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 1.436 2009/03/20 13:15:30 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 "3.6.12" 103#define SQLITE_VERSION_NUMBER 3006012 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)) 385 386#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) 387 388/* 389** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> 390** 391** These bit values are intended for use in the 392** 3rd parameter to the [sqlite3_open_v2()] interface and 393** in the 4th parameter to the xOpen method of the 394** [sqlite3_vfs] object. 395*/ 396#define SQLITE_OPEN_READONLY 0x00000001 397#define SQLITE_OPEN_READWRITE 0x00000002 398#define SQLITE_OPEN_CREATE 0x00000004 399#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 400#define SQLITE_OPEN_EXCLUSIVE 0x00000010 401#define SQLITE_OPEN_AUTOPROXY 0x00000020 402#define SQLITE_OPEN_MAIN_DB 0x00000100 403#define SQLITE_OPEN_TEMP_DB 0x00000200 404#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 405#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 406#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 407#define SQLITE_OPEN_SUBJOURNAL 0x00002000 408#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 409#define SQLITE_OPEN_NOMUTEX 0x00008000 410#define SQLITE_OPEN_FULLMUTEX 0x00010000 411 412/* 413** CAPI3REF: Device Characteristics {H10240} <H11120> 414** 415** The xDeviceCapabilities method of the [sqlite3_io_methods] 416** object returns an integer which is a vector of the these 417** bit values expressing I/O characteristics of the mass storage 418** device that holds the file that the [sqlite3_io_methods] 419** refers to. 420** 421** The SQLITE_IOCAP_ATOMIC property means that all writes of 422** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 423** mean that writes of blocks that are nnn bytes in size and 424** are aligned to an address which is an integer multiple of 425** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 426** that when data is appended to a file, the data is appended 427** first then the size of the file is extended, never the other 428** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 429** information is written to disk in the same order as calls 430** to xWrite(). 431*/ 432#define SQLITE_IOCAP_ATOMIC 0x00000001 433#define SQLITE_IOCAP_ATOMIC512 0x00000002 434#define SQLITE_IOCAP_ATOMIC1K 0x00000004 435#define SQLITE_IOCAP_ATOMIC2K 0x00000008 436#define SQLITE_IOCAP_ATOMIC4K 0x00000010 437#define SQLITE_IOCAP_ATOMIC8K 0x00000020 438#define SQLITE_IOCAP_ATOMIC16K 0x00000040 439#define SQLITE_IOCAP_ATOMIC32K 0x00000080 440#define SQLITE_IOCAP_ATOMIC64K 0x00000100 441#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 442#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 443 444/* 445** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> 446** 447** SQLite uses one of these integer values as the second 448** argument to calls it makes to the xLock() and xUnlock() methods 449** of an [sqlite3_io_methods] object. 450*/ 451#define SQLITE_LOCK_NONE 0 452#define SQLITE_LOCK_SHARED 1 453#define SQLITE_LOCK_RESERVED 2 454#define SQLITE_LOCK_PENDING 3 455#define SQLITE_LOCK_EXCLUSIVE 4 456 457/* 458** CAPI3REF: Synchronization Type Flags {H10260} <H11120> 459** 460** When SQLite invokes the xSync() method of an 461** [sqlite3_io_methods] object it uses a combination of 462** these integer values as the second argument. 463** 464** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 465** sync operation only needs to flush data to mass storage. Inode 466** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 467** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 468** to use Mac OS X style fullsync instead of fsync(). 469*/ 470#define SQLITE_SYNC_NORMAL 0x00002 471#define SQLITE_SYNC_FULL 0x00003 472#define SQLITE_SYNC_DATAONLY 0x00010 473 474/* 475** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> 476** 477** An [sqlite3_file] object represents an open file in the OS 478** interface layer. Individual OS interface implementations will 479** want to subclass this object by appending additional fields 480** for their own use. The pMethods entry is a pointer to an 481** [sqlite3_io_methods] object that defines methods for performing 482** I/O operations on the open file. 483*/ 484typedef struct sqlite3_file sqlite3_file; 485struct sqlite3_file { 486 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 487}; 488 489/* 490** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> 491** 492** Every file opened by the [sqlite3_vfs] xOpen method populates an 493** [sqlite3_file] object (or, more commonly, a subclass of the 494** [sqlite3_file] object) with a pointer to an instance of this object. 495** This object defines the methods used to perform various operations 496** against the open file represented by the [sqlite3_file] object. 497** 498** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 499** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 500** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 501** flag may be ORed in to indicate that only the data of the file 502** and not its inode needs to be synced. 503** 504** The integer values to xLock() and xUnlock() are one of 505** <ul> 506** <li> [SQLITE_LOCK_NONE], 507** <li> [SQLITE_LOCK_SHARED], 508** <li> [SQLITE_LOCK_RESERVED], 509** <li> [SQLITE_LOCK_PENDING], or 510** <li> [SQLITE_LOCK_EXCLUSIVE]. 511** </ul> 512** xLock() increases the lock. xUnlock() decreases the lock. 513** The xCheckReservedLock() method checks whether any database connection, 514** either in this process or in some other process, is holding a RESERVED, 515** PENDING, or EXCLUSIVE lock on the file. It returns true 516** if such a lock exists and false otherwise. 517** 518** The xFileControl() method is a generic interface that allows custom 519** VFS implementations to directly control an open file using the 520** [sqlite3_file_control()] interface. The second "op" argument is an 521** integer opcode. The third argument is a generic pointer intended to 522** point to a structure that may contain arguments or space in which to 523** write return values. Potential uses for xFileControl() might be 524** functions to enable blocking locks with timeouts, to change the 525** locking strategy (for example to use dot-file locks), to inquire 526** about the status of a lock, or to break stale locks. The SQLite 527** core reserves all opcodes less than 100 for its own use. 528** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 529** Applications that define a custom xFileControl method should use opcodes 530** greater than 100 to avoid conflicts. 531** 532** The xSectorSize() method returns the sector size of the 533** device that underlies the file. The sector size is the 534** minimum write that can be performed without disturbing 535** other bytes in the file. The xDeviceCharacteristics() 536** method returns a bit vector describing behaviors of the 537** underlying device: 538** 539** <ul> 540** <li> [SQLITE_IOCAP_ATOMIC] 541** <li> [SQLITE_IOCAP_ATOMIC512] 542** <li> [SQLITE_IOCAP_ATOMIC1K] 543** <li> [SQLITE_IOCAP_ATOMIC2K] 544** <li> [SQLITE_IOCAP_ATOMIC4K] 545** <li> [SQLITE_IOCAP_ATOMIC8K] 546** <li> [SQLITE_IOCAP_ATOMIC16K] 547** <li> [SQLITE_IOCAP_ATOMIC32K] 548** <li> [SQLITE_IOCAP_ATOMIC64K] 549** <li> [SQLITE_IOCAP_SAFE_APPEND] 550** <li> [SQLITE_IOCAP_SEQUENTIAL] 551** </ul> 552** 553** The SQLITE_IOCAP_ATOMIC property means that all writes of 554** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 555** mean that writes of blocks that are nnn bytes in size and 556** are aligned to an address which is an integer multiple of 557** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 558** that when data is appended to a file, the data is appended 559** first then the size of the file is extended, never the other 560** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 561** information is written to disk in the same order as calls 562** to xWrite(). 563** 564** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 565** in the unread portions of the buffer with zeros. A VFS that 566** fails to zero-fill short reads might seem to work. However, 567** failure to zero-fill short reads will eventually lead to 568** database corruption. 569*/ 570typedef struct sqlite3_io_methods sqlite3_io_methods; 571struct sqlite3_io_methods { 572 int iVersion; 573 int (*xClose)(sqlite3_file*); 574 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 575 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 576 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 577 int (*xSync)(sqlite3_file*, int flags); 578 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 579 int (*xLock)(sqlite3_file*, int); 580 int (*xUnlock)(sqlite3_file*, int); 581 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 582 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 583 int (*xSectorSize)(sqlite3_file*); 584 int (*xDeviceCharacteristics)(sqlite3_file*); 585 /* Additional methods may be added in future releases */ 586}; 587 588/* 589** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> 590** 591** These integer constants are opcodes for the xFileControl method 592** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 593** interface. 594** 595** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 596** opcode causes the xFileControl method to write the current state of 597** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 598** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 599** into an integer that the pArg argument points to. This capability 600** is used during testing and only needs to be supported when SQLITE_TEST 601** is defined. 602*/ 603#define SQLITE_FCNTL_LOCKSTATE 1 604#define SQLITE_GET_LOCKPROXYFILE 2 605#define SQLITE_SET_LOCKPROXYFILE 3 606#define SQLITE_LAST_ERRNO 4 607 608/* 609** CAPI3REF: Mutex Handle {H17110} <S20130> 610** 611** The mutex module within SQLite defines [sqlite3_mutex] to be an 612** abstract type for a mutex object. The SQLite core never looks 613** at the internal representation of an [sqlite3_mutex]. It only 614** deals with pointers to the [sqlite3_mutex] object. 615** 616** Mutexes are created using [sqlite3_mutex_alloc()]. 617*/ 618typedef struct sqlite3_mutex sqlite3_mutex; 619 620/* 621** CAPI3REF: OS Interface Object {H11140} <S20100> 622** 623** An instance of the sqlite3_vfs object defines the interface between 624** the SQLite core and the underlying operating system. The "vfs" 625** in the name of the object stands for "virtual file system". 626** 627** The value of the iVersion field is initially 1 but may be larger in 628** future versions of SQLite. Additional fields may be appended to this 629** object when the iVersion value is increased. Note that the structure 630** of the sqlite3_vfs object changes in the transaction between 631** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 632** modified. 633** 634** The szOsFile field is the size of the subclassed [sqlite3_file] 635** structure used by this VFS. mxPathname is the maximum length of 636** a pathname in this VFS. 637** 638** Registered sqlite3_vfs objects are kept on a linked list formed by 639** the pNext pointer. The [sqlite3_vfs_register()] 640** and [sqlite3_vfs_unregister()] interfaces manage this list 641** in a thread-safe way. The [sqlite3_vfs_find()] interface 642** searches the list. Neither the application code nor the VFS 643** implementation should use the pNext pointer. 644** 645** The pNext field is the only field in the sqlite3_vfs 646** structure that SQLite will ever modify. SQLite will only access 647** or modify this field while holding a particular static mutex. 648** The application should never modify anything within the sqlite3_vfs 649** object once the object has been registered. 650** 651** The zName field holds the name of the VFS module. The name must 652** be unique across all VFS modules. 653** 654** SQLite will guarantee that the zFilename parameter to xOpen 655** is either a NULL pointer or string obtained 656** from xFullPathname(). SQLite further guarantees that 657** the string will be valid and unchanged until xClose() is 658** called. Because of the previous sentense, 659** the [sqlite3_file] can safely store a pointer to the 660** filename if it needs to remember the filename for some reason. 661** If the zFilename parameter is xOpen is a NULL pointer then xOpen 662** must invite its own temporary name for the file. Whenever the 663** xFilename parameter is NULL it will also be the case that the 664** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 665** 666** The flags argument to xOpen() includes all bits set in 667** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 668** or [sqlite3_open16()] is used, then flags includes at least 669** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 670** If xOpen() opens a file read-only then it sets *pOutFlags to 671** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 672** 673** SQLite will also add one of the following flags to the xOpen() 674** call, depending on the object being opened: 675** 676** <ul> 677** <li> [SQLITE_OPEN_MAIN_DB] 678** <li> [SQLITE_OPEN_MAIN_JOURNAL] 679** <li> [SQLITE_OPEN_TEMP_DB] 680** <li> [SQLITE_OPEN_TEMP_JOURNAL] 681** <li> [SQLITE_OPEN_TRANSIENT_DB] 682** <li> [SQLITE_OPEN_SUBJOURNAL] 683** <li> [SQLITE_OPEN_MASTER_JOURNAL] 684** </ul> 685** 686** The file I/O implementation can use the object type flags to 687** change the way it deals with files. For example, an application 688** that does not care about crash recovery or rollback might make 689** the open of a journal file a no-op. Writes to this journal would 690** also be no-ops, and any attempt to read the journal would return 691** SQLITE_IOERR. Or the implementation might recognize that a database 692** file will be doing page-aligned sector reads and writes in a random 693** order and set up its I/O subsystem accordingly. 694** 695** SQLite might also add one of the following flags to the xOpen method: 696** 697** <ul> 698** <li> [SQLITE_OPEN_DELETEONCLOSE] 699** <li> [SQLITE_OPEN_EXCLUSIVE] 700** </ul> 701** 702** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 703** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] 704** will be set for TEMP databases, journals and for subjournals. 705** 706** The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 707** for exclusive access. This flag is set for all files except 708** for the main database file. 709** 710** At least szOsFile bytes of memory are allocated by SQLite 711** to hold the [sqlite3_file] structure passed as the third 712** argument to xOpen. The xOpen method does not have to 713** allocate the structure; it should just fill it in. 714** 715** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 716** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 717** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 718** to test whether a file is at least readable. The file can be a 719** directory. 720** 721** SQLite will always allocate at least mxPathname+1 bytes for the 722** output buffer xFullPathname. The exact size of the output buffer 723** is also passed as a parameter to both methods. If the output buffer 724** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 725** handled as a fatal error by SQLite, vfs implementations should endeavor 726** to prevent this by setting mxPathname to a sufficiently large value. 727** 728** The xRandomness(), xSleep(), and xCurrentTime() interfaces 729** are not strictly a part of the filesystem, but they are 730** included in the VFS structure for completeness. 731** The xRandomness() function attempts to return nBytes bytes 732** of good-quality randomness into zOut. The return value is 733** the actual number of bytes of randomness obtained. 734** The xSleep() method causes the calling thread to sleep for at 735** least the number of microseconds given. The xCurrentTime() 736** method returns a Julian Day Number for the current date and time. 737** 738*/ 739typedef struct sqlite3_vfs sqlite3_vfs; 740struct sqlite3_vfs { 741 int iVersion; /* Structure version number */ 742 int szOsFile; /* Size of subclassed sqlite3_file */ 743 int mxPathname; /* Maximum file pathname length */ 744 sqlite3_vfs *pNext; /* Next registered VFS */ 745 const char *zName; /* Name of this virtual file system */ 746 void *pAppData; /* Pointer to application-specific data */ 747 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 748 int flags, int *pOutFlags); 749 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 750 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 751 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 752 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 753 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 754 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 755 void (*xDlClose)(sqlite3_vfs*, void*); 756 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 757 int (*xSleep)(sqlite3_vfs*, int microseconds); 758 int (*xCurrentTime)(sqlite3_vfs*, double*); 759 int (*xGetLastError)(sqlite3_vfs*, int, char *); 760 /* New fields may be appended in figure versions. The iVersion 761 ** value will increment whenever this happens. */ 762}; 763 764/* 765** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> 766** 767** These integer constants can be used as the third parameter to 768** the xAccess method of an [sqlite3_vfs] object. {END} They determine 769** what kind of permissions the xAccess method is looking for. 770** With SQLITE_ACCESS_EXISTS, the xAccess method 771** simply checks whether the file exists. 772** With SQLITE_ACCESS_READWRITE, the xAccess method 773** checks whether the file is both readable and writable. 774** With SQLITE_ACCESS_READ, the xAccess method 775** checks whether the file is readable. 776*/ 777#define SQLITE_ACCESS_EXISTS 0 778#define SQLITE_ACCESS_READWRITE 1 779#define SQLITE_ACCESS_READ 2 780 781/* 782** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> 783** 784** The sqlite3_initialize() routine initializes the 785** SQLite library. The sqlite3_shutdown() routine 786** deallocates any resources that were allocated by sqlite3_initialize(). 787** 788** A call to sqlite3_initialize() is an "effective" call if it is 789** the first time sqlite3_initialize() is invoked during the lifetime of 790** the process, or if it is the first time sqlite3_initialize() is invoked 791** following a call to sqlite3_shutdown(). Only an effective call 792** of sqlite3_initialize() does any initialization. All other calls 793** are harmless no-ops. 794** 795** Among other things, sqlite3_initialize() shall invoke 796** sqlite3_os_init(). Similarly, sqlite3_shutdown() 797** shall invoke sqlite3_os_end(). 798** 799** The sqlite3_initialize() routine returns [SQLITE_OK] on success. 800** If for some reason, sqlite3_initialize() is unable to initialize 801** the library (perhaps it is unable to allocate a needed resource such 802** as a mutex) it returns an [error code] other than [SQLITE_OK]. 803** 804** The sqlite3_initialize() routine is called internally by many other 805** SQLite interfaces so that an application usually does not need to 806** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 807** calls sqlite3_initialize() so the SQLite library will be automatically 808** initialized when [sqlite3_open()] is called if it has not be initialized 809** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 810** compile-time option, then the automatic calls to sqlite3_initialize() 811** are omitted and the application must call sqlite3_initialize() directly 812** prior to using any other SQLite interface. For maximum portability, 813** it is recommended that applications always invoke sqlite3_initialize() 814** directly prior to using any other SQLite interface. Future releases 815** of SQLite may require this. In other words, the behavior exhibited 816** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 817** default behavior in some future release of SQLite. 818** 819** The sqlite3_os_init() routine does operating-system specific 820** initialization of the SQLite library. The sqlite3_os_end() 821** routine undoes the effect of sqlite3_os_init(). Typical tasks 822** performed by these routines include allocation or deallocation 823** of static resources, initialization of global variables, 824** setting up a default [sqlite3_vfs] module, or setting up 825** a default configuration using [sqlite3_config()]. 826** 827** The application should never invoke either sqlite3_os_init() 828** or sqlite3_os_end() directly. The application should only invoke 829** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 830** interface is called automatically by sqlite3_initialize() and 831** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 832** implementations for sqlite3_os_init() and sqlite3_os_end() 833** are built into SQLite when it is compiled for unix, windows, or os/2. 834** When built for other platforms (using the [SQLITE_OS_OTHER=1] compile-time 835** option) the application must supply a suitable implementation for 836** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 837** implementation of sqlite3_os_init() or sqlite3_os_end() 838** must return [SQLITE_OK] on success and some other [error code] upon 839** failure. 840*/ 841int sqlite3_initialize(void); 842int sqlite3_shutdown(void); 843int sqlite3_os_init(void); 844int sqlite3_os_end(void); 845 846/* 847** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> 848** EXPERIMENTAL 849** 850** The sqlite3_config() interface is used to make global configuration 851** changes to SQLite in order to tune SQLite to the specific needs of 852** the application. The default configuration is recommended for most 853** applications and so this routine is usually not necessary. It is 854** provided to support rare applications with unusual needs. 855** 856** The sqlite3_config() interface is not threadsafe. The application 857** must insure that no other SQLite interfaces are invoked by other 858** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 859** may only be invoked prior to library initialization using 860** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 861** Note, however, that sqlite3_config() can be called as part of the 862** implementation of an application-defined [sqlite3_os_init()]. 863** 864** The first argument to sqlite3_config() is an integer 865** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 866** what property of SQLite is to be configured. Subsequent arguments 867** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 868** in the first argument. 869** 870** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 871** If the option is unknown or SQLite is unable to set the option 872** then this routine returns a non-zero [error code]. 873** 874** Requirements: 875** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] 876** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] 877** [H14162] [H14165] [H14168] 878*/ 879SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); 880 881/* 882** CAPI3REF: Configure database connections {H14200} <S20000> 883** EXPERIMENTAL 884** 885** The sqlite3_db_config() interface is used to make configuration 886** changes to a [database connection]. The interface is similar to 887** [sqlite3_config()] except that the changes apply to a single 888** [database connection] (specified in the first argument). The 889** sqlite3_db_config() interface can only be used immediately after 890** the database connection is created using [sqlite3_open()], 891** [sqlite3_open16()], or [sqlite3_open_v2()]. 892** 893** The second argument to sqlite3_db_config(D,V,...) is the 894** configuration verb - an integer code that indicates what 895** aspect of the [database connection] is being configured. 896** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. 897** New verbs are likely to be added in future releases of SQLite. 898** Additional arguments depend on the verb. 899** 900** Requirements: 901** [H14203] [H14206] [H14209] [H14212] [H14215] 902*/ 903SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); 904 905/* 906** CAPI3REF: Memory Allocation Routines {H10155} <S20120> 907** EXPERIMENTAL 908** 909** An instance of this object defines the interface between SQLite 910** and low-level memory allocation routines. 911** 912** This object is used in only one place in the SQLite interface. 913** A pointer to an instance of this object is the argument to 914** [sqlite3_config()] when the configuration option is 915** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object 916** and passing it to [sqlite3_config()] during configuration, an 917** application can specify an alternative memory allocation subsystem 918** for SQLite to use for all of its dynamic memory needs. 919** 920** Note that SQLite comes with a built-in memory allocator that is 921** perfectly adequate for the overwhelming majority of applications 922** and that this object is only useful to a tiny minority of applications 923** with specialized memory allocation requirements. This object is 924** also used during testing of SQLite in order to specify an alternative 925** memory allocator that simulates memory out-of-memory conditions in 926** order to verify that SQLite recovers gracefully from such 927** conditions. 928** 929** The xMalloc, xFree, and xRealloc methods must work like the 930** malloc(), free(), and realloc() functions from the standard library. 931** 932** xSize should return the allocated size of a memory allocation 933** previously obtained from xMalloc or xRealloc. The allocated size 934** is always at least as big as the requested size but may be larger. 935** 936** The xRoundup method returns what would be the allocated size of 937** a memory allocation given a particular requested size. Most memory 938** allocators round up memory allocations at least to the next multiple 939** of 8. Some allocators round up to a larger multiple or to a power of 2. 940** 941** The xInit method initializes the memory allocator. (For example, 942** it might allocate any require mutexes or initialize internal data 943** structures. The xShutdown method is invoked (indirectly) by 944** [sqlite3_shutdown()] and should deallocate any resources acquired 945** by xInit. The pAppData pointer is used as the only parameter to 946** xInit and xShutdown. 947*/ 948typedef struct sqlite3_mem_methods sqlite3_mem_methods; 949struct sqlite3_mem_methods { 950 void *(*xMalloc)(int); /* Memory allocation function */ 951 void (*xFree)(void*); /* Free a prior allocation */ 952 void *(*xRealloc)(void*,int); /* Resize an allocation */ 953 int (*xSize)(void*); /* Return the size of an allocation */ 954 int (*xRoundup)(int); /* Round up request size to allocation size */ 955 int (*xInit)(void*); /* Initialize the memory allocator */ 956 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 957 void *pAppData; /* Argument to xInit() and xShutdown() */ 958}; 959 960/* 961** CAPI3REF: Configuration Options {H10160} <S20000> 962** EXPERIMENTAL 963** 964** These constants are the available integer configuration options that 965** can be passed as the first argument to the [sqlite3_config()] interface. 966** 967** New configuration options may be added in future releases of SQLite. 968** Existing configuration options might be discontinued. Applications 969** should check the return code from [sqlite3_config()] to make sure that 970** the call worked. The [sqlite3_config()] interface will return a 971** non-zero [error code] if a discontinued or unsupported configuration option 972** is invoked. 973** 974** <dl> 975** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 976** <dd>There are no arguments to this option. This option disables 977** all mutexing and puts SQLite into a mode where it can only be used 978** by a single thread.</dd> 979** 980** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 981** <dd>There are no arguments to this option. This option disables 982** mutexing on [database connection] and [prepared statement] objects. 983** The application is responsible for serializing access to 984** [database connections] and [prepared statements]. But other mutexes 985** are enabled so that SQLite will be safe to use in a multi-threaded 986** environment as long as no two threads attempt to use the same 987** [database connection] at the same time. See the [threading mode] 988** documentation for additional information.</dd> 989** 990** <dt>SQLITE_CONFIG_SERIALIZED</dt> 991** <dd>There are no arguments to this option. This option enables 992** all mutexes including the recursive 993** mutexes on [database connection] and [prepared statement] objects. 994** In this mode (which is the default when SQLite is compiled with 995** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 996** to [database connections] and [prepared statements] so that the 997** application is free to use the same [database connection] or the 998** same [prepared statement] in different threads at the same time. 999** See the [threading mode] documentation for additional information.</dd> 1000** 1001** <dt>SQLITE_CONFIG_MALLOC</dt> 1002** <dd>This option takes a single argument which is a pointer to an 1003** instance of the [sqlite3_mem_methods] structure. The argument specifies 1004** alternative low-level memory allocation routines to be used in place of 1005** the memory allocation routines built into SQLite.</dd> 1006** 1007** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1008** <dd>This option takes a single argument which is a pointer to an 1009** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1010** structure is filled with the currently defined memory allocation routines. 1011** This option can be used to overload the default memory allocation 1012** routines with a wrapper that simulations memory allocation failure or 1013** tracks memory usage, for example.</dd> 1014** 1015** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1016** <dd>This option takes single argument of type int, interpreted as a 1017** boolean, which enables or disables the collection of memory allocation 1018** statistics. When disabled, the following SQLite interfaces become 1019** non-operational: 1020** <ul> 1021** <li> [sqlite3_memory_used()] 1022** <li> [sqlite3_memory_highwater()] 1023** <li> [sqlite3_soft_heap_limit()] 1024** <li> [sqlite3_status()] 1025** </ul> 1026** </dd> 1027** 1028** <dt>SQLITE_CONFIG_SCRATCH</dt> 1029** <dd>This option specifies a static memory buffer that SQLite can use for 1030** scratch memory. There are three arguments: A pointer to the memory, the 1031** size of each scratch buffer (sz), and the number of buffers (N). The sz 1032** argument must be a multiple of 16. The sz parameter should be a few bytes 1033** larger than the actual scratch space required due internal overhead. 1034** The first 1035** argument should point to an allocation of at least sz*N bytes of memory. 1036** SQLite will use no more than one scratch buffer at once per thread, so 1037** N should be set to the expected maximum number of threads. The sz 1038** parameter should be 6 times the size of the largest database page size. 1039** Scratch buffers are used as part of the btree balance operation. If 1040** The btree balancer needs additional memory beyond what is provided by 1041** scratch buffers or if no scratch buffer space is specified, then SQLite 1042** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> 1043** 1044** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1045** <dd>This option specifies a static memory buffer that SQLite can use for 1046** the database page cache with the default page cache implemenation. 1047** This configuration should not be used if an application-define page 1048** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1049** There are three arguments to this option: A pointer to the 1050** memory, the size of each page buffer (sz), and the number of pages (N). 1051** The sz argument must be a power of two between 512 and 32768. The first 1052** argument should point to an allocation of at least sz*N bytes of memory. 1053** SQLite will use the memory provided by the first argument to satisfy its 1054** memory needs for the first N pages that it adds to cache. If additional 1055** page cache memory is needed beyond what is provided by this option, then 1056** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1057** The implementation might use one or more of the N buffers to hold 1058** memory accounting information. </dd> 1059** 1060** <dt>SQLITE_CONFIG_HEAP</dt> 1061** <dd>This option specifies a static memory buffer that SQLite will use 1062** for all of its dynamic memory allocation needs beyond those provided 1063** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1064** There are three arguments: A pointer to the memory, the number of 1065** bytes in the memory buffer, and the minimum allocation size. If 1066** the first pointer (the memory pointer) is NULL, then SQLite reverts 1067** to using its default memory allocator (the system malloc() implementation), 1068** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the 1069** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1070** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1071** allocator is engaged to handle all of SQLites memory allocation needs.</dd> 1072** 1073** <dt>SQLITE_CONFIG_MUTEX</dt> 1074** <dd>This option takes a single argument which is a pointer to an 1075** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1076** alternative low-level mutex routines to be used in place 1077** the mutex routines built into SQLite.</dd> 1078** 1079** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1080** <dd>This option takes a single argument which is a pointer to an 1081** instance of the [sqlite3_mutex_methods] structure. The 1082** [sqlite3_mutex_methods] 1083** structure is filled with the currently defined mutex routines. 1084** This option can be used to overload the default mutex allocation 1085** routines with a wrapper used to track mutex usage for performance 1086** profiling or testing, for example.</dd> 1087** 1088** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1089** <dd>This option takes two arguments that determine the default 1090** memory allcation lookaside optimization. The first argument is the 1091** size of each lookaside buffer slot and the second is the number of 1092** slots allocated to each database connection.</dd> 1093** 1094** <dt>SQLITE_CONFIG_PCACHE</dt> 1095** <dd>This option takes a single argument which is a pointer to 1096** an [sqlite3_pcache_methods] object. This object specifies the interface 1097** to a custom page cache implementation. SQLite makes a copy of the 1098** object and uses it for page cache memory allocations.</dd> 1099** 1100** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1101** <dd>This option takes a single argument which is a pointer to an 1102** [sqlite3_pcache_methods] object. SQLite copies of the current 1103** page cache implementation into that object.</dd> 1104** 1105** </dl> 1106*/ 1107#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1108#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1109#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1110#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1111#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1112#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1113#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1114#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1115#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1116#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1117#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1118/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1119#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1120#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1121#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1122 1123/* 1124** CAPI3REF: Configuration Options {H10170} <S20000> 1125** EXPERIMENTAL 1126** 1127** These constants are the available integer configuration options that 1128** can be passed as the second argument to the [sqlite3_db_config()] interface. 1129** 1130** New configuration options may be added in future releases of SQLite. 1131** Existing configuration options might be discontinued. Applications 1132** should check the return code from [sqlite3_db_config()] to make sure that 1133** the call worked. The [sqlite3_db_config()] interface will return a 1134** non-zero [error code] if a discontinued or unsupported configuration option 1135** is invoked. 1136** 1137** <dl> 1138** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1139** <dd>This option takes three additional arguments that determine the 1140** [lookaside memory allocator] configuration for the [database connection]. 1141** The first argument (the third parameter to [sqlite3_db_config()] is a 1142** pointer to a memory buffer to use for lookaside memory. The first 1143** argument may be NULL in which case SQLite will allocate the lookaside 1144** buffer itself using [sqlite3_malloc()]. The second argument is the 1145** size of each lookaside buffer slot and the third argument is the number of 1146** slots. The size of the buffer in the first argument must be greater than 1147** or equal to the product of the second and third arguments.</dd> 1148** 1149** </dl> 1150*/ 1151#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1152 1153 1154/* 1155** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> 1156** 1157** The sqlite3_extended_result_codes() routine enables or disables the 1158** [extended result codes] feature of SQLite. The extended result 1159** codes are disabled by default for historical compatibility considerations. 1160** 1161** Requirements: 1162** [H12201] [H12202] 1163*/ 1164int sqlite3_extended_result_codes(sqlite3*, int onoff); 1165 1166/* 1167** CAPI3REF: Last Insert Rowid {H12220} <S10700> 1168** 1169** Each entry in an SQLite table has a unique 64-bit signed 1170** integer key called the [ROWID | "rowid"]. The rowid is always available 1171** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1172** names are not also used by explicitly declared columns. If 1173** the table has a column of type [INTEGER PRIMARY KEY] then that column 1174** is another alias for the rowid. 1175** 1176** This routine returns the [rowid] of the most recent 1177** successful [INSERT] into the database from the [database connection] 1178** in the first argument. If no successful [INSERT]s 1179** have ever occurred on that database connection, zero is returned. 1180** 1181** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1182** row is returned by this routine as long as the trigger is running. 1183** But once the trigger terminates, the value returned by this routine 1184** reverts to the last value inserted before the trigger fired. 1185** 1186** An [INSERT] that fails due to a constraint violation is not a 1187** successful [INSERT] and does not change the value returned by this 1188** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1189** and INSERT OR ABORT make no changes to the return value of this 1190** routine when their insertion fails. When INSERT OR REPLACE 1191** encounters a constraint violation, it does not fail. The 1192** INSERT continues to completion after deleting rows that caused 1193** the constraint problem so INSERT OR REPLACE will always change 1194** the return value of this interface. 1195** 1196** For the purposes of this routine, an [INSERT] is considered to 1197** be successful even if it is subsequently rolled back. 1198** 1199** Requirements: 1200** [H12221] [H12223] 1201** 1202** If a separate thread performs a new [INSERT] on the same 1203** database connection while the [sqlite3_last_insert_rowid()] 1204** function is running and thus changes the last insert [rowid], 1205** then the value returned by [sqlite3_last_insert_rowid()] is 1206** unpredictable and might not equal either the old or the new 1207** last insert [rowid]. 1208*/ 1209sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1210 1211/* 1212** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> 1213** 1214** This function returns the number of database rows that were changed 1215** or inserted or deleted by the most recently completed SQL statement 1216** on the [database connection] specified by the first parameter. 1217** Only changes that are directly specified by the [INSERT], [UPDATE], 1218** or [DELETE] statement are counted. Auxiliary changes caused by 1219** triggers are not counted. Use the [sqlite3_total_changes()] function 1220** to find the total number of changes including changes caused by triggers. 1221** 1222** A "row change" is a change to a single row of a single table 1223** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1224** are changed as side effects of REPLACE constraint resolution, 1225** rollback, ABORT processing, DROP TABLE, or by any other 1226** mechanisms do not count as direct row changes. 1227** 1228** A "trigger context" is a scope of execution that begins and 1229** ends with the script of a trigger. Most SQL statements are 1230** evaluated outside of any trigger. This is the "top level" 1231** trigger context. If a trigger fires from the top level, a 1232** new trigger context is entered for the duration of that one 1233** trigger. Subtriggers create subcontexts for their duration. 1234** 1235** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1236** not create a new trigger context. 1237** 1238** This function returns the number of direct row changes in the 1239** most recent INSERT, UPDATE, or DELETE statement within the same 1240** trigger context. 1241** 1242** Thus, when called from the top level, this function returns the 1243** number of changes in the most recent INSERT, UPDATE, or DELETE 1244** that also occurred at the top level. Within the body of a trigger, 1245** the sqlite3_changes() interface can be called to find the number of 1246** changes in the most recently completed INSERT, UPDATE, or DELETE 1247** statement within the body of the same trigger. 1248** However, the number returned does not include changes 1249** caused by subtriggers since those have their own context. 1250** 1251** SQLite implements the command "DELETE FROM table" without a WHERE clause 1252** by dropping and recreating the table. Doing so is much faster than going 1253** through and deleting individual elements from the table. Because of this 1254** optimization, the deletions in "DELETE FROM table" are not row changes and 1255** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1256** functions, regardless of the number of elements that were originally 1257** in the table. To get an accurate count of the number of rows deleted, use 1258** "DELETE FROM table WHERE 1" instead. Or recompile using the 1259** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1260** optimization on all queries. 1261** 1262** Requirements: 1263** [H12241] [H12243] 1264** 1265** If a separate thread makes changes on the same database connection 1266** while [sqlite3_changes()] is running then the value returned 1267** is unpredictable and not meaningful. 1268*/ 1269int sqlite3_changes(sqlite3*); 1270 1271/* 1272** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> 1273** 1274** This function returns the number of row changes caused by INSERT, 1275** UPDATE or DELETE statements since the [database connection] was opened. 1276** The count includes all changes from all trigger contexts. However, 1277** the count does not include changes used to implement REPLACE constraints, 1278** do rollbacks or ABORT processing, or DROP table processing. 1279** The changes are counted as soon as the statement that makes them is 1280** completed (when the statement handle is passed to [sqlite3_reset()] or 1281** [sqlite3_finalize()]). 1282** 1283** SQLite implements the command "DELETE FROM table" without a WHERE clause 1284** by dropping and recreating the table. (This is much faster than going 1285** through and deleting individual elements from the table.) Because of this 1286** optimization, the deletions in "DELETE FROM table" are not row changes and 1287** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1288** functions, regardless of the number of elements that were originally 1289** in the table. To get an accurate count of the number of rows deleted, use 1290** "DELETE FROM table WHERE 1" instead. Or recompile using the 1291** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1292** optimization on all queries. 1293** 1294** See also the [sqlite3_changes()] interface. 1295** 1296** Requirements: 1297** [H12261] [H12263] 1298** 1299** If a separate thread makes changes on the same database connection 1300** while [sqlite3_total_changes()] is running then the value 1301** returned is unpredictable and not meaningful. 1302*/ 1303int sqlite3_total_changes(sqlite3*); 1304 1305/* 1306** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> 1307** 1308** This function causes any pending database operation to abort and 1309** return at its earliest opportunity. This routine is typically 1310** called in response to a user action such as pressing "Cancel" 1311** or Ctrl-C where the user wants a long query operation to halt 1312** immediately. 1313** 1314** It is safe to call this routine from a thread different from the 1315** thread that is currently running the database operation. But it 1316** is not safe to call this routine with a [database connection] that 1317** is closed or might close before sqlite3_interrupt() returns. 1318** 1319** If an SQL operation is very nearly finished at the time when 1320** sqlite3_interrupt() is called, then it might not have an opportunity 1321** to be interrupted and might continue to completion. 1322** 1323** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1324** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1325** that is inside an explicit transaction, then the entire transaction 1326** will be rolled back automatically. 1327** 1328** A call to sqlite3_interrupt() has no effect on SQL statements 1329** that are started after sqlite3_interrupt() returns. 1330** 1331** Requirements: 1332** [H12271] [H12272] 1333** 1334** If the database connection closes while [sqlite3_interrupt()] 1335** is running then bad things will likely happen. 1336*/ 1337void sqlite3_interrupt(sqlite3*); 1338 1339/* 1340** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> 1341** 1342** These routines are useful for command-line input to determine if the 1343** currently entered text seems to form complete a SQL statement or 1344** if additional input is needed before sending the text into 1345** SQLite for parsing. These routines return true if the input string 1346** appears to be a complete SQL statement. A statement is judged to be 1347** complete if it ends with a semicolon token and is not a fragment of a 1348** CREATE TRIGGER statement. Semicolons that are embedded within 1349** string literals or quoted identifier names or comments are not 1350** independent tokens (they are part of the token in which they are 1351** embedded) and thus do not count as a statement terminator. 1352** 1353** These routines do not parse the SQL statements thus 1354** will not detect syntactically incorrect SQL. 1355** 1356** Requirements: [H10511] [H10512] 1357** 1358** The input to [sqlite3_complete()] must be a zero-terminated 1359** UTF-8 string. 1360** 1361** The input to [sqlite3_complete16()] must be a zero-terminated 1362** UTF-16 string in native byte order. 1363*/ 1364int sqlite3_complete(const char *sql); 1365int sqlite3_complete16(const void *sql); 1366 1367/* 1368** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> 1369** 1370** This routine sets a callback function that might be invoked whenever 1371** an attempt is made to open a database table that another thread 1372** or process has locked. 1373** 1374** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1375** is returned immediately upon encountering the lock. If the busy callback 1376** is not NULL, then the callback will be invoked with two arguments. 1377** 1378** The first argument to the handler is a copy of the void* pointer which 1379** is the third argument to sqlite3_busy_handler(). The second argument to 1380** the handler callback is the number of times that the busy handler has 1381** been invoked for this locking event. If the 1382** busy callback returns 0, then no additional attempts are made to 1383** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1384** If the callback returns non-zero, then another attempt 1385** is made to open the database for reading and the cycle repeats. 1386** 1387** The presence of a busy handler does not guarantee that it will be invoked 1388** when there is lock contention. If SQLite determines that invoking the busy 1389** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1390** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1391** Consider a scenario where one process is holding a read lock that 1392** it is trying to promote to a reserved lock and 1393** a second process is holding a reserved lock that it is trying 1394** to promote to an exclusive lock. The first process cannot proceed 1395** because it is blocked by the second and the second process cannot 1396** proceed because it is blocked by the first. If both processes 1397** invoke the busy handlers, neither will make any progress. Therefore, 1398** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1399** will induce the first process to release its read lock and allow 1400** the second process to proceed. 1401** 1402** The default busy callback is NULL. 1403** 1404** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1405** when SQLite is in the middle of a large transaction where all the 1406** changes will not fit into the in-memory cache. SQLite will 1407** already hold a RESERVED lock on the database file, but it needs 1408** to promote this lock to EXCLUSIVE so that it can spill cache 1409** pages into the database file without harm to concurrent 1410** readers. If it is unable to promote the lock, then the in-memory 1411** cache will be left in an inconsistent state and so the error 1412** code is promoted from the relatively benign [SQLITE_BUSY] to 1413** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1414** forces an automatic rollback of the changes. See the 1415** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1416** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1417** this is important. 1418** 1419** There can only be a single busy handler defined for each 1420** [database connection]. Setting a new busy handler clears any 1421** previously set handler. Note that calling [sqlite3_busy_timeout()] 1422** will also set or clear the busy handler. 1423** 1424** The busy callback should not take any actions which modify the 1425** database connection that invoked the busy handler. Any such actions 1426** result in undefined behavior. 1427** 1428** Requirements: 1429** [H12311] [H12312] [H12314] [H12316] [H12318] 1430** 1431** A busy handler must not close the database connection 1432** or [prepared statement] that invoked the busy handler. 1433*/ 1434int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1435 1436/* 1437** CAPI3REF: Set A Busy Timeout {H12340} <S40410> 1438** 1439** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1440** for a specified amount of time when a table is locked. The handler 1441** will sleep multiple times until at least "ms" milliseconds of sleeping 1442** have accumulated. {H12343} After "ms" milliseconds of sleeping, 1443** the handler returns 0 which causes [sqlite3_step()] to return 1444** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1445** 1446** Calling this routine with an argument less than or equal to zero 1447** turns off all busy handlers. 1448** 1449** There can only be a single busy handler for a particular 1450** [database connection] any any given moment. If another busy handler 1451** was defined (using [sqlite3_busy_handler()]) prior to calling 1452** this routine, that other busy handler is cleared. 1453** 1454** Requirements: 1455** [H12341] [H12343] [H12344] 1456*/ 1457int sqlite3_busy_timeout(sqlite3*, int ms); 1458 1459/* 1460** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> 1461** 1462** Definition: A <b>result table</b> is memory data structure created by the 1463** [sqlite3_get_table()] interface. A result table records the 1464** complete query results from one or more queries. 1465** 1466** The table conceptually has a number of rows and columns. But 1467** these numbers are not part of the result table itself. These 1468** numbers are obtained separately. Let N be the number of rows 1469** and M be the number of columns. 1470** 1471** A result table is an array of pointers to zero-terminated UTF-8 strings. 1472** There are (N+1)*M elements in the array. The first M pointers point 1473** to zero-terminated strings that contain the names of the columns. 1474** The remaining entries all point to query results. NULL values result 1475** in NULL pointers. All other values are in their UTF-8 zero-terminated 1476** string representation as returned by [sqlite3_column_text()]. 1477** 1478** A result table might consist of one or more memory allocations. 1479** It is not safe to pass a result table directly to [sqlite3_free()]. 1480** A result table should be deallocated using [sqlite3_free_table()]. 1481** 1482** As an example of the result table format, suppose a query result 1483** is as follows: 1484** 1485** <blockquote><pre> 1486** Name | Age 1487** ----------------------- 1488** Alice | 43 1489** Bob | 28 1490** Cindy | 21 1491** </pre></blockquote> 1492** 1493** There are two column (M==2) and three rows (N==3). Thus the 1494** result table has 8 entries. Suppose the result table is stored 1495** in an array names azResult. Then azResult holds this content: 1496** 1497** <blockquote><pre> 1498** azResult[0] = "Name"; 1499** azResult[1] = "Age"; 1500** azResult[2] = "Alice"; 1501** azResult[3] = "43"; 1502** azResult[4] = "Bob"; 1503** azResult[5] = "28"; 1504** azResult[6] = "Cindy"; 1505** azResult[7] = "21"; 1506** </pre></blockquote> 1507** 1508** The sqlite3_get_table() function evaluates one or more 1509** semicolon-separated SQL statements in the zero-terminated UTF-8 1510** string of its 2nd parameter. It returns a result table to the 1511** pointer given in its 3rd parameter. 1512** 1513** After the calling function has finished using the result, it should 1514** pass the pointer to the result table to sqlite3_free_table() in order to 1515** release the memory that was malloced. Because of the way the 1516** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1517** function must not try to call [sqlite3_free()] directly. Only 1518** [sqlite3_free_table()] is able to release the memory properly and safely. 1519** 1520** The sqlite3_get_table() interface is implemented as a wrapper around 1521** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1522** to any internal data structures of SQLite. It uses only the public 1523** interface defined here. As a consequence, errors that occur in the 1524** wrapper layer outside of the internal [sqlite3_exec()] call are not 1525** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. 1526** 1527** Requirements: 1528** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] 1529*/ 1530int sqlite3_get_table( 1531 sqlite3 *db, /* An open database */ 1532 const char *zSql, /* SQL to be evaluated */ 1533 char ***pazResult, /* Results of the query */ 1534 int *pnRow, /* Number of result rows written here */ 1535 int *pnColumn, /* Number of result columns written here */ 1536 char **pzErrmsg /* Error msg written here */ 1537); 1538void sqlite3_free_table(char **result); 1539 1540/* 1541** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> 1542** 1543** These routines are workalikes of the "printf()" family of functions 1544** from the standard C library. 1545** 1546** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1547** results into memory obtained from [sqlite3_malloc()]. 1548** The strings returned by these two routines should be 1549** released by [sqlite3_free()]. Both routines return a 1550** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1551** memory to hold the resulting string. 1552** 1553** In sqlite3_snprintf() routine is similar to "snprintf()" from 1554** the standard C library. The result is written into the 1555** buffer supplied as the second parameter whose size is given by 1556** the first parameter. Note that the order of the 1557** first two parameters is reversed from snprintf(). This is an 1558** historical accident that cannot be fixed without breaking 1559** backwards compatibility. Note also that sqlite3_snprintf() 1560** returns a pointer to its buffer instead of the number of 1561** characters actually written into the buffer. We admit that 1562** the number of characters written would be a more useful return 1563** value but we cannot change the implementation of sqlite3_snprintf() 1564** now without breaking compatibility. 1565** 1566** As long as the buffer size is greater than zero, sqlite3_snprintf() 1567** guarantees that the buffer is always zero-terminated. The first 1568** parameter "n" is the total size of the buffer, including space for 1569** the zero terminator. So the longest string that can be completely 1570** written will be n-1 characters. 1571** 1572** These routines all implement some additional formatting 1573** options that are useful for constructing SQL statements. 1574** All of the usual printf() formatting options apply. In addition, there 1575** is are "%q", "%Q", and "%z" options. 1576** 1577** The %q option works like %s in that it substitutes a null-terminated 1578** string from the argument list. But %q also doubles every '\'' character. 1579** %q is designed for use inside a string literal. By doubling each '\'' 1580** character it escapes that character and allows it to be inserted into 1581** the string. 1582** 1583** For example, assume the string variable zText contains text as follows: 1584** 1585** <blockquote><pre> 1586** char *zText = "It's a happy day!"; 1587** </pre></blockquote> 1588** 1589** One can use this text in an SQL statement as follows: 1590** 1591** <blockquote><pre> 1592** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1593** sqlite3_exec(db, zSQL, 0, 0, 0); 1594** sqlite3_free(zSQL); 1595** </pre></blockquote> 1596** 1597** Because the %q format string is used, the '\'' character in zText 1598** is escaped and the SQL generated is as follows: 1599** 1600** <blockquote><pre> 1601** INSERT INTO table1 VALUES('It''s a happy day!') 1602** </pre></blockquote> 1603** 1604** This is correct. Had we used %s instead of %q, the generated SQL 1605** would have looked like this: 1606** 1607** <blockquote><pre> 1608** INSERT INTO table1 VALUES('It's a happy day!'); 1609** </pre></blockquote> 1610** 1611** This second example is an SQL syntax error. As a general rule you should 1612** always use %q instead of %s when inserting text into a string literal. 1613** 1614** The %Q option works like %q except it also adds single quotes around 1615** the outside of the total string. Additionally, if the parameter in the 1616** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1617** single quotes) in place of the %Q option. So, for example, one could say: 1618** 1619** <blockquote><pre> 1620** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1621** sqlite3_exec(db, zSQL, 0, 0, 0); 1622** sqlite3_free(zSQL); 1623** </pre></blockquote> 1624** 1625** The code above will render a correct SQL statement in the zSQL 1626** variable even if the zText variable is a NULL pointer. 1627** 1628** The "%z" formatting option works exactly like "%s" with the 1629** addition that after the string has been read and copied into 1630** the result, [sqlite3_free()] is called on the input string. {END} 1631** 1632** Requirements: 1633** [H17403] [H17406] [H17407] 1634*/ 1635char *sqlite3_mprintf(const char*,...); 1636char *sqlite3_vmprintf(const char*, va_list); 1637char *sqlite3_snprintf(int,char*,const char*, ...); 1638 1639/* 1640** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> 1641** 1642** The SQLite core uses these three routines for all of its own 1643** internal memory allocation needs. "Core" in the previous sentence 1644** does not include operating-system specific VFS implementation. The 1645** Windows VFS uses native malloc() and free() for some operations. 1646** 1647** The sqlite3_malloc() routine returns a pointer to a block 1648** of memory at least N bytes in length, where N is the parameter. 1649** If sqlite3_malloc() is unable to obtain sufficient free 1650** memory, it returns a NULL pointer. If the parameter N to 1651** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1652** a NULL pointer. 1653** 1654** Calling sqlite3_free() with a pointer previously returned 1655** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1656** that it might be reused. The sqlite3_free() routine is 1657** a no-op if is called with a NULL pointer. Passing a NULL pointer 1658** to sqlite3_free() is harmless. After being freed, memory 1659** should neither be read nor written. Even reading previously freed 1660** memory might result in a segmentation fault or other severe error. 1661** Memory corruption, a segmentation fault, or other severe error 1662** might result if sqlite3_free() is called with a non-NULL pointer that 1663** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 1664** 1665** The sqlite3_realloc() interface attempts to resize a 1666** prior memory allocation to be at least N bytes, where N is the 1667** second parameter. The memory allocation to be resized is the first 1668** parameter. If the first parameter to sqlite3_realloc() 1669** is a NULL pointer then its behavior is identical to calling 1670** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1671** If the second parameter to sqlite3_realloc() is zero or 1672** negative then the behavior is exactly the same as calling 1673** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1674** sqlite3_realloc() returns a pointer to a memory allocation 1675** of at least N bytes in size or NULL if sufficient memory is unavailable. 1676** If M is the size of the prior allocation, then min(N,M) bytes 1677** of the prior allocation are copied into the beginning of buffer returned 1678** by sqlite3_realloc() and the prior allocation is freed. 1679** If sqlite3_realloc() returns NULL, then the prior allocation 1680** is not freed. 1681** 1682** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1683** is always aligned to at least an 8 byte boundary. {END} 1684** 1685** The default implementation of the memory allocation subsystem uses 1686** the malloc(), realloc() and free() provided by the standard C library. 1687** {H17382} However, if SQLite is compiled with the 1688** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> 1689** is an integer), then SQLite create a static array of at least 1690** <i>NNN</i> bytes in size and uses that array for all of its dynamic 1691** memory allocation needs. {END} Additional memory allocator options 1692** may be added in future releases. 1693** 1694** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1695** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1696** implementation of these routines to be omitted. That capability 1697** is no longer provided. Only built-in memory allocators can be used. 1698** 1699** The Windows OS interface layer calls 1700** the system malloc() and free() directly when converting 1701** filenames between the UTF-8 encoding used by SQLite 1702** and whatever filename encoding is used by the particular Windows 1703** installation. Memory allocation errors are detected, but 1704** they are reported back as [SQLITE_CANTOPEN] or 1705** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1706** 1707** Requirements: 1708** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] 1709** [H17321] [H17322] [H17323] 1710** 1711** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1712** must be either NULL or else pointers obtained from a prior 1713** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 1714** not yet been released. 1715** 1716** The application must not read or write any part of 1717** a block of memory after it has been released using 1718** [sqlite3_free()] or [sqlite3_realloc()]. 1719*/ 1720void *sqlite3_malloc(int); 1721void *sqlite3_realloc(void*, int); 1722void sqlite3_free(void*); 1723 1724/* 1725** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> 1726** 1727** SQLite provides these two interfaces for reporting on the status 1728** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1729** routines, which form the built-in memory allocation subsystem. 1730** 1731** Requirements: 1732** [H17371] [H17373] [H17374] [H17375] 1733*/ 1734sqlite3_int64 sqlite3_memory_used(void); 1735sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1736 1737/* 1738** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> 1739** 1740** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1741** select random [ROWID | ROWIDs] when inserting new records into a table that 1742** already uses the largest possible [ROWID]. The PRNG is also used for 1743** the build-in random() and randomblob() SQL functions. This interface allows 1744** applications to access the same PRNG for other purposes. 1745** 1746** A call to this routine stores N bytes of randomness into buffer P. 1747** 1748** The first time this routine is invoked (either internally or by 1749** the application) the PRNG is seeded using randomness obtained 1750** from the xRandomness method of the default [sqlite3_vfs] object. 1751** On all subsequent invocations, the pseudo-randomness is generated 1752** internally and without recourse to the [sqlite3_vfs] xRandomness 1753** method. 1754** 1755** Requirements: 1756** [H17392] 1757*/ 1758void sqlite3_randomness(int N, void *P); 1759 1760/* 1761** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> 1762** 1763** This routine registers a authorizer callback with a particular 1764** [database connection], supplied in the first argument. 1765** The authorizer callback is invoked as SQL statements are being compiled 1766** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1767** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1768** points during the compilation process, as logic is being created 1769** to perform various actions, the authorizer callback is invoked to 1770** see if those actions are allowed. The authorizer callback should 1771** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1772** specific action but allow the SQL statement to continue to be 1773** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1774** rejected with an error. If the authorizer callback returns 1775** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1776** then the [sqlite3_prepare_v2()] or equivalent call that triggered 1777** the authorizer will fail with an error message. 1778** 1779** When the callback returns [SQLITE_OK], that means the operation 1780** requested is ok. When the callback returns [SQLITE_DENY], the 1781** [sqlite3_prepare_v2()] or equivalent call that triggered the 1782** authorizer will fail with an error message explaining that 1783** access is denied. If the authorizer code is [SQLITE_READ] 1784** and the callback returns [SQLITE_IGNORE] then the 1785** [prepared statement] statement is constructed to substitute 1786** a NULL value in place of the table column that would have 1787** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1788** return can be used to deny an untrusted user access to individual 1789** columns of a table. 1790** 1791** The first parameter to the authorizer callback is a copy of the third 1792** parameter to the sqlite3_set_authorizer() interface. The second parameter 1793** to the callback is an integer [SQLITE_COPY | action code] that specifies 1794** the particular action to be authorized. The third through sixth parameters 1795** to the callback are zero-terminated strings that contain additional 1796** details about the action to be authorized. 1797** 1798** An authorizer is used when [sqlite3_prepare | preparing] 1799** SQL statements from an untrusted source, to ensure that the SQL statements 1800** do not try to access data they are not allowed to see, or that they do not 1801** try to execute malicious statements that damage the database. For 1802** example, an application may allow a user to enter arbitrary 1803** SQL queries for evaluation by a database. But the application does 1804** not want the user to be able to make arbitrary changes to the 1805** database. An authorizer could then be put in place while the 1806** user-entered SQL is being [sqlite3_prepare | prepared] that 1807** disallows everything except [SELECT] statements. 1808** 1809** Applications that need to process SQL from untrusted sources 1810** might also consider lowering resource limits using [sqlite3_limit()] 1811** and limiting database size using the [max_page_count] [PRAGMA] 1812** in addition to using an authorizer. 1813** 1814** Only a single authorizer can be in place on a database connection 1815** at a time. Each call to sqlite3_set_authorizer overrides the 1816** previous call. Disable the authorizer by installing a NULL callback. 1817** The authorizer is disabled by default. 1818** 1819** The authorizer callback must not do anything that will modify 1820** the database connection that invoked the authorizer callback. 1821** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1822** database connections for the meaning of "modify" in this paragraph. 1823** 1824** When [sqlite3_prepare_v2()] is used to prepare a statement, the 1825** statement might be reprepared during [sqlite3_step()] due to a 1826** schema change. Hence, the application should ensure that the 1827** correct authorizer callback remains in place during the [sqlite3_step()]. 1828** 1829** Note that the authorizer callback is invoked only during 1830** [sqlite3_prepare()] or its variants. Authorization is not 1831** performed during statement evaluation in [sqlite3_step()]. 1832** 1833** Requirements: 1834** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] 1835** [H12511] [H12512] [H12520] [H12521] [H12522] 1836*/ 1837int sqlite3_set_authorizer( 1838 sqlite3*, 1839 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1840 void *pUserData 1841); 1842 1843/* 1844** CAPI3REF: Authorizer Return Codes {H12590} <H12500> 1845** 1846** The [sqlite3_set_authorizer | authorizer callback function] must 1847** return either [SQLITE_OK] or one of these two constants in order 1848** to signal SQLite whether or not the action is permitted. See the 1849** [sqlite3_set_authorizer | authorizer documentation] for additional 1850** information. 1851*/ 1852#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1853#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1854 1855/* 1856** CAPI3REF: Authorizer Action Codes {H12550} <H12500> 1857** 1858** The [sqlite3_set_authorizer()] interface registers a callback function 1859** that is invoked to authorize certain SQL statement actions. The 1860** second parameter to the callback is an integer code that specifies 1861** what action is being authorized. These are the integer action codes that 1862** the authorizer callback may be passed. 1863** 1864** These action code values signify what kind of operation is to be 1865** authorized. The 3rd and 4th parameters to the authorization 1866** callback function will be parameters or NULL depending on which of these 1867** codes is used as the second parameter. The 5th parameter to the 1868** authorizer callback is the name of the database ("main", "temp", 1869** etc.) if applicable. The 6th parameter to the authorizer callback 1870** is the name of the inner-most trigger or view that is responsible for 1871** the access attempt or NULL if this access attempt is directly from 1872** top-level SQL code. 1873** 1874** Requirements: 1875** [H12551] [H12552] [H12553] [H12554] 1876*/ 1877/******************************************* 3rd ************ 4th ***********/ 1878#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1879#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1880#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1881#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1882#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1883#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1884#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1885#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1886#define SQLITE_DELETE 9 /* Table Name NULL */ 1887#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1888#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1889#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1890#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1891#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1892#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1893#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1894#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1895#define SQLITE_INSERT 18 /* Table Name NULL */ 1896#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1897#define SQLITE_READ 20 /* Table Name Column Name */ 1898#define SQLITE_SELECT 21 /* NULL NULL */ 1899#define SQLITE_TRANSACTION 22 /* Operation NULL */ 1900#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1901#define SQLITE_ATTACH 24 /* Filename NULL */ 1902#define SQLITE_DETACH 25 /* Database Name NULL */ 1903#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1904#define SQLITE_REINDEX 27 /* Index Name NULL */ 1905#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1906#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1907#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1908#define SQLITE_FUNCTION 31 /* NULL Function Name */ 1909#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 1910#define SQLITE_COPY 0 /* No longer used */ 1911 1912/* 1913** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> 1914** EXPERIMENTAL 1915** 1916** These routines register callback functions that can be used for 1917** tracing and profiling the execution of SQL statements. 1918** 1919** The callback function registered by sqlite3_trace() is invoked at 1920** various times when an SQL statement is being run by [sqlite3_step()]. 1921** The callback returns a UTF-8 rendering of the SQL statement text 1922** as the statement first begins executing. Additional callbacks occur 1923** as each triggered subprogram is entered. The callbacks for triggers 1924** contain a UTF-8 SQL comment that identifies the trigger. 1925** 1926** The callback function registered by sqlite3_profile() is invoked 1927** as each SQL statement finishes. The profile callback contains 1928** the original statement text and an estimate of wall-clock time 1929** of how long that statement took to run. 1930** 1931** Requirements: 1932** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] 1933** [H12290] 1934*/ 1935SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1936SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 1937 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1938 1939/* 1940** CAPI3REF: Query Progress Callbacks {H12910} <S60400> 1941** 1942** This routine configures a callback function - the 1943** progress callback - that is invoked periodically during long 1944** running calls to [sqlite3_exec()], [sqlite3_step()] and 1945** [sqlite3_get_table()]. An example use for this 1946** interface is to keep a GUI updated during a large query. 1947** 1948** If the progress callback returns non-zero, the operation is 1949** interrupted. This feature can be used to implement a 1950** "Cancel" button on a GUI progress dialog box. 1951** 1952** The progress handler must not do anything that will modify 1953** the database connection that invoked the progress handler. 1954** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1955** database connections for the meaning of "modify" in this paragraph. 1956** 1957** Requirements: 1958** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] 1959** 1960*/ 1961void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1962 1963/* 1964** CAPI3REF: Opening A New Database Connection {H12700} <S40200> 1965** 1966** These routines open an SQLite database file whose name is given by the 1967** filename argument. The filename argument is interpreted as UTF-8 for 1968** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 1969** order for sqlite3_open16(). A [database connection] handle is usually 1970** returned in *ppDb, even if an error occurs. The only exception is that 1971** if SQLite is unable to allocate memory to hold the [sqlite3] object, 1972** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 1973** object. If the database is opened (and/or created) successfully, then 1974** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The 1975** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1976** an English language description of the error. 1977** 1978** The default encoding for the database will be UTF-8 if 1979** sqlite3_open() or sqlite3_open_v2() is called and 1980** UTF-16 in the native byte order if sqlite3_open16() is used. 1981** 1982** Whether or not an error occurs when it is opened, resources 1983** associated with the [database connection] handle should be released by 1984** passing it to [sqlite3_close()] when it is no longer required. 1985** 1986** The sqlite3_open_v2() interface works like sqlite3_open() 1987** except that it accepts two additional parameters for additional control 1988** over the new database connection. The flags parameter can take one of 1989** the following three values, optionally combined with the 1990** [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags: 1991** 1992** <dl> 1993** <dt>[SQLITE_OPEN_READONLY]</dt> 1994** <dd>The database is opened in read-only mode. If the database does not 1995** already exist, an error is returned.</dd> 1996** 1997** <dt>[SQLITE_OPEN_READWRITE]</dt> 1998** <dd>The database is opened for reading and writing if possible, or reading 1999** only if the file is write protected by the operating system. In either 2000** case the database must already exist, otherwise an error is returned.</dd> 2001** 2002** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2003** <dd>The database is opened for reading and writing, and is creates it if 2004** it does not already exist. This is the behavior that is always used for 2005** sqlite3_open() and sqlite3_open16().</dd> 2006** </dl> 2007** 2008** If the 3rd parameter to sqlite3_open_v2() is not one of the 2009** combinations shown above or one of the combinations shown above combined 2010** with the [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags, 2011** then the behavior is undefined. 2012** 2013** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2014** opens in the multi-thread [threading mode] as long as the single-thread 2015** mode has not been set at compile-time or start-time. If the 2016** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2017** in the serialized [threading mode] unless single-thread was 2018** previously selected at compile-time or start-time. 2019** 2020** If the filename is ":memory:", then a private, temporary in-memory database 2021** is created for the connection. This in-memory database will vanish when 2022** the database connection is closed. Future versions of SQLite might 2023** make use of additional special filenames that begin with the ":" character. 2024** It is recommended that when a database filename actually does begin with 2025** a ":" character you should prefix the filename with a pathname such as 2026** "./" to avoid ambiguity. 2027** 2028** If the filename is an empty string, then a private, temporary 2029** on-disk database will be created. This private database will be 2030** automatically deleted as soon as the database connection is closed. 2031** 2032** The fourth parameter to sqlite3_open_v2() is the name of the 2033** [sqlite3_vfs] object that defines the operating system interface that 2034** the new database connection should use. If the fourth parameter is 2035** a NULL pointer then the default [sqlite3_vfs] object is used. 2036** 2037** <b>Note to Windows users:</b> The encoding used for the filename argument 2038** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2039** codepage is currently defined. Filenames containing international 2040** characters must be converted to UTF-8 prior to passing them into 2041** sqlite3_open() or sqlite3_open_v2(). 2042** 2043** Requirements: 2044** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] 2045** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] 2046*/ 2047int sqlite3_open( 2048 const char *filename, /* Database filename (UTF-8) */ 2049 sqlite3 **ppDb /* OUT: SQLite db handle */ 2050); 2051int sqlite3_open16( 2052 const void *filename, /* Database filename (UTF-16) */ 2053 sqlite3 **ppDb /* OUT: SQLite db handle */ 2054); 2055int sqlite3_open_v2( 2056 const char *filename, /* Database filename (UTF-8) */ 2057 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2058 int flags, /* Flags */ 2059 const char *zVfs /* Name of VFS module to use */ 2060); 2061 2062/* 2063** CAPI3REF: Error Codes And Messages {H12800} <S60200> 2064** 2065** The sqlite3_errcode() interface returns the numeric [result code] or 2066** [extended result code] for the most recent failed sqlite3_* API call 2067** associated with a [database connection]. If a prior API call failed 2068** but the most recent API call succeeded, the return value from 2069** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() 2070** interface is the same except that it always returns the 2071** [extended result code] even when extended result codes are 2072** disabled. 2073** 2074** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2075** text that describes the error, as either UTF-8 or UTF-16 respectively. 2076** Memory to hold the error message string is managed internally. 2077** The application does not need to worry about freeing the result. 2078** However, the error string might be overwritten or deallocated by 2079** subsequent calls to other SQLite interface functions. 2080** 2081** When the serialized [threading mode] is in use, it might be the 2082** case that a second error occurs on a separate thread in between 2083** the time of the first error and the call to these interfaces. 2084** When that happens, the second error will be reported since these 2085** interfaces always report the most recent result. To avoid 2086** this, each thread can obtain exclusive use of the [database connection] D 2087** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2088** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2089** all calls to the interfaces listed here are completed. 2090** 2091** If an interface fails with SQLITE_MISUSE, that means the interface 2092** was invoked incorrectly by the application. In that case, the 2093** error code and message may or may not be set. 2094** 2095** Requirements: 2096** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] 2097*/ 2098int sqlite3_errcode(sqlite3 *db); 2099int sqlite3_extended_errcode(sqlite3 *db); 2100const char *sqlite3_errmsg(sqlite3*); 2101const void *sqlite3_errmsg16(sqlite3*); 2102 2103/* 2104** CAPI3REF: SQL Statement Object {H13000} <H13010> 2105** KEYWORDS: {prepared statement} {prepared statements} 2106** 2107** An instance of this object represents a single SQL statement. 2108** This object is variously known as a "prepared statement" or a 2109** "compiled SQL statement" or simply as a "statement". 2110** 2111** The life of a statement object goes something like this: 2112** 2113** <ol> 2114** <li> Create the object using [sqlite3_prepare_v2()] or a related 2115** function. 2116** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2117** interfaces. 2118** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2119** <li> Reset the statement using [sqlite3_reset()] then go back 2120** to step 2. Do this zero or more times. 2121** <li> Destroy the object using [sqlite3_finalize()]. 2122** </ol> 2123** 2124** Refer to documentation on individual methods above for additional 2125** information. 2126*/ 2127typedef struct sqlite3_stmt sqlite3_stmt; 2128 2129/* 2130** CAPI3REF: Run-time Limits {H12760} <S20600> 2131** 2132** This interface allows the size of various constructs to be limited 2133** on a connection by connection basis. The first parameter is the 2134** [database connection] whose limit is to be set or queried. The 2135** second parameter is one of the [limit categories] that define a 2136** class of constructs to be size limited. The third parameter is the 2137** new limit for that construct. The function returns the old limit. 2138** 2139** If the new limit is a negative number, the limit is unchanged. 2140** For the limit category of SQLITE_LIMIT_XYZ there is a 2141** [limits | hard upper bound] 2142** set by a compile-time C preprocessor macro named 2143** [limits | SQLITE_MAX_XYZ]. 2144** (The "_LIMIT_" in the name is changed to "_MAX_".) 2145** Attempts to increase a limit above its hard upper bound are 2146** silently truncated to the hard upper limit. 2147** 2148** Run time limits are intended for use in applications that manage 2149** both their own internal database and also databases that are controlled 2150** by untrusted external sources. An example application might be a 2151** web browser that has its own databases for storing history and 2152** separate databases controlled by JavaScript applications downloaded 2153** off the Internet. The internal databases can be given the 2154** large, default limits. Databases managed by external sources can 2155** be given much smaller limits designed to prevent a denial of service 2156** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2157** interface to further control untrusted SQL. The size of the database 2158** created by an untrusted script can be contained using the 2159** [max_page_count] [PRAGMA]. 2160** 2161** New run-time limit categories may be added in future releases. 2162** 2163** Requirements: 2164** [H12762] [H12766] [H12769] 2165*/ 2166int sqlite3_limit(sqlite3*, int id, int newVal); 2167 2168/* 2169** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> 2170** KEYWORDS: {limit category} {limit categories} 2171** 2172** These constants define various performance limits 2173** that can be lowered at run-time using [sqlite3_limit()]. 2174** The synopsis of the meanings of the various limits is shown below. 2175** Additional information is available at [limits | Limits in SQLite]. 2176** 2177** <dl> 2178** <dt>SQLITE_LIMIT_LENGTH</dt> 2179** <dd>The maximum size of any string or BLOB or table row.<dd> 2180** 2181** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2182** <dd>The maximum length of an SQL statement.</dd> 2183** 2184** <dt>SQLITE_LIMIT_COLUMN</dt> 2185** <dd>The maximum number of columns in a table definition or in the 2186** result set of a [SELECT] or the maximum number of columns in an index 2187** or in an ORDER BY or GROUP BY clause.</dd> 2188** 2189** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2190** <dd>The maximum depth of the parse tree on any expression.</dd> 2191** 2192** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2193** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2194** 2195** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2196** <dd>The maximum number of instructions in a virtual machine program 2197** used to implement an SQL statement.</dd> 2198** 2199** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2200** <dd>The maximum number of arguments on a function.</dd> 2201** 2202** <dt>SQLITE_LIMIT_ATTACHED</dt> 2203** <dd>The maximum number of [ATTACH | attached databases].</dd> 2204** 2205** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2206** <dd>The maximum length of the pattern argument to the [LIKE] or 2207** [GLOB] operators.</dd> 2208** 2209** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2210** <dd>The maximum number of variables in an SQL statement that can 2211** be bound.</dd> 2212** </dl> 2213*/ 2214#define SQLITE_LIMIT_LENGTH 0 2215#define SQLITE_LIMIT_SQL_LENGTH 1 2216#define SQLITE_LIMIT_COLUMN 2 2217#define SQLITE_LIMIT_EXPR_DEPTH 3 2218#define SQLITE_LIMIT_COMPOUND_SELECT 4 2219#define SQLITE_LIMIT_VDBE_OP 5 2220#define SQLITE_LIMIT_FUNCTION_ARG 6 2221#define SQLITE_LIMIT_ATTACHED 7 2222#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2223#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2224 2225/* 2226** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> 2227** KEYWORDS: {SQL statement compiler} 2228** 2229** To execute an SQL query, it must first be compiled into a byte-code 2230** program using one of these routines. 2231** 2232** The first argument, "db", is a [database connection] obtained from a 2233** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()]. 2234** 2235** The second argument, "zSql", is the statement to be compiled, encoded 2236** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2237** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2238** use UTF-16. 2239** 2240** If the nByte argument is less than zero, then zSql is read up to the 2241** first zero terminator. If nByte is non-negative, then it is the maximum 2242** number of bytes read from zSql. When nByte is non-negative, the 2243** zSql string ends at either the first '\000' or '\u0000' character or 2244** the nByte-th byte, whichever comes first. If the caller knows 2245** that the supplied string is nul-terminated, then there is a small 2246** performance advantage to be gained by passing an nByte parameter that 2247** is equal to the number of bytes in the input string <i>including</i> 2248** the nul-terminator bytes. 2249** 2250** *pzTail is made to point to the first byte past the end of the 2251** first SQL statement in zSql. These routines only compile the first 2252** statement in zSql, so *pzTail is left pointing to what remains 2253** uncompiled. 2254** 2255** *ppStmt is left pointing to a compiled [prepared statement] that can be 2256** executed using [sqlite3_step()]. If there is an error, *ppStmt is set 2257** to NULL. If the input text contains no SQL (if the input is an empty 2258** string or a comment) then *ppStmt is set to NULL. 2259** {A13018} The calling procedure is responsible for deleting the compiled 2260** SQL statement using [sqlite3_finalize()] after it has finished with it. 2261** 2262** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. 2263** 2264** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2265** recommended for all new programs. The two older interfaces are retained 2266** for backwards compatibility, but their use is discouraged. 2267** In the "v2" interfaces, the prepared statement 2268** that is returned (the [sqlite3_stmt] object) contains a copy of the 2269** original SQL text. This causes the [sqlite3_step()] interface to 2270** behave a differently in two ways: 2271** 2272** <ol> 2273** <li> 2274** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2275** always used to do, [sqlite3_step()] will automatically recompile the SQL 2276** statement and try to run it again. If the schema has changed in 2277** a way that makes the statement no longer valid, [sqlite3_step()] will still 2278** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is 2279** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the 2280** error go away. Note: use [sqlite3_errmsg()] to find the text 2281** of the parsing error that results in an [SQLITE_SCHEMA] return. 2282** </li> 2283** 2284** <li> 2285** When an error occurs, [sqlite3_step()] will return one of the detailed 2286** [error codes] or [extended error codes]. The legacy behavior was that 2287** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2288** and you would have to make a second call to [sqlite3_reset()] in order 2289** to find the underlying cause of the problem. With the "v2" prepare 2290** interfaces, the underlying reason for the error is returned immediately. 2291** </li> 2292** </ol> 2293** 2294** Requirements: 2295** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] 2296** 2297*/ 2298int sqlite3_prepare( 2299 sqlite3 *db, /* Database handle */ 2300 const char *zSql, /* SQL statement, UTF-8 encoded */ 2301 int nByte, /* Maximum length of zSql in bytes. */ 2302 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2303 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2304); 2305int sqlite3_prepare_v2( 2306 sqlite3 *db, /* Database handle */ 2307 const char *zSql, /* SQL statement, UTF-8 encoded */ 2308 int nByte, /* Maximum length of zSql in bytes. */ 2309 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2310 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2311); 2312int sqlite3_prepare16( 2313 sqlite3 *db, /* Database handle */ 2314 const void *zSql, /* SQL statement, UTF-16 encoded */ 2315 int nByte, /* Maximum length of zSql in bytes. */ 2316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2317 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2318); 2319int sqlite3_prepare16_v2( 2320 sqlite3 *db, /* Database handle */ 2321 const void *zSql, /* SQL statement, UTF-16 encoded */ 2322 int nByte, /* Maximum length of zSql in bytes. */ 2323 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2324 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2325); 2326 2327/* 2328** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> 2329** 2330** This interface can be used to retrieve a saved copy of the original 2331** SQL text used to create a [prepared statement] if that statement was 2332** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2333** 2334** Requirements: 2335** [H13101] [H13102] [H13103] 2336*/ 2337const char *sqlite3_sql(sqlite3_stmt *pStmt); 2338 2339/* 2340** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> 2341** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2342** 2343** SQLite uses the sqlite3_value object to represent all values 2344** that can be stored in a database table. SQLite uses dynamic typing 2345** for the values it stores. Values stored in sqlite3_value objects 2346** can be integers, floating point values, strings, BLOBs, or NULL. 2347** 2348** An sqlite3_value object may be either "protected" or "unprotected". 2349** Some interfaces require a protected sqlite3_value. Other interfaces 2350** will accept either a protected or an unprotected sqlite3_value. 2351** Every interface that accepts sqlite3_value arguments specifies 2352** whether or not it requires a protected sqlite3_value. 2353** 2354** The terms "protected" and "unprotected" refer to whether or not 2355** a mutex is held. A internal mutex is held for a protected 2356** sqlite3_value object but no mutex is held for an unprotected 2357** sqlite3_value object. If SQLite is compiled to be single-threaded 2358** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2359** or if SQLite is run in one of reduced mutex modes 2360** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2361** then there is no distinction between protected and unprotected 2362** sqlite3_value objects and they can be used interchangeably. However, 2363** for maximum code portability it is recommended that applications 2364** still make the distinction between between protected and unprotected 2365** sqlite3_value objects even when not strictly required. 2366** 2367** The sqlite3_value objects that are passed as parameters into the 2368** implementation of [application-defined SQL functions] are protected. 2369** The sqlite3_value object returned by 2370** [sqlite3_column_value()] is unprotected. 2371** Unprotected sqlite3_value objects may only be used with 2372** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2373** The [sqlite3_value_blob | sqlite3_value_type()] family of 2374** interfaces require protected sqlite3_value objects. 2375*/ 2376typedef struct Mem sqlite3_value; 2377 2378/* 2379** CAPI3REF: SQL Function Context Object {H16001} <S20200> 2380** 2381** The context in which an SQL function executes is stored in an 2382** sqlite3_context object. A pointer to an sqlite3_context object 2383** is always first parameter to [application-defined SQL functions]. 2384** The application-defined SQL function implementation will pass this 2385** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2386** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2387** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2388** and/or [sqlite3_set_auxdata()]. 2389*/ 2390typedef struct sqlite3_context sqlite3_context; 2391 2392/* 2393** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> 2394** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2395** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2396** 2397** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, 2398** literals may be replaced by a [parameter] in one of these forms: 2399** 2400** <ul> 2401** <li> ? 2402** <li> ?NNN 2403** <li> :VVV 2404** <li> @VVV 2405** <li> $VVV 2406** </ul> 2407** 2408** In the parameter forms shown above NNN is an integer literal, 2409** and VVV is an alpha-numeric parameter name. The values of these 2410** parameters (also called "host parameter names" or "SQL parameters") 2411** can be set using the sqlite3_bind_*() routines defined here. 2412** 2413** The first argument to the sqlite3_bind_*() routines is always 2414** a pointer to the [sqlite3_stmt] object returned from 2415** [sqlite3_prepare_v2()] or its variants. 2416** 2417** The second argument is the index of the SQL parameter to be set. 2418** The leftmost SQL parameter has an index of 1. When the same named 2419** SQL parameter is used more than once, second and subsequent 2420** occurrences have the same index as the first occurrence. 2421** The index for named parameters can be looked up using the 2422** [sqlite3_bind_parameter_index()] API if desired. The index 2423** for "?NNN" parameters is the value of NNN. 2424** The NNN value must be between 1 and the [sqlite3_limit()] 2425** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2426** 2427** The third argument is the value to bind to the parameter. 2428** 2429** In those routines that have a fourth argument, its value is the 2430** number of bytes in the parameter. To be clear: the value is the 2431** number of <u>bytes</u> in the value, not the number of characters. 2432** If the fourth parameter is negative, the length of the string is 2433** the number of bytes up to the first zero terminator. 2434** 2435** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2436** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2437** string after SQLite has finished with it. If the fifth argument is 2438** the special value [SQLITE_STATIC], then SQLite assumes that the 2439** information is in static, unmanaged space and does not need to be freed. 2440** If the fifth argument has the value [SQLITE_TRANSIENT], then 2441** SQLite makes its own private copy of the data immediately, before 2442** the sqlite3_bind_*() routine returns. 2443** 2444** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2445** is filled with zeroes. A zeroblob uses a fixed amount of memory 2446** (just an integer to hold its size) while it is being processed. 2447** Zeroblobs are intended to serve as placeholders for BLOBs whose 2448** content is later written using 2449** [sqlite3_blob_open | incremental BLOB I/O] routines. 2450** A negative value for the zeroblob results in a zero-length BLOB. 2451** 2452** The sqlite3_bind_*() routines must be called after 2453** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2454** before [sqlite3_step()]. 2455** Bindings are not cleared by the [sqlite3_reset()] routine. 2456** Unbound parameters are interpreted as NULL. 2457** 2458** These routines return [SQLITE_OK] on success or an error code if 2459** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2460** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. 2461** [SQLITE_MISUSE] might be returned if these routines are called on a 2462** virtual machine that is the wrong state or which has already been finalized. 2463** Detection of misuse is unreliable. Applications should not depend 2464** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2465** a logic error in the application. Future versions of SQLite might 2466** panic rather than return SQLITE_MISUSE. 2467** 2468** See also: [sqlite3_bind_parameter_count()], 2469** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2470** 2471** Requirements: 2472** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] 2473** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] 2474** 2475*/ 2476int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2477int sqlite3_bind_double(sqlite3_stmt*, int, double); 2478int sqlite3_bind_int(sqlite3_stmt*, int, int); 2479int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2480int sqlite3_bind_null(sqlite3_stmt*, int); 2481int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2482int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2483int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2484int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2485 2486/* 2487** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> 2488** 2489** This routine can be used to find the number of [SQL parameters] 2490** in a [prepared statement]. SQL parameters are tokens of the 2491** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2492** placeholders for values that are [sqlite3_bind_blob | bound] 2493** to the parameters at a later time. 2494** 2495** This routine actually returns the index of the largest (rightmost) 2496** parameter. For all forms except ?NNN, this will correspond to the 2497** number of unique parameters. If parameters of the ?NNN are used, 2498** there may be gaps in the list. 2499** 2500** See also: [sqlite3_bind_blob|sqlite3_bind()], 2501** [sqlite3_bind_parameter_name()], and 2502** [sqlite3_bind_parameter_index()]. 2503** 2504** Requirements: 2505** [H13601] 2506*/ 2507int sqlite3_bind_parameter_count(sqlite3_stmt*); 2508 2509/* 2510** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> 2511** 2512** This routine returns a pointer to the name of the n-th 2513** [SQL parameter] in a [prepared statement]. 2514** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2515** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2516** respectively. 2517** In other words, the initial ":" or "$" or "@" or "?" 2518** is included as part of the name. 2519** Parameters of the form "?" without a following integer have no name 2520** and are also referred to as "anonymous parameters". 2521** 2522** The first host parameter has an index of 1, not 0. 2523** 2524** If the value n is out of range or if the n-th parameter is 2525** nameless, then NULL is returned. The returned string is 2526** always in UTF-8 encoding even if the named parameter was 2527** originally specified as UTF-16 in [sqlite3_prepare16()] or 2528** [sqlite3_prepare16_v2()]. 2529** 2530** See also: [sqlite3_bind_blob|sqlite3_bind()], 2531** [sqlite3_bind_parameter_count()], and 2532** [sqlite3_bind_parameter_index()]. 2533** 2534** Requirements: 2535** [H13621] 2536*/ 2537const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2538 2539/* 2540** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> 2541** 2542** Return the index of an SQL parameter given its name. The 2543** index value returned is suitable for use as the second 2544** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2545** is returned if no matching parameter is found. The parameter 2546** name must be given in UTF-8 even if the original statement 2547** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2548** 2549** See also: [sqlite3_bind_blob|sqlite3_bind()], 2550** [sqlite3_bind_parameter_count()], and 2551** [sqlite3_bind_parameter_index()]. 2552** 2553** Requirements: 2554** [H13641] 2555*/ 2556int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2557 2558/* 2559** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> 2560** 2561** Contrary to the intuition of many, [sqlite3_reset()] does not reset 2562** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2563** Use this routine to reset all host parameters to NULL. 2564** 2565** Requirements: 2566** [H13661] 2567*/ 2568int sqlite3_clear_bindings(sqlite3_stmt*); 2569 2570/* 2571** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> 2572** 2573** Return the number of columns in the result set returned by the 2574** [prepared statement]. This routine returns 0 if pStmt is an SQL 2575** statement that does not return data (for example an [UPDATE]). 2576** 2577** Requirements: 2578** [H13711] 2579*/ 2580int sqlite3_column_count(sqlite3_stmt *pStmt); 2581 2582/* 2583** CAPI3REF: Column Names In A Result Set {H13720} <S10700> 2584** 2585** These routines return the name assigned to a particular column 2586** in the result set of a [SELECT] statement. The sqlite3_column_name() 2587** interface returns a pointer to a zero-terminated UTF-8 string 2588** and sqlite3_column_name16() returns a pointer to a zero-terminated 2589** UTF-16 string. The first parameter is the [prepared statement] 2590** that implements the [SELECT] statement. The second parameter is the 2591** column number. The leftmost column is number 0. 2592** 2593** The returned string pointer is valid until either the [prepared statement] 2594** is destroyed by [sqlite3_finalize()] or until the next call to 2595** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2596** 2597** If sqlite3_malloc() fails during the processing of either routine 2598** (for example during a conversion from UTF-8 to UTF-16) then a 2599** NULL pointer is returned. 2600** 2601** The name of a result column is the value of the "AS" clause for 2602** that column, if there is an AS clause. If there is no AS clause 2603** then the name of the column is unspecified and may change from 2604** one release of SQLite to the next. 2605** 2606** Requirements: 2607** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] 2608*/ 2609const char *sqlite3_column_name(sqlite3_stmt*, int N); 2610const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2611 2612/* 2613** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> 2614** 2615** These routines provide a means to determine what column of what 2616** table in which database a result of a [SELECT] statement comes from. 2617** The name of the database or table or column can be returned as 2618** either a UTF-8 or UTF-16 string. The _database_ routines return 2619** the database name, the _table_ routines return the table name, and 2620** the origin_ routines return the column name. 2621** The returned string is valid until the [prepared statement] is destroyed 2622** using [sqlite3_finalize()] or until the same information is requested 2623** again in a different encoding. 2624** 2625** The names returned are the original un-aliased names of the 2626** database, table, and column. 2627** 2628** The first argument to the following calls is a [prepared statement]. 2629** These functions return information about the Nth column returned by 2630** the statement, where N is the second function argument. 2631** 2632** If the Nth column returned by the statement is an expression or 2633** subquery and is not a column value, then all of these functions return 2634** NULL. These routine might also return NULL if a memory allocation error 2635** occurs. Otherwise, they return the name of the attached database, table 2636** and column that query result column was extracted from. 2637** 2638** As with all other SQLite APIs, those postfixed with "16" return 2639** UTF-16 encoded strings, the other functions return UTF-8. {END} 2640** 2641** These APIs are only available if the library was compiled with the 2642** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 2643** 2644** {A13751} 2645** If two or more threads call one or more of these routines against the same 2646** prepared statement and column at the same time then the results are 2647** undefined. 2648** 2649** Requirements: 2650** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] 2651** 2652** If two or more threads call one or more 2653** [sqlite3_column_database_name | column metadata interfaces] 2654** for the same [prepared statement] and result column 2655** at the same time then the results are undefined. 2656*/ 2657const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2658const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2659const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2660const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2661const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2662const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2663 2664/* 2665** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> 2666** 2667** The first parameter is a [prepared statement]. 2668** If this statement is a [SELECT] statement and the Nth column of the 2669** returned result set of that [SELECT] is a table column (not an 2670** expression or subquery) then the declared type of the table 2671** column is returned. If the Nth column of the result set is an 2672** expression or subquery, then a NULL pointer is returned. 2673** The returned string is always UTF-8 encoded. {END} 2674** 2675** For example, given the database schema: 2676** 2677** CREATE TABLE t1(c1 VARIANT); 2678** 2679** and the following statement to be compiled: 2680** 2681** SELECT c1 + 1, c1 FROM t1; 2682** 2683** this routine would return the string "VARIANT" for the second result 2684** column (i==1), and a NULL pointer for the first result column (i==0). 2685** 2686** SQLite uses dynamic run-time typing. So just because a column 2687** is declared to contain a particular type does not mean that the 2688** data stored in that column is of the declared type. SQLite is 2689** strongly typed, but the typing is dynamic not static. Type 2690** is associated with individual values, not with the containers 2691** used to hold those values. 2692** 2693** Requirements: 2694** [H13761] [H13762] [H13763] 2695*/ 2696const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2697const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2698 2699/* 2700** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> 2701** 2702** After a [prepared statement] has been prepared using either 2703** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 2704** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 2705** must be called one or more times to evaluate the statement. 2706** 2707** The details of the behavior of the sqlite3_step() interface depend 2708** on whether the statement was prepared using the newer "v2" interface 2709** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 2710** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 2711** new "v2" interface is recommended for new applications but the legacy 2712** interface will continue to be supported. 2713** 2714** In the legacy interface, the return value will be either [SQLITE_BUSY], 2715** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 2716** With the "v2" interface, any of the other [result codes] or 2717** [extended result codes] might be returned as well. 2718** 2719** [SQLITE_BUSY] means that the database engine was unable to acquire the 2720** database locks it needs to do its job. If the statement is a [COMMIT] 2721** or occurs outside of an explicit transaction, then you can retry the 2722** statement. If the statement is not a [COMMIT] and occurs within a 2723** explicit transaction then you should rollback the transaction before 2724** continuing. 2725** 2726** [SQLITE_DONE] means that the statement has finished executing 2727** successfully. sqlite3_step() should not be called again on this virtual 2728** machine without first calling [sqlite3_reset()] to reset the virtual 2729** machine back to its initial state. 2730** 2731** If the SQL statement being executed returns any data, then [SQLITE_ROW] 2732** is returned each time a new row of data is ready for processing by the 2733** caller. The values may be accessed using the [column access functions]. 2734** sqlite3_step() is called again to retrieve the next row of data. 2735** 2736** [SQLITE_ERROR] means that a run-time error (such as a constraint 2737** violation) has occurred. sqlite3_step() should not be called again on 2738** the VM. More information may be found by calling [sqlite3_errmsg()]. 2739** With the legacy interface, a more specific error code (for example, 2740** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 2741** can be obtained by calling [sqlite3_reset()] on the 2742** [prepared statement]. In the "v2" interface, 2743** the more specific error code is returned directly by sqlite3_step(). 2744** 2745** [SQLITE_MISUSE] means that the this routine was called inappropriately. 2746** Perhaps it was called on a [prepared statement] that has 2747** already been [sqlite3_finalize | finalized] or on one that had 2748** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 2749** be the case that the same database connection is being used by two or 2750** more threads at the same moment in time. 2751** 2752** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 2753** API always returns a generic error code, [SQLITE_ERROR], following any 2754** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 2755** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 2756** specific [error codes] that better describes the error. 2757** We admit that this is a goofy design. The problem has been fixed 2758** with the "v2" interface. If you prepare all of your SQL statements 2759** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 2760** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 2761** then the more specific [error codes] are returned directly 2762** by sqlite3_step(). The use of the "v2" interface is recommended. 2763** 2764** Requirements: 2765** [H13202] [H15304] [H15306] [H15308] [H15310] 2766*/ 2767int sqlite3_step(sqlite3_stmt*); 2768 2769/* 2770** CAPI3REF: Number of columns in a result set {H13770} <S10700> 2771** 2772** Returns the number of values in the current row of the result set. 2773** 2774** Requirements: 2775** [H13771] [H13772] 2776*/ 2777int sqlite3_data_count(sqlite3_stmt *pStmt); 2778 2779/* 2780** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> 2781** KEYWORDS: SQLITE_TEXT 2782** 2783** {H10266} Every value in SQLite has one of five fundamental datatypes: 2784** 2785** <ul> 2786** <li> 64-bit signed integer 2787** <li> 64-bit IEEE floating point number 2788** <li> string 2789** <li> BLOB 2790** <li> NULL 2791** </ul> {END} 2792** 2793** These constants are codes for each of those types. 2794** 2795** Note that the SQLITE_TEXT constant was also used in SQLite version 2 2796** for a completely different meaning. Software that links against both 2797** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 2798** SQLITE_TEXT. 2799*/ 2800#define SQLITE_INTEGER 1 2801#define SQLITE_FLOAT 2 2802#define SQLITE_BLOB 4 2803#define SQLITE_NULL 5 2804#ifdef SQLITE_TEXT 2805# undef SQLITE_TEXT 2806#else 2807# define SQLITE_TEXT 3 2808#endif 2809#define SQLITE3_TEXT 3 2810 2811/* 2812** CAPI3REF: Result Values From A Query {H13800} <S10700> 2813** KEYWORDS: {column access functions} 2814** 2815** These routines form the "result set query" interface. 2816** 2817** These routines return information about a single column of the current 2818** result row of a query. In every case the first argument is a pointer 2819** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 2820** that was returned from [sqlite3_prepare_v2()] or one of its variants) 2821** and the second argument is the index of the column for which information 2822** should be returned. The leftmost column of the result set has the index 0. 2823** 2824** If the SQL statement does not currently point to a valid row, or if the 2825** column index is out of range, the result is undefined. 2826** These routines may only be called when the most recent call to 2827** [sqlite3_step()] has returned [SQLITE_ROW] and neither 2828** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 2829** If any of these routines are called after [sqlite3_reset()] or 2830** [sqlite3_finalize()] or after [sqlite3_step()] has returned 2831** something other than [SQLITE_ROW], the results are undefined. 2832** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 2833** are called from a different thread while any of these routines 2834** are pending, then the results are undefined. 2835** 2836** The sqlite3_column_type() routine returns the 2837** [SQLITE_INTEGER | datatype code] for the initial data type 2838** of the result column. The returned value is one of [SQLITE_INTEGER], 2839** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 2840** returned by sqlite3_column_type() is only meaningful if no type 2841** conversions have occurred as described below. After a type conversion, 2842** the value returned by sqlite3_column_type() is undefined. Future 2843** versions of SQLite may change the behavior of sqlite3_column_type() 2844** following a type conversion. 2845** 2846** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 2847** routine returns the number of bytes in that BLOB or string. 2848** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 2849** the string to UTF-8 and then returns the number of bytes. 2850** If the result is a numeric value then sqlite3_column_bytes() uses 2851** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 2852** the number of bytes in that string. 2853** The value returned does not include the zero terminator at the end 2854** of the string. For clarity: the value returned is the number of 2855** bytes in the string, not the number of characters. 2856** 2857** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 2858** even empty strings, are always zero terminated. The return 2859** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary 2860** pointer, possibly even a NULL pointer. 2861** 2862** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 2863** but leaves the result in UTF-16 in native byte order instead of UTF-8. 2864** The zero terminator is not included in this count. 2865** 2866** The object returned by [sqlite3_column_value()] is an 2867** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 2868** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 2869** If the [unprotected sqlite3_value] object returned by 2870** [sqlite3_column_value()] is used in any other way, including calls 2871** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 2872** or [sqlite3_value_bytes()], then the behavior is undefined. 2873** 2874** These routines attempt to convert the value where appropriate. For 2875** example, if the internal representation is FLOAT and a text result 2876** is requested, [sqlite3_snprintf()] is used internally to perform the 2877** conversion automatically. The following table details the conversions 2878** that are applied: 2879** 2880** <blockquote> 2881** <table border="1"> 2882** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 2883** 2884** <tr><td> NULL <td> INTEGER <td> Result is 0 2885** <tr><td> NULL <td> FLOAT <td> Result is 0.0 2886** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 2887** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 2888** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 2889** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 2890** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 2891** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 2892** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 2893** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 2894** <tr><td> TEXT <td> INTEGER <td> Use atoi() 2895** <tr><td> TEXT <td> FLOAT <td> Use atof() 2896** <tr><td> TEXT <td> BLOB <td> No change 2897** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 2898** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 2899** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 2900** </table> 2901** </blockquote> 2902** 2903** The table above makes reference to standard C library functions atoi() 2904** and atof(). SQLite does not really use these functions. It has its 2905** own equivalent internal routines. The atoi() and atof() names are 2906** used in the table for brevity and because they are familiar to most 2907** C programmers. 2908** 2909** Note that when type conversions occur, pointers returned by prior 2910** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 2911** sqlite3_column_text16() may be invalidated. 2912** Type conversions and pointer invalidations might occur 2913** in the following cases: 2914** 2915** <ul> 2916** <li> The initial content is a BLOB and sqlite3_column_text() or 2917** sqlite3_column_text16() is called. A zero-terminator might 2918** need to be added to the string.</li> 2919** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 2920** sqlite3_column_text16() is called. The content must be converted 2921** to UTF-16.</li> 2922** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 2923** sqlite3_column_text() is called. The content must be converted 2924** to UTF-8.</li> 2925** </ul> 2926** 2927** Conversions between UTF-16be and UTF-16le are always done in place and do 2928** not invalidate a prior pointer, though of course the content of the buffer 2929** that the prior pointer points to will have been modified. Other kinds 2930** of conversion are done in place when it is possible, but sometimes they 2931** are not possible and in those cases prior pointers are invalidated. 2932** 2933** The safest and easiest to remember policy is to invoke these routines 2934** in one of the following ways: 2935** 2936** <ul> 2937** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 2938** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 2939** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 2940** </ul> 2941** 2942** In other words, you should call sqlite3_column_text(), 2943** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 2944** into the desired format, then invoke sqlite3_column_bytes() or 2945** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 2946** to sqlite3_column_text() or sqlite3_column_blob() with calls to 2947** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 2948** with calls to sqlite3_column_bytes(). 2949** 2950** The pointers returned are valid until a type conversion occurs as 2951** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 2952** [sqlite3_finalize()] is called. The memory space used to hold strings 2953** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 2954** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 2955** [sqlite3_free()]. 2956** 2957** If a memory allocation error occurs during the evaluation of any 2958** of these routines, a default value is returned. The default value 2959** is either the integer 0, the floating point number 0.0, or a NULL 2960** pointer. Subsequent calls to [sqlite3_errcode()] will return 2961** [SQLITE_NOMEM]. 2962** 2963** Requirements: 2964** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] 2965** [H13827] [H13830] 2966*/ 2967const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 2968int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 2969int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 2970double sqlite3_column_double(sqlite3_stmt*, int iCol); 2971int sqlite3_column_int(sqlite3_stmt*, int iCol); 2972sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 2973const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 2974const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 2975int sqlite3_column_type(sqlite3_stmt*, int iCol); 2976sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 2977 2978/* 2979** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> 2980** 2981** The sqlite3_finalize() function is called to delete a [prepared statement]. 2982** If the statement was executed successfully or not executed at all, then 2983** SQLITE_OK is returned. If execution of the statement failed then an 2984** [error code] or [extended error code] is returned. 2985** 2986** This routine can be called at any point during the execution of the 2987** [prepared statement]. If the virtual machine has not 2988** completed execution when this routine is called, that is like 2989** encountering an error or an [sqlite3_interrupt | interrupt]. 2990** Incomplete updates may be rolled back and transactions canceled, 2991** depending on the circumstances, and the 2992** [error code] returned will be [SQLITE_ABORT]. 2993** 2994** Requirements: 2995** [H11302] [H11304] 2996*/ 2997int sqlite3_finalize(sqlite3_stmt *pStmt); 2998 2999/* 3000** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> 3001** 3002** The sqlite3_reset() function is called to reset a [prepared statement] 3003** object back to its initial state, ready to be re-executed. 3004** Any SQL statement variables that had values bound to them using 3005** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3006** Use [sqlite3_clear_bindings()] to reset the bindings. 3007** 3008** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3009** back to the beginning of its program. 3010** 3011** {H11334} If the most recent call to [sqlite3_step(S)] for the 3012** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3013** or if [sqlite3_step(S)] has never before been called on S, 3014** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3015** 3016** {H11336} If the most recent call to [sqlite3_step(S)] for the 3017** [prepared statement] S indicated an error, then 3018** [sqlite3_reset(S)] returns an appropriate [error code]. 3019** 3020** {H11338} The [sqlite3_reset(S)] interface does not change the values 3021** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3022*/ 3023int sqlite3_reset(sqlite3_stmt *pStmt); 3024 3025/* 3026** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> 3027** KEYWORDS: {function creation routines} 3028** KEYWORDS: {application-defined SQL function} 3029** KEYWORDS: {application-defined SQL functions} 3030** 3031** These two functions (collectively known as "function creation routines") 3032** are used to add SQL functions or aggregates or to redefine the behavior 3033** of existing SQL functions or aggregates. The only difference between the 3034** two is that the second parameter, the name of the (scalar) function or 3035** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 3036** for sqlite3_create_function16(). 3037** 3038** The first parameter is the [database connection] to which the SQL 3039** function is to be added. If a single program uses more than one database 3040** connection internally, then SQL functions must be added individually to 3041** each database connection. 3042** 3043** The second parameter is the name of the SQL function to be created or 3044** redefined. The length of the name is limited to 255 bytes, exclusive of 3045** the zero-terminator. Note that the name length limit is in bytes, not 3046** characters. Any attempt to create a function with a longer name 3047** will result in [SQLITE_ERROR] being returned. 3048** 3049** The third parameter (nArg) 3050** is the number of arguments that the SQL function or 3051** aggregate takes. If this parameter is negative, then the SQL function or 3052** aggregate may take any number of arguments. 3053** 3054** The fourth parameter, eTextRep, specifies what 3055** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3056** its parameters. Any SQL function implementation should be able to work 3057** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3058** more efficient with one encoding than another. It is allowed to 3059** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3060** times with the same function but with different values of eTextRep. 3061** When multiple implementations of the same function are available, SQLite 3062** will pick the one that involves the least amount of data conversion. 3063** If there is only a single implementation which does not care what text 3064** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3065** 3066** The fifth parameter is an arbitrary pointer. The implementation of the 3067** function can gain access to this pointer using [sqlite3_user_data()]. 3068** 3069** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3070** pointers to C-language functions that implement the SQL function or 3071** aggregate. A scalar SQL function requires an implementation of the xFunc 3072** callback only, NULL pointers should be passed as the xStep and xFinal 3073** parameters. An aggregate SQL function requires an implementation of xStep 3074** and xFinal and NULL should be passed for xFunc. To delete an existing 3075** SQL function or aggregate, pass NULL for all three function callbacks. 3076** 3077** It is permitted to register multiple implementations of the same 3078** functions with the same name but with either differing numbers of 3079** arguments or differing preferred text encodings. SQLite will use 3080** the implementation most closely matches the way in which the 3081** SQL function is used. A function implementation with a non-negative 3082** nArg parameter is a better match than a function implementation with 3083** a negative nArg. A function where the preferred text encoding 3084** matches the database encoding is a better 3085** match than a function where the encoding is different. 3086** A function where the encoding difference is between UTF16le and UTF16be 3087** is a closer match than a function where the encoding difference is 3088** between UTF8 and UTF16. 3089** 3090** Built-in functions may be overloaded by new application-defined functions. 3091** The first application-defined function with a given name overrides all 3092** built-in functions in the same [database connection] with the same name. 3093** Subsequent application-defined functions of the same name only override 3094** prior application-defined functions that are an exact match for the 3095** number of parameters and preferred encoding. 3096** 3097** An application-defined function is permitted to call other 3098** SQLite interfaces. However, such calls must not 3099** close the database connection nor finalize or reset the prepared 3100** statement in which the function is running. 3101** 3102** Requirements: 3103** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16124] [H16127] 3104** [H16130] [H16133] [H16136] [H16139] [H16142] 3105*/ 3106int sqlite3_create_function( 3107 sqlite3 *db, 3108 const char *zFunctionName, 3109 int nArg, 3110 int eTextRep, 3111 void *pApp, 3112 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3113 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3114 void (*xFinal)(sqlite3_context*) 3115); 3116int sqlite3_create_function16( 3117 sqlite3 *db, 3118 const void *zFunctionName, 3119 int nArg, 3120 int eTextRep, 3121 void *pApp, 3122 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3123 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3124 void (*xFinal)(sqlite3_context*) 3125); 3126 3127/* 3128** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> 3129** 3130** These constant define integer codes that represent the various 3131** text encodings supported by SQLite. 3132*/ 3133#define SQLITE_UTF8 1 3134#define SQLITE_UTF16LE 2 3135#define SQLITE_UTF16BE 3 3136#define SQLITE_UTF16 4 /* Use native byte order */ 3137#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3138#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3139 3140/* 3141** CAPI3REF: Deprecated Functions 3142** DEPRECATED 3143** 3144** These functions are [deprecated]. In order to maintain 3145** backwards compatibility with older code, these functions continue 3146** to be supported. However, new applications should avoid 3147** the use of these functions. To help encourage people to avoid 3148** using these functions, we are not going to tell you what they do. 3149*/ 3150#ifndef SQLITE_OMIT_DEPRECATED 3151SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3152SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3153SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3154SQLITE_DEPRECATED int sqlite3_global_recover(void); 3155SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3156SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3157#endif 3158 3159/* 3160** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> 3161** 3162** The C-language implementation of SQL functions and aggregates uses 3163** this set of interface routines to access the parameter values on 3164** the function or aggregate. 3165** 3166** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3167** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3168** define callbacks that implement the SQL functions and aggregates. 3169** The 4th parameter to these callbacks is an array of pointers to 3170** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3171** each parameter to the SQL function. These routines are used to 3172** extract values from the [sqlite3_value] objects. 3173** 3174** These routines work only with [protected sqlite3_value] objects. 3175** Any attempt to use these routines on an [unprotected sqlite3_value] 3176** object results in undefined behavior. 3177** 3178** These routines work just like the corresponding [column access functions] 3179** except that these routines take a single [protected sqlite3_value] object 3180** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3181** 3182** The sqlite3_value_text16() interface extracts a UTF-16 string 3183** in the native byte-order of the host machine. The 3184** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3185** extract UTF-16 strings as big-endian and little-endian respectively. 3186** 3187** The sqlite3_value_numeric_type() interface attempts to apply 3188** numeric affinity to the value. This means that an attempt is 3189** made to convert the value to an integer or floating point. If 3190** such a conversion is possible without loss of information (in other 3191** words, if the value is a string that looks like a number) 3192** then the conversion is performed. Otherwise no conversion occurs. 3193** The [SQLITE_INTEGER | datatype] after conversion is returned. 3194** 3195** Please pay particular attention to the fact that the pointer returned 3196** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3197** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3198** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3199** or [sqlite3_value_text16()]. 3200** 3201** These routines must be called from the same thread as 3202** the SQL function that supplied the [sqlite3_value*] parameters. 3203** 3204** Requirements: 3205** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] 3206** [H15127] [H15130] [H15133] [H15136] 3207*/ 3208const void *sqlite3_value_blob(sqlite3_value*); 3209int sqlite3_value_bytes(sqlite3_value*); 3210int sqlite3_value_bytes16(sqlite3_value*); 3211double sqlite3_value_double(sqlite3_value*); 3212int sqlite3_value_int(sqlite3_value*); 3213sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3214const unsigned char *sqlite3_value_text(sqlite3_value*); 3215const void *sqlite3_value_text16(sqlite3_value*); 3216const void *sqlite3_value_text16le(sqlite3_value*); 3217const void *sqlite3_value_text16be(sqlite3_value*); 3218int sqlite3_value_type(sqlite3_value*); 3219int sqlite3_value_numeric_type(sqlite3_value*); 3220 3221/* 3222** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> 3223** 3224** The implementation of aggregate SQL functions use this routine to allocate 3225** a structure for storing their state. 3226** 3227** The first time the sqlite3_aggregate_context() routine is called for a 3228** particular aggregate, SQLite allocates nBytes of memory, zeroes out that 3229** memory, and returns a pointer to it. On second and subsequent calls to 3230** sqlite3_aggregate_context() for the same aggregate function index, 3231** the same buffer is returned. The implementation of the aggregate can use 3232** the returned buffer to accumulate data. 3233** 3234** SQLite automatically frees the allocated buffer when the aggregate 3235** query concludes. 3236** 3237** The first parameter should be a copy of the 3238** [sqlite3_context | SQL function context] that is the first parameter 3239** to the callback routine that implements the aggregate function. 3240** 3241** This routine must be called from the same thread in which 3242** the aggregate SQL function is running. 3243** 3244** Requirements: 3245** [H16211] [H16213] [H16215] [H16217] 3246*/ 3247void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3248 3249/* 3250** CAPI3REF: User Data For Functions {H16240} <S20200> 3251** 3252** The sqlite3_user_data() interface returns a copy of 3253** the pointer that was the pUserData parameter (the 5th parameter) 3254** of the [sqlite3_create_function()] 3255** and [sqlite3_create_function16()] routines that originally 3256** registered the application defined function. {END} 3257** 3258** This routine must be called from the same thread in which 3259** the application-defined function is running. 3260** 3261** Requirements: 3262** [H16243] 3263*/ 3264void *sqlite3_user_data(sqlite3_context*); 3265 3266/* 3267** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> 3268** 3269** The sqlite3_context_db_handle() interface returns a copy of 3270** the pointer to the [database connection] (the 1st parameter) 3271** of the [sqlite3_create_function()] 3272** and [sqlite3_create_function16()] routines that originally 3273** registered the application defined function. 3274** 3275** Requirements: 3276** [H16253] 3277*/ 3278sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3279 3280/* 3281** CAPI3REF: Function Auxiliary Data {H16270} <S20200> 3282** 3283** The following two functions may be used by scalar SQL functions to 3284** associate metadata with argument values. If the same value is passed to 3285** multiple invocations of the same SQL function during query execution, under 3286** some circumstances the associated metadata may be preserved. This may 3287** be used, for example, to add a regular-expression matching scalar 3288** function. The compiled version of the regular expression is stored as 3289** metadata associated with the SQL value passed as the regular expression 3290** pattern. The compiled regular expression can be reused on multiple 3291** invocations of the same function so that the original pattern string 3292** does not need to be recompiled on each invocation. 3293** 3294** The sqlite3_get_auxdata() interface returns a pointer to the metadata 3295** associated by the sqlite3_set_auxdata() function with the Nth argument 3296** value to the application-defined function. If no metadata has been ever 3297** been set for the Nth argument of the function, or if the corresponding 3298** function parameter has changed since the meta-data was set, 3299** then sqlite3_get_auxdata() returns a NULL pointer. 3300** 3301** The sqlite3_set_auxdata() interface saves the metadata 3302** pointed to by its 3rd parameter as the metadata for the N-th 3303** argument of the application-defined function. Subsequent 3304** calls to sqlite3_get_auxdata() might return this data, if it has 3305** not been destroyed. 3306** If it is not NULL, SQLite will invoke the destructor 3307** function given by the 4th parameter to sqlite3_set_auxdata() on 3308** the metadata when the corresponding function parameter changes 3309** or when the SQL statement completes, whichever comes first. 3310** 3311** SQLite is free to call the destructor and drop metadata on any 3312** parameter of any function at any time. The only guarantee is that 3313** the destructor will be called before the metadata is dropped. 3314** 3315** In practice, metadata is preserved between function calls for 3316** expressions that are constant at compile time. This includes literal 3317** values and SQL variables. 3318** 3319** These routines must be called from the same thread in which 3320** the SQL function is running. 3321** 3322** Requirements: 3323** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] 3324*/ 3325void *sqlite3_get_auxdata(sqlite3_context*, int N); 3326void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3327 3328 3329/* 3330** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> 3331** 3332** These are special values for the destructor that is passed in as the 3333** final argument to routines like [sqlite3_result_blob()]. If the destructor 3334** argument is SQLITE_STATIC, it means that the content pointer is constant 3335** and will never change. It does not need to be destroyed. The 3336** SQLITE_TRANSIENT value means that the content will likely change in 3337** the near future and that SQLite should make its own private copy of 3338** the content before returning. 3339** 3340** The typedef is necessary to work around problems in certain 3341** C++ compilers. See ticket #2191. 3342*/ 3343typedef void (*sqlite3_destructor_type)(void*); 3344#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3345#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3346 3347/* 3348** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> 3349** 3350** These routines are used by the xFunc or xFinal callbacks that 3351** implement SQL functions and aggregates. See 3352** [sqlite3_create_function()] and [sqlite3_create_function16()] 3353** for additional information. 3354** 3355** These functions work very much like the [parameter binding] family of 3356** functions used to bind values to host parameters in prepared statements. 3357** Refer to the [SQL parameter] documentation for additional information. 3358** 3359** The sqlite3_result_blob() interface sets the result from 3360** an application-defined function to be the BLOB whose content is pointed 3361** to by the second parameter and which is N bytes long where N is the 3362** third parameter. 3363** 3364** The sqlite3_result_zeroblob() interfaces set the result of 3365** the application-defined function to be a BLOB containing all zero 3366** bytes and N bytes in size, where N is the value of the 2nd parameter. 3367** 3368** The sqlite3_result_double() interface sets the result from 3369** an application-defined function to be a floating point value specified 3370** by its 2nd argument. 3371** 3372** The sqlite3_result_error() and sqlite3_result_error16() functions 3373** cause the implemented SQL function to throw an exception. 3374** SQLite uses the string pointed to by the 3375** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3376** as the text of an error message. SQLite interprets the error 3377** message string from sqlite3_result_error() as UTF-8. SQLite 3378** interprets the string from sqlite3_result_error16() as UTF-16 in native 3379** byte order. If the third parameter to sqlite3_result_error() 3380** or sqlite3_result_error16() is negative then SQLite takes as the error 3381** message all text up through the first zero character. 3382** If the third parameter to sqlite3_result_error() or 3383** sqlite3_result_error16() is non-negative then SQLite takes that many 3384** bytes (not characters) from the 2nd parameter as the error message. 3385** The sqlite3_result_error() and sqlite3_result_error16() 3386** routines make a private copy of the error message text before 3387** they return. Hence, the calling function can deallocate or 3388** modify the text after they return without harm. 3389** The sqlite3_result_error_code() function changes the error code 3390** returned by SQLite as a result of an error in a function. By default, 3391** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3392** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3393** 3394** The sqlite3_result_toobig() interface causes SQLite to throw an error 3395** indicating that a string or BLOB is to long to represent. 3396** 3397** The sqlite3_result_nomem() interface causes SQLite to throw an error 3398** indicating that a memory allocation failed. 3399** 3400** The sqlite3_result_int() interface sets the return value 3401** of the application-defined function to be the 32-bit signed integer 3402** value given in the 2nd argument. 3403** The sqlite3_result_int64() interface sets the return value 3404** of the application-defined function to be the 64-bit signed integer 3405** value given in the 2nd argument. 3406** 3407** The sqlite3_result_null() interface sets the return value 3408** of the application-defined function to be NULL. 3409** 3410** The sqlite3_result_text(), sqlite3_result_text16(), 3411** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3412** set the return value of the application-defined function to be 3413** a text string which is represented as UTF-8, UTF-16 native byte order, 3414** UTF-16 little endian, or UTF-16 big endian, respectively. 3415** SQLite takes the text result from the application from 3416** the 2nd parameter of the sqlite3_result_text* interfaces. 3417** If the 3rd parameter to the sqlite3_result_text* interfaces 3418** is negative, then SQLite takes result text from the 2nd parameter 3419** through the first zero character. 3420** If the 3rd parameter to the sqlite3_result_text* interfaces 3421** is non-negative, then as many bytes (not characters) of the text 3422** pointed to by the 2nd parameter are taken as the application-defined 3423** function result. 3424** If the 4th parameter to the sqlite3_result_text* interfaces 3425** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3426** function as the destructor on the text or BLOB result when it has 3427** finished using that result. 3428** If the 4th parameter to the sqlite3_result_text* interfaces or 3429** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3430** assumes that the text or BLOB result is in constant space and does not 3431** copy the it or call a destructor when it has finished using that result. 3432** If the 4th parameter to the sqlite3_result_text* interfaces 3433** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3434** then SQLite makes a copy of the result into space obtained from 3435** from [sqlite3_malloc()] before it returns. 3436** 3437** The sqlite3_result_value() interface sets the result of 3438** the application-defined function to be a copy the 3439** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3440** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3441** so that the [sqlite3_value] specified in the parameter may change or 3442** be deallocated after sqlite3_result_value() returns without harm. 3443** A [protected sqlite3_value] object may always be used where an 3444** [unprotected sqlite3_value] object is required, so either 3445** kind of [sqlite3_value] object can be used with this interface. 3446** 3447** If these routines are called from within the different thread 3448** than the one containing the application-defined function that received 3449** the [sqlite3_context] pointer, the results are undefined. 3450** 3451** Requirements: 3452** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] 3453** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] 3454** [H16451] [H16454] [H16457] [H16460] [H16463] 3455*/ 3456void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3457void sqlite3_result_double(sqlite3_context*, double); 3458void sqlite3_result_error(sqlite3_context*, const char*, int); 3459void sqlite3_result_error16(sqlite3_context*, const void*, int); 3460void sqlite3_result_error_toobig(sqlite3_context*); 3461void sqlite3_result_error_nomem(sqlite3_context*); 3462void sqlite3_result_error_code(sqlite3_context*, int); 3463void sqlite3_result_int(sqlite3_context*, int); 3464void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3465void sqlite3_result_null(sqlite3_context*); 3466void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3467void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3468void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3469void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3470void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3471void sqlite3_result_zeroblob(sqlite3_context*, int n); 3472 3473/* 3474** CAPI3REF: Define New Collating Sequences {H16600} <S20300> 3475** 3476** These functions are used to add new collation sequences to the 3477** [database connection] specified as the first argument. 3478** 3479** The name of the new collation sequence is specified as a UTF-8 string 3480** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3481** and a UTF-16 string for sqlite3_create_collation16(). In all cases 3482** the name is passed as the second function argument. 3483** 3484** The third argument may be one of the constants [SQLITE_UTF8], 3485** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 3486** routine expects to be passed pointers to strings encoded using UTF-8, 3487** UTF-16 little-endian, or UTF-16 big-endian, respectively. The 3488** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 3489** the routine expects pointers to 16-bit word aligned strings 3490** of UTF-16 in the native byte order of the host computer. 3491** 3492** A pointer to the user supplied routine must be passed as the fifth 3493** argument. If it is NULL, this is the same as deleting the collation 3494** sequence (so that SQLite cannot call it anymore). 3495** Each time the application supplied function is invoked, it is passed 3496** as its first parameter a copy of the void* passed as the fourth argument 3497** to sqlite3_create_collation() or sqlite3_create_collation16(). 3498** 3499** The remaining arguments to the application-supplied routine are two strings, 3500** each represented by a (length, data) pair and encoded in the encoding 3501** that was passed as the third argument when the collation sequence was 3502** registered. {END} The application defined collation routine should 3503** return negative, zero or positive if the first string is less than, 3504** equal to, or greater than the second string. i.e. (STRING1 - STRING2). 3505** 3506** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3507** except that it takes an extra argument which is a destructor for 3508** the collation. The destructor is called when the collation is 3509** destroyed and is passed a copy of the fourth parameter void* pointer 3510** of the sqlite3_create_collation_v2(). 3511** Collations are destroyed when they are overridden by later calls to the 3512** collation creation functions or when the [database connection] is closed 3513** using [sqlite3_close()]. 3514** 3515** Requirements: 3516** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] 3517** [H16624] [H16627] [H16630] 3518*/ 3519int sqlite3_create_collation( 3520 sqlite3*, 3521 const char *zName, 3522 int eTextRep, 3523 void*, 3524 int(*xCompare)(void*,int,const void*,int,const void*) 3525); 3526int sqlite3_create_collation_v2( 3527 sqlite3*, 3528 const char *zName, 3529 int eTextRep, 3530 void*, 3531 int(*xCompare)(void*,int,const void*,int,const void*), 3532 void(*xDestroy)(void*) 3533); 3534int sqlite3_create_collation16( 3535 sqlite3*, 3536 const void *zName, 3537 int eTextRep, 3538 void*, 3539 int(*xCompare)(void*,int,const void*,int,const void*) 3540); 3541 3542/* 3543** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> 3544** 3545** To avoid having to register all collation sequences before a database 3546** can be used, a single callback function may be registered with the 3547** [database connection] to be called whenever an undefined collation 3548** sequence is required. 3549** 3550** If the function is registered using the sqlite3_collation_needed() API, 3551** then it is passed the names of undefined collation sequences as strings 3552** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, 3553** the names are passed as UTF-16 in machine native byte order. 3554** A call to either function replaces any existing callback. 3555** 3556** When the callback is invoked, the first argument passed is a copy 3557** of the second argument to sqlite3_collation_needed() or 3558** sqlite3_collation_needed16(). The second argument is the database 3559** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 3560** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 3561** sequence function required. The fourth parameter is the name of the 3562** required collation sequence. 3563** 3564** The callback function should register the desired collation using 3565** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 3566** [sqlite3_create_collation_v2()]. 3567** 3568** Requirements: 3569** [H16702] [H16704] [H16706] 3570*/ 3571int sqlite3_collation_needed( 3572 sqlite3*, 3573 void*, 3574 void(*)(void*,sqlite3*,int eTextRep,const char*) 3575); 3576int sqlite3_collation_needed16( 3577 sqlite3*, 3578 void*, 3579 void(*)(void*,sqlite3*,int eTextRep,const void*) 3580); 3581 3582/* 3583** Specify the key for an encrypted database. This routine should be 3584** called right after sqlite3_open(). 3585** 3586** The code to implement this API is not available in the public release 3587** of SQLite. 3588*/ 3589int sqlite3_key( 3590 sqlite3 *db, /* Database to be rekeyed */ 3591 const void *pKey, int nKey /* The key */ 3592); 3593 3594/* 3595** Change the key on an open database. If the current database is not 3596** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 3597** database is decrypted. 3598** 3599** The code to implement this API is not available in the public release 3600** of SQLite. 3601*/ 3602int sqlite3_rekey( 3603 sqlite3 *db, /* Database to be rekeyed */ 3604 const void *pKey, int nKey /* The new key */ 3605); 3606 3607/* 3608** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> 3609** 3610** The sqlite3_sleep() function causes the current thread to suspend execution 3611** for at least a number of milliseconds specified in its parameter. 3612** 3613** If the operating system does not support sleep requests with 3614** millisecond time resolution, then the time will be rounded up to 3615** the nearest second. The number of milliseconds of sleep actually 3616** requested from the operating system is returned. 3617** 3618** SQLite implements this interface by calling the xSleep() 3619** method of the default [sqlite3_vfs] object. 3620** 3621** Requirements: [H10533] [H10536] 3622*/ 3623int sqlite3_sleep(int); 3624 3625/* 3626** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> 3627** 3628** If this global variable is made to point to a string which is 3629** the name of a folder (a.k.a. directory), then all temporary files 3630** created by SQLite will be placed in that directory. If this variable 3631** is a NULL pointer, then SQLite performs a search for an appropriate 3632** temporary file directory. 3633** 3634** It is not safe to modify this variable once a [database connection] 3635** has been opened. It is intended that this variable be set once 3636** as part of process initialization and before any SQLite interface 3637** routines have been call and remain unchanged thereafter. 3638*/ 3639SQLITE_EXTERN char *sqlite3_temp_directory; 3640 3641/* 3642** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> 3643** KEYWORDS: {autocommit mode} 3644** 3645** The sqlite3_get_autocommit() interface returns non-zero or 3646** zero if the given database connection is or is not in autocommit mode, 3647** respectively. Autocommit mode is on by default. 3648** Autocommit mode is disabled by a [BEGIN] statement. 3649** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 3650** 3651** If certain kinds of errors occur on a statement within a multi-statement 3652** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 3653** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 3654** transaction might be rolled back automatically. The only way to 3655** find out whether SQLite automatically rolled back the transaction after 3656** an error is to use this function. 3657** 3658** If another thread changes the autocommit status of the database 3659** connection while this routine is running, then the return value 3660** is undefined. 3661** 3662** Requirements: [H12931] [H12932] [H12933] [H12934] 3663*/ 3664int sqlite3_get_autocommit(sqlite3*); 3665 3666/* 3667** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> 3668** 3669** The sqlite3_db_handle interface returns the [database connection] handle 3670** to which a [prepared statement] belongs. The [database connection] 3671** returned by sqlite3_db_handle is the same [database connection] that was the first argument 3672** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 3673** create the statement in the first place. 3674** 3675** Requirements: [H13123] 3676*/ 3677sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 3678 3679/* 3680** CAPI3REF: Find the next prepared statement {H13140} <S60600> 3681** 3682** This interface returns a pointer to the next [prepared statement] after 3683** pStmt associated with the [database connection] pDb. If pStmt is NULL 3684** then this interface returns a pointer to the first prepared statement 3685** associated with the database connection pDb. If no prepared statement 3686** satisfies the conditions of this routine, it returns NULL. 3687** 3688** The [database connection] pointer D in a call to 3689** [sqlite3_next_stmt(D,S)] must refer to an open database 3690** connection and in particular must not be a NULL pointer. 3691** 3692** Requirements: [H13143] [H13146] [H13149] [H13152] 3693*/ 3694sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 3695 3696/* 3697** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> 3698** 3699** The sqlite3_commit_hook() interface registers a callback 3700** function to be invoked whenever a transaction is committed. 3701** Any callback set by a previous call to sqlite3_commit_hook() 3702** for the same database connection is overridden. 3703** The sqlite3_rollback_hook() interface registers a callback 3704** function to be invoked whenever a transaction is committed. 3705** Any callback set by a previous call to sqlite3_commit_hook() 3706** for the same database connection is overridden. 3707** The pArg argument is passed through to the callback. 3708** If the callback on a commit hook function returns non-zero, 3709** then the commit is converted into a rollback. 3710** 3711** If another function was previously registered, its 3712** pArg value is returned. Otherwise NULL is returned. 3713** 3714** The callback implementation must not do anything that will modify 3715** the database connection that invoked the callback. Any actions 3716** to modify the database connection must be deferred until after the 3717** completion of the [sqlite3_step()] call that triggered the commit 3718** or rollback hook in the first place. 3719** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3720** database connections for the meaning of "modify" in this paragraph. 3721** 3722** Registering a NULL function disables the callback. 3723** 3724** For the purposes of this API, a transaction is said to have been 3725** rolled back if an explicit "ROLLBACK" statement is executed, or 3726** an error or constraint causes an implicit rollback to occur. 3727** The rollback callback is not invoked if a transaction is 3728** automatically rolled back because the database connection is closed. 3729** The rollback callback is not invoked if a transaction is 3730** rolled back because a commit callback returned non-zero. 3731** <todo> Check on this </todo> 3732** 3733** Requirements: 3734** [H12951] [H12952] [H12953] [H12954] [H12955] 3735** [H12961] [H12962] [H12963] [H12964] 3736*/ 3737void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 3738void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 3739 3740/* 3741** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> 3742** 3743** The sqlite3_update_hook() interface registers a callback function 3744** with the [database connection] identified by the first argument 3745** to be invoked whenever a row is updated, inserted or deleted. 3746** Any callback set by a previous call to this function 3747** for the same database connection is overridden. 3748** 3749** The second argument is a pointer to the function to invoke when a 3750** row is updated, inserted or deleted. 3751** The first argument to the callback is a copy of the third argument 3752** to sqlite3_update_hook(). 3753** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 3754** or [SQLITE_UPDATE], depending on the operation that caused the callback 3755** to be invoked. 3756** The third and fourth arguments to the callback contain pointers to the 3757** database and table name containing the affected row. 3758** The final callback parameter is the [rowid] of the row. 3759** In the case of an update, this is the [rowid] after the update takes place. 3760** 3761** The update hook is not invoked when internal system tables are 3762** modified (i.e. sqlite_master and sqlite_sequence). 3763** 3764** The update hook implementation must not do anything that will modify 3765** the database connection that invoked the update hook. Any actions 3766** to modify the database connection must be deferred until after the 3767** completion of the [sqlite3_step()] call that triggered the update hook. 3768** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3769** database connections for the meaning of "modify" in this paragraph. 3770** 3771** If another function was previously registered, its pArg value 3772** is returned. Otherwise NULL is returned. 3773** 3774** Requirements: 3775** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] 3776*/ 3777void *sqlite3_update_hook( 3778 sqlite3*, 3779 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 3780 void* 3781); 3782 3783/* 3784** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> 3785** KEYWORDS: {shared cache} {shared cache mode} 3786** 3787** This routine enables or disables the sharing of the database cache 3788** and schema data structures between [database connection | connections] 3789** to the same database. Sharing is enabled if the argument is true 3790** and disabled if the argument is false. 3791** 3792** Cache sharing is enabled and disabled for an entire process. 3793** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 3794** sharing was enabled or disabled for each thread separately. 3795** 3796** The cache sharing mode set by this interface effects all subsequent 3797** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 3798** Existing database connections continue use the sharing mode 3799** that was in effect at the time they were opened. 3800** 3801** Virtual tables cannot be used with a shared cache. When shared 3802** cache is enabled, the [sqlite3_create_module()] API used to register 3803** virtual tables will always return an error. 3804** 3805** This routine returns [SQLITE_OK] if shared cache was enabled or disabled 3806** successfully. An [error code] is returned otherwise. 3807** 3808** Shared cache is disabled by default. But this might change in 3809** future releases of SQLite. Applications that care about shared 3810** cache setting should set it explicitly. 3811** 3812** See Also: [SQLite Shared-Cache Mode] 3813** 3814** Requirements: [H10331] [H10336] [H10337] [H10339] 3815*/ 3816int sqlite3_enable_shared_cache(int); 3817 3818/* 3819** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> 3820** 3821** The sqlite3_release_memory() interface attempts to free N bytes 3822** of heap memory by deallocating non-essential memory allocations 3823** held by the database library. {END} Memory used to cache database 3824** pages to improve performance is an example of non-essential memory. 3825** sqlite3_release_memory() returns the number of bytes actually freed, 3826** which might be more or less than the amount requested. 3827** 3828** Requirements: [H17341] [H17342] 3829*/ 3830int sqlite3_release_memory(int); 3831 3832/* 3833** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> 3834** 3835** The sqlite3_soft_heap_limit() interface places a "soft" limit 3836** on the amount of heap memory that may be allocated by SQLite. 3837** If an internal allocation is requested that would exceed the 3838** soft heap limit, [sqlite3_release_memory()] is invoked one or 3839** more times to free up some space before the allocation is performed. 3840** 3841** The limit is called "soft", because if [sqlite3_release_memory()] 3842** cannot free sufficient memory to prevent the limit from being exceeded, 3843** the memory is allocated anyway and the current operation proceeds. 3844** 3845** A negative or zero value for N means that there is no soft heap limit and 3846** [sqlite3_release_memory()] will only be called when memory is exhausted. 3847** The default value for the soft heap limit is zero. 3848** 3849** SQLite makes a best effort to honor the soft heap limit. 3850** But if the soft heap limit cannot be honored, execution will 3851** continue without error or notification. This is why the limit is 3852** called a "soft" limit. It is advisory only. 3853** 3854** Prior to SQLite version 3.5.0, this routine only constrained the memory 3855** allocated by a single thread - the same thread in which this routine 3856** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 3857** applied to all threads. The value specified for the soft heap limit 3858** is an upper bound on the total memory allocation for all threads. In 3859** version 3.5.0 there is no mechanism for limiting the heap usage for 3860** individual threads. 3861** 3862** Requirements: 3863** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] 3864*/ 3865void sqlite3_soft_heap_limit(int); 3866 3867/* 3868** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> 3869** 3870** This routine returns metadata about a specific column of a specific 3871** database table accessible using the [database connection] handle 3872** passed as the first function argument. 3873** 3874** The column is identified by the second, third and fourth parameters to 3875** this function. The second parameter is either the name of the database 3876** (i.e. "main", "temp" or an attached database) containing the specified 3877** table or NULL. If it is NULL, then all attached databases are searched 3878** for the table using the same algorithm used by the database engine to 3879** resolve unqualified table references. 3880** 3881** The third and fourth parameters to this function are the table and column 3882** name of the desired column, respectively. Neither of these parameters 3883** may be NULL. 3884** 3885** Metadata is returned by writing to the memory locations passed as the 5th 3886** and subsequent parameters to this function. Any of these arguments may be 3887** NULL, in which case the corresponding element of metadata is omitted. 3888** 3889** <blockquote> 3890** <table border="1"> 3891** <tr><th> Parameter <th> Output<br>Type <th> Description 3892** 3893** <tr><td> 5th <td> const char* <td> Data type 3894** <tr><td> 6th <td> const char* <td> Name of default collation sequence 3895** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 3896** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 3897** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 3898** </table> 3899** </blockquote> 3900** 3901** The memory pointed to by the character pointers returned for the 3902** declaration type and collation sequence is valid only until the next 3903** call to any SQLite API function. 3904** 3905** If the specified table is actually a view, an [error code] is returned. 3906** 3907** If the specified column is "rowid", "oid" or "_rowid_" and an 3908** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 3909** parameters are set for the explicitly declared column. If there is no 3910** explicitly declared [INTEGER PRIMARY KEY] column, then the output 3911** parameters are set as follows: 3912** 3913** <pre> 3914** data type: "INTEGER" 3915** collation sequence: "BINARY" 3916** not null: 0 3917** primary key: 1 3918** auto increment: 0 3919** </pre> 3920** 3921** This function may load one or more schemas from database files. If an 3922** error occurs during this process, or if the requested table or column 3923** cannot be found, an [error code] is returned and an error message left 3924** in the [database connection] (to be retrieved using sqlite3_errmsg()). 3925** 3926** This API is only available if the library was compiled with the 3927** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 3928*/ 3929int sqlite3_table_column_metadata( 3930 sqlite3 *db, /* Connection handle */ 3931 const char *zDbName, /* Database name or NULL */ 3932 const char *zTableName, /* Table name */ 3933 const char *zColumnName, /* Column name */ 3934 char const **pzDataType, /* OUTPUT: Declared data type */ 3935 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 3936 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 3937 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 3938 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 3939); 3940 3941/* 3942** CAPI3REF: Load An Extension {H12600} <S20500> 3943** 3944** This interface loads an SQLite extension library from the named file. 3945** 3946** {H12601} The sqlite3_load_extension() interface attempts to load an 3947** SQLite extension library contained in the file zFile. 3948** 3949** {H12602} The entry point is zProc. 3950** 3951** {H12603} zProc may be 0, in which case the name of the entry point 3952** defaults to "sqlite3_extension_init". 3953** 3954** {H12604} The sqlite3_load_extension() interface shall return 3955** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 3956** 3957** {H12605} If an error occurs and pzErrMsg is not 0, then the 3958** [sqlite3_load_extension()] interface shall attempt to 3959** fill *pzErrMsg with error message text stored in memory 3960** obtained from [sqlite3_malloc()]. {END} The calling function 3961** should free this memory by calling [sqlite3_free()]. 3962** 3963** {H12606} Extension loading must be enabled using 3964** [sqlite3_enable_load_extension()] prior to calling this API, 3965** otherwise an error will be returned. 3966*/ 3967int sqlite3_load_extension( 3968 sqlite3 *db, /* Load the extension into this database connection */ 3969 const char *zFile, /* Name of the shared library containing extension */ 3970 const char *zProc, /* Entry point. Derived from zFile if 0 */ 3971 char **pzErrMsg /* Put error message here if not 0 */ 3972); 3973 3974/* 3975** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> 3976** 3977** So as not to open security holes in older applications that are 3978** unprepared to deal with extension loading, and as a means of disabling 3979** extension loading while evaluating user-entered SQL, the following API 3980** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 3981** 3982** Extension loading is off by default. See ticket #1863. 3983** 3984** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 3985** to turn extension loading on and call it with onoff==0 to turn 3986** it back off again. 3987** 3988** {H12622} Extension loading is off by default. 3989*/ 3990int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 3991 3992/* 3993** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> 3994** 3995** This API can be invoked at program startup in order to register 3996** one or more statically linked extensions that will be available 3997** to all new [database connections]. {END} 3998** 3999** This routine stores a pointer to the extension in an array that is 4000** obtained from [sqlite3_malloc()]. If you run a memory leak checker 4001** on your program and it reports a leak because of this array, invoke 4002** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. 4003** 4004** {H12641} This function registers an extension entry point that is 4005** automatically invoked whenever a new [database connection] 4006** is opened using [sqlite3_open()], [sqlite3_open16()], 4007** or [sqlite3_open_v2()]. 4008** 4009** {H12642} Duplicate extensions are detected so calling this routine 4010** multiple times with the same extension is harmless. 4011** 4012** {H12643} This routine stores a pointer to the extension in an array 4013** that is obtained from [sqlite3_malloc()]. 4014** 4015** {H12644} Automatic extensions apply across all threads. 4016*/ 4017int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4018 4019/* 4020** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> 4021** 4022** This function disables all previously registered automatic 4023** extensions. {END} It undoes the effect of all prior 4024** [sqlite3_auto_extension()] calls. 4025** 4026** {H12661} This function disables all previously registered 4027** automatic extensions. 4028** 4029** {H12662} This function disables automatic extensions in all threads. 4030*/ 4031void sqlite3_reset_auto_extension(void); 4032 4033/* 4034****** EXPERIMENTAL - subject to change without notice ************** 4035** 4036** The interface to the virtual-table mechanism is currently considered 4037** to be experimental. The interface might change in incompatible ways. 4038** If this is a problem for you, do not use the interface at this time. 4039** 4040** When the virtual-table mechanism stabilizes, we will declare the 4041** interface fixed, support it indefinitely, and remove this comment. 4042*/ 4043 4044/* 4045** Structures used by the virtual table interface 4046*/ 4047typedef struct sqlite3_vtab sqlite3_vtab; 4048typedef struct sqlite3_index_info sqlite3_index_info; 4049typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4050typedef struct sqlite3_module sqlite3_module; 4051 4052/* 4053** CAPI3REF: Virtual Table Object {H18000} <S20400> 4054** KEYWORDS: sqlite3_module 4055** EXPERIMENTAL 4056** 4057** A module is a class of virtual tables. Each module is defined 4058** by an instance of the following structure. This structure consists 4059** mostly of methods for the module. 4060** 4061** This interface is experimental and is subject to change or 4062** removal in future releases of SQLite. 4063*/ 4064struct sqlite3_module { 4065 int iVersion; 4066 int (*xCreate)(sqlite3*, void *pAux, 4067 int argc, const char *const*argv, 4068 sqlite3_vtab **ppVTab, char**); 4069 int (*xConnect)(sqlite3*, void *pAux, 4070 int argc, const char *const*argv, 4071 sqlite3_vtab **ppVTab, char**); 4072 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4073 int (*xDisconnect)(sqlite3_vtab *pVTab); 4074 int (*xDestroy)(sqlite3_vtab *pVTab); 4075 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4076 int (*xClose)(sqlite3_vtab_cursor*); 4077 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4078 int argc, sqlite3_value **argv); 4079 int (*xNext)(sqlite3_vtab_cursor*); 4080 int (*xEof)(sqlite3_vtab_cursor*); 4081 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4082 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4083 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4084 int (*xBegin)(sqlite3_vtab *pVTab); 4085 int (*xSync)(sqlite3_vtab *pVTab); 4086 int (*xCommit)(sqlite3_vtab *pVTab); 4087 int (*xRollback)(sqlite3_vtab *pVTab); 4088 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4089 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4090 void **ppArg); 4091 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4092}; 4093 4094/* 4095** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> 4096** KEYWORDS: sqlite3_index_info 4097** EXPERIMENTAL 4098** 4099** The sqlite3_index_info structure and its substructures is used to 4100** pass information into and receive the reply from the xBestIndex 4101** method of an sqlite3_module. The fields under **Inputs** are the 4102** inputs to xBestIndex and are read-only. xBestIndex inserts its 4103** results into the **Outputs** fields. 4104** 4105** The aConstraint[] array records WHERE clause constraints of the form: 4106** 4107** <pre>column OP expr</pre> 4108** 4109** where OP is =, <, <=, >, or >=. The particular operator is 4110** stored in aConstraint[].op. The index of the column is stored in 4111** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4112** expr on the right-hand side can be evaluated (and thus the constraint 4113** is usable) and false if it cannot. 4114** 4115** The optimizer automatically inverts terms of the form "expr OP column" 4116** and makes other simplifications to the WHERE clause in an attempt to 4117** get as many WHERE clause terms into the form shown above as possible. 4118** The aConstraint[] array only reports WHERE clause terms in the correct 4119** form that refer to the particular virtual table being queried. 4120** 4121** Information about the ORDER BY clause is stored in aOrderBy[]. 4122** Each term of aOrderBy records a column of the ORDER BY clause. 4123** 4124** The xBestIndex method must fill aConstraintUsage[] with information 4125** about what parameters to pass to xFilter. If argvIndex>0 then 4126** the right-hand side of the corresponding aConstraint[] is evaluated 4127** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4128** is true, then the constraint is assumed to be fully handled by the 4129** virtual table and is not checked again by SQLite. 4130** 4131** The idxNum and idxPtr values are recorded and passed into xFilter. 4132** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 4133** 4134** The orderByConsumed means that output from xFilter will occur in 4135** the correct order to satisfy the ORDER BY clause so that no separate 4136** sorting step is required. 4137** 4138** The estimatedCost value is an estimate of the cost of doing the 4139** particular lookup. A full scan of a table with N entries should have 4140** a cost of N. A binary search of a table of N entries should have a 4141** cost of approximately log(N). 4142** 4143** This interface is experimental and is subject to change or 4144** removal in future releases of SQLite. 4145*/ 4146struct sqlite3_index_info { 4147 /* Inputs */ 4148 int nConstraint; /* Number of entries in aConstraint */ 4149 struct sqlite3_index_constraint { 4150 int iColumn; /* Column on left-hand side of constraint */ 4151 unsigned char op; /* Constraint operator */ 4152 unsigned char usable; /* True if this constraint is usable */ 4153 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4154 } *aConstraint; /* Table of WHERE clause constraints */ 4155 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4156 struct sqlite3_index_orderby { 4157 int iColumn; /* Column number */ 4158 unsigned char desc; /* True for DESC. False for ASC. */ 4159 } *aOrderBy; /* The ORDER BY clause */ 4160 /* Outputs */ 4161 struct sqlite3_index_constraint_usage { 4162 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4163 unsigned char omit; /* Do not code a test for this constraint */ 4164 } *aConstraintUsage; 4165 int idxNum; /* Number used to identify the index */ 4166 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4167 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4168 int orderByConsumed; /* True if output is already ordered */ 4169 double estimatedCost; /* Estimated cost of using this index */ 4170}; 4171#define SQLITE_INDEX_CONSTRAINT_EQ 2 4172#define SQLITE_INDEX_CONSTRAINT_GT 4 4173#define SQLITE_INDEX_CONSTRAINT_LE 8 4174#define SQLITE_INDEX_CONSTRAINT_LT 16 4175#define SQLITE_INDEX_CONSTRAINT_GE 32 4176#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4177 4178/* 4179** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> 4180** EXPERIMENTAL 4181** 4182** This routine is used to register a new module name with a 4183** [database connection]. Module names must be registered before 4184** creating new virtual tables on the module, or before using 4185** preexisting virtual tables of the module. 4186** 4187** This interface is experimental and is subject to change or 4188** removal in future releases of SQLite. 4189*/ 4190SQLITE_EXPERIMENTAL int sqlite3_create_module( 4191 sqlite3 *db, /* SQLite connection to register module with */ 4192 const char *zName, /* Name of the module */ 4193 const sqlite3_module *, /* Methods for the module */ 4194 void * /* Client data for xCreate/xConnect */ 4195); 4196 4197/* 4198** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> 4199** EXPERIMENTAL 4200** 4201** This routine is identical to the [sqlite3_create_module()] method above, 4202** except that it allows a destructor function to be specified. It is 4203** even more experimental than the rest of the virtual tables API. 4204*/ 4205SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( 4206 sqlite3 *db, /* SQLite connection to register module with */ 4207 const char *zName, /* Name of the module */ 4208 const sqlite3_module *, /* Methods for the module */ 4209 void *, /* Client data for xCreate/xConnect */ 4210 void(*xDestroy)(void*) /* Module destructor function */ 4211); 4212 4213/* 4214** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> 4215** KEYWORDS: sqlite3_vtab 4216** EXPERIMENTAL 4217** 4218** Every module implementation uses a subclass of the following structure 4219** to describe a particular instance of the module. Each subclass will 4220** be tailored to the specific needs of the module implementation. 4221** The purpose of this superclass is to define certain fields that are 4222** common to all module implementations. 4223** 4224** Virtual tables methods can set an error message by assigning a 4225** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4226** take care that any prior string is freed by a call to [sqlite3_free()] 4227** prior to assigning a new string to zErrMsg. After the error message 4228** is delivered up to the client application, the string will be automatically 4229** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 4230** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 4231** since virtual tables are commonly implemented in loadable extensions which 4232** do not have access to sqlite3MPrintf() or sqlite3Free(). 4233** 4234** This interface is experimental and is subject to change or 4235** removal in future releases of SQLite. 4236*/ 4237struct sqlite3_vtab { 4238 const sqlite3_module *pModule; /* The module for this virtual table */ 4239 int nRef; /* Used internally */ 4240 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4241 /* Virtual table implementations will typically add additional fields */ 4242}; 4243 4244/* 4245** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> 4246** KEYWORDS: sqlite3_vtab_cursor 4247** EXPERIMENTAL 4248** 4249** Every module implementation uses a subclass of the following structure 4250** to describe cursors that point into the virtual table and are used 4251** to loop through the virtual table. Cursors are created using the 4252** xOpen method of the module. Each module implementation will define 4253** the content of a cursor structure to suit its own needs. 4254** 4255** This superclass exists in order to define fields of the cursor that 4256** are common to all implementations. 4257** 4258** This interface is experimental and is subject to change or 4259** removal in future releases of SQLite. 4260*/ 4261struct sqlite3_vtab_cursor { 4262 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4263 /* Virtual table implementations will typically add additional fields */ 4264}; 4265 4266/* 4267** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> 4268** EXPERIMENTAL 4269** 4270** The xCreate and xConnect methods of a module use the following API 4271** to declare the format (the names and datatypes of the columns) of 4272** the virtual tables they implement. 4273** 4274** This interface is experimental and is subject to change or 4275** removal in future releases of SQLite. 4276*/ 4277SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 4278 4279/* 4280** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> 4281** EXPERIMENTAL 4282** 4283** Virtual tables can provide alternative implementations of functions 4284** using the xFindFunction method. But global versions of those functions 4285** must exist in order to be overloaded. 4286** 4287** This API makes sure a global version of a function with a particular 4288** name and number of parameters exists. If no such function exists 4289** before this API is called, a new function is created. The implementation 4290** of the new function always causes an exception to be thrown. So 4291** the new function is not good for anything by itself. Its only 4292** purpose is to be a placeholder function that can be overloaded 4293** by virtual tables. 4294** 4295** This API should be considered part of the virtual table interface, 4296** which is experimental and subject to change. 4297*/ 4298SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4299 4300/* 4301** The interface to the virtual-table mechanism defined above (back up 4302** to a comment remarkably similar to this one) is currently considered 4303** to be experimental. The interface might change in incompatible ways. 4304** If this is a problem for you, do not use the interface at this time. 4305** 4306** When the virtual-table mechanism stabilizes, we will declare the 4307** interface fixed, support it indefinitely, and remove this comment. 4308** 4309****** EXPERIMENTAL - subject to change without notice ************** 4310*/ 4311 4312/* 4313** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> 4314** KEYWORDS: {BLOB handle} {BLOB handles} 4315** 4316** An instance of this object represents an open BLOB on which 4317** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4318** Objects of this type are created by [sqlite3_blob_open()] 4319** and destroyed by [sqlite3_blob_close()]. 4320** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4321** can be used to read or write small subsections of the BLOB. 4322** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4323*/ 4324typedef struct sqlite3_blob sqlite3_blob; 4325 4326/* 4327** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> 4328** 4329** This interfaces opens a [BLOB handle | handle] to the BLOB located 4330** in row iRow, column zColumn, table zTable in database zDb; 4331** in other words, the same BLOB that would be selected by: 4332** 4333** <pre> 4334** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4335** </pre> {END} 4336** 4337** If the flags parameter is non-zero, the the BLOB is opened for read 4338** and write access. If it is zero, the BLOB is opened for read access. 4339** 4340** Note that the database name is not the filename that contains 4341** the database but rather the symbolic name of the database that 4342** is assigned when the database is connected using [ATTACH]. 4343** For the main database file, the database name is "main". 4344** For TEMP tables, the database name is "temp". 4345** 4346** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4347** to *ppBlob. Otherwise an [error code] is returned and any value written 4348** to *ppBlob should not be used by the caller. 4349** This function sets the [database connection] error code and message 4350** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 4351** 4352** If the row that a BLOB handle points to is modified by an 4353** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4354** then the BLOB handle is marked as "expired". 4355** This is true if any column of the row is changed, even a column 4356** other than the one the BLOB handle is open on. 4357** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4358** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. 4359** Changes written into a BLOB prior to the BLOB expiring are not 4360** rollback by the expiration of the BLOB. Such changes will eventually 4361** commit if the transaction continues to completion. 4362** 4363** Requirements: 4364** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] 4365*/ 4366int sqlite3_blob_open( 4367 sqlite3*, 4368 const char *zDb, 4369 const char *zTable, 4370 const char *zColumn, 4371 sqlite3_int64 iRow, 4372 int flags, 4373 sqlite3_blob **ppBlob 4374); 4375 4376/* 4377** CAPI3REF: Close A BLOB Handle {H17830} <S30230> 4378** 4379** Closes an open [BLOB handle]. 4380** 4381** Closing a BLOB shall cause the current transaction to commit 4382** if there are no other BLOBs, no pending prepared statements, and the 4383** database connection is in [autocommit mode]. 4384** If any writes were made to the BLOB, they might be held in cache 4385** until the close operation if they will fit. {END} 4386** 4387** Closing the BLOB often forces the changes 4388** out to disk and so if any I/O errors occur, they will likely occur 4389** at the time when the BLOB is closed. {H17833} Any errors that occur during 4390** closing are reported as a non-zero return value. 4391** 4392** The BLOB is closed unconditionally. Even if this routine returns 4393** an error code, the BLOB is still closed. 4394** 4395** Requirements: 4396** [H17833] [H17836] [H17839] 4397*/ 4398int sqlite3_blob_close(sqlite3_blob *); 4399 4400/* 4401** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> 4402** 4403** Returns the size in bytes of the BLOB accessible via the open 4404** []BLOB handle] in its only argument. 4405** 4406** Requirements: 4407** [H17843] 4408*/ 4409int sqlite3_blob_bytes(sqlite3_blob *); 4410 4411/* 4412** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> 4413** 4414** This function is used to read data from an open [BLOB handle] into a 4415** caller-supplied buffer. N bytes of data are copied into buffer Z 4416** from the open BLOB, starting at offset iOffset. 4417** 4418** If offset iOffset is less than N bytes from the end of the BLOB, 4419** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 4420** less than zero, [SQLITE_ERROR] is returned and no data is read. 4421** 4422** An attempt to read from an expired [BLOB handle] fails with an 4423** error code of [SQLITE_ABORT]. 4424** 4425** On success, SQLITE_OK is returned. 4426** Otherwise, an [error code] or an [extended error code] is returned. 4427** 4428** Requirements: 4429** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] 4430*/ 4431int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 4432 4433/* 4434** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> 4435** 4436** This function is used to write data into an open [BLOB handle] from a 4437** caller-supplied buffer. N bytes of data are copied from the buffer Z 4438** into the open BLOB, starting at offset iOffset. 4439** 4440** If the [BLOB handle] passed as the first argument was not opened for 4441** writing (the flags parameter to [sqlite3_blob_open()] was zero), 4442** this function returns [SQLITE_READONLY]. 4443** 4444** This function may only modify the contents of the BLOB; it is 4445** not possible to increase the size of a BLOB using this API. 4446** If offset iOffset is less than N bytes from the end of the BLOB, 4447** [SQLITE_ERROR] is returned and no data is written. If N is 4448** less than zero [SQLITE_ERROR] is returned and no data is written. 4449** 4450** An attempt to write to an expired [BLOB handle] fails with an 4451** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred 4452** before the [BLOB handle] expired are not rolled back by the 4453** expiration of the handle, though of course those changes might 4454** have been overwritten by the statement that expired the BLOB handle 4455** or by other independent statements. 4456** 4457** On success, SQLITE_OK is returned. 4458** Otherwise, an [error code] or an [extended error code] is returned. 4459** 4460** Requirements: 4461** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] 4462** [H17888] 4463*/ 4464int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 4465 4466/* 4467** CAPI3REF: Virtual File System Objects {H11200} <S20100> 4468** 4469** A virtual filesystem (VFS) is an [sqlite3_vfs] object 4470** that SQLite uses to interact 4471** with the underlying operating system. Most SQLite builds come with a 4472** single default VFS that is appropriate for the host computer. 4473** New VFSes can be registered and existing VFSes can be unregistered. 4474** The following interfaces are provided. 4475** 4476** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 4477** Names are case sensitive. 4478** Names are zero-terminated UTF-8 strings. 4479** If there is no match, a NULL pointer is returned. 4480** If zVfsName is NULL then the default VFS is returned. 4481** 4482** New VFSes are registered with sqlite3_vfs_register(). 4483** Each new VFS becomes the default VFS if the makeDflt flag is set. 4484** The same VFS can be registered multiple times without injury. 4485** To make an existing VFS into the default VFS, register it again 4486** with the makeDflt flag set. If two different VFSes with the 4487** same name are registered, the behavior is undefined. If a 4488** VFS is registered with a name that is NULL or an empty string, 4489** then the behavior is undefined. 4490** 4491** Unregister a VFS with the sqlite3_vfs_unregister() interface. 4492** If the default VFS is unregistered, another VFS is chosen as 4493** the default. The choice for the new VFS is arbitrary. 4494** 4495** Requirements: 4496** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] 4497*/ 4498sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 4499int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 4500int sqlite3_vfs_unregister(sqlite3_vfs*); 4501 4502/* 4503** CAPI3REF: Mutexes {H17000} <S20000> 4504** 4505** The SQLite core uses these routines for thread 4506** synchronization. Though they are intended for internal 4507** use by SQLite, code that links against SQLite is 4508** permitted to use any of these routines. 4509** 4510** The SQLite source code contains multiple implementations 4511** of these mutex routines. An appropriate implementation 4512** is selected automatically at compile-time. The following 4513** implementations are available in the SQLite core: 4514** 4515** <ul> 4516** <li> SQLITE_MUTEX_OS2 4517** <li> SQLITE_MUTEX_PTHREAD 4518** <li> SQLITE_MUTEX_W32 4519** <li> SQLITE_MUTEX_NOOP 4520** </ul> 4521** 4522** The SQLITE_MUTEX_NOOP implementation is a set of routines 4523** that does no real locking and is appropriate for use in 4524** a single-threaded application. The SQLITE_MUTEX_OS2, 4525** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 4526** are appropriate for use on OS/2, Unix, and Windows. 4527** 4528** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 4529** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 4530** implementation is included with the library. In this case the 4531** application must supply a custom mutex implementation using the 4532** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 4533** before calling sqlite3_initialize() or any other public sqlite3_ 4534** function that calls sqlite3_initialize(). 4535** 4536** {H17011} The sqlite3_mutex_alloc() routine allocates a new 4537** mutex and returns a pointer to it. {H17012} If it returns NULL 4538** that means that a mutex could not be allocated. {H17013} SQLite 4539** will unwind its stack and return an error. {H17014} The argument 4540** to sqlite3_mutex_alloc() is one of these integer constants: 4541** 4542** <ul> 4543** <li> SQLITE_MUTEX_FAST 4544** <li> SQLITE_MUTEX_RECURSIVE 4545** <li> SQLITE_MUTEX_STATIC_MASTER 4546** <li> SQLITE_MUTEX_STATIC_MEM 4547** <li> SQLITE_MUTEX_STATIC_MEM2 4548** <li> SQLITE_MUTEX_STATIC_PRNG 4549** <li> SQLITE_MUTEX_STATIC_LRU 4550** <li> SQLITE_MUTEX_STATIC_LRU2 4551** </ul> 4552** 4553** {H17015} The first two constants cause sqlite3_mutex_alloc() to create 4554** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 4555** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 4556** The mutex implementation does not need to make a distinction 4557** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 4558** not want to. {H17016} But SQLite will only request a recursive mutex in 4559** cases where it really needs one. {END} If a faster non-recursive mutex 4560** implementation is available on the host platform, the mutex subsystem 4561** might return such a mutex in response to SQLITE_MUTEX_FAST. 4562** 4563** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return 4564** a pointer to a static preexisting mutex. {END} Four static mutexes are 4565** used by the current version of SQLite. Future versions of SQLite 4566** may add additional static mutexes. Static mutexes are for internal 4567** use by SQLite only. Applications that use SQLite mutexes should 4568** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 4569** SQLITE_MUTEX_RECURSIVE. 4570** 4571** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 4572** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 4573** returns a different mutex on every call. {H17034} But for the static 4574** mutex types, the same mutex is returned on every call that has 4575** the same type number. 4576** 4577** {H17019} The sqlite3_mutex_free() routine deallocates a previously 4578** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every 4579** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in 4580** use when they are deallocated. {A17022} Attempting to deallocate a static 4581** mutex results in undefined behavior. {H17023} SQLite never deallocates 4582** a static mutex. {END} 4583** 4584** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 4585** to enter a mutex. {H17024} If another thread is already within the mutex, 4586** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 4587** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] 4588** upon successful entry. {H17026} Mutexes created using 4589** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 4590** {H17027} In such cases the, 4591** mutex must be exited an equal number of times before another thread 4592** can enter. {A17028} If the same thread tries to enter any other 4593** kind of mutex more than once, the behavior is undefined. 4594** {H17029} SQLite will never exhibit 4595** such behavior in its own use of mutexes. 4596** 4597** Some systems (for example, Windows 95) do not support the operation 4598** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 4599** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses 4600** sqlite3_mutex_try() as an optimization so this is acceptable behavior. 4601** 4602** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was 4603** previously entered by the same thread. {A17032} The behavior 4604** is undefined if the mutex is not currently entered by the 4605** calling thread or is not currently allocated. {H17033} SQLite will 4606** never do either. {END} 4607** 4608** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 4609** sqlite3_mutex_leave() is a NULL pointer, then all three routines 4610** behave as no-ops. 4611** 4612** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 4613*/ 4614sqlite3_mutex *sqlite3_mutex_alloc(int); 4615void sqlite3_mutex_free(sqlite3_mutex*); 4616void sqlite3_mutex_enter(sqlite3_mutex*); 4617int sqlite3_mutex_try(sqlite3_mutex*); 4618void sqlite3_mutex_leave(sqlite3_mutex*); 4619 4620/* 4621** CAPI3REF: Mutex Methods Object {H17120} <S20130> 4622** EXPERIMENTAL 4623** 4624** An instance of this structure defines the low-level routines 4625** used to allocate and use mutexes. 4626** 4627** Usually, the default mutex implementations provided by SQLite are 4628** sufficient, however the user has the option of substituting a custom 4629** implementation for specialized deployments or systems for which SQLite 4630** does not provide a suitable implementation. In this case, the user 4631** creates and populates an instance of this structure to pass 4632** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 4633** Additionally, an instance of this structure can be used as an 4634** output variable when querying the system for the current mutex 4635** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 4636** 4637** The xMutexInit method defined by this structure is invoked as 4638** part of system initialization by the sqlite3_initialize() function. 4639** {H17001} The xMutexInit routine shall be called by SQLite once for each 4640** effective call to [sqlite3_initialize()]. 4641** 4642** The xMutexEnd method defined by this structure is invoked as 4643** part of system shutdown by the sqlite3_shutdown() function. The 4644** implementation of this method is expected to release all outstanding 4645** resources obtained by the mutex methods implementation, especially 4646** those obtained by the xMutexInit method. {H17003} The xMutexEnd() 4647** interface shall be invoked once for each call to [sqlite3_shutdown()]. 4648** 4649** The remaining seven methods defined by this structure (xMutexAlloc, 4650** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 4651** xMutexNotheld) implement the following interfaces (respectively): 4652** 4653** <ul> 4654** <li> [sqlite3_mutex_alloc()] </li> 4655** <li> [sqlite3_mutex_free()] </li> 4656** <li> [sqlite3_mutex_enter()] </li> 4657** <li> [sqlite3_mutex_try()] </li> 4658** <li> [sqlite3_mutex_leave()] </li> 4659** <li> [sqlite3_mutex_held()] </li> 4660** <li> [sqlite3_mutex_notheld()] </li> 4661** </ul> 4662** 4663** The only difference is that the public sqlite3_XXX functions enumerated 4664** above silently ignore any invocations that pass a NULL pointer instead 4665** of a valid mutex handle. The implementations of the methods defined 4666** by this structure are not required to handle this case, the results 4667** of passing a NULL pointer instead of a valid mutex handle are undefined 4668** (i.e. it is acceptable to provide an implementation that segfaults if 4669** it is passed a NULL pointer). 4670*/ 4671typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 4672struct sqlite3_mutex_methods { 4673 int (*xMutexInit)(void); 4674 int (*xMutexEnd)(void); 4675 sqlite3_mutex *(*xMutexAlloc)(int); 4676 void (*xMutexFree)(sqlite3_mutex *); 4677 void (*xMutexEnter)(sqlite3_mutex *); 4678 int (*xMutexTry)(sqlite3_mutex *); 4679 void (*xMutexLeave)(sqlite3_mutex *); 4680 int (*xMutexHeld)(sqlite3_mutex *); 4681 int (*xMutexNotheld)(sqlite3_mutex *); 4682}; 4683 4684/* 4685** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> 4686** 4687** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 4688** are intended for use inside assert() statements. {H17081} The SQLite core 4689** never uses these routines except inside an assert() and applications 4690** are advised to follow the lead of the core. {H17082} The core only 4691** provides implementations for these routines when it is compiled 4692** with the SQLITE_DEBUG flag. {A17087} External mutex implementations 4693** are only required to provide these routines if SQLITE_DEBUG is 4694** defined and if NDEBUG is not defined. 4695** 4696** {H17083} These routines should return true if the mutex in their argument 4697** is held or not held, respectively, by the calling thread. 4698** 4699** {X17084} The implementation is not required to provided versions of these 4700** routines that actually work. If the implementation does not provide working 4701** versions of these routines, it should at least provide stubs that always 4702** return true so that one does not get spurious assertion failures. 4703** 4704** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 4705** the routine should return 1. {END} This seems counter-intuitive since 4706** clearly the mutex cannot be held if it does not exist. But the 4707** the reason the mutex does not exist is because the build is not 4708** using mutexes. And we do not want the assert() containing the 4709** call to sqlite3_mutex_held() to fail, so a non-zero return is 4710** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() 4711** interface should also return 1 when given a NULL pointer. 4712*/ 4713int sqlite3_mutex_held(sqlite3_mutex*); 4714int sqlite3_mutex_notheld(sqlite3_mutex*); 4715 4716/* 4717** CAPI3REF: Mutex Types {H17001} <H17000> 4718** 4719** The [sqlite3_mutex_alloc()] interface takes a single argument 4720** which is one of these integer constants. 4721** 4722** The set of static mutexes may change from one SQLite release to the 4723** next. Applications that override the built-in mutex logic must be 4724** prepared to accommodate additional static mutexes. 4725*/ 4726#define SQLITE_MUTEX_FAST 0 4727#define SQLITE_MUTEX_RECURSIVE 1 4728#define SQLITE_MUTEX_STATIC_MASTER 2 4729#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 4730#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 4731#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 4732#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 4733#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 4734#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 4735 4736/* 4737** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> 4738** 4739** This interface returns a pointer the [sqlite3_mutex] object that 4740** serializes access to the [database connection] given in the argument 4741** when the [threading mode] is Serialized. 4742** If the [threading mode] is Single-thread or Multi-thread then this 4743** routine returns a NULL pointer. 4744*/ 4745sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 4746 4747/* 4748** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> 4749** 4750** {H11301} The [sqlite3_file_control()] interface makes a direct call to the 4751** xFileControl method for the [sqlite3_io_methods] object associated 4752** with a particular database identified by the second argument. {H11302} The 4753** name of the database is the name assigned to the database by the 4754** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 4755** database. {H11303} To control the main database file, use the name "main" 4756** or a NULL pointer. {H11304} The third and fourth parameters to this routine 4757** are passed directly through to the second and third parameters of 4758** the xFileControl method. {H11305} The return value of the xFileControl 4759** method becomes the return value of this routine. 4760** 4761** {H11306} If the second parameter (zDbName) does not match the name of any 4762** open database file, then SQLITE_ERROR is returned. {H11307} This error 4763** code is not remembered and will not be recalled by [sqlite3_errcode()] 4764** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might 4765** also return SQLITE_ERROR. {A11309} There is no way to distinguish between 4766** an incorrect zDbName and an SQLITE_ERROR return from the underlying 4767** xFileControl method. {END} 4768** 4769** See also: [SQLITE_FCNTL_LOCKSTATE] 4770*/ 4771int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 4772 4773/* 4774** CAPI3REF: Testing Interface {H11400} <S30800> 4775** 4776** The sqlite3_test_control() interface is used to read out internal 4777** state of SQLite and to inject faults into SQLite for testing 4778** purposes. The first parameter is an operation code that determines 4779** the number, meaning, and operation of all subsequent parameters. 4780** 4781** This interface is not for use by applications. It exists solely 4782** for verifying the correct operation of the SQLite library. Depending 4783** on how the SQLite library is compiled, this interface might not exist. 4784** 4785** The details of the operation codes, their meanings, the parameters 4786** they take, and what they do are all subject to change without notice. 4787** Unlike most of the SQLite API, this function is not guaranteed to 4788** operate consistently from one release to the next. 4789*/ 4790int sqlite3_test_control(int op, ...); 4791 4792/* 4793** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> 4794** 4795** These constants are the valid operation code parameters used 4796** as the first argument to [sqlite3_test_control()]. 4797** 4798** These parameters and their meanings are subject to change 4799** without notice. These values are for testing purposes only. 4800** Applications should not use any of these parameters or the 4801** [sqlite3_test_control()] interface. 4802*/ 4803#define SQLITE_TESTCTRL_PRNG_SAVE 5 4804#define SQLITE_TESTCTRL_PRNG_RESTORE 6 4805#define SQLITE_TESTCTRL_PRNG_RESET 7 4806#define SQLITE_TESTCTRL_BITVEC_TEST 8 4807#define SQLITE_TESTCTRL_FAULT_INSTALL 9 4808#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 4809#define SQLITE_TESTCTRL_PENDING_BYTE 11 4810 4811/* 4812** CAPI3REF: SQLite Runtime Status {H17200} <S60200> 4813** EXPERIMENTAL 4814** 4815** This interface is used to retrieve runtime status information 4816** about the preformance of SQLite, and optionally to reset various 4817** highwater marks. The first argument is an integer code for 4818** the specific parameter to measure. Recognized integer codes 4819** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. 4820** The current value of the parameter is returned into *pCurrent. 4821** The highest recorded value is returned in *pHighwater. If the 4822** resetFlag is true, then the highest record value is reset after 4823** *pHighwater is written. Some parameters do not record the highest 4824** value. For those parameters 4825** nothing is written into *pHighwater and the resetFlag is ignored. 4826** Other parameters record only the highwater mark and not the current 4827** value. For these latter parameters nothing is written into *pCurrent. 4828** 4829** This routine returns SQLITE_OK on success and a non-zero 4830** [error code] on failure. 4831** 4832** This routine is threadsafe but is not atomic. This routine can 4833** called while other threads are running the same or different SQLite 4834** interfaces. However the values returned in *pCurrent and 4835** *pHighwater reflect the status of SQLite at different points in time 4836** and it is possible that another thread might change the parameter 4837** in between the times when *pCurrent and *pHighwater are written. 4838** 4839** See also: [sqlite3_db_status()] 4840*/ 4841SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 4842 4843 4844/* 4845** CAPI3REF: Status Parameters {H17250} <H17200> 4846** EXPERIMENTAL 4847** 4848** These integer constants designate various run-time status parameters 4849** that can be returned by [sqlite3_status()]. 4850** 4851** <dl> 4852** <dt>SQLITE_STATUS_MEMORY_USED</dt> 4853** <dd>This parameter is the current amount of memory checked out 4854** using [sqlite3_malloc()], either directly or indirectly. The 4855** figure includes calls made to [sqlite3_malloc()] by the application 4856** and internal memory usage by the SQLite library. Scratch memory 4857** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 4858** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 4859** this parameter. The amount returned is the sum of the allocation 4860** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> 4861** 4862** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> 4863** <dd>This parameter records the largest memory allocation request 4864** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 4865** internal equivalents). Only the value returned in the 4866** *pHighwater parameter to [sqlite3_status()] is of interest. 4867** The value written into the *pCurrent parameter is undefined.</dd> 4868** 4869** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> 4870** <dd>This parameter returns the number of pages used out of the 4871** [pagecache memory allocator] that was configured using 4872** [SQLITE_CONFIG_PAGECACHE]. The 4873** value returned is in pages, not in bytes.</dd> 4874** 4875** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 4876** <dd>This parameter returns the number of bytes of page cache 4877** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] 4878** buffer and where forced to overflow to [sqlite3_malloc()]. The 4879** returned value includes allocations that overflowed because they 4880** where too large (they were larger than the "sz" parameter to 4881** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 4882** no space was left in the page cache.</dd> 4883** 4884** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 4885** <dd>This parameter records the largest memory allocation request 4886** handed to [pagecache memory allocator]. Only the value returned in the 4887** *pHighwater parameter to [sqlite3_status()] is of interest. 4888** The value written into the *pCurrent parameter is undefined.</dd> 4889** 4890** <dt>SQLITE_STATUS_SCRATCH_USED</dt> 4891** <dd>This parameter returns the number of allocations used out of the 4892** [scratch memory allocator] configured using 4893** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 4894** in bytes. Since a single thread may only have one scratch allocation 4895** outstanding at time, this parameter also reports the number of threads 4896** using scratch memory at the same time.</dd> 4897** 4898** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 4899** <dd>This parameter returns the number of bytes of scratch memory 4900** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] 4901** buffer and where forced to overflow to [sqlite3_malloc()]. The values 4902** returned include overflows because the requested allocation was too 4903** larger (that is, because the requested allocation was larger than the 4904** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 4905** slots were available. 4906** </dd> 4907** 4908** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 4909** <dd>This parameter records the largest memory allocation request 4910** handed to [scratch memory allocator]. Only the value returned in the 4911** *pHighwater parameter to [sqlite3_status()] is of interest. 4912** The value written into the *pCurrent parameter is undefined.</dd> 4913** 4914** <dt>SQLITE_STATUS_PARSER_STACK</dt> 4915** <dd>This parameter records the deepest parser stack. It is only 4916** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> 4917** </dl> 4918** 4919** New status parameters may be added from time to time. 4920*/ 4921#define SQLITE_STATUS_MEMORY_USED 0 4922#define SQLITE_STATUS_PAGECACHE_USED 1 4923#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 4924#define SQLITE_STATUS_SCRATCH_USED 3 4925#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 4926#define SQLITE_STATUS_MALLOC_SIZE 5 4927#define SQLITE_STATUS_PARSER_STACK 6 4928#define SQLITE_STATUS_PAGECACHE_SIZE 7 4929#define SQLITE_STATUS_SCRATCH_SIZE 8 4930 4931/* 4932** CAPI3REF: Database Connection Status {H17500} <S60200> 4933** EXPERIMENTAL 4934** 4935** This interface is used to retrieve runtime status information 4936** about a single [database connection]. The first argument is the 4937** database connection object to be interrogated. The second argument 4938** is the parameter to interrogate. Currently, the only allowed value 4939** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. 4940** Additional options will likely appear in future releases of SQLite. 4941** 4942** The current value of the requested parameter is written into *pCur 4943** and the highest instantaneous value is written into *pHiwtr. If 4944** the resetFlg is true, then the highest instantaneous value is 4945** reset back down to the current value. 4946** 4947** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 4948*/ 4949SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 4950 4951/* 4952** CAPI3REF: Status Parameters for database connections {H17520} <H17500> 4953** EXPERIMENTAL 4954** 4955** Status verbs for [sqlite3_db_status()]. 4956** 4957** <dl> 4958** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 4959** <dd>This parameter returns the number of lookaside memory slots currently 4960** checked out.</dd> 4961** </dl> 4962*/ 4963#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 4964 4965 4966/* 4967** CAPI3REF: Prepared Statement Status {H17550} <S60200> 4968** EXPERIMENTAL 4969** 4970** Each prepared statement maintains various 4971** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 4972** of times it has performed specific operations. These counters can 4973** be used to monitor the performance characteristics of the prepared 4974** statements. For example, if the number of table steps greatly exceeds 4975** the number of table searches or result rows, that would tend to indicate 4976** that the prepared statement is using a full table scan rather than 4977** an index. 4978** 4979** This interface is used to retrieve and reset counter values from 4980** a [prepared statement]. The first argument is the prepared statement 4981** object to be interrogated. The second argument 4982** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 4983** to be interrogated. 4984** The current value of the requested counter is returned. 4985** If the resetFlg is true, then the counter is reset to zero after this 4986** interface call returns. 4987** 4988** See also: [sqlite3_status()] and [sqlite3_db_status()]. 4989*/ 4990SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 4991 4992/* 4993** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> 4994** EXPERIMENTAL 4995** 4996** These preprocessor macros define integer codes that name counter 4997** values associated with the [sqlite3_stmt_status()] interface. 4998** The meanings of the various counters are as follows: 4999** 5000** <dl> 5001** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5002** <dd>This is the number of times that SQLite has stepped forward in 5003** a table as part of a full table scan. Large numbers for this counter 5004** may indicate opportunities for performance improvement through 5005** careful use of indices.</dd> 5006** 5007** <dt>SQLITE_STMTSTATUS_SORT</dt> 5008** <dd>This is the number of sort operations that have occurred. 5009** A non-zero value in this counter may indicate an opportunity to 5010** improvement performance through careful use of indices.</dd> 5011** 5012** </dl> 5013*/ 5014#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5015#define SQLITE_STMTSTATUS_SORT 2 5016 5017/* 5018** CAPI3REF: Custom Page Cache Object 5019** EXPERIMENTAL 5020** 5021** The sqlite3_pcache type is opaque. It is implemented by 5022** the pluggable module. The SQLite core has no knowledge of 5023** its size or internal structure and never deals with the 5024** sqlite3_pcache object except by holding and passing pointers 5025** to the object. 5026** 5027** See [sqlite3_pcache_methods] for additional information. 5028*/ 5029typedef struct sqlite3_pcache sqlite3_pcache; 5030 5031/* 5032** CAPI3REF: Application Defined Page Cache. 5033** EXPERIMENTAL 5034** 5035** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5036** register an alternative page cache implementation by passing in an 5037** instance of the sqlite3_pcache_methods structure. The majority of the 5038** heap memory used by sqlite is used by the page cache to cache data read 5039** from, or ready to be written to, the database file. By implementing a 5040** custom page cache using this API, an application can control more 5041** precisely the amount of memory consumed by sqlite, the way in which 5042** said memory is allocated and released, and the policies used to 5043** determine exactly which parts of a database file are cached and for 5044** how long. 5045** 5046** The contents of the structure are copied to an internal buffer by sqlite 5047** within the call to [sqlite3_config]. 5048** 5049** The xInit() method is called once for each call to [sqlite3_initialize()] 5050** (usually only once during the lifetime of the process). It is passed 5051** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set 5052** up global structures and mutexes required by the custom page cache 5053** implementation. The xShutdown() method is called from within 5054** [sqlite3_shutdown()], if the application invokes this API. It can be used 5055** to clean up any outstanding resources before process shutdown, if required. 5056** 5057** The xCreate() method is used to construct a new cache instance. The 5058** first parameter, szPage, is the size in bytes of the pages that must 5059** be allocated by the cache. szPage will not be a power of two. The 5060** second argument, bPurgeable, is true if the cache being created will 5061** be used to cache database pages read from a file stored on disk, or 5062** false if it is used for an in-memory database. The cache implementation 5063** does not have to do anything special based on the value of bPurgeable, 5064** it is purely advisory. 5065** 5066** The xCachesize() method may be called at any time by SQLite to set the 5067** suggested maximum cache-size (number of pages stored by) the cache 5068** instance passed as the first argument. This is the value configured using 5069** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, 5070** the implementation is not required to do anything special with this 5071** value, it is advisory only. 5072** 5073** The xPagecount() method should return the number of pages currently 5074** stored in the cache supplied as an argument. 5075** 5076** The xFetch() method is used to fetch a page and return a pointer to it. 5077** A 'page', in this context, is a buffer of szPage bytes aligned at an 5078** 8-byte boundary. The page to be fetched is determined by the key. The 5079** mimimum key value is 1. After it has been retrieved using xFetch, the page 5080** is considered to be pinned. 5081** 5082** If the requested page is already in the page cache, then a pointer to 5083** the cached buffer should be returned with its contents intact. If the 5084** page is not already in the cache, then the expected behaviour of the 5085** cache is determined by the value of the createFlag parameter passed 5086** to xFetch, according to the following table: 5087** 5088** <table border=1 width=85% align=center> 5089** <tr><th>createFlag<th>Expected Behaviour 5090** <tr><td>0<td>NULL should be returned. No new cache entry is created. 5091** <tr><td>1<td>If createFlag is set to 1, this indicates that 5092** SQLite is holding pinned pages that can be unpinned 5093** by writing their contents to the database file (a 5094** relatively expensive operation). In this situation the 5095** cache implementation has two choices: it can return NULL, 5096** in which case SQLite will attempt to unpin one or more 5097** pages before re-requesting the same page, or it can 5098** allocate a new page and return a pointer to it. If a new 5099** page is allocated, then the first sizeof(void*) bytes of 5100** it (at least) must be zeroed before it is returned. 5101** <tr><td>2<td>If createFlag is set to 2, then SQLite is not holding any 5102** pinned pages associated with the specific cache passed 5103** as the first argument to xFetch() that can be unpinned. The 5104** cache implementation should attempt to allocate a new 5105** cache entry and return a pointer to it. Again, the first 5106** sizeof(void*) bytes of the page should be zeroed before 5107** it is returned. If the xFetch() method returns NULL when 5108** createFlag==2, SQLite assumes that a memory allocation 5109** failed and returns SQLITE_NOMEM to the user. 5110** </table> 5111** 5112** xUnpin() is called by SQLite with a pointer to a currently pinned page 5113** as its second argument. If the third parameter, discard, is non-zero, 5114** then the page should be evicted from the cache. In this case SQLite 5115** assumes that the next time the page is retrieved from the cache using 5116** the xFetch() method, it will be zeroed. If the discard parameter is 5117** zero, then the page is considered to be unpinned. The cache implementation 5118** may choose to reclaim (free or recycle) unpinned pages at any time. 5119** SQLite assumes that next time the page is retrieved from the cache 5120** it will either be zeroed, or contain the same data that it did when it 5121** was unpinned. 5122** 5123** The cache is not required to perform any reference counting. A single 5124** call to xUnpin() unpins the page regardless of the number of prior calls 5125** to xFetch(). 5126** 5127** The xRekey() method is used to change the key value associated with the 5128** page passed as the second argument from oldKey to newKey. If the cache 5129** previously contains an entry associated with newKey, it should be 5130** discarded. Any prior cache entry associated with newKey is guaranteed not 5131** to be pinned. 5132** 5133** When SQLite calls the xTruncate() method, the cache must discard all 5134** existing cache entries with page numbers (keys) greater than or equal 5135** to the value of the iLimit parameter passed to xTruncate(). If any 5136** of these pages are pinned, they are implicitly unpinned, meaning that 5137** they can be safely discarded. 5138** 5139** The xDestroy() method is used to delete a cache allocated by xCreate(). 5140** All resources associated with the specified cache should be freed. After 5141** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5142** handle invalid, and will not use it with any other sqlite3_pcache_methods 5143** functions. 5144*/ 5145typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5146struct sqlite3_pcache_methods { 5147 void *pArg; 5148 int (*xInit)(void*); 5149 void (*xShutdown)(void*); 5150 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5151 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5152 int (*xPagecount)(sqlite3_pcache*); 5153 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5154 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5155 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5156 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5157 void (*xDestroy)(sqlite3_pcache*); 5158}; 5159 5160/* 5161** CAPI3REF: Online Backup Object 5162** EXPERIMENTAL 5163** 5164** The sqlite3_backup object records state information about an ongoing 5165** online backup operation. The sqlite3_backup object is created by 5166** a call to [sqlite3_backup_init()] and is destroyed by a call to 5167** [sqlite3_backup_finish()]. 5168** 5169** See Also: [Using the SQLite Online Backup API] 5170*/ 5171typedef struct sqlite3_backup sqlite3_backup; 5172 5173/* 5174** CAPI3REF: Online Backup API. 5175** EXPERIMENTAL 5176** 5177** This API is used to overwrite the contents of one database with that 5178** of another. It is useful either for creating backups of databases or 5179** for copying in-memory databases to or from persistent files. 5180** 5181** See Also: [Using the SQLite Online Backup API] 5182** 5183** Exclusive access is required to the destination database for the 5184** duration of the operation. However the source database is only 5185** read-locked while it is actually being read, it is not locked 5186** continuously for the entire operation. Thus, the backup may be 5187** performed on a live database without preventing other users from 5188** writing to the database for an extended period of time. 5189** 5190** To perform a backup operation: 5191** <ol> 5192** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5193** backup, 5194** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5195** the data between the two databases, and finally 5196** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5197** associated with the backup operation. 5198** </ol> 5199** There should be exactly one call to sqlite3_backup_finish() for each 5200** successful call to sqlite3_backup_init(). 5201** 5202** <b>sqlite3_backup_init()</b> 5203** 5204** The first two arguments passed to [sqlite3_backup_init()] are the database 5205** handle associated with the destination database and the database name 5206** used to attach the destination database to the handle. The database name 5207** is "main" for the main database, "temp" for the temporary database, or 5208** the name specified as part of the [ATTACH] statement if the destination is 5209** an attached database. The third and fourth arguments passed to 5210** sqlite3_backup_init() identify the [database connection] 5211** and database name used 5212** to access the source database. The values passed for the source and 5213** destination [database connection] parameters must not be the same. 5214** 5215** If an error occurs within sqlite3_backup_init(), then NULL is returned 5216** and an error code and error message written into the [database connection] 5217** passed as the first argument. They may be retrieved using the 5218** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. 5219** Otherwise, if successful, a pointer to an [sqlite3_backup] object is 5220** returned. This pointer may be used with the sqlite3_backup_step() and 5221** sqlite3_backup_finish() functions to perform the specified backup 5222** operation. 5223** 5224** <b>sqlite3_backup_step()</b> 5225** 5226** Function [sqlite3_backup_step()] is used to copy up to nPage pages between 5227** the source and destination databases, where nPage is the value of the 5228** second parameter passed to sqlite3_backup_step(). If nPage is a negative 5229** value, all remaining source pages are copied. If the required pages are 5230** succesfully copied, but there are still more pages to copy before the 5231** backup is complete, it returns [SQLITE_OK]. If no error occured and there 5232** are no more pages to copy, then [SQLITE_DONE] is returned. If an error 5233** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and 5234** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5235** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5236** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5237** 5238** As well as the case where the destination database file was opened for 5239** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if 5240** the destination is an in-memory database with a different page size 5241** from the source database. 5242** 5243** If sqlite3_backup_step() cannot obtain a required file-system lock, then 5244** the [sqlite3_busy_handler | busy-handler function] 5245** is invoked (if one is specified). If the 5246** busy-handler returns non-zero before the lock is available, then 5247** [SQLITE_BUSY] is returned to the caller. In this case the call to 5248** sqlite3_backup_step() can be retried later. If the source 5249** [database connection] 5250** is being used to write to the source database when sqlite3_backup_step() 5251** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this 5252** case the call to sqlite3_backup_step() can be retried later on. If 5253** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5254** [SQLITE_READONLY] is returned, then 5255** there is no point in retrying the call to sqlite3_backup_step(). These 5256** errors are considered fatal. At this point the application must accept 5257** that the backup operation has failed and pass the backup operation handle 5258** to the sqlite3_backup_finish() to release associated resources. 5259** 5260** Following the first call to sqlite3_backup_step(), an exclusive lock is 5261** obtained on the destination file. It is not released until either 5262** sqlite3_backup_finish() is called or the backup operation is complete 5263** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time 5264** a call to sqlite3_backup_step() is made a [shared lock] is obtained on 5265** the source database file. This lock is released before the 5266** sqlite3_backup_step() call returns. Because the source database is not 5267** locked between calls to sqlite3_backup_step(), it may be modified mid-way 5268** through the backup procedure. If the source database is modified by an 5269** external process or via a database connection other than the one being 5270** used by the backup operation, then the backup will be transparently 5271** restarted by the next call to sqlite3_backup_step(). If the source 5272** database is modified by the using the same database connection as is used 5273** by the backup operation, then the backup database is transparently 5274** updated at the same time. 5275** 5276** <b>sqlite3_backup_finish()</b> 5277** 5278** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5279** application wishes to abandon the backup operation, the [sqlite3_backup] 5280** object should be passed to sqlite3_backup_finish(). This releases all 5281** resources associated with the backup operation. If sqlite3_backup_step() 5282** has not yet returned [SQLITE_DONE], then any active write-transaction on the 5283** destination database is rolled back. The [sqlite3_backup] object is invalid 5284** and may not be used following a call to sqlite3_backup_finish(). 5285** 5286** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error 5287** occurred, regardless or whether or not sqlite3_backup_step() was called 5288** a sufficient number of times to complete the backup operation. Or, if 5289** an out-of-memory condition or IO error occured during a call to 5290** sqlite3_backup_step() then [SQLITE_NOMEM] or an 5291** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code 5292** is returned. In this case the error code and an error message are 5293** written to the destination [database connection]. 5294** 5295** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is 5296** not a permanent error and does not affect the return value of 5297** sqlite3_backup_finish(). 5298** 5299** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 5300** 5301** Each call to sqlite3_backup_step() sets two values stored internally 5302** by an [sqlite3_backup] object. The number of pages still to be backed 5303** up, which may be queried by sqlite3_backup_remaining(), and the total 5304** number of pages in the source database file, which may be queried by 5305** sqlite3_backup_pagecount(). 5306** 5307** The values returned by these functions are only updated by 5308** sqlite3_backup_step(). If the source database is modified during a backup 5309** operation, then the values are not updated to account for any extra 5310** pages that need to be updated or the size of the source database file 5311** changing. 5312** 5313** <b>Concurrent Usage of Database Handles</b> 5314** 5315** The source [database connection] may be used by the application for other 5316** purposes while a backup operation is underway or being initialized. 5317** If SQLite is compiled and configured to support threadsafe database 5318** connections, then the source database connection may be used concurrently 5319** from within other threads. 5320** 5321** However, the application must guarantee that the destination database 5322** connection handle is not passed to any other API (by any thread) after 5323** sqlite3_backup_init() is called and before the corresponding call to 5324** sqlite3_backup_finish(). Unfortunately SQLite does not currently check 5325** for this, if the application does use the destination [database connection] 5326** for some other purpose during a backup operation, things may appear to 5327** work correctly but in fact be subtly malfunctioning. Use of the 5328** destination database connection while a backup is in progress might 5329** also cause a mutex deadlock. 5330** 5331** Furthermore, if running in [shared cache mode], the application must 5332** guarantee that the shared cache used by the destination database 5333** is not accessed while the backup is running. In practice this means 5334** that the application must guarantee that the file-system file being 5335** backed up to is not accessed by any connection within the process, 5336** not just the specific connection that was passed to sqlite3_backup_init(). 5337** 5338** The [sqlite3_backup] object itself is partially threadsafe. Multiple 5339** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 5340** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 5341** APIs are not strictly speaking threadsafe. If they are invoked at the 5342** same time as another thread is invoking sqlite3_backup_step() it is 5343** possible that they return invalid values. 5344*/ 5345sqlite3_backup *sqlite3_backup_init( 5346 sqlite3 *pDest, /* Destination database handle */ 5347 const char *zDestName, /* Destination database name */ 5348 sqlite3 *pSource, /* Source database handle */ 5349 const char *zSourceName /* Source database name */ 5350); 5351int sqlite3_backup_step(sqlite3_backup *p, int nPage); 5352int sqlite3_backup_finish(sqlite3_backup *p); 5353int sqlite3_backup_remaining(sqlite3_backup *p); 5354int sqlite3_backup_pagecount(sqlite3_backup *p); 5355 5356/* 5357** CAPI3REF: Unlock Notification 5358** EXPERIMENTAL 5359** 5360** When running in shared-cache mode, a database operation may fail with 5361** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 5362** individual tables within the shared-cache cannot be obtained. See 5363** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 5364** This API may be used to register a callback that SQLite will invoke 5365** when the connection currently holding the required lock relinquishes it. 5366** This API is only available if the library was compiled with the 5367** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 5368** 5369** See Also: [Using the SQLite Unlock Notification Feature]. 5370** 5371** Shared-cache locks are released when a database connection concludes 5372** its current transaction, either by committing it or rolling it back. 5373** 5374** When a connection (known as the blocked connection) fails to obtain a 5375** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 5376** identity of the database connection (the blocking connection) that 5377** has locked the required resource is stored internally. After an 5378** application receives an SQLITE_LOCKED error, it may call the 5379** sqlite3_unlock_notify() method with the blocked connection handle as 5380** the first argument to register for a callback that will be invoked 5381** when the blocking connections current transaction is concluded. The 5382** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 5383** call that concludes the blocking connections transaction. 5384** 5385** If sqlite3_unlock_notify() is called in a multi-threaded application, 5386** there is a chance that the blocking connection will have already 5387** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 5388** If this happens, then the specified callback is invoked immediately, 5389** from within the call to sqlite3_unlock_notify(). 5390** 5391** If the blocked connection is attempting to obtain a write-lock on a 5392** shared-cache table, and more than one other connection currently holds 5393** a read-lock on the same table, then SQLite arbitrarily selects one of 5394** the other connections to use as the blocking connection. 5395** 5396** There may be at most one unlock-notify callback registered by a 5397** blocked connection. If sqlite3_unlock_notify() is called when the 5398** blocked connection already has a registered unlock-notify callback, 5399** then the new callback replaces the old. If sqlite3_unlock_notify() is 5400** called with a NULL pointer as its second argument, then any existing 5401** unlock-notify callback is cancelled. The blocked connections 5402** unlock-notify callback may also be canceled by closing the blocked 5403** connection using [sqlite3_close()]. 5404** 5405** The unlock-notify callback is not reentrant. If an application invokes 5406** any sqlite3_xxx API functions from within an unlock-notify callback, a 5407** crash or deadlock may be the result. 5408** 5409** Unless deadlock is detected (see below), sqlite3_unlock_notify() always 5410** returns SQLITE_OK. 5411** 5412** <b>Callback Invocation Details</b> 5413** 5414** When an unlock-notify callback is registered, the application provides a 5415** single void* pointer that is passed to the callback when it is invoked. 5416** However, the signature of the callback function allows SQLite to pass 5417** it an array of void* context pointers. The first argument passed to 5418** an unlock-notify callback is a pointer to an array of void* pointers, 5419** and the second is the number of entries in the array. 5420** 5421** When a blocking connections transaction is concluded, there may be 5422** more than one blocked connection that has registered for an unlock-notify 5423** callback. If two or more such blocked connections have specified the 5424** same callback function, then instead of invoking the callback function 5425** multiple times, it is invoked once with the set of void* context pointers 5426** specified by the blocked connections bundled together into an array. 5427** This gives the application an opportunity to prioritize any actions 5428** related to the set of unblocked database connections. 5429** 5430** <b>Deadlock Detection</b> 5431** 5432** Assuming that after registering for an unlock-notify callback a 5433** database waits for the callback to be issued before taking any further 5434** action (a reasonable assumption), then using this API may cause the 5435** application to deadlock. For example, if connection X is waiting for 5436** connection Y's transaction to be concluded, and similarly connection 5437** Y is waiting on connection X's transaction, then neither connection 5438** will proceed and the system may remain deadlocked indefinitely. 5439** 5440** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 5441** detection. If a given call to sqlite3_unlock_notify() would put the 5442** system in a deadlocked state, then SQLITE_LOCKED is returned and no 5443** unlock-notify callback is registered. The system is said to be in 5444** a deadlocked state if connection A has registered for an unlock-notify 5445** callback on the conclusion of connection B's transaction, and connection 5446** B has itself registered for an unlock-notify callback when connection 5447** A's transaction is concluded. Indirect deadlock is also detected, so 5448** the system is also considered to be deadlocked if connection B has 5449** registered for an unlock-notify callback on the conclusion of connection 5450** C's transaction, where connection C is waiting on connection A. Any 5451** number of levels of indirection are allowed. 5452** 5453** <b>The "DROP TABLE" Exception</b> 5454** 5455** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 5456** always appropriate to call sqlite3_unlock_notify(). There is however, 5457** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 5458** SQLite checks if there are any currently executing SELECT statements 5459** that belong to the same connection. If there are, SQLITE_LOCKED is 5460** returned. In this case there is no "blocking connection", so invoking 5461** sqlite3_unlock_notify() results in the unlock-notify callback being 5462** invoked immediately. If the application then re-attempts the "DROP TABLE" 5463** or "DROP INDEX" query, an infinite loop might be the result. 5464** 5465** One way around this problem is to check the extended error code returned 5466** by an sqlite3_step() call. If there is a blocking connection, then the 5467** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 5468** the special "DROP TABLE/INDEX" case, the extended error code is just 5469** SQLITE_LOCKED. 5470*/ 5471int sqlite3_unlock_notify( 5472 sqlite3 *pBlocked, /* Waiting connection */ 5473 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 5474 void *pNotifyArg /* Argument to pass to xNotify */ 5475); 5476 5477/* 5478** Undo the hack that converts floating point types to integer for 5479** builds on processors without floating point support. 5480*/ 5481#ifdef SQLITE_OMIT_FLOATING_POINT 5482# undef double 5483#endif 5484 5485#ifdef __cplusplus 5486} /* End of the 'extern "C"' block */ 5487#endif 5488#endif 5489