */ 5382 sqlite3 *pSource, /* Source database handle */ 5383 const char *zSourceName /* Source database name */ 5384); 5385int sqlite3_backup_step(sqlite3_backup *p, int nPage); 5386int sqlite3_backup_finish(sqlite3_backup *p); 5387int sqlite3_backup_remaining(sqlite3_backup *p); 5388int sqlite3_backup_pagecount(sqlite3_backup *p); 5389 5390/* 5391** CAPI3REF: Unlock Notification 5392** EXPERIMENTAL 5393** 5394** When running in shared-cache mode, a database operation may fail with 5395** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 5396** individual tables within the shared-cache cannot be obtained. See 5397** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 5398** This API may be used to register a callback that SQLite will invoke 5399** when the connection currently holding the required lock relinquishes it. 5400** This API is only available if the library was compiled with the 5401** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 5402** 5403** See Also: [Using the SQLite Unlock Notification Feature]. 5404** 5405** Shared-cache locks are released when a database connection concludes 5406** its current transaction, either by committing it or rolling it back. 5407** 5408** When a connection (known as the blocked connection) fails to obtain a 5409** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 5410** identity of the database connection (the blocking connection) that 5411** has locked the required resource is stored internally. After an 5412** application receives an SQLITE_LOCKED error, it may call the 5413** sqlite3_unlock_notify() method with the blocked connection handle as 5414** the first argument to register for a callback that will be invoked 5415** when the blocking connections current transaction is concluded. The 5416** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 5417** call that concludes the blocking connections transaction. 5418** 5419** If sqlite3_unlock_notify() is called in a multi-threaded application, 5420** there is a chance that the blocking connection will have already 5421** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 5422** If this happens, then the specified callback is invoked immediately, 5423** from within the call to sqlite3_unlock_notify(). 5424** 5425** If the blocked connection is attempting to obtain a write-lock on a 5426** shared-cache table, and more than one other connection currently holds 5427** a read-lock on the same table, then SQLite arbitrarily selects one of 5428** the other connections to use as the blocking connection. 5429** 5430** There may be at most one unlock-notify callback registered by a 5431** blocked connection. If sqlite3_unlock_notify() is called when the 5432** blocked connection already has a registered unlock-notify callback, 5433** then the new callback replaces the old. If sqlite3_unlock_notify() is 5434** called with a NULL pointer as its second argument, then any existing 5435** unlock-notify callback is cancelled. The blocked connections 5436** unlock-notify callback may also be canceled by closing the blocked 5437** connection using [sqlite3_close()]. 5438** 5439** The unlock-notify callback is not reentrant. If an application invokes 5440** any sqlite3_xxx API functions from within an unlock-notify callback, a 5441** crash or deadlock may be the result. 5442** 5443** Unless deadlock is detected (see below), sqlite3_unlock_notify() always 5444** returns SQLITE_OK. 5445** 5446** <b>Callback Invocation Details</b> 5447** 5448** When an unlock-notify callback is registered, the application provides a 5449** single void* pointer that is passed to the callback when it is invoked. 5450** However, the signature of the callback function allows SQLite to pass 5451** it an array of void* context pointers. The first argument passed to 5452** an unlock-notify callback is a pointer to an array of void* pointers, 5453** and the second is the number of entries in the array. 5454** 5455** When a blocking connections transaction is concluded, there may be 5456** more than one blocked connection that has registered for an unlock-notify 5457** callback. If two or more such blocked connections have specified the 5458** same callback function, then instead of invoking the callback function 5459** multiple times, it is invoked once with the set of void* context pointers 5460** specified by the blocked connections bundled together into an array. 5461** This gives the application an opportunity to prioritize any actions 5462** related to the set of unblocked database connections. 5463** 5464** <b>Deadlock Detection</b> 5465** 5466** Assuming that after registering for an unlock-notify callback a 5467** database waits for the callback to be issued before taking any further 5468** action (a reasonable assumption), then using this API may cause the 5469** application to deadlock. For example, if connection X is waiting for 5470** connection Y's transaction to be concluded, and similarly connection 5471** Y is waiting on connection X's transaction, then neither connection 5472** will proceed and the system may remain deadlocked indefinitely. 5473** 5474** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 5475** detection. If a given call to sqlite3_unlock_notify() would put the 5476** system in a deadlocked state, then SQLITE_LOCKED is returned and no 5477** unlock-notify callback is registered. The system is said to be in 5478** a deadlocked state if connection A has registered for an unlock-notify 5479** callback on the conclusion of connection B's transaction, and connection 5480** B has itself registered for an unlock-notify callback when connection 5481** A's transaction is concluded. Indirect deadlock is also detected, so 5482** the system is also considered to be deadlocked if connection B has 5483** registered for an unlock-notify callback on the conclusion of connection 5484** C's transaction, where connection C is waiting on connection A. Any 5485** number of levels of indirection are allowed. 5486** 5487** <b>The "DROP TABLE" Exception</b> 5488** 5489** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 5490** always appropriate to call sqlite3_unlock_notify(). There is however, 5491** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 5492** SQLite checks if there are any currently executing SELECT statements 5493** that belong to the same connection. If there are, SQLITE_LOCKED is 5494** returned. In this case there is no "blocking connection", so invoking 5495** sqlite3_unlock_notify() results in the unlock-notify callback being 5496** invoked immediately. If the application then re-attempts the "DROP TABLE" 5497** or "DROP INDEX" query, an infinite loop might be the result. 5498** 5499** One way around this problem is to check the extended error code returned 5500** by an sqlite3_step() call. If there is a blocking connection, then the 5501** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 5502** the special "DROP TABLE/INDEX" case, the extended error code is just 5503** SQLITE_LOCKED. 5504*/ 5505int sqlite3_unlock_notify( 5506 sqlite3 *pBlocked, /* Waiting connection */ 5507 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 5508 void *pNotifyArg /* Argument to pass to xNotify */ 5509); 5510 5511/* 5512** Undo the hack that converts floating point types to integer for 5513** builds on processors without floating point support. 5514*/ 5515#ifdef SQLITE_OMIT_FLOATING_POINT 5516# undef double 5517#endif 5518 5519#ifdef __cplusplus 5520} /* End of the 'extern "C"' block */ 5521#endif 5522#endif 5523