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                 return $this->mConn->lastInsertId();
 346         }
 347
 348         /**
 349          * @param $res ResultWrapper
 350          * @param $row
 351          */
 352         function dataSeek( $res, $row ) {
 353                 if ( $res instanceof ResultWrapper ) {
 354                         $r =& $res->result;
 355                 } else {
 356                         $r =& $res;
 357                 }
 358                 reset( $r );
 359                 if ( $row > 0 ) {
 360                         for ( $i = 0; $i < $row; $i++ ) {
 361                                 next( $r );
 362                         }
 363                 }
 364         }
 365
 366         /**
 367          * @return string
 368          */
 369         function lastError() {
 370                 if ( !is_object( $this->mConn ) ) {
 371                         return "Cannot return last error, no db connection";
 372                 }
 373                 $e = $this->mConn->errorInfo();
 374                 return isset( $e[2] ) ? $e[2] : '';
 375         }
 376
 377         /**
 378          * @return string
 379          */
 380         function lastErrno() {
 381                 if ( !is_object( $this->mConn ) ) {
 382                         return "Cannot return last error, no db connection";
 383                 } else {
 384                         $info = $this->mConn->errorInfo();
 385                         return $info[1];
 386                 }
 387         }
 388
 389         /**
 390          * @return int
 391          */
 392         function affectedRows() {
 393                 return $this->mAffectedRows;
 394         }
 395
 396         /**
 397          * Returns information about an index
 398          * Returns false if the index does not exist
 399          * - if errors are explicitly ignored, returns NULL on failure
 400          *
 401          * @return array
 402          */
 403         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 404                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 405                 $res = $this->query( $sql, $fname );
 406                 if ( !$res ) {
 407                         return null;
 408                 }
 409                 if ( $res->numRows() == 0 ) {
 410                         return false;
 411                 }
 412                 $info = array();
 413                 foreach ( $res as $row ) {
 414                         $info[] = $row->name;
 415                 }
 416                 return $info;
 417         }
 418
 419         /**
 420          * @param $table
 421          * @param $index
 422          * @param $fname string
 423          * @return bool|null
 424          */
 425         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 426                 $row = $this->selectRow( 'sqlite_master', '*',
 427                         array(
 428                                 'type' => 'index',
 429                                 'name' => $this->indexName( $index ),
 430                         ), $fname );
 431                 if ( !$row || !isset( $row->sql ) ) {
 432                         return null;
 433                 }
 434
 435                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 436                 $indexPos = strpos( $row->sql, 'INDEX' );
 437                 if ( $indexPos === false ) {
 438                         return null;
 439                 }
 440                 $firstPart = substr( $row->sql, 0, $indexPos );
 441                 $options = explode( ' ', $firstPart );
 442                 return in_array( 'UNIQUE', $options );
 443         }
 444
 445         /**
 446          * Filter the options used in SELECT statements
 447          *
 448          * @param $options array
 449          *
 450          * @return array
 451          */
 452         function makeSelectOptions( $options ) {
 453                 foreach ( $options as $k => $v ) {
 454                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 455                                 $options[$k] = '';
 456                         }
 457                 }
 458                 return parent::makeSelectOptions( $options );
 459         }
 460
 461         /**
 462          * @param $options array
 463          * @return string
 464          */
 465         function makeUpdateOptions( $options ) {
 466                 $options = self::fixIgnore( $options );
 467                 return parent::makeUpdateOptions( $options );
 468         }
 469
 470         /**
 471          * @param $options array
 472          * @return array
 473          */
 474         static function fixIgnore( $options ) {
 475                 # SQLite uses OR IGNORE not just IGNORE
 476                 foreach ( $options as $k => $v ) {
 477                         if ( $v == 'IGNORE' ) {
 478                                 $options[$k] = 'OR IGNORE';
 479                         }
 480                 }
 481                 return $options;
 482         }
 483
 484         /**
 485          * @param $options array
 486          * @return string
 487          */
 488         function makeInsertOptions( $options ) {
 489                 $options = self::fixIgnore( $options );
 490                 return parent::makeInsertOptions( $options );
 491         }
 492
 493         /**
 494          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 495          * @return bool
 496          */
 497         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 498                 if ( !count( $a ) ) {
 499                         return true;
 500                 }
 501
 502                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 503                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 504                         $ret = true;
 505                         foreach ( $a as $v ) {
 506                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 507                                         $ret = false;
 508                                 }
 509                         }
 510                 } else {
 511                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 512                 }
 513
 514                 return $ret;
 515         }
 516
 517         /**
 518          * @param $table
 519          * @param $uniqueIndexes
 520          * @param $rows
 521          * @param $fname string
 522          * @return bool|ResultWrapper
 523          */
 524         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 525                 if ( !count( $rows ) ) return true;
 526
 527                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 528                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 529                         $ret = true;
 530                         foreach ( $rows as $v ) {
 531                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 532                                         $ret = false;
 533                                 }
 534                         }
 535                 } else {
 536                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 537                 }
 538
 539                 return $ret;
 540         }
 541
 542         /**
 543          * Returns the size of a text field, or -1 for "unlimited"
 544          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 545          *
 546          * @return int
 547          */
 548         function textFieldSize( $table, $field ) {
 549                 return -1;
 550         }
 551
 552         /**
 553          * @return bool
 554          */
 555         function unionSupportsOrderAndLimit() {
 556                 return false;
 557         }
 558
 559         /**
 560          * @param $sqls
 561          * @param $all
 562          * @return string
 563          */
 564         function unionQueries( $sqls, $all ) {
 565                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 566                 return implode( $glue, $sqls );
 567         }
 568
 569         /**
 570          * @return bool
 571          */
 572         function wasDeadlock() {
 573                 return $this->lastErrno() == 5; // SQLITE_BUSY
 574         }
 575
 576         /**
 577          * @return bool
 578          */
 579         function wasErrorReissuable() {
 580                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 581         }
 582
 583         /**
 584          * @return bool
 585          */
 586         function wasReadOnlyError() {
 587                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 588         }
 589
 590         /**
 591          * @return string wikitext of a link to the server software's web site
 592          */
 593         public static function getSoftwareLink() {
 594                 return "[http://sqlite.org/ SQLite]";
 595         }
 596
 597         /**
 598          * @return string Version information from the database
 599          */
 600         function getServerVersion() {
 601                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 602                 return $ver;
 603         }
 604
 605         /**
 606          * @return string User-friendly database information
 607          */
 608         public function getServerInfo() {
 609                 return wfMsg( self::getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 610         }
 611
 612         /**
 613          * Get information about a given field
 614          * Returns false if the field does not exist.
 615          *
 616          * @param $table string
 617          * @param $field string
 618          * @return SQLiteField|bool False on failure
 619          */
 620         function fieldInfo( $table, $field ) {
 621                 $tableName = $this->tableName( $table );
 622                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 623                 $res = $this->query( $sql, __METHOD__ );
 624                 foreach ( $res as $row ) {
 625                         if ( $row->name == $field ) {
 626                                 return new SQLiteField( $row, $tableName );
 627                         }
 628                 }
 629                 return false;
 630         }
 631
 632         function begin( $fname = '' ) {
 633                 if ( $this->mTrxLevel == 1 ) {
 634                         $this->commit( __METHOD__ );
 635                 }
 636                 $this->mConn->beginTransaction();
 637                 $this->mTrxLevel = 1;
 638         }
 639
 640         function commit( $fname = '' ) {
 641                 if ( $this->mTrxLevel == 0 ) {
 642                         return;
 643                 }
 644                 $this->mConn->commit();
 645                 $this->mTrxLevel = 0;
 646         }
 647
 648         function rollback( $fname = '' ) {
 649                 if ( $this->mTrxLevel == 0 ) {
 650                         return;
 651                 }
 652                 $this->mConn->rollBack();
 653                 $this->mTrxLevel = 0;
 654         }
 655
 656         /**
 657          * @param  $sql
 658          * @param  $num
 659          * @return string
 660          */
 661         function limitResultForUpdate( $sql, $num ) {
 662                 return $this->limitResult( $sql, $num );
 663         }
 664
 665         /**
 666          * @param $s string
 667          * @return string
 668          */
 669         function strencode( $s ) {
 670                 return substr( $this->addQuotes( $s ), 1, - 1 );
 671         }
 672
 673         /**
 674          * @param $b
 675          * @return Blob
 676          */
 677         function encodeBlob( $b ) {
 678                 return new Blob( $b );
 679         }
 680
 681         /**
 682          * @param $b Blob|string
 683          * @return string
 684          */
 685         function decodeBlob( $b ) {
 686                 if ( $b instanceof Blob ) {
 687                         $b = $b->fetch();
 688                 }
 689                 return $b;
 690         }
 691
 692         /**
 693          * @param $s Blob|string
 694          * @return string
 695          */
 696         function addQuotes( $s ) {
 697                 if ( $s instanceof Blob ) {
 698                         return "x'" . bin2hex( $s->fetch() ) . "'";
 699                 } else {
 700                         return $this->mConn->quote( $s );
 701                 }
 702         }
 703
 704         /**
 705          * @return string
 706          */
 707         function buildLike() {
 708                 $params = func_get_args();
 709                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 710                         $params = $params[0];
 711                 }
 712                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 713         }
 714
 715         /**
 716          * @return string
 717          */
 718         public function getSearchEngine() {
 719                 return "SearchSqlite";
 720         }
 721
 722         /**
 723          * No-op version of deadlockLoop
 724          * @return mixed
 725          */
 726         public function deadlockLoop( /*...*/ ) {
 727                 $args = func_get_args();
 728                 $function = array_shift( $args );
 729                 return call_user_func_array( $function, $args );
 730         }
 731
 732         /**
 733          * @param $s string
 734          * @return string
 735          */
 736         protected function replaceVars( $s ) {
 737                 $s = parent::replaceVars( $s );
 738                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 739                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 740
 741                         // binary/varbinary column type -> blob
 742                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 743                         // no such thing as unsigned
 744                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 745                         // INT -> INTEGER
 746                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 747                         // floating point types -> REAL
 748                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 749                         // varchar -> TEXT
 750                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 751                         // TEXT normalization
 752                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 753                         // BLOB normalization
 754                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 755                         // BOOL -> INTEGER
 756                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 757                         // DATETIME -> TEXT
 758                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 759                         // No ENUM type
 760                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 761                         // binary collation type -> nothing
 762                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 763                         // auto_increment -> autoincrement
 764                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 765                         // No explicit options
 766                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 767                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 768                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 769                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 770                         // No truncated indexes
 771                         $s = preg_replace( '/\(\d+\)/', '', $s );
 772                         // No FULLTEXT
 773                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 774                 }
 775                 return $s;
 776         }
 777
 778         /**
 779          * Build a concatenation list to feed into a SQL query
 780          *
 781          * @param $stringList array
 782          *
 783          * @return string
 784          */
 785         function buildConcat( $stringList ) {
 786                 return '(' . implode( ') || (', $stringList ) . ')';
 787         }
 788
 789         /**
 790          * @throws MWException
 791          * @param $oldName
 792          * @param $newName
 793          * @param $temporary bool
 794          * @param $fname string
 795          * @return bool|ResultWrapper
 796          */
 797         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 798                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" . $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 799                 $obj = $this->fetchObject( $res );
 800                 if ( !$obj ) {
 801                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 802                 }
 803                 $sql = $obj->sql;
 804                 $sql = preg_replace( '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/', $this->addIdentifierQuotes( $newName ), $sql, 1 );
 805                 if ( $temporary ) {
 806                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 807                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 808                         } else {
 809                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 810                         }
 811                 }
 812                 return $this->query( $sql, $fname );
 813         }
 814
 815
 816         /**
 817          * List all tables on the database
 818          *
 819          * @param $prefix string Only show tables with this prefix, e.g. mw_
 820          * @param $fname String: calling function name
 821          *
 822          * @return array
 823          */
 824         function listTables( $prefix = null, $fname = 'DatabaseSqlite::listTables' ) {
 825                 $result = $this->select(
 826                         'sqlite_master',
 827                         'name',
 828                         "type='table'"
 829                 );
 830
 831                 $endArray = array();
 832
 833                 foreach( $result as $table ) {
 834                         $vars = get_object_vars($table);
 835                         $table = array_pop( $vars );
 836
 837                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 838                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 839                                         $endArray[] = $table;
 840                                 }
 841
 842                         }
 843                 }
 844
 845                 return $endArray;
 846         }
 847
 848 } // end DatabaseSqlite class
 849
 850 /**
 851  * This class allows simple acccess to a SQLite database independently from main database settings
 852  * @ingroup Database
 853  */
 854 class DatabaseSqliteStandalone extends DatabaseSqlite {
 855         public function __construct( $fileName, $flags = 0 ) {
 856                 $this->mFlags = $flags;
 857                 $this->tablePrefix( null );
 858                 $this->openFile( $fileName );
 859         }
 860 }
 861
 862 /**
 863  * @ingroup Database
 864  */
 865 class SQLiteField implements Field {
 866         private $info, $tableName;
 867         function __construct( $info, $tableName ) {
 868                 $this->info = $info;
 869                 $this->tableName = $tableName;
 870         }
 871
 872         function name() {
 873                 return $this->info->name;
 874         }
 875
 876         function tableName() {
 877                 return $this->tableName;
 878         }
 879
 880         function defaultValue() {
 881                 if ( is_string( $this->info->dflt_value ) ) {
 882                         // Typically quoted
 883                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 884                                 return str_replace( "''", "'", $this->info->dflt_value );
 885                         }
 886                 }
 887                 return $this->info->dflt_value;
 888         }
 889
 890         /**
 891          * @return bool
 892          */
 893         function isNullable() {
 894                 return !$this->info->notnull;
 895         }
 896
 897         function type() {
 898                 return $this->info->type;
 899         }
 900
 901 } // end SQLiteField