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  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24
  25 /**
  26  * @ingroup Database
  27  */
  28 class DatabaseSqlite extends DatabaseBase {
  29
  30         private static $fulltextEnabled = null;
  31
  32         var $mAffectedRows;
  33         var $mLastResult;
  34         var $mDatabaseFile;
  35         var $mName;
  36
  37         /**
  38          * @var PDO
  39          */
  40         protected $mConn;
  41
  42         /**
  43          * Constructor.
  44          * Parameters $server, $user and $password are not used.
  45          * @param $server string
  46          * @param $user string
  47          * @param $password string
  48          * @param $dbName string
  49          * @param $flags int
  50          */
  51         function __construct( $server = false, $user = false, $password = false, $dbName = false, $flags = 0 ) {
  52                 $this->mName = $dbName;
  53                 parent::__construct( $server, $user, $password, $dbName, $flags );
  54                 // parent doesn't open when $user is false, but we can work with $dbName
  55                 if ( $dbName && !$this->isOpen() ) {
  56                         global $wgSharedDB;
  57                         if ( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  58                                 $this->attachDatabase( $wgSharedDB );
  59                         }
  60                 }
  61         }
  62
  63         /**
  64          * @return string
  65          */
  66         function getType() {
  67                 return 'sqlite';
  68         }
  69
  70         /**
  71          * @todo Check if it should be true like parent class
  72          *
  73          * @return bool
  74          */
  75         function implicitGroupby() {
  76                 return false;
  77         }
  78
  79         /** Open an SQLite database and return a resource handle to it
  80          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  81          *
  82          * @param string $server
  83          * @param string $user
  84          * @param string $pass
  85          * @param string $dbName
  86          *
  87          * @throws DBConnectionError
  88          * @return PDO
  89          */
  90         function open( $server, $user, $pass, $dbName ) {
  91                 global $wgSQLiteDataDir;
  92
  93                 $this->close();
  94                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  95                 if ( !is_readable( $fileName ) ) {
  96                         $this->mConn = false;
  97                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  98                 }
  99                 $this->openFile( $fileName );
 100                 return $this->mConn;
 101         }
 102
 103         /**
 104          * Opens a database file
 105          *
 106          * @param $fileName string
 107          *
 108          * @throws DBConnectionError
 109          * @return PDO|bool SQL connection or false if failed
 110          */
 111         function openFile( $fileName ) {
 112                 $this->mDatabaseFile = $fileName;
 113                 try {
 114                         if ( $this->mFlags & DBO_PERSISTENT ) {
 115                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 116                                         array( PDO::ATTR_PERSISTENT => true ) );
 117                         } else {
 118                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 119                         }
 120                 } catch ( PDOException $e ) {
 121                         $err = $e->getMessage();
 122                 }
 123                 if ( !$this->mConn ) {
 124                         wfDebug( "DB connection error: $err\n" );
 125                         throw new DBConnectionError( $this, $err );
 126                 }
 127                 $this->mOpened = !!$this->mConn;
 128                 # set error codes only, don't raise exceptions
 129                 if ( $this->mOpened ) {
 130                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 131                         # Enforce LIKE to be case sensitive, just like MySQL
 132                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 133                         return true;
 134                 }
 135         }
 136
 137         /**
 138          * Does not actually close the connection, just destroys the reference for GC to do its work
 139          * @return bool
 140          */
 141         protected function closeConnection() {
 142                 $this->mConn = null;
 143                 return true;
 144         }
 145
 146         /**
 147          * Generates a database file name. Explicitly public for installer.
 148          * @param string $dir Directory where database resides
 149          * @param string $dbName Database name
 150          * @return String
 151          */
 152         public static function generateFileName( $dir, $dbName ) {
 153                 return "$dir/$dbName.sqlite";
 154         }
 155
 156         /**
 157          * Check if the searchindext table is FTS enabled.
 158          * @return bool False if not enabled.
 159          */
 160         function checkForEnabledSearch() {
 161                 if ( self::$fulltextEnabled === null ) {
 162                         self::$fulltextEnabled = false;
 163                         $table = $this->tableName( 'searchindex' );
 164                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 165                         if ( $res ) {
 166                                 $row = $res->fetchRow();
 167                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 168                         }
 169                 }
 170                 return self::$fulltextEnabled;
 171         }
 172
 173         /**
 174          * Returns version of currently supported SQLite fulltext search module or false if none present.
 175          * @return String
 176          */
 177         static function getFulltextSearchModule() {
 178                 static $cachedResult = null;
 179                 if ( $cachedResult !== null ) {
 180                         return $cachedResult;
 181                 }
 182                 $cachedResult = false;
 183                 $table = 'dummy_search_test';
 184
 185                 $db = new DatabaseSqliteStandalone( ':memory:' );
 186
 187                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 188                         $cachedResult = 'FTS3';
 189                 }
 190                 $db->close();
 191                 return $cachedResult;
 192         }
 193
 194         /**
 195          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 196          * for details.
 197          *
 198          * @param string $name database name to be used in queries like SELECT foo FROM dbname.table
 199          * @param string $file database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 200          * @param string $fname calling function name
 201          *
 202          * @return ResultWrapper
 203          */
 204         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 205                 global $wgSQLiteDataDir;
 206                 if ( !$file ) {
 207                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 208                 }
 209                 $file = $this->addQuotes( $file );
 210                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 211         }
 212
 213         /**
 214          * @see DatabaseBase::isWriteQuery()
 215          *
 216          * @param $sql string
 217          *
 218          * @return bool
 219          */
 220         function isWriteQuery( $sql ) {
 221                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 222         }
 223
 224         /**
 225          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 226          *
 227          * @param $sql string
 228          *
 229          * @return ResultWrapper
 230          */
 231         protected function doQuery( $sql ) {
 232                 $res = $this->mConn->query( $sql );
 233                 if ( $res === false ) {
 234                         return false;
 235                 } else {
 236                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 237                         $this->mAffectedRows = $r->rowCount();
 238                         $res = new ResultWrapper( $this, $r->fetchAll() );
 239                 }
 240                 return $res;
 241         }
 242
 243         /**
 244          * @param $res ResultWrapper
 245          */
 246         function freeResult( $res ) {
 247                 if ( $res instanceof ResultWrapper ) {
 248                         $res->result = null;
 249                 } else {
 250                         $res = null;
 251                 }
 252         }
 253
 254         /**
 255          * @param $res ResultWrapper
 256          * @return object|bool
 257          */
 258         function fetchObject( $res ) {
 259                 if ( $res instanceof ResultWrapper ) {
 260                         $r =& $res->result;
 261                 } else {
 262                         $r =& $res;
 263                 }
 264
 265                 $cur = current( $r );
 266                 if ( is_array( $cur ) ) {
 267                         next( $r );
 268                         $obj = new stdClass;
 269                         foreach ( $cur as $k => $v ) {
 270                                 if ( !is_numeric( $k ) ) {
 271                                         $obj->$k = $v;
 272                                 }
 273                         }
 274
 275                         return $obj;
 276                 }
 277                 return false;
 278         }
 279
 280         /**
 281          * @param $res ResultWrapper
 282          * @return array|bool
 283          */
 284         function fetchRow( $res ) {
 285                 if ( $res instanceof ResultWrapper ) {
 286                         $r =& $res->result;
 287                 } else {
 288                         $r =& $res;
 289                 }
 290                 $cur = current( $r );
 291                 if ( is_array( $cur ) ) {
 292                         next( $r );
 293                         return $cur;
 294                 }
 295                 return false;
 296         }
 297
 298         /**
 299          * The PDO::Statement class implements the array interface so count() will work
 300          *
 301          * @param $res ResultWrapper
 302          *
 303          * @return int
 304          */
 305         function numRows( $res ) {
 306                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 307                 return count( $r );
 308         }
 309
 310         /**
 311          * @param $res ResultWrapper
 312          * @return int
 313          */
 314         function numFields( $res ) {
 315                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 316                 return is_array( $r ) ? count( $r[0] ) : 0;
 317         }
 318
 319         /**
 320          * @param $res ResultWrapper
 321          * @param $n
 322          * @return bool
 323          */
 324         function fieldName( $res, $n ) {
 325                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 326                 if ( is_array( $r ) ) {
 327                         $keys = array_keys( $r[0] );
 328                         return $keys[$n];
 329                 }
 330                 return false;
 331         }
 332
 333         /**
 334          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 335          *
 336          * @param $name
 337          * @param $format String
 338          * @return string
 339          */
 340         function tableName( $name, $format = 'quoted' ) {
 341                 // table names starting with sqlite_ are reserved
 342                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 343                         return $name;
 344                 }
 345                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 346         }
 347
 348         /**
 349          * Index names have DB scope
 350          *
 351          * @param $index string
 352          *
 353          * @return string
 354          */
 355         function indexName( $index ) {
 356                 return $index;
 357         }
 358
 359         /**
 360          * This must be called after nextSequenceVal
 361          *
 362          * @return int
 363          */
 364         function insertId() {
 365                 // PDO::lastInsertId yields a string :(
 366                 return intval( $this->mConn->lastInsertId() );
 367         }
 368
 369         /**
 370          * @param $res ResultWrapper
 371          * @param $row
 372          */
 373         function dataSeek( $res, $row ) {
 374                 if ( $res instanceof ResultWrapper ) {
 375                         $r =& $res->result;
 376                 } else {
 377                         $r =& $res;
 378                 }
 379                 reset( $r );
 380                 if ( $row > 0 ) {
 381                         for ( $i = 0; $i < $row; $i++ ) {
 382                                 next( $r );
 383                         }
 384                 }
 385         }
 386
 387         /**
 388          * @return string
 389          */
 390         function lastError() {
 391                 if ( !is_object( $this->mConn ) ) {
 392                         return "Cannot return last error, no db connection";
 393                 }
 394                 $e = $this->mConn->errorInfo();
 395                 return isset( $e[2] ) ? $e[2] : '';
 396         }
 397
 398         /**
 399          * @return string
 400          */
 401         function lastErrno() {
 402                 if ( !is_object( $this->mConn ) ) {
 403                         return "Cannot return last error, no db connection";
 404                 } else {
 405                         $info = $this->mConn->errorInfo();
 406                         return $info[1];
 407                 }
 408         }
 409
 410         /**
 411          * @return int
 412          */
 413         function affectedRows() {
 414                 return $this->mAffectedRows;
 415         }
 416
 417         /**
 418          * Returns information about an index
 419          * Returns false if the index does not exist
 420          * - if errors are explicitly ignored, returns NULL on failure
 421          *
 422          * @return array
 423          */
 424         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 425                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 426                 $res = $this->query( $sql, $fname );
 427                 if ( !$res ) {
 428                         return null;
 429                 }
 430                 if ( $res->numRows() == 0 ) {
 431                         return false;
 432                 }
 433                 $info = array();
 434                 foreach ( $res as $row ) {
 435                         $info[] = $row->name;
 436                 }
 437                 return $info;
 438         }
 439
 440         /**
 441          * @param $table
 442          * @param $index
 443          * @param $fname string
 444          * @return bool|null
 445          */
 446         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 447                 $row = $this->selectRow( 'sqlite_master', '*',
 448                         array(
 449                                 'type' => 'index',
 450                                 'name' => $this->indexName( $index ),
 451                         ), $fname );
 452                 if ( !$row || !isset( $row->sql ) ) {
 453                         return null;
 454                 }
 455
 456                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 457                 $indexPos = strpos( $row->sql, 'INDEX' );
 458                 if ( $indexPos === false ) {
 459                         return null;
 460                 }
 461                 $firstPart = substr( $row->sql, 0, $indexPos );
 462                 $options = explode( ' ', $firstPart );
 463                 return in_array( 'UNIQUE', $options );
 464         }
 465
 466         /**
 467          * Filter the options used in SELECT statements
 468          *
 469          * @param $options array
 470          *
 471          * @return array
 472          */
 473         function makeSelectOptions( $options ) {
 474                 foreach ( $options as $k => $v ) {
 475                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 476                                 $options[$k] = '';
 477                         }
 478                 }
 479                 return parent::makeSelectOptions( $options );
 480         }
 481
 482         /**
 483          * @param $options array
 484          * @return string
 485          */
 486         function makeUpdateOptions( $options ) {
 487                 $options = self::fixIgnore( $options );
 488                 return parent::makeUpdateOptions( $options );
 489         }
 490
 491         /**
 492          * @param $options array
 493          * @return array
 494          */
 495         static function fixIgnore( $options ) {
 496                 # SQLite uses OR IGNORE not just IGNORE
 497                 foreach ( $options as $k => $v ) {
 498                         if ( $v == 'IGNORE' ) {
 499                                 $options[$k] = 'OR IGNORE';
 500                         }
 501                 }
 502                 return $options;
 503         }
 504
 505         /**
 506          * @param $options array
 507          * @return string
 508          */
 509         function makeInsertOptions( $options ) {
 510                 $options = self::fixIgnore( $options );
 511                 return parent::makeInsertOptions( $options );
 512         }
 513
 514         /**
 515          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 516          * @return bool
 517          */
 518         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 519                 if ( !count( $a ) ) {
 520                         return true;
 521                 }
 522
 523                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 524                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 525                         $ret = true;
 526                         foreach ( $a as $v ) {
 527                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 528                                         $ret = false;
 529                                 }
 530                         }
 531                 } else {
 532                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 533                 }
 534
 535                 return $ret;
 536         }
 537
 538         /**
 539          * @param $table
 540          * @param $uniqueIndexes
 541          * @param $rows
 542          * @param $fname string
 543          * @return bool|ResultWrapper
 544          */
 545         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 546                 if ( !count( $rows ) ) {
 547                         return true;
 548                 }
 549
 550                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 551                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 552                         $ret = true;
 553                         foreach ( $rows as $v ) {
 554                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 555                                         $ret = false;
 556                                 }
 557                         }
 558                 } else {
 559                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 560                 }
 561
 562                 return $ret;
 563         }
 564
 565         /**
 566          * Returns the size of a text field, or -1 for "unlimited"
 567          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 568          *
 569          * @return int
 570          */
 571         function textFieldSize( $table, $field ) {
 572                 return -1;
 573         }
 574
 575         /**
 576          * @return bool
 577          */
 578         function unionSupportsOrderAndLimit() {
 579                 return false;
 580         }
 581
 582         /**
 583          * @param $sqls
 584          * @param $all
 585          * @return string
 586          */
 587         function unionQueries( $sqls, $all ) {
 588                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 589                 return implode( $glue, $sqls );
 590         }
 591
 592         /**
 593          * @return bool
 594          */
 595         function wasDeadlock() {
 596                 return $this->lastErrno() == 5; // SQLITE_BUSY
 597         }
 598
 599         /**
 600          * @return bool
 601          */
 602         function wasErrorReissuable() {
 603                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 604         }
 605
 606         /**
 607          * @return bool
 608          */
 609         function wasReadOnlyError() {
 610                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 611         }
 612
 613         /**
 614          * @return string wikitext of a link to the server software's web site
 615          */
 616         public function getSoftwareLink() {
 617                 return "[http://sqlite.org/ SQLite]";
 618         }
 619
 620         /**
 621          * @return string Version information from the database
 622          */
 623         function getServerVersion() {
 624                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 625                 return $ver;
 626         }
 627
 628         /**
 629          * @return string User-friendly database information
 630          */
 631         public function getServerInfo() {
 632                 return wfMessage( self::getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() )->text();
 633         }
 634
 635         /**
 636          * Get information about a given field
 637          * Returns false if the field does not exist.
 638          *
 639          * @param $table string
 640          * @param $field string
 641          * @return SQLiteField|bool False on failure
 642          */
 643         function fieldInfo( $table, $field ) {
 644                 $tableName = $this->tableName( $table );
 645                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 646                 $res = $this->query( $sql, __METHOD__ );
 647                 foreach ( $res as $row ) {
 648                         if ( $row->name == $field ) {
 649                                 return new SQLiteField( $row, $tableName );
 650                         }
 651                 }
 652                 return false;
 653         }
 654
 655         protected function doBegin( $fname = '' ) {
 656                 if ( $this->mTrxLevel == 1 ) {
 657                         $this->commit( __METHOD__ );
 658                 }
 659                 try {
 660                         $this->mConn->beginTransaction();
 661                 } catch ( PDOException $e ) {
 662                         throw new DBUnexpectedError( $this, 'Error in BEGIN query: ' . $e->getMessage() );
 663                 }
 664                 $this->mTrxLevel = 1;
 665         }
 666
 667         protected function doCommit( $fname = '' ) {
 668                 if ( $this->mTrxLevel == 0 ) {
 669                         return;
 670                 }
 671                 try {
 672                         $this->mConn->commit();
 673                 } catch ( PDOException $e ) {
 674                         throw new DBUnexpectedError( $this, 'Error in COMMIT query: ' . $e->getMessage() );
 675                 }
 676                 $this->mTrxLevel = 0;
 677         }
 678
 679         protected function doRollback( $fname = '' ) {
 680                 if ( $this->mTrxLevel == 0 ) {
 681                         return;
 682                 }
 683                 $this->mConn->rollBack();
 684                 $this->mTrxLevel = 0;
 685         }
 686
 687         /**
 688          * @param $s string
 689          * @return string
 690          */
 691         function strencode( $s ) {
 692                 return substr( $this->addQuotes( $s ), 1, - 1 );
 693         }
 694
 695         /**
 696          * @param $b
 697          * @return Blob
 698          */
 699         function encodeBlob( $b ) {
 700                 return new Blob( $b );
 701         }
 702
 703         /**
 704          * @param $b Blob|string
 705          * @return string
 706          */
 707         function decodeBlob( $b ) {
 708                 if ( $b instanceof Blob ) {
 709                         $b = $b->fetch();
 710                 }
 711                 return $b;
 712         }
 713
 714         /**
 715          * @param $s Blob|string
 716          * @return string
 717          */
 718         function addQuotes( $s ) {
 719                 if ( $s instanceof Blob ) {
 720                         return "x'" . bin2hex( $s->fetch() ) . "'";
 721                 } elseif ( is_bool( $s ) ) {
 722                         return (int)$s;
 723                 } elseif ( strpos( $s, "\0" ) !== false ) {
 724                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 725                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 726                         // but doesn't. I have reported this to php.net as bug #63419:
 727                         // https://bugs.php.net/bug.php?id=63419
 728                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 729                         // https://bugs.php.net/bug.php?id=62361
 730                         return "x'" . bin2hex( $s ) . "'";
 731                 } else {
 732                         return $this->mConn->quote( $s );
 733                 }
 734         }
 735
 736         /**
 737          * @return string
 738          */
 739         function buildLike() {
 740                 $params = func_get_args();
 741                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 742                         $params = $params[0];
 743                 }
 744                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 745         }
 746
 747         /**
 748          * @return string
 749          */
 750         public function getSearchEngine() {
 751                 return "SearchSqlite";
 752         }
 753
 754         /**
 755          * No-op version of deadlockLoop
 756          * @return mixed
 757          */
 758         public function deadlockLoop( /*...*/ ) {
 759                 $args = func_get_args();
 760                 $function = array_shift( $args );
 761                 return call_user_func_array( $function, $args );
 762         }
 763
 764         /**
 765          * @param $s string
 766          * @return string
 767          */
 768         protected function replaceVars( $s ) {
 769                 $s = parent::replaceVars( $s );
 770                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 771                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 772
 773                         // binary/varbinary column type -> blob
 774                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 775                         // no such thing as unsigned
 776                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 777                         // INT -> INTEGER
 778                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 779                         // floating point types -> REAL
 780                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 781                         // varchar -> TEXT
 782                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 783                         // TEXT normalization
 784                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 785                         // BLOB normalization
 786                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 787                         // BOOL -> INTEGER
 788                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 789                         // DATETIME -> TEXT
 790                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 791                         // No ENUM type
 792                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 793                         // binary collation type -> nothing
 794                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 795                         // auto_increment -> autoincrement
 796                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 797                         // No explicit options
 798                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 799                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 800                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 801                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 802                         // No truncated indexes
 803                         $s = preg_replace( '/\(\d+\)/', '', $s );
 804                         // No FULLTEXT
 805                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 806                 }
 807                 return $s;
 808         }
 809
 810         /**
 811          * Build a concatenation list to feed into a SQL query
 812          *
 813          * @param $stringList array
 814          *
 815          * @return string
 816          */
 817         function buildConcat( $stringList ) {
 818                 return '(' . implode( ') || (', $stringList ) . ')';
 819         }
 820
 821         /**
 822          * @throws MWException
 823          * @param $oldName
 824          * @param $newName
 825          * @param $temporary bool
 826          * @param $fname string
 827          * @return bool|ResultWrapper
 828          */
 829         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 830                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" . $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 831                 $obj = $this->fetchObject( $res );
 832                 if ( !$obj ) {
 833                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 834                 }
 835                 $sql = $obj->sql;
 836                 $sql = preg_replace( '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/', $this->addIdentifierQuotes( $newName ), $sql, 1 );
 837                 if ( $temporary ) {
 838                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 839                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 840                         } else {
 841                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 842                         }
 843                 }
 844                 return $this->query( $sql, $fname );
 845         }
 846
 847         /**
 848          * List all tables on the database
 849          *
 850          * @param string $prefix Only show tables with this prefix, e.g. mw_
 851          * @param string $fname calling function name
 852          *
 853          * @return array
 854          */
 855         function listTables( $prefix = null, $fname = __METHOD__ ) {
 856                 $result = $this->select(
 857                         'sqlite_master',
 858                         'name',
 859                         "type='table'"
 860                 );
 861
 862                 $endArray = array();
 863
 864                 foreach ( $result as $table ) {
 865                         $vars = get_object_vars( $table );
 866                         $table = array_pop( $vars );
 867
 868                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 869                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 870                                         $endArray[] = $table;
 871                                 }
 872
 873                         }
 874                 }
 875
 876                 return $endArray;
 877         }
 878
 879 } // end DatabaseSqlite class
 880
 881 /**
 882  * This class allows simple acccess to a SQLite database independently from main database settings
 883  * @ingroup Database
 884  */
 885 class DatabaseSqliteStandalone extends DatabaseSqlite {
 886         public function __construct( $fileName, $flags = 0 ) {
 887                 $this->mFlags = $flags;
 888                 $this->tablePrefix( null );
 889                 $this->openFile( $fileName );
 890         }
 891 }
 892
 893 /**
 894  * @ingroup Database
 895  */
 896 class SQLiteField implements Field {
 897         private $info, $tableName;
 898         function __construct( $info, $tableName ) {
 899                 $this->info = $info;
 900                 $this->tableName = $tableName;
 901         }
 902
 903         function name() {
 904                 return $this->info->name;
 905         }
 906
 907         function tableName() {
 908                 return $this->tableName;
 909         }
 910
 911         function defaultValue() {
 912                 if ( is_string( $this->info->dflt_value ) ) {
 913                         // Typically quoted
 914                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 915                                 return str_replace( "''", "'", $this->info->dflt_value );
 916                         }
 917                 }
 918                 return $this->info->dflt_value;
 919         }
 920
 921         /**
 922          * @return bool
 923          */
 924         function isNullable() {
 925                 return !$this->info->notnull;
 926         }
 927
 928         function type() {
 929                 return $this->info->type;
 930         }
 931
 932 } // end SQLiteField