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          * Does not actually close the connection, just destroys the reference for GC to do its work
 119          * @return bool
 120          */
 121         protected function closeConnection() {
 122                 $this->mConn = null;
 123                 return true;
 124         }
 125
 126         /**
 127          * Generates a database file name. Explicitly public for installer.
 128          * @param $dir String: Directory where database resides
 129          * @param $dbName String: Database name
 130          * @return String
 131          */
 132         public static function generateFileName( $dir, $dbName ) {
 133                 return "$dir/$dbName.sqlite";
 134         }
 135
 136         /**
 137          * Check if the searchindext table is FTS enabled.
 138          * @return bool False if not enabled.
 139          */
 140         function checkForEnabledSearch() {
 141                 if ( self::$fulltextEnabled === null ) {
 142                         self::$fulltextEnabled = false;
 143                         $table = $this->tableName( 'searchindex' );
 144                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 145                         if ( $res ) {
 146                                 $row = $res->fetchRow();
 147                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 148                         }
 149                 }
 150                 return self::$fulltextEnabled;
 151         }
 152
 153         /**
 154          * Returns version of currently supported SQLite fulltext search module or false if none present.
 155          * @return String
 156          */
 157         static function getFulltextSearchModule() {
 158                 static $cachedResult = null;
 159                 if ( $cachedResult !== null ) {
 160                         return $cachedResult;
 161                 }
 162                 $cachedResult = false;
 163                 $table = 'dummy_search_test';
 164
 165                 $db = new DatabaseSqliteStandalone( ':memory:' );
 166
 167                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 168                         $cachedResult = 'FTS3';
 169                 }
 170                 $db->close();
 171                 return $cachedResult;
 172         }
 173
 174         /**
 175          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 176          * for details.
 177          *
 178          * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
 179          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 180          * @param $fname String: calling function name
 181          *
 182          * @return ResultWrapper
 183          */
 184         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 185                 global $wgSQLiteDataDir;
 186                 if ( !$file ) {
 187                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 188                 }
 189                 $file = $this->addQuotes( $file );
 190                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 191         }
 192
 193         /**
 194          * @see DatabaseBase::isWriteQuery()
 195          *
 196          * @param $sql string
 197          *
 198          * @return bool
 199          */
 200         function isWriteQuery( $sql ) {
 201                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 202         }
 203
 204         /**
 205          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 206          *
 207          * @param $sql string
 208          *
 209          * @return ResultWrapper
 210          */
 211         protected function doQuery( $sql ) {
 212                 $res = $this->mConn->query( $sql );
 213                 if ( $res === false ) {
 214                         return false;
 215                 } else {
 216                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 217                         $this->mAffectedRows = $r->rowCount();
 218                         $res = new ResultWrapper( $this, $r->fetchAll() );
 219                 }
 220                 return $res;
 221         }
 222
 223         /**
 224          * @param $res ResultWrapper
 225          */
 226         function freeResult( $res ) {
 227                 if ( $res instanceof ResultWrapper ) {
 228                         $res->result = null;
 229                 } else {
 230                         $res = null;
 231                 }
 232         }
 233
 234         /**
 235          * @param $res ResultWrapper
 236          * @return
 237          */
 238         function fetchObject( $res ) {
 239                 if ( $res instanceof ResultWrapper ) {
 240                         $r =& $res->result;
 241                 } else {
 242                         $r =& $res;
 243                 }
 244
 245                 $cur = current( $r );
 246                 if ( is_array( $cur ) ) {
 247                         next( $r );
 248                         $obj = new stdClass;
 249                         foreach ( $cur as $k => $v ) {
 250                                 if ( !is_numeric( $k ) ) {
 251                                         $obj->$k = $v;
 252                                 }
 253                         }
 254
 255                         return $obj;
 256                 }
 257                 return false;
 258         }
 259
 260         /**
 261          * @param $res ResultWrapper
 262          * @return bool|mixed
 263          */
 264         function fetchRow( $res ) {
 265                 if ( $res instanceof ResultWrapper ) {
 266                         $r =& $res->result;
 267                 } else {
 268                         $r =& $res;
 269                 }
 270                 $cur = current( $r );
 271                 if ( is_array( $cur ) ) {
 272                         next( $r );
 273                         return $cur;
 274                 }
 275                 return false;
 276         }
 277
 278         /**
 279          * The PDO::Statement class implements the array interface so count() will work
 280          *
 281          * @param $res ResultWrapper
 282          *
 283          * @return int
 284          */
 285         function numRows( $res ) {
 286                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 287                 return count( $r );
 288         }
 289
 290         /**
 291          * @param $res ResultWrapper
 292          * @return int
 293          */
 294         function numFields( $res ) {
 295                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 296                 return is_array( $r ) ? count( $r[0] ) : 0;
 297         }
 298
 299         /**
 300          * @param $res ResultWrapper
 301          * @param $n
 302          * @return bool
 303          */
 304         function fieldName( $res, $n ) {
 305                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 306                 if ( is_array( $r ) ) {
 307                         $keys = array_keys( $r[0] );
 308                         return $keys[$n];
 309                 }
 310                 return false;
 311         }
 312
 313         /**
 314          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 315          *
 316          * @param $name
 317          * @param $format String
 318          * @return string
 319          */
 320         function tableName( $name, $format = 'quoted' ) {
 321                 // table names starting with sqlite_ are reserved
 322                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 323                         return $name;
 324                 }
 325                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 326         }
 327
 328         /**
 329          * Index names have DB scope
 330          *
 331          * @param $index string
 332          *
 333          * @return string
 334          */
 335         function indexName( $index ) {
 336                 return $index;
 337         }
 338
 339         /**
 340          * This must be called after nextSequenceVal
 341          *
 342          * @return int
 343          */
 344         function insertId() {
 345                 // PDO::lastInsertId yields a string :(
 346                 return intval( $this->mConn->lastInsertId() );
 347         }
 348
 349         /**
 350          * @param $res ResultWrapper
 351          * @param $row
 352          */
 353         function dataSeek( $res, $row ) {
 354                 if ( $res instanceof ResultWrapper ) {
 355                         $r =& $res->result;
 356                 } else {
 357                         $r =& $res;
 358                 }
 359                 reset( $r );
 360                 if ( $row > 0 ) {
 361                         for ( $i = 0; $i < $row; $i++ ) {
 362                                 next( $r );
 363                         }
 364                 }
 365         }
 366
 367         /**
 368          * @return string
 369          */
 370         function lastError() {
 371                 if ( !is_object( $this->mConn ) ) {
 372                         return "Cannot return last error, no db connection";
 373                 }
 374                 $e = $this->mConn->errorInfo();
 375                 return isset( $e[2] ) ? $e[2] : '';
 376         }
 377
 378         /**
 379          * @return string
 380          */
 381         function lastErrno() {
 382                 if ( !is_object( $this->mConn ) ) {
 383                         return "Cannot return last error, no db connection";
 384                 } else {
 385                         $info = $this->mConn->errorInfo();
 386                         return $info[1];
 387                 }
 388         }
 389
 390         /**
 391          * @return int
 392          */
 393         function affectedRows() {
 394                 return $this->mAffectedRows;
 395         }
 396
 397         /**
 398          * Returns information about an index
 399          * Returns false if the index does not exist
 400          * - if errors are explicitly ignored, returns NULL on failure
 401          *
 402          * @return array
 403          */
 404         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 405                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 406                 $res = $this->query( $sql, $fname );
 407                 if ( !$res ) {
 408                         return null;
 409                 }
 410                 if ( $res->numRows() == 0 ) {
 411                         return false;
 412                 }
 413                 $info = array();
 414                 foreach ( $res as $row ) {
 415                         $info[] = $row->name;
 416                 }
 417                 return $info;
 418         }
 419
 420         /**
 421          * @param $table
 422          * @param $index
 423          * @param $fname string
 424          * @return bool|null
 425          */
 426         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 427                 $row = $this->selectRow( 'sqlite_master', '*',
 428                         array(
 429                                 'type' => 'index',
 430                                 'name' => $this->indexName( $index ),
 431                         ), $fname );
 432                 if ( !$row || !isset( $row->sql ) ) {
 433                         return null;
 434                 }
 435
 436                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 437                 $indexPos = strpos( $row->sql, 'INDEX' );
 438                 if ( $indexPos === false ) {
 439                         return null;
 440                 }
 441                 $firstPart = substr( $row->sql, 0, $indexPos );
 442                 $options = explode( ' ', $firstPart );
 443                 return in_array( 'UNIQUE', $options );
 444         }
 445
 446         /**
 447          * Filter the options used in SELECT statements
 448          *
 449          * @param $options array
 450          *
 451          * @return array
 452          */
 453         function makeSelectOptions( $options ) {
 454                 foreach ( $options as $k => $v ) {
 455                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 456                                 $options[$k] = '';
 457                         }
 458                 }
 459                 return parent::makeSelectOptions( $options );
 460         }
 461
 462         /**
 463          * @param $options array
 464          * @return string
 465          */
 466         function makeUpdateOptions( $options ) {
 467                 $options = self::fixIgnore( $options );
 468                 return parent::makeUpdateOptions( $options );
 469         }
 470
 471         /**
 472          * @param $options array
 473          * @return array
 474          */
 475         static function fixIgnore( $options ) {
 476                 # SQLite uses OR IGNORE not just IGNORE
 477                 foreach ( $options as $k => $v ) {
 478                         if ( $v == 'IGNORE' ) {
 479                                 $options[$k] = 'OR IGNORE';
 480                         }
 481                 }
 482                 return $options;
 483         }
 484
 485         /**
 486          * @param $options array
 487          * @return string
 488          */
 489         function makeInsertOptions( $options ) {
 490                 $options = self::fixIgnore( $options );
 491                 return parent::makeInsertOptions( $options );
 492         }
 493
 494         /**
 495          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 496          * @return bool
 497          */
 498         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 499                 if ( !count( $a ) ) {
 500                         return true;
 501                 }
 502
 503                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 504                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 505                         $ret = true;
 506                         foreach ( $a as $v ) {
 507                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 508                                         $ret = false;
 509                                 }
 510                         }
 511                 } else {
 512                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 513                 }
 514
 515                 return $ret;
 516         }
 517
 518         /**
 519          * @param $table
 520          * @param $uniqueIndexes
 521          * @param $rows
 522          * @param $fname string
 523          * @return bool|ResultWrapper
 524          */
 525         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 526                 if ( !count( $rows ) ) return true;
 527
 528                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 529                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 530                         $ret = true;
 531                         foreach ( $rows as $v ) {
 532                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 533                                         $ret = false;
 534                                 }
 535                         }
 536                 } else {
 537                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 538                 }
 539
 540                 return $ret;
 541         }
 542
 543         /**
 544          * Returns the size of a text field, or -1 for "unlimited"
 545          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 546          *
 547          * @return int
 548          */
 549         function textFieldSize( $table, $field ) {
 550                 return -1;
 551         }
 552
 553         /**
 554          * @return bool
 555          */
 556         function unionSupportsOrderAndLimit() {
 557                 return false;
 558         }
 559
 560         /**
 561          * @param $sqls
 562          * @param $all
 563          * @return string
 564          */
 565         function unionQueries( $sqls, $all ) {
 566                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 567                 return implode( $glue, $sqls );
 568         }
 569
 570         /**
 571          * @return bool
 572          */
 573         function wasDeadlock() {
 574                 return $this->lastErrno() == 5; // SQLITE_BUSY
 575         }
 576
 577         /**
 578          * @return bool
 579          */
 580         function wasErrorReissuable() {
 581                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 582         }
 583
 584         /**
 585          * @return bool
 586          */
 587         function wasReadOnlyError() {
 588                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 589         }
 590
 591         /**
 592          * @return string wikitext of a link to the server software's web site
 593          */
 594         public static function getSoftwareLink() {
 595                 return "[http://sqlite.org/ SQLite]";
 596         }
 597
 598         /**
 599          * @return string Version information from the database
 600          */
 601         function getServerVersion() {
 602                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 603                 return $ver;
 604         }
 605
 606         /**
 607          * @return string User-friendly database information
 608          */
 609         public function getServerInfo() {
 610                 return wfMsg( self::getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 611         }
 612
 613         /**
 614          * Get information about a given field
 615          * Returns false if the field does not exist.
 616          *
 617          * @param $table string
 618          * @param $field string
 619          * @return SQLiteField|bool False on failure
 620          */
 621         function fieldInfo( $table, $field ) {
 622                 $tableName = $this->tableName( $table );
 623                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 624                 $res = $this->query( $sql, __METHOD__ );
 625                 foreach ( $res as $row ) {
 626                         if ( $row->name == $field ) {
 627                                 return new SQLiteField( $row, $tableName );
 628                         }
 629                 }
 630                 return false;
 631         }
 632
 633         function begin( $fname = '' ) {
 634                 if ( $this->mTrxLevel == 1 ) {
 635                         $this->commit( __METHOD__ );
 636                 }
 637                 $this->mConn->beginTransaction();
 638                 $this->mTrxLevel = 1;
 639         }
 640
 641         function commit( $fname = '' ) {
 642                 if ( $this->mTrxLevel == 0 ) {
 643                         return;
 644                 }
 645                 $this->mConn->commit();
 646                 $this->mTrxLevel = 0;
 647         }
 648
 649         function rollback( $fname = '' ) {
 650                 if ( $this->mTrxLevel == 0 ) {
 651                         return;
 652                 }
 653                 $this->mConn->rollBack();
 654                 $this->mTrxLevel = 0;
 655         }
 656
 657         /**
 658          * @param  $sql
 659          * @param  $num
 660          * @return string
 661          */
 662         function limitResultForUpdate( $sql, $num ) {
 663                 return $this->limitResult( $sql, $num );
 664         }
 665
 666         /**
 667          * @param $s string
 668          * @return string
 669          */
 670         function strencode( $s ) {
 671                 return substr( $this->addQuotes( $s ), 1, - 1 );
 672         }
 673
 674         /**
 675          * @param $b
 676          * @return Blob
 677          */
 678         function encodeBlob( $b ) {
 679                 return new Blob( $b );
 680         }
 681
 682         /**
 683          * @param $b Blob|string
 684          * @return string
 685          */
 686         function decodeBlob( $b ) {
 687                 if ( $b instanceof Blob ) {
 688                         $b = $b->fetch();
 689                 }
 690                 return $b;
 691         }
 692
 693         /**
 694          * @param $s Blob|string
 695          * @return string
 696          */
 697         function addQuotes( $s ) {
 698                 if ( $s instanceof Blob ) {
 699                         return "x'" . bin2hex( $s->fetch() ) . "'";
 700                 } else {
 701                         return $this->mConn->quote( $s );
 702                 }
 703         }
 704
 705         /**
 706          * @return string
 707          */
 708         function buildLike() {
 709                 $params = func_get_args();
 710                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 711                         $params = $params[0];
 712                 }
 713                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 714         }
 715
 716         /**
 717          * @return string
 718          */
 719         public function getSearchEngine() {
 720                 return "SearchSqlite";
 721         }
 722
 723         /**
 724          * No-op version of deadlockLoop
 725          * @return mixed
 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 string 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