includes/db/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * @file
   7  * @ingroup Database
   8  */
   9
  10 /**
  11  * @ingroup Database
  12  */
  13 class DatabaseSqlite extends DatabaseBase {
  14
  15         private static $fulltextEnabled = null;
  16
  17         var $mAffectedRows;
  18         var $mLastResult;
  19         var $mDatabaseFile;
  20         var $mName;
  21
  22         /**
  23          * @var PDO
  24          */
  25         protected $mConn;
  26
  27         /**
  28          * Constructor.
  29          * Parameters $server, $user and $password are not used.
  30          * @param $server string
  31          * @param $user string
  32          * @param $password string
  33          * @param $dbName string
  34          * @param $flags int
  35          */
  36         function __construct( $server = false, $user = false, $password = false, $dbName = false, $flags = 0 ) {
  37                 $this->mName = $dbName;
  38                 parent::__construct( $server, $user, $password, $dbName, $flags );
  39                 // parent doesn't open when $user is false, but we can work with $dbName
  40                 if( $dbName ) {
  41                         global $wgSharedDB;
  42                         if( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  43                                 $this->attachDatabase( $wgSharedDB );
  44                         }
  45                 }
  46         }
  47
  48         /**
  49          * @return string
  50          */
  51         function getType() {
  52                 return 'sqlite';
  53         }
  54
  55         /**
  56          * @todo: check if it should be true like parent class
  57          *
  58          * @return bool
  59          */
  60         function implicitGroupby() {
  61                 return false;
  62         }
  63
  64         /** Open an SQLite database and return a resource handle to it
  65          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  66          *
  67          * @param $server
  68          * @param $user
  69          * @param $pass
  70          * @param $dbName
  71          *
  72          * @return PDO
  73          */
  74         function open( $server, $user, $pass, $dbName ) {
  75                 global $wgSQLiteDataDir;
  76
  77                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  78                 if ( !is_readable( $fileName ) ) {
  79                         $this->mConn = false;
  80                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  81                 }
  82                 $this->openFile( $fileName );
  83                 return $this->mConn;
  84         }
  85
  86         /**
  87          * Opens a database file
  88          *
  89          * @param $fileName string
  90          *
  91          * @return PDO|bool SQL connection or false if failed
  92          */
  93         function openFile( $fileName ) {
  94                 $this->mDatabaseFile = $fileName;
  95                 try {
  96                         if ( $this->mFlags & DBO_PERSISTENT ) {
  97                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  98                                         array( PDO::ATTR_PERSISTENT => true ) );
  99                         } else {
 100                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 101                         }
 102                 } catch ( PDOException $e ) {
 103                         $err = $e->getMessage();
 104                 }
 105                 if ( !$this->mConn ) {
 106                         wfDebug( "DB connection error: $err\n" );
 107                         throw new DBConnectionError( $this, $err );
 108                 }
 109                 $this->mOpened = !!$this->mConn;
 110                 # set error codes only, don't raise exceptions
 111                 if ( $this->mOpened ) {
 112                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 113                         return true;
 114                 }
 115         }
 116
 117         /**
 118          * Close an SQLite database
 119          *
 120          * @return bool
 121          */
 122         function close() {
 123                 $this->mOpened = false;
 124                 if ( is_object( $this->mConn ) ) {
 125                         if ( $this->trxLevel() ) $this->commit();
 126                         $this->mConn = null;
 127                 }
 128                 return true;
 129         }
 130
 131         /**
 132          * Generates a database file name. Explicitly public for installer.
 133          * @param $dir String: Directory where database resides
 134          * @param $dbName String: Database name
 135          * @return String
 136          */
 137         public static function generateFileName( $dir, $dbName ) {
 138                 return "$dir/$dbName.sqlite";
 139         }
 140
 141         /**
 142          * Check if the searchindext table is FTS enabled.
 143          * @return bool if not enabled.
 144          */
 145         function checkForEnabledSearch() {
 146                 if ( self::$fulltextEnabled === null ) {
 147                         self::$fulltextEnabled = false;
 148                         $table = $this->tableName( 'searchindex' );
 149                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 150                         if ( $res ) {
 151                                 $row = $res->fetchRow();
 152                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 153                         }
 154                 }
 155                 return self::$fulltextEnabled;
 156         }
 157
 158         /**
 159          * Returns version of currently supported SQLite fulltext search module or false if none present.
 160          * @return String
 161          */
 162         static function getFulltextSearchModule() {
 163                 static $cachedResult = null;
 164                 if ( $cachedResult !== null ) {
 165                         return $cachedResult;
 166                 }
 167                 $cachedResult = false;
 168                 $table = 'dummy_search_test';
 169
 170                 $db = new DatabaseSqliteStandalone( ':memory:' );
 171
 172                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 173                         $cachedResult = 'FTS3';
 174                 }
 175                 $db->close();
 176                 return $cachedResult;
 177         }
 178
 179         /**
 180          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 181          * for details.
 182          *
 183          * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
 184          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 185          * @param $fname String: calling function name
 186          *
 187          * @return ResultWrapper
 188          */
 189         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 190                 global $wgSQLiteDataDir;
 191                 if ( !$file ) {
 192                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 193                 }
 194                 $file = $this->addQuotes( $file );
 195                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 196         }
 197
 198         /**
 199          * @see DatabaseBase::isWriteQuery()
 200          *
 201          * @param $sql string
 202          *
 203          * @return bool
 204          */
 205         function isWriteQuery( $sql ) {
 206                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 207         }
 208
 209         /**
 210          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 211          *
 212          * @param $sql string
 213          *
 214          * @return ResultWrapper
 215          */
 216         protected function doQuery( $sql ) {
 217                 $res = $this->mConn->query( $sql );
 218                 if ( $res === false ) {
 219                         return false;
 220                 } else {
 221                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 222                         $this->mAffectedRows = $r->rowCount();
 223                         $res = new ResultWrapper( $this, $r->fetchAll() );
 224                 }
 225                 return $res;
 226         }
 227
 228         /**
 229          * @param $res ResultWrapper
 230          */
 231         function freeResult( $res ) {
 232                 if ( $res instanceof ResultWrapper ) {
 233                         $res->result = null;
 234                 } else {
 235                         $res = null;
 236                 }
 237         }
 238
 239         /**
 240          * @param $res ResultWrapper
 241          * @return
 242          */
 243         function fetchObject( $res ) {
 244                 if ( $res instanceof ResultWrapper ) {
 245                         $r =& $res->result;
 246                 } else {
 247                         $r =& $res;
 248                 }
 249
 250                 $cur = current( $r );
 251                 if ( is_array( $cur ) ) {
 252                         next( $r );
 253                         $obj = new stdClass;
 254                         foreach ( $cur as $k => $v ) {
 255                                 if ( !is_numeric( $k ) ) {
 256                                         $obj->$k = $v;
 257                                 }
 258                         }
 259
 260                         return $obj;
 261                 }
 262                 return false;
 263         }
 264
 265         /**
 266          * @param $res ResultWrapper
 267          * @return bool|mixed
 268          */
 269         function fetchRow( $res ) {
 270                 if ( $res instanceof ResultWrapper ) {
 271                         $r =& $res->result;
 272                 } else {
 273                         $r =& $res;
 274                 }
 275                 $cur = current( $r );
 276                 if ( is_array( $cur ) ) {
 277                         next( $r );
 278                         return $cur;
 279                 }
 280                 return false;
 281         }
 282
 283         /**
 284          * The PDO::Statement class implements the array interface so count() will work
 285          *
 286          * @param $res ResultWrapper
 287          *
 288          * @return int
 289          */
 290         function numRows( $res ) {
 291                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 292                 return count( $r );
 293         }
 294
 295         /**
 296          * @param $res ResultWrapper
 297          * @return int
 298          */
 299         function numFields( $res ) {
 300                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 301                 return is_array( $r ) ? count( $r[0] ) : 0;
 302         }
 303
 304         /**
 305          * @param $res ResultWrapper
 306          * @param $n
 307          * @return bool
 308          */
 309         function fieldName( $res, $n ) {
 310                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 311                 if ( is_array( $r ) ) {
 312                         $keys = array_keys( $r[0] );
 313                         return $keys[$n];
 314                 }
 315                 return false;
 316         }
 317
 318         /**
 319          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 320          *
 321          * @param $name
 322          * @param $format String
 323          * @return string
 324          */
 325         function tableName( $name, $format = 'quoted' ) {
 326                 // table names starting with sqlite_ are reserved
 327                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 328                         return $name;
 329                 }
 330                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 331         }
 332
 333         /**
 334          * Index names have DB scope
 335          *
 336          * @param $index string
 337          *
 338          * @return string
 339          */
 340         function indexName( $index ) {
 341                 return $index;
 342         }
 343
 344         /**
 345          * This must be called after nextSequenceVal
 346          *
 347          * @return int
 348          */
 349         function insertId() {
 350                 return $this->mConn->lastInsertId();
 351         }
 352
 353         /**
 354          * @param $res ResultWrapper
 355          * @param $row
 356          */
 357         function dataSeek( $res, $row ) {
 358                 if ( $res instanceof ResultWrapper ) {
 359                         $r =& $res->result;
 360                 } else {
 361                         $r =& $res;
 362                 }
 363                 reset( $r );
 364                 if ( $row > 0 ) {
 365                         for ( $i = 0; $i < $row; $i++ ) {
 366                                 next( $r );
 367                         }
 368                 }
 369         }
 370
 371         /**
 372          * @return string
 373          */
 374         function lastError() {
 375                 if ( !is_object( $this->mConn ) ) {
 376                         return "Cannot return last error, no db connection";
 377                 }
 378                 $e = $this->mConn->errorInfo();
 379                 return isset( $e[2] ) ? $e[2] : '';
 380         }
 381
 382         /**
 383          * @return string
 384          */
 385         function lastErrno() {
 386                 if ( !is_object( $this->mConn ) ) {
 387                         return "Cannot return last error, no db connection";
 388                 } else {
 389                         $info = $this->mConn->errorInfo();
 390                         return $info[1];
 391                 }
 392         }
 393
 394         /**
 395          * @return int
 396          */
 397         function affectedRows() {
 398                 return $this->mAffectedRows;
 399         }
 400
 401         /**
 402          * Returns information about an index
 403          * Returns false if the index does not exist
 404          * - if errors are explicitly ignored, returns NULL on failure
 405          *
 406          * @return array
 407          */
 408         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 409                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 410                 $res = $this->query( $sql, $fname );
 411                 if ( !$res ) {
 412                         return null;
 413                 }
 414                 if ( $res->numRows() == 0 ) {
 415                         return false;
 416                 }
 417                 $info = array();
 418                 foreach ( $res as $row ) {
 419                         $info[] = $row->name;
 420                 }
 421                 return $info;
 422         }
 423
 424         /**
 425          * @param $table
 426          * @param $index
 427          * @param $fname string
 428          * @return bool|null
 429          */
 430         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 431                 $row = $this->selectRow( 'sqlite_master', '*',
 432                         array(
 433                                 'type' => 'index',
 434                                 'name' => $this->indexName( $index ),
 435                         ), $fname );
 436                 if ( !$row || !isset( $row->sql ) ) {
 437                         return null;
 438                 }
 439
 440                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 441                 $indexPos = strpos( $row->sql, 'INDEX' );
 442                 if ( $indexPos === false ) {
 443                         return null;
 444                 }
 445                 $firstPart = substr( $row->sql, 0, $indexPos );
 446                 $options = explode( ' ', $firstPart );
 447                 return in_array( 'UNIQUE', $options );
 448         }
 449
 450         /**
 451          * Filter the options used in SELECT statements
 452          *
 453          * @param $options array
 454          *
 455          * @return array
 456          */
 457         function makeSelectOptions( $options ) {
 458                 foreach ( $options as $k => $v ) {
 459                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 460                                 $options[$k] = '';
 461                         }
 462                 }
 463                 return parent::makeSelectOptions( $options );
 464         }
 465
 466         /**
 467          * @param $options array
 468          * @return string
 469          */
 470         function makeUpdateOptions( $options ) {
 471                 $options = self::fixIgnore( $options );
 472                 return parent::makeUpdateOptions( $options );
 473         }
 474
 475         /**
 476          * @param $options array
 477          * @return array
 478          */
 479         static function fixIgnore( $options ) {
 480                 # SQLite uses OR IGNORE not just IGNORE
 481                 foreach ( $options as $k => $v ) {
 482                         if ( $v == 'IGNORE' ) {
 483                                 $options[$k] = 'OR IGNORE';
 484                         }
 485                 }
 486                 return $options;
 487         }
 488
 489         /**
 490          * @param $options array
 491          * @return string
 492          */
 493         function makeInsertOptions( $options ) {
 494                 $options = self::fixIgnore( $options );
 495                 return parent::makeInsertOptions( $options );
 496         }
 497
 498         /**
 499          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 500          */
 501         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 502                 if ( !count( $a ) ) {
 503                         return true;
 504                 }
 505
 506                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 507                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 508                         $ret = true;
 509                         foreach ( $a as $v ) {
 510                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 511                                         $ret = false;
 512                                 }
 513                         }
 514                 } else {
 515                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 516                 }
 517
 518                 return $ret;
 519         }
 520
 521         /**
 522          * @param $table
 523          * @param $uniqueIndexes
 524          * @param $rows
 525          * @param $fname string
 526          * @return bool|ResultWrapper
 527          */
 528         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 529                 if ( !count( $rows ) ) return true;
 530
 531                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 532                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 533                         $ret = true;
 534                         foreach ( $rows as $v ) {
 535                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 536                                         $ret = false;
 537                                 }
 538                         }
 539                 } else {
 540                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 541                 }
 542
 543                 return $ret;
 544         }
 545
 546         /**
 547          * Returns the size of a text field, or -1 for "unlimited"
 548          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 549          *
 550          * @return int
 551          */
 552         function textFieldSize( $table, $field ) {
 553                 return -1;
 554         }
 555
 556         /**
 557          * @return bool
 558          */
 559         function unionSupportsOrderAndLimit() {
 560                 return false;
 561         }
 562
 563         /**
 564          * @param $sqls
 565          * @param $all
 566          * @return string
 567          */
 568         function unionQueries( $sqls, $all ) {
 569                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 570                 return implode( $glue, $sqls );
 571         }
 572
 573         /**
 574          * @return bool
 575          */
 576         function wasDeadlock() {
 577                 return $this->lastErrno() == 5; // SQLITE_BUSY
 578         }
 579
 580         /**
 581          * @return bool
 582          */
 583         function wasErrorReissuable() {
 584                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 585         }
 586
 587         /**
 588          * @return bool
 589          */
 590         function wasReadOnlyError() {
 591                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 592         }
 593
 594         /**
 595          * @return string wikitext of a link to the server software's web site
 596          */
 597         public static function getSoftwareLink() {
 598                 return "[http://sqlite.org/ SQLite]";
 599         }
 600
 601         /**
 602          * @return string Version information from the database
 603          */
 604         function getServerVersion() {
 605                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 606                 return $ver;
 607         }
 608
 609         /**
 610          * @return string User-friendly database information
 611          */
 612         public function getServerInfo() {
 613                 return wfMsg( self::getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 614         }
 615
 616         /**
 617          * Get information about a given field
 618          * Returns false if the field does not exist.
 619          *
 620          * @return SQLiteField|bool
 621          */
 622         function fieldInfo( $table, $field ) {
 623                 $tableName = $this->tableName( $table );
 624                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 625                 $res = $this->query( $sql, __METHOD__ );
 626                 foreach ( $res as $row ) {
 627                         if ( $row->name == $field ) {
 628                                 return new SQLiteField( $row, $tableName );
 629                         }
 630                 }
 631                 return false;
 632         }
 633
 634         function begin( $fname = '' ) {
 635                 if ( $this->mTrxLevel == 1 ) {
 636                         $this->commit();
 637                 }
 638                 $this->mConn->beginTransaction();
 639                 $this->mTrxLevel = 1;
 640         }
 641
 642         function commit( $fname = '' ) {
 643                 if ( $this->mTrxLevel == 0 ) {
 644                         return;
 645                 }
 646                 $this->mConn->commit();
 647                 $this->mTrxLevel = 0;
 648         }
 649
 650         function rollback( $fname = '' ) {
 651                 if ( $this->mTrxLevel == 0 ) {
 652                         return;
 653                 }
 654                 $this->mConn->rollBack();
 655                 $this->mTrxLevel = 0;
 656         }
 657
 658         /**
 659          * @param  $sql
 660          * @param  $num
 661          * @return string
 662          */
 663         function limitResultForUpdate( $sql, $num ) {
 664                 return $this->limitResult( $sql, $num );
 665         }
 666
 667         /**
 668          * @param $s string
 669          * @return string
 670          */
 671         function strencode( $s ) {
 672                 return substr( $this->addQuotes( $s ), 1, - 1 );
 673         }
 674
 675         /**
 676          * @param $b
 677          * @return Blob
 678          */
 679         function encodeBlob( $b ) {
 680                 return new Blob( $b );
 681         }
 682
 683         /**
 684          * @param $b Blob|string
 685          * @return string
 686          */
 687         function decodeBlob( $b ) {
 688                 if ( $b instanceof Blob ) {
 689                         $b = $b->fetch();
 690                 }
 691                 return $b;
 692         }
 693
 694         /**
 695          * @param $s Blob|string
 696          * @return string
 697          */
 698         function addQuotes( $s ) {
 699                 if ( $s instanceof Blob ) {
 700                         return "x'" . bin2hex( $s->fetch() ) . "'";
 701                 } else {
 702                         return $this->mConn->quote( $s );
 703                 }
 704         }
 705
 706         /**
 707          * @return string
 708          */
 709         function buildLike() {
 710                 $params = func_get_args();
 711                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 712                         $params = $params[0];
 713                 }
 714                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 715         }
 716
 717         /**
 718          * @return string
 719          */
 720         public function getSearchEngine() {
 721                 return "SearchSqlite";
 722         }
 723
 724         /**
 725          * No-op version of deadlockLoop
 726          */
 727         public function deadlockLoop( /*...*/ ) {
 728                 $args = func_get_args();
 729                 $function = array_shift( $args );
 730                 return call_user_func_array( $function, $args );
 731         }
 732
 733         /**
 734          * @param $s string
 735          * @return string
 736          */
 737         protected function replaceVars( $s ) {
 738                 $s = parent::replaceVars( $s );
 739                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 740                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 741
 742                         // binary/varbinary column type -> blob
 743                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 744                         // no such thing as unsigned
 745                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 746                         // INT -> INTEGER
 747                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 748                         // floating point types -> REAL
 749                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 750                         // varchar -> TEXT
 751                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 752                         // TEXT normalization
 753                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 754                         // BLOB normalization
 755                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 756                         // BOOL -> INTEGER
 757                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 758                         // DATETIME -> TEXT
 759                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 760                         // No ENUM type
 761                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 762                         // binary collation type -> nothing
 763                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 764                         // auto_increment -> autoincrement
 765                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 766                         // No explicit options
 767                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 768                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 769                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 770                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 771                         // No truncated indexes
 772                         $s = preg_replace( '/\(\d+\)/', '', $s );
 773                         // No FULLTEXT
 774                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 775                 }
 776                 return $s;
 777         }
 778
 779         /**
 780          * Build a concatenation list to feed into a SQL query
 781          *
 782          * @param $stringList array
 783          *
 784          * @return string
 785          */
 786         function buildConcat( $stringList ) {
 787                 return '(' . implode( ') || (', $stringList ) . ')';
 788         }
 789
 790         /**
 791          * @throws MWException
 792          * @param $oldName
 793          * @param $newName
 794          * @param $temporary bool
 795          * @param $fname string
 796          * @return bool|ResultWrapper
 797          */
 798         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 799                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" . $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 800                 $obj = $this->fetchObject( $res );
 801                 if ( !$obj ) {
 802                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 803                 }
 804                 $sql = $obj->sql;
 805                 $sql = preg_replace( '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/', $this->addIdentifierQuotes( $newName ), $sql, 1 );
 806                 if ( $temporary ) {
 807                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 808                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 809                         } else {
 810                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 811                         }
 812                 }
 813                 return $this->query( $sql, $fname );
 814         }
 815
 816
 817         /**
 818          * List all tables on the database
 819          *
 820          * @param $prefix Only show tables with this prefix, e.g. mw_
 821          * @param $fname String: calling function name
 822          *
 823          * @return array
 824          */
 825         function listTables( $prefix = null, $fname = 'DatabaseSqlite::listTables' ) {
 826                 $result = $this->select(
 827                         'sqlite_master',
 828                         'name',
 829                         "type='table'"
 830                 );
 831
 832                 $endArray = array();
 833
 834                 foreach( $result as $table ) {
 835                         $vars = get_object_vars($table);
 836                         $table = array_pop( $vars );
 837
 838                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 839                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 840                                         $endArray[] = $table;
 841                                 }
 842
 843                         }
 844                 }
 845
 846                 return $endArray;
 847         }
 848
 849 } // end DatabaseSqlite class
 850
 851 /**
 852  * This class allows simple acccess to a SQLite database independently from main database settings
 853  * @ingroup Database
 854  */
 855 class DatabaseSqliteStandalone extends DatabaseSqlite {
 856         public function __construct( $fileName, $flags = 0 ) {
 857                 $this->mFlags = $flags;
 858                 $this->tablePrefix( null );
 859                 $this->openFile( $fileName );
 860         }
 861 }
 862
 863 /**
 864  * @ingroup Database
 865  */
 866 class SQLiteField implements Field {
 867         private $info, $tableName;
 868         function __construct( $info, $tableName ) {
 869                 $this->info = $info;
 870                 $this->tableName = $tableName;
 871         }
 872
 873         function name() {
 874                 return $this->info->name;
 875         }
 876
 877         function tableName() {
 878                 return $this->tableName;
 879         }
 880
 881         function defaultValue() {
 882                 if ( is_string( $this->info->dflt_value ) ) {
 883                         // Typically quoted
 884                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 885                                 return str_replace( "''", "'", $this->info->dflt_value );
 886                         }
 887                 }
 888                 return $this->info->dflt_value;
 889         }
 890
 891         /**
 892          * @return bool
 893          */
 894         function isNullable() {
 895                 return !$this->info->notnull;
 896         }
 897
 898         function type() {
 899                 return $this->info->type;
 900         }
 901
 902 } // end SQLiteField