includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  */
   6
   7 /** Number of times to re-try an operation in case of deadlock */
   8 define( 'DEADLOCK_TRIES', 4 );
   9 /** Minimum time to wait before retry, in microseconds */
  10 define( 'DEADLOCK_DELAY_MIN', 500000 );
  11 /** Maximum time to wait before retry */
  12 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  13
  14 /******************************************************************************
  15  * Utility classes
  16  *****************************************************************************/
  17
  18 class DBObject {
  19         public $mData;
  20
  21         function DBObject($data) {
  22                 $this->mData = $data;
  23         }
  24
  25         function isLOB() {
  26                 return false;
  27         }
  28
  29         function data() {
  30                 return $this->mData;
  31         }
  32 };
  33
  34 /******************************************************************************
  35  * Error classes
  36  *****************************************************************************/
  37
  38 /**
  39  * Database error base class
  40  */
  41 class DBError extends MWException {
  42         public $db;
  43
  44         /**
  45          * Construct a database error
  46          * @param Database $db The database object which threw the error
  47          * @param string $error A simple error message to be used for debugging
  48          */
  49         function __construct( Database &$db, $error ) {
  50                 $this->db =& $db;
  51                 parent::__construct( $error );
  52         }
  53 }
  54
  55 class DBConnectionError extends DBError {
  56         public $error;
  57
  58         function __construct( Database &$db, $error = 'unknown error' ) {
  59                 $msg = 'DB connection error';
  60                 if ( trim( $error ) != '' ) {
  61                         $msg .= ": $error";
  62                 }
  63                 $this->error = $error;
  64                 parent::__construct( $db, $msg );
  65         }
  66
  67         function useOutputPage() {
  68                 // Not likely to work
  69                 return false;
  70         }
  71
  72         function useMessageCache() {
  73                 // Not likely to work
  74                 return false;
  75         }
  76
  77         function getText() {
  78                 return $this->getMessage() . "\n";
  79         }
  80
  81         function getLogMessage() {
  82                 # Don't send to the exception log
  83                 return false;
  84         }
  85
  86         function getPageTitle() {
  87                 global $wgSitename;
  88                 return "$wgSitename has a problem";
  89         }
  90
  91         function getHTML() {
  92                 global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding;
  93                 global $wgSitename, $wgServer, $wgMessageCache;
  94
  95                 # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
  96                 # Hard coding strings instead.
  97
  98                 $noconnect = "<p><strong>Sorry! This site is experiencing technical difficulties.</strong></p><p>Try waiting a few minutes and reloading.</p><p><small>(Can't contact the database server: $1)</small></p>";
  99                 $mainpage = 'Main Page';
 100                 $searchdisabled = <<<EOT
 101 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
 102 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
 103 EOT;
 104
 105                 $googlesearch = "
 106 <!-- SiteSearch Google -->
 107 <FORM method=GET action=\"http://www.google.com/search\">
 108 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
 109 <A HREF=\"http://www.google.com/\">
 110 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
 111 border=\"0\" ALT=\"Google\"></A>
 112 </td>
 113 <td>
 114 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
 115 <INPUT type=submit name=btnG VALUE=\"Google Search\">
 116 <font size=-1>
 117 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
 118 <input type='hidden' name='ie' value='$2'>
 119 <input type='hidden' name='oe' value='$2'>
 120 </font>
 121 </td></tr></TABLE>
 122 </FORM>
 123 <!-- SiteSearch Google -->";
 124                 $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
 125
 126                 # No database access
 127                 if ( is_object( $wgMessageCache ) ) {
 128                         $wgMessageCache->disable();
 129                 }
 130
 131                 if ( trim( $this->error ) == '' ) {
 132                         $this->error = $this->db->getProperty('mServer');
 133                 }
 134
 135                 $text = str_replace( '$1', $this->error, $noconnect );
 136                 $text .= wfGetSiteNotice();
 137
 138                 if($wgUseFileCache) {
 139                         if($wgTitle) {
 140                                 $t =& $wgTitle;
 141                         } else {
 142                                 if($title) {
 143                                         $t = Title::newFromURL( $title );
 144                                 } elseif (@/**/$_REQUEST['search']) {
 145                                         $search = $_REQUEST['search'];
 146                                         return $searchdisabled .
 147                                           str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
 148                                           $wgInputEncoding ), $googlesearch );
 149                                 } else {
 150                                         $t = Title::newFromText( $mainpage );
 151                                 }
 152                         }
 153
 154                         $cache = new HTMLFileCache( $t );
 155                         if( $cache->isFileCached() ) {
 156                                 // FIXME: $msg is not defined on the next line.
 157                                 $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
 158                                         $cachederror . "</b></p>\n";
 159
 160                                 $tag = '<div id="article">';
 161                                 $text = str_replace(
 162                                         $tag,
 163                                         $tag . $msg,
 164                                         $cache->fetchPageText() );
 165                         }
 166                 }
 167
 168                 return $text;
 169         }
 170 }
 171
 172 class DBQueryError extends DBError {
 173         public $error, $errno, $sql, $fname;
 174
 175         function __construct( Database &$db, $error, $errno, $sql, $fname ) {
 176                 $message = "A database error has occurred\n" .
 177                   "Query: $sql\n" .
 178                   "Function: $fname\n" .
 179                   "Error: $errno $error\n";
 180
 181                 parent::__construct( $db, $message );
 182                 $this->error = $error;
 183                 $this->errno = $errno;
 184                 $this->sql = $sql;
 185                 $this->fname = $fname;
 186         }
 187
 188         function getText() {
 189                 if ( $this->useMessageCache() ) {
 190                         return wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
 191                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
 192                 } else {
 193                         return $this->getMessage();
 194                 }
 195         }
 196
 197         function getSQL() {
 198                 global $wgShowSQLErrors;
 199                 if( !$wgShowSQLErrors ) {
 200                         return $this->msg( 'sqlhidden', 'SQL hidden' );
 201                 } else {
 202                         return $this->sql;
 203                 }
 204         }
 205
 206         function getLogMessage() {
 207                 # Don't send to the exception log
 208                 return false;
 209         }
 210
 211         function getPageTitle() {
 212                 return $this->msg( 'databaseerror', 'Database error' );
 213         }
 214
 215         function getHTML() {
 216                 if ( $this->useMessageCache() ) {
 217                         return wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
 218                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
 219                 } else {
 220                         return nl2br( htmlspecialchars( $this->getMessage() ) );
 221                 }
 222         }
 223 }
 224
 225 class DBUnexpectedError extends DBError {}
 226
 227 /******************************************************************************/
 228
 229 /**
 230  * Database abstraction object
 231  */
 232 class Database {
 233
 234 #------------------------------------------------------------------------------
 235 # Variables
 236 #------------------------------------------------------------------------------
 237
 238         protected $mLastQuery = '';
 239
 240         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
 241         protected $mOut, $mOpened = false;
 242
 243         protected $mFailFunction;
 244         protected $mTablePrefix;
 245         protected $mFlags;
 246         protected $mTrxLevel = 0;
 247         protected $mErrorCount = 0;
 248         protected $mLBInfo = array();
 249         protected $mCascadingDeletes = false;
 250         protected $mCleanupTriggers = false;
 251         protected $mStrictIPs = false;
 252
 253 #------------------------------------------------------------------------------
 254 # Accessors
 255 #------------------------------------------------------------------------------
 256         # These optionally set a variable and return the previous state
 257
 258         /**
 259          * Fail function, takes a Database as a parameter
 260          * Set to false for default, 1 for ignore errors
 261          */
 262         function failFunction( $function = NULL ) {
 263                 return wfSetVar( $this->mFailFunction, $function );
 264         }
 265
 266         /**
 267          * Output page, used for reporting errors
 268          * FALSE means discard output
 269          */
 270         function setOutputPage( $out ) {
 271                 $this->mOut = $out;
 272         }
 273
 274         /**
 275          * Boolean, controls output of large amounts of debug information
 276          */
 277         function debug( $debug = NULL ) {
 278                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
 279         }
 280
 281         /**
 282          * Turns buffering of SQL result sets on (true) or off (false).
 283          * Default is "on" and it should not be changed without good reasons.
 284          */
 285         function bufferResults( $buffer = NULL ) {
 286                 if ( is_null( $buffer ) ) {
 287                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
 288                 } else {
 289                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
 290                 }
 291         }
 292
 293         /**
 294          * Turns on (false) or off (true) the automatic generation and sending
 295          * of a "we're sorry, but there has been a database error" page on
 296          * database errors. Default is on (false). When turned off, the
 297          * code should use lastErrno() and lastError() to handle the
 298          * situation as appropriate.
 299          */
 300         function ignoreErrors( $ignoreErrors = NULL ) {
 301                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 302         }
 303
 304         /**
 305          * The current depth of nested transactions
 306          * @param $level Integer: , default NULL.
 307          */
 308         function trxLevel( $level = NULL ) {
 309                 return wfSetVar( $this->mTrxLevel, $level );
 310         }
 311
 312         /**
 313          * Number of errors logged, only useful when errors are ignored
 314          */
 315         function errorCount( $count = NULL ) {
 316                 return wfSetVar( $this->mErrorCount, $count );
 317         }
 318
 319         /**
 320          * Properties passed down from the server info array of the load balancer
 321          */
 322         function getLBInfo( $name = NULL ) {
 323                 if ( is_null( $name ) ) {
 324                         return $this->mLBInfo;
 325                 } else {
 326                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 327                                 return $this->mLBInfo[$name];
 328                         } else {
 329                                 return NULL;
 330                         }
 331                 }
 332         }
 333
 334         function setLBInfo( $name, $value = NULL ) {
 335                 if ( is_null( $value ) ) {
 336                         $this->mLBInfo = $name;
 337                 } else {
 338                         $this->mLBInfo[$name] = $value;
 339                 }
 340         }
 341
 342         /**
 343          * Returns true if this database supports (and uses) cascading deletes
 344          */
 345         function cascadingDeletes() {
 346                 return $this->mCascadingDeletes;
 347         }
 348
 349         /**
 350          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 351          */
 352         function cleanupTriggers() {
 353                 return $this->mCleanupTriggers;
 354         }
 355
 356         /**
 357          * Returns true if this database is strict about what can be put into an IP field.
 358          * Specifically, it uses a NULL value instead of an empty string.
 359          */
 360         function strictIPs() {
 361                 return $this->mStrictIPs;
 362         }
 363
 364         /**
 365          * Returns true if this database uses timestamps rather than integers
 366         */
 367         function realTimestamps() {
 368                 return false;
 369         }
 370
 371         /**
 372          * Returns true if this database does an implicit sort when doing GROUP BY
 373          */
 374         function implicitGroupby() {
 375                 return true;
 376         }
 377
 378         /**
 379          * Returns true if this database can do a native search on IP columns
 380          * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
 381          */
 382         function searchableIPs() {
 383                 return false;
 384         }
 385
 386         /**#@+
 387          * Get function
 388          */
 389         function lastQuery() { return $this->mLastQuery; }
 390         function isOpen() { return $this->mOpened; }
 391         /**#@-*/
 392
 393         function setFlag( $flag ) {
 394                 $this->mFlags |= $flag;
 395         }
 396
 397         function clearFlag( $flag ) {
 398                 $this->mFlags &= ~$flag;
 399         }
 400
 401         function getFlag( $flag ) {
 402                 return !!($this->mFlags & $flag);
 403         }
 404
 405         /**
 406          * General read-only accessor
 407          */
 408         function getProperty( $name ) {
 409                 return $this->$name;
 410         }
 411
 412 #------------------------------------------------------------------------------
 413 # Other functions
 414 #------------------------------------------------------------------------------
 415
 416         /**@{{
 417          * @param string $server database server host
 418          * @param string $user database user name
 419          * @param string $password database user password
 420          * @param string $dbname database name
 421          */
 422
 423         /**
 424          * @param failFunction
 425          * @param $flags
 426          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 427          */
 428         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 429                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 430
 431                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 432                 # Can't get a reference if it hasn't been set yet
 433                 if ( !isset( $wgOut ) ) {
 434                         $wgOut = NULL;
 435                 }
 436                 $this->mOut =& $wgOut;
 437
 438                 $this->mFailFunction = $failFunction;
 439                 $this->mFlags = $flags;
 440
 441                 if ( $this->mFlags & DBO_DEFAULT ) {
 442                         if ( $wgCommandLineMode ) {
 443                                 $this->mFlags &= ~DBO_TRX;
 444                         } else {
 445                                 $this->mFlags |= DBO_TRX;
 446                         }
 447                 }
 448
 449                 /*
 450                 // Faster read-only access
 451                 if ( wfReadOnly() ) {
 452                         $this->mFlags |= DBO_PERSISTENT;
 453                         $this->mFlags &= ~DBO_TRX;
 454                 }*/
 455
 456                 /** Get the default table prefix*/
 457                 if ( $tablePrefix == 'get from global' ) {
 458                         $this->mTablePrefix = $wgDBprefix;
 459                 } else {
 460                         $this->mTablePrefix = $tablePrefix;
 461                 }
 462
 463                 if ( $server ) {
 464                         $this->open( $server, $user, $password, $dbName );
 465                 }
 466         }
 467
 468         /**
 469          * @static
 470          * @param failFunction
 471          * @param $flags
 472          */
 473         static function newFromParams( $server, $user, $password, $dbName,
 474                 $failFunction = false, $flags = 0 )
 475         {
 476                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 477         }
 478
 479         /**
 480          * Usually aborts on failure
 481          * If the failFunction is set to a non-zero integer, returns success
 482          */
 483         function open( $server, $user, $password, $dbName ) {
 484                 global $wguname;
 485                 wfProfileIn( __METHOD__ );
 486
 487                 # Test for missing mysql.so
 488                 # First try to load it
 489                 if (!@extension_loaded('mysql')) {
 490                         @dl('mysql.so');
 491                 }
 492
 493                 # Fail now
 494                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 495                 if ( !function_exists( 'mysql_connect' ) ) {
 496                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 497                 }
 498
 499                 $this->close();
 500                 $this->mServer = $server;
 501                 $this->mUser = $user;
 502                 $this->mPassword = $password;
 503                 $this->mDBname = $dbName;
 504
 505                 $success = false;
 506
 507                 wfProfileIn("dbconnect-$server");
 508
 509                 # LIVE PATCH by Tim, ask Domas for why: retry loop
 510                 $this->mConn = false;
 511                 $max = 3;
 512                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 513                         if ( $i > 1 ) {
 514                                 usleep( 1000 );
 515                         }
 516                         if ( $this->mFlags & DBO_PERSISTENT ) {
 517                                 @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 518                         } else {
 519                                 # Create a new connection...
 520                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 521                         }
 522                         if ($this->mConn === false) {
 523                                 $iplus = $i + 1;
 524                                 wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 525                         }
 526                 }
 527
 528                 wfProfileOut("dbconnect-$server");
 529
 530                 if ( $dbName != '' ) {
 531                         if ( $this->mConn !== false ) {
 532                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 533                                 if ( !$success ) {
 534                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 535                                                 "from client host {$wguname['nodename']}\n";
 536                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 537                                         wfDebug( $error );
 538                                 }
 539                         } else {
 540                                 wfDebug( "DB connection error\n" );
 541                                 wfDebug( "Server: $server, User: $user, Password: " .
 542                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 543                                 $success = false;
 544                         }
 545                 } else {
 546                         # Delay USE query
 547                         $success = (bool)$this->mConn;
 548                 }
 549
 550                 if ( $success ) {
 551                         global $wgDBmysql5;
 552                         if( $wgDBmysql5 ) {
 553                                 // Tell the server we're communicating with it in UTF-8.
 554                                 // This may engage various charset conversions.
 555                                 $this->query( 'SET NAMES utf8' );
 556                         }
 557                 } else {
 558                         $this->reportConnectionError();
 559                 }
 560
 561                 $this->mOpened = $success;
 562                 wfProfileOut( __METHOD__ );
 563                 return $success;
 564         }
 565         /**@}}*/
 566
 567         /**
 568          * Closes a database connection.
 569          * if it is open : commits any open transactions
 570          *
 571          * @return bool operation success. true if already closed.
 572          */
 573         function close()
 574         {
 575                 $this->mOpened = false;
 576                 if ( $this->mConn ) {
 577                         if ( $this->trxLevel() ) {
 578                                 $this->immediateCommit();
 579                         }
 580                         return mysql_close( $this->mConn );
 581                 } else {
 582                         return true;
 583                 }
 584         }
 585
 586         /**
 587          * @param string $error fallback error message, used if none is given by MySQL
 588          */
 589         function reportConnectionError( $error = 'Unknown error' ) {
 590                 $myError = $this->lastError();
 591                 if ( $myError ) {
 592                         $error = $myError;
 593                 }
 594
 595                 if ( $this->mFailFunction ) {
 596                         # Legacy error handling method
 597                         if ( !is_int( $this->mFailFunction ) ) {
 598                                 $ff = $this->mFailFunction;
 599                                 $ff( $this, $error );
 600                         }
 601                 } else {
 602                         # New method
 603                         wfLogDBError( "Connection error: $error\n" );
 604                         throw new DBConnectionError( $this, $error );
 605                 }
 606         }
 607
 608         /**
 609          * Usually aborts on failure
 610          * If errors are explicitly ignored, returns success
 611          */
 612         function query( $sql, $fname = '', $tempIgnore = false ) {
 613                 global $wgProfiling;
 614
 615                 if ( $wgProfiling ) {
 616                         # generalizeSQL will probably cut down the query to reasonable
 617                         # logging size most of the time. The substr is really just a sanity check.
 618
 619                         # Who's been wasting my precious column space? -- TS
 620                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 621
 622                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 623                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 624                                 $totalProf = 'Database::query';
 625                         } else {
 626                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 627                                 $totalProf = 'Database::query-master';
 628                         }
 629                         wfProfileIn( $totalProf );
 630                         wfProfileIn( $queryProf );
 631                 }
 632
 633                 $this->mLastQuery = $sql;
 634
 635                 # Add a comment for easy SHOW PROCESSLIST interpretation
 636                 if ( $fname ) {
 637                         $commentedSql = preg_replace('/\s/', " /* $fname */ ", $sql, 1);
 638                 } else {
 639                         $commentedSql = $sql;
 640                 }
 641
 642                 # If DBO_TRX is set, start a transaction
 643                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 644                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 645                 ) {
 646                         $this->begin();
 647                 }
 648
 649                 if ( $this->debug() ) {
 650                         $sqlx = substr( $commentedSql, 0, 500 );
 651                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 652                         wfDebug( "SQL: $sqlx\n" );
 653                 }
 654
 655                 # Do the query and handle errors
 656                 $ret = $this->doQuery( $commentedSql );
 657
 658                 # Try reconnecting if the connection was lost
 659                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 660                         # Transaction is gone, like it or not
 661                         $this->mTrxLevel = 0;
 662                         wfDebug( "Connection lost, reconnecting...\n" );
 663                         if ( $this->ping() ) {
 664                                 wfDebug( "Reconnected\n" );
 665                                 $ret = $this->doQuery( $commentedSql );
 666                         } else {
 667                                 wfDebug( "Failed\n" );
 668                         }
 669                 }
 670
 671                 if ( false === $ret ) {
 672                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 673                 }
 674
 675                 if ( $wgProfiling ) {
 676                         wfProfileOut( $queryProf );
 677                         wfProfileOut( $totalProf );
 678                 }
 679                 return $ret;
 680         }
 681
 682         /**
 683          * The DBMS-dependent part of query()
 684          * @param string $sql SQL query.
 685          */
 686         function doQuery( $sql ) {
 687                 if( $this->bufferResults() ) {
 688                         $ret = mysql_query( $sql, $this->mConn );
 689                 } else {
 690                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 691                 }
 692                 return $ret;
 693         }
 694
 695         /**
 696          * @param $error
 697          * @param $errno
 698          * @param $sql
 699          * @param string $fname
 700          * @param bool $tempIgnore
 701          */
 702         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 703                 global $wgCommandLineMode;
 704                 # Ignore errors during error handling to avoid infinite recursion
 705                 $ignore = $this->ignoreErrors( true );
 706                 ++$this->mErrorCount;
 707
 708                 if( $ignore || $tempIgnore ) {
 709                         wfDebug("SQL ERROR (ignored): $error\n");
 710                         $this->ignoreErrors( $ignore );
 711                 } else {
 712                         $sql1line = str_replace( "\n", "\\n", $sql );
 713                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 714                         wfDebug("SQL ERROR: " . $error . "\n");
 715                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 716                 }
 717         }
 718
 719
 720         /**
 721          * Intended to be compatible with the PEAR::DB wrapper functions.
 722          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 723          *
 724          * ? = scalar value, quoted as necessary
 725          * ! = raw SQL bit (a function for instance)
 726          * & = filename; reads the file and inserts as a blob
 727          *     (we don't use this though...)
 728          */
 729         function prepare( $sql, $func = 'Database::prepare' ) {
 730                 /* MySQL doesn't support prepared statements (yet), so just
 731                    pack up the query for reference. We'll manually replace
 732                    the bits later. */
 733                 return array( 'query' => $sql, 'func' => $func );
 734         }
 735
 736         function freePrepared( $prepared ) {
 737                 /* No-op for MySQL */
 738         }
 739
 740         /**
 741          * Execute a prepared query with the various arguments
 742          * @param string $prepared the prepared sql
 743          * @param mixed $args Either an array here, or put scalars as varargs
 744          */
 745         function execute( $prepared, $args = null ) {
 746                 if( !is_array( $args ) ) {
 747                         # Pull the var args
 748                         $args = func_get_args();
 749                         array_shift( $args );
 750                 }
 751                 $sql = $this->fillPrepared( $prepared['query'], $args );
 752                 return $this->query( $sql, $prepared['func'] );
 753         }
 754
 755         /**
 756          * Prepare & execute an SQL statement, quoting and inserting arguments
 757          * in the appropriate places.
 758          * @param string $query
 759          * @param string $args ...
 760          */
 761         function safeQuery( $query, $args = null ) {
 762                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 763                 if( !is_array( $args ) ) {
 764                         # Pull the var args
 765                         $args = func_get_args();
 766                         array_shift( $args );
 767                 }
 768                 $retval = $this->execute( $prepared, $args );
 769                 $this->freePrepared( $prepared );
 770                 return $retval;
 771         }
 772
 773         /**
 774          * For faking prepared SQL statements on DBs that don't support
 775          * it directly.
 776          * @param string $preparedSql - a 'preparable' SQL statement
 777          * @param array $args - array of arguments to fill it with
 778          * @return string executable SQL
 779          */
 780         function fillPrepared( $preparedQuery, $args ) {
 781                 reset( $args );
 782                 $this->preparedArgs =& $args;
 783                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 784                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 785         }
 786
 787         /**
 788          * preg_callback func for fillPrepared()
 789          * The arguments should be in $this->preparedArgs and must not be touched
 790          * while we're doing this.
 791          *
 792          * @param array $matches
 793          * @return string
 794          * @private
 795          */
 796         function fillPreparedArg( $matches ) {
 797                 switch( $matches[1] ) {
 798                         case '\\?': return '?';
 799                         case '\\!': return '!';
 800                         case '\\&': return '&';
 801                 }
 802                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 803                 switch( $matches[1] ) {
 804                         case '?': return $this->addQuotes( $arg );
 805                         case '!': return $arg;
 806                         case '&':
 807                                 # return $this->addQuotes( file_get_contents( $arg ) );
 808                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 809                         default:
 810                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 811                 }
 812         }
 813
 814         /**#@+
 815          * @param mixed $res A SQL result
 816          */
 817         /**
 818          * Free a result object
 819          */
 820         function freeResult( $res ) {
 821                 if ( !@/**/mysql_free_result( $res ) ) {
 822                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 823                 }
 824         }
 825
 826         /**
 827          * Fetch the next row from the given result object, in object form
 828          */
 829         function fetchObject( $res ) {
 830                 @/**/$row = mysql_fetch_object( $res );
 831                 if( $this->lastErrno() ) {
 832                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 833                 }
 834                 return $row;
 835         }
 836
 837         /**
 838          * Fetch the next row from the given result object
 839          * Returns an array
 840          */
 841         function fetchRow( $res ) {
 842                 @/**/$row = mysql_fetch_array( $res );
 843                 if ( $this->lastErrno() ) {
 844                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 845                 }
 846                 return $row;
 847         }
 848
 849         /**
 850          * Get the number of rows in a result object
 851          */
 852         function numRows( $res ) {
 853                 @/**/$n = mysql_num_rows( $res );
 854                 if( $this->lastErrno() ) {
 855                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 856                 }
 857                 return $n;
 858         }
 859
 860         /**
 861          * Get the number of fields in a result object
 862          * See documentation for mysql_num_fields()
 863          */
 864         function numFields( $res ) { return mysql_num_fields( $res ); }
 865
 866         /**
 867          * Get a field name in a result object
 868          * See documentation for mysql_field_name():
 869          * http://www.php.net/mysql_field_name
 870          */
 871         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 872
 873         /**
 874          * Get the inserted value of an auto-increment row
 875          *
 876          * The value inserted should be fetched from nextSequenceValue()
 877          *
 878          * Example:
 879          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 880          * $dbw->insert('page',array('page_id' => $id));
 881          * $id = $dbw->insertId();
 882          */
 883         function insertId() { return mysql_insert_id( $this->mConn ); }
 884
 885         /**
 886          * Change the position of the cursor in a result object
 887          * See mysql_data_seek()
 888          */
 889         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 890
 891         /**
 892          * Get the last error number
 893          * See mysql_errno()
 894          */
 895         function lastErrno() {
 896                 if ( $this->mConn ) {
 897                         return mysql_errno( $this->mConn );
 898                 } else {
 899                         return mysql_errno();
 900                 }
 901         }
 902
 903         /**
 904          * Get a description of the last error
 905          * See mysql_error() for more details
 906          */
 907         function lastError() {
 908                 if ( $this->mConn ) {
 909                         # Even if it's non-zero, it can still be invalid
 910                         wfSuppressWarnings();
 911                         $error = mysql_error( $this->mConn );
 912                         if ( !$error ) {
 913                                 $error = mysql_error();
 914                         }
 915                         wfRestoreWarnings();
 916                 } else {
 917                         $error = mysql_error();
 918                 }
 919                 if( $error ) {
 920                         $error .= ' (' . $this->mServer . ')';
 921                 }
 922                 return $error;
 923         }
 924         /**
 925          * Get the number of rows affected by the last write query
 926          * See mysql_affected_rows() for more details
 927          */
 928         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 929         /**#@-*/ // end of template : @param $result
 930
 931         /**
 932          * Simple UPDATE wrapper
 933          * Usually aborts on failure
 934          * If errors are explicitly ignored, returns success
 935          *
 936          * This function exists for historical reasons, Database::update() has a more standard
 937          * calling convention and feature set
 938          */
 939         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 940         {
 941                 $table = $this->tableName( $table );
 942                 $sql = "UPDATE $table SET $var = '" .
 943                   $this->strencode( $value ) . "' WHERE ($cond)";
 944                 return (bool)$this->query( $sql, $fname );
 945         }
 946
 947         /**
 948          * Simple SELECT wrapper, returns a single field, input must be encoded
 949          * Usually aborts on failure
 950          * If errors are explicitly ignored, returns FALSE on failure
 951          */
 952         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 953                 if ( !is_array( $options ) ) {
 954                         $options = array( $options );
 955                 }
 956                 $options['LIMIT'] = 1;
 957
 958                 $res = $this->select( $table, $var, $cond, $fname, $options );
 959                 if ( $res === false || !$this->numRows( $res ) ) {
 960                         return false;
 961                 }
 962                 $row = $this->fetchRow( $res );
 963                 if ( $row !== false ) {
 964                         $this->freeResult( $res );
 965                         return $row[0];
 966                 } else {
 967                         return false;
 968                 }
 969         }
 970
 971         /**
 972          * Returns an optional USE INDEX clause to go after the table, and a
 973          * string to go at the end of the query
 974          *
 975          * @private
 976          *
 977          * @param array $options an associative array of options to be turned into
 978          *              an SQL query, valid keys are listed in the function.
 979          * @return array
 980          */
 981         function makeSelectOptions( $options ) {
 982                 $tailOpts = '';
 983                 $startOpts = '';
 984
 985                 $noKeyOptions = array();
 986                 foreach ( $options as $key => $option ) {
 987                         if ( is_numeric( $key ) ) {
 988                                 $noKeyOptions[$option] = true;
 989                         }
 990                 }
 991
 992                 if ( isset( $options['GROUP BY'] ) ) $tailOpts .= " GROUP BY {$options['GROUP BY']}";
 993                 if ( isset( $options['ORDER BY'] ) ) $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 994
 995                 if (isset($options['LIMIT'])) {
 996                         $tailOpts .= $this->limitResult('', $options['LIMIT'],
 997                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
 998                 }
 999
1000                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
1001                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
1002                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1003
1004                 # Various MySQL extensions
1005                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
1006                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
1007                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
1008                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
1009                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
1010                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
1011                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
1012                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1013
1014                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1015                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1016                 } else {
1017                         $useIndex = '';
1018                 }
1019
1020                 return array( $startOpts, $useIndex, $tailOpts );
1021         }
1022
1023         /**
1024          * SELECT wrapper
1025          *
1026          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
1027          * @param mixed  $vars    Array or string, field name(s) to be retrieved
1028          * @param mixed  $conds   Array or string, condition(s) for WHERE
1029          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
1030          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1031          *                        see Database::makeSelectOptions code for list of supported stuff
1032          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
1033          */
1034         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1035         {
1036                 if( is_array( $vars ) ) {
1037                         $vars = implode( ',', $vars );
1038                 }
1039                 if( !is_array( $options ) ) {
1040                         $options = array( $options );
1041                 }
1042                 if( is_array( $table ) ) {
1043                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1044                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1045                         else
1046                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1047                 } elseif ($table!='') {
1048                         $from = ' FROM ' . $this->tableName( $table );
1049                 } else {
1050                         $from = '';
1051                 }
1052
1053                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
1054
1055                 if( !empty( $conds ) ) {
1056                         if ( is_array( $conds ) ) {
1057                                 $conds = $this->makeList( $conds, LIST_AND );
1058                         }
1059                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $tailOpts";
1060                 } else {
1061                         $sql = "SELECT $startOpts $vars $from $useIndex $tailOpts";
1062                 }
1063
1064                 return $this->query( $sql, $fname );
1065         }
1066
1067         /**
1068          * Single row SELECT wrapper
1069          * Aborts or returns FALSE on error
1070          *
1071          * $vars: the selected variables
1072          * $conds: a condition map, terms are ANDed together.
1073          *   Items with numeric keys are taken to be literal conditions
1074          * Takes an array of selected variables, and a condition map, which is ANDed
1075          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1076          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1077          * $obj- >page_id is the ID of the Astronomy article
1078          *
1079          * @todo migrate documentation to phpdocumentor format
1080          */
1081         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1082                 $options['LIMIT'] = 1;
1083                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1084                 if ( $res === false )
1085                         return false;
1086                 if ( !$this->numRows($res) ) {
1087                         $this->freeResult($res);
1088                         return false;
1089                 }
1090                 $obj = $this->fetchObject( $res );
1091                 $this->freeResult( $res );
1092                 return $obj;
1093
1094         }
1095
1096         /**
1097          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1098          * It's only slightly flawed. Don't use for anything important.
1099          *
1100          * @param string $sql A SQL Query
1101          * @static
1102          */
1103         static function generalizeSQL( $sql ) {
1104                 # This does the same as the regexp below would do, but in such a way
1105                 # as to avoid crashing php on some large strings.
1106                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1107
1108                 $sql = str_replace ( "\\\\", '', $sql);
1109                 $sql = str_replace ( "\\'", '', $sql);
1110                 $sql = str_replace ( "\\\"", '', $sql);
1111                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1112                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1113
1114                 # All newlines, tabs, etc replaced by single space
1115                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1116
1117                 # All numbers => N
1118                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1119
1120                 return $sql;
1121         }
1122
1123         /**
1124          * Determines whether a field exists in a table
1125          * Usually aborts on failure
1126          * If errors are explicitly ignored, returns NULL on failure
1127          */
1128         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1129                 $table = $this->tableName( $table );
1130                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1131                 if ( !$res ) {
1132                         return NULL;
1133                 }
1134
1135                 $found = false;
1136
1137                 while ( $row = $this->fetchObject( $res ) ) {
1138                         if ( $row->Field == $field ) {
1139                                 $found = true;
1140                                 break;
1141                         }
1142                 }
1143                 return $found;
1144         }
1145
1146         /**
1147          * Determines whether an index exists
1148          * Usually aborts on failure
1149          * If errors are explicitly ignored, returns NULL on failure
1150          */
1151         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1152                 $info = $this->indexInfo( $table, $index, $fname );
1153                 if ( is_null( $info ) ) {
1154                         return NULL;
1155                 } else {
1156                         return $info !== false;
1157                 }
1158         }
1159
1160
1161         /**
1162          * Get information about an index into an object
1163          * Returns false if the index does not exist
1164          */
1165         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1166                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1167                 # SHOW INDEX should work for 3.x and up:
1168                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1169                 $table = $this->tableName( $table );
1170                 $sql = 'SHOW INDEX FROM '.$table;
1171                 $res = $this->query( $sql, $fname );
1172                 if ( !$res ) {
1173                         return NULL;
1174                 }
1175
1176                 $result = array();
1177                 while ( $row = $this->fetchObject( $res ) ) {
1178                         if ( $row->Key_name == $index ) {
1179                                 $result[] = $row;
1180                         }
1181                 }
1182                 $this->freeResult($res);
1183
1184                 return empty($result) ? false : $result;
1185         }
1186
1187         /**
1188          * Query whether a given table exists
1189          */
1190         function tableExists( $table ) {
1191                 $table = $this->tableName( $table );
1192                 $old = $this->ignoreErrors( true );
1193                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1194                 $this->ignoreErrors( $old );
1195                 if( $res ) {
1196                         $this->freeResult( $res );
1197                         return true;
1198                 } else {
1199                         return false;
1200                 }
1201         }
1202
1203         /**
1204          * mysql_fetch_field() wrapper
1205          * Returns false if the field doesn't exist
1206          *
1207          * @param $table
1208          * @param $field
1209          */
1210         function fieldInfo( $table, $field ) {
1211                 $table = $this->tableName( $table );
1212                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1213                 $n = mysql_num_fields( $res );
1214                 for( $i = 0; $i < $n; $i++ ) {
1215                         $meta = mysql_fetch_field( $res, $i );
1216                         if( $field == $meta->name ) {
1217                                 return $meta;
1218                         }
1219                 }
1220                 return false;
1221         }
1222
1223         /**
1224          * mysql_field_type() wrapper
1225          */
1226         function fieldType( $res, $index ) {
1227                 return mysql_field_type( $res, $index );
1228         }
1229
1230         /**
1231          * Determines if a given index is unique
1232          */
1233         function indexUnique( $table, $index ) {
1234                 $indexInfo = $this->indexInfo( $table, $index );
1235                 if ( !$indexInfo ) {
1236                         return NULL;
1237                 }
1238                 return !$indexInfo[0]->Non_unique;
1239         }
1240
1241         /**
1242          * INSERT wrapper, inserts an array into a table
1243          *
1244          * $a may be a single associative array, or an array of these with numeric keys, for
1245          * multi-row insert.
1246          *
1247          * Usually aborts on failure
1248          * If errors are explicitly ignored, returns success
1249          */
1250         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1251                 # No rows to insert, easy just return now
1252                 if ( !count( $a ) ) {
1253                         return true;
1254                 }
1255
1256                 $table = $this->tableName( $table );
1257                 if ( !is_array( $options ) ) {
1258                         $options = array( $options );
1259                 }
1260                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1261                         $multi = true;
1262                         $keys = array_keys( $a[0] );
1263                 } else {
1264                         $multi = false;
1265                         $keys = array_keys( $a );
1266                 }
1267
1268                 $sql = 'INSERT ' . implode( ' ', $options ) .
1269                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1270
1271                 if ( $multi ) {
1272                         $first = true;
1273                         foreach ( $a as $row ) {
1274                                 if ( $first ) {
1275                                         $first = false;
1276                                 } else {
1277                                         $sql .= ',';
1278                                 }
1279                                 $sql .= '(' . $this->makeList( $row ) . ')';
1280                         }
1281                 } else {
1282                         $sql .= '(' . $this->makeList( $a ) . ')';
1283                 }
1284                 return (bool)$this->query( $sql, $fname );
1285         }
1286
1287         /**
1288          * Make UPDATE options for the Database::update function
1289          *
1290          * @private
1291          * @param array $options The options passed to Database::update
1292          * @return string
1293          */
1294         function makeUpdateOptions( $options ) {
1295                 if( !is_array( $options ) ) {
1296                         $options = array( $options );
1297                 }
1298                 $opts = array();
1299                 if ( in_array( 'LOW_PRIORITY', $options ) )
1300                         $opts[] = $this->lowPriorityOption();
1301                 if ( in_array( 'IGNORE', $options ) )
1302                         $opts[] = 'IGNORE';
1303                 return implode(' ', $opts);
1304         }
1305
1306         /**
1307          * UPDATE wrapper, takes a condition array and a SET array
1308          *
1309          * @param string $table  The table to UPDATE
1310          * @param array  $values An array of values to SET
1311          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1312          * @param string $fname  The Class::Function calling this function
1313          *                       (for the log)
1314          * @param array  $options An array of UPDATE options, can be one or
1315          *                        more of IGNORE, LOW_PRIORITY
1316          */
1317         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1318                 $table = $this->tableName( $table );
1319                 $opts = $this->makeUpdateOptions( $options );
1320                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1321                 if ( $conds != '*' ) {
1322                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1323                 }
1324                 $this->query( $sql, $fname );
1325         }
1326
1327         /**
1328          * Makes an encoded list of strings from an array
1329          * $mode:
1330          *        LIST_COMMA         - comma separated, no field names
1331          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1332          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1333          *        LIST_SET           - comma separated with field names, like a SET clause
1334          *        LIST_NAMES         - comma separated field names
1335          */
1336         function makeList( $a, $mode = LIST_COMMA ) {
1337                 if ( !is_array( $a ) ) {
1338                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1339                 }
1340
1341                 $first = true;
1342                 $list = '';
1343                 foreach ( $a as $field => $value ) {
1344                         if ( !$first ) {
1345                                 if ( $mode == LIST_AND ) {
1346                                         $list .= ' AND ';
1347                                 } elseif($mode == LIST_OR) {
1348                                         $list .= ' OR ';
1349                                 } else {
1350                                         $list .= ',';
1351                                 }
1352                         } else {
1353                                 $first = false;
1354                         }
1355                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1356                                 $list .= "($value)";
1357                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1358                                 $list .= "$value";
1359                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1360                                 $list .= $field." IN (".$this->makeList($value).") ";
1361                         } else {
1362                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1363                                         $list .= "$field = ";
1364                                 }
1365                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1366                         }
1367                 }
1368                 return $list;
1369         }
1370
1371         /**
1372          * Change the current database
1373          */
1374         function selectDB( $db ) {
1375                 $this->mDBname = $db;
1376                 return mysql_select_db( $db, $this->mConn );
1377         }
1378
1379         /**
1380          * Format a table name ready for use in constructing an SQL query
1381          *
1382          * This does two important things: it quotes table names which as necessary,
1383          * and it adds a table prefix if there is one.
1384          *
1385          * All functions of this object which require a table name call this function
1386          * themselves. Pass the canonical name to such functions. This is only needed
1387          * when calling query() directly.
1388          *
1389          * @param string $name database table name
1390          */
1391         function tableName( $name ) {
1392                 global $wgSharedDB;
1393                 # Skip quoted literals
1394                 if ( $name{0} != '`' ) {
1395                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1396                                 $name = "{$this->mTablePrefix}$name";
1397                         }
1398                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1399                                 $name = "`$wgSharedDB`.`$name`";
1400                         } else {
1401                                 # Standard quoting
1402                                 $name = "`$name`";
1403                         }
1404                 }
1405                 return $name;
1406         }
1407
1408         /**
1409          * Fetch a number of table names into an array
1410          * This is handy when you need to construct SQL for joins
1411          *
1412          * Example:
1413          * extract($dbr->tableNames('user','watchlist'));
1414          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1415          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1416          */
1417         public function tableNames() {
1418                 $inArray = func_get_args();
1419                 $retVal = array();
1420                 foreach ( $inArray as $name ) {
1421                         $retVal[$name] = $this->tableName( $name );
1422                 }
1423                 return $retVal;
1424         }
1425
1426         /**
1427          * @desc: Fetch a number of table names into an zero-indexed numerical array
1428          * This is handy when you need to construct SQL for joins
1429          *
1430          * Example:
1431          * list( $user, $watchlist ) = $dbr->tableNames('user','watchlist');
1432          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1433          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1434          */
1435         public function tableNamesN() {
1436                 $inArray = func_get_args();
1437                 $retVal = array();
1438                 foreach ( $inArray as $name ) {
1439                         $retVal[] = $this->tableName( $name );
1440                 }
1441                 return $retVal;
1442         }
1443
1444         /**
1445          * @private
1446          */
1447         function tableNamesWithUseIndex( $tables, $use_index ) {
1448                 $ret = array();
1449
1450                 foreach ( $tables as $table )
1451                         if ( @$use_index[$table] !== null )
1452                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1453                         else
1454                                 $ret[] = $this->tableName( $table );
1455
1456                 return implode( ',', $ret );
1457         }
1458
1459         /**
1460          * Wrapper for addslashes()
1461          * @param string $s String to be slashed.
1462          * @return string slashed string.
1463          */
1464         function strencode( $s ) {
1465                 return mysql_real_escape_string( $s, $this->mConn );
1466         }
1467
1468         /**
1469          * If it's a string, adds quotes and backslashes
1470          * Otherwise returns as-is
1471          */
1472         function addQuotes( $s ) {
1473                 if ( is_null( $s ) ) {
1474                         return 'NULL';
1475                 } else {
1476                         # This will also quote numeric values. This should be harmless,
1477                         # and protects against weird problems that occur when they really
1478                         # _are_ strings such as article titles and string->number->string
1479                         # conversion is not 1:1.
1480                         return "'" . $this->strencode( $s ) . "'";
1481                 }
1482         }
1483
1484         /**
1485          * Escape string for safe LIKE usage
1486          */
1487         function escapeLike( $s ) {
1488                 $s=$this->strencode( $s );
1489                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1490                 return $s;
1491         }
1492
1493         /**
1494          * Returns an appropriately quoted sequence value for inserting a new row.
1495          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1496          * subclass will return an integer, and save the value for insertId()
1497          */
1498         function nextSequenceValue( $seqName ) {
1499                 return NULL;
1500         }
1501
1502         /**
1503          * USE INDEX clause
1504          * PostgreSQL doesn't have them and returns ""
1505          */
1506         function useIndexClause( $index ) {
1507                 return "FORCE INDEX ($index)";
1508         }
1509
1510         /**
1511          * REPLACE query wrapper
1512          * PostgreSQL simulates this with a DELETE followed by INSERT
1513          * $row is the row to insert, an associative array
1514          * $uniqueIndexes is an array of indexes. Each element may be either a
1515          * field name or an array of field names
1516          *
1517          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1518          * However if you do this, you run the risk of encountering errors which wouldn't have
1519          * occurred in MySQL
1520          *
1521          * @todo migrate comment to phodocumentor format
1522          */
1523         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1524                 $table = $this->tableName( $table );
1525
1526                 # Single row case
1527                 if ( !is_array( reset( $rows ) ) ) {
1528                         $rows = array( $rows );
1529                 }
1530
1531                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1532                 $first = true;
1533                 foreach ( $rows as $row ) {
1534                         if ( $first ) {
1535                                 $first = false;
1536                         } else {
1537                                 $sql .= ',';
1538                         }
1539                         $sql .= '(' . $this->makeList( $row ) . ')';
1540                 }
1541                 return $this->query( $sql, $fname );
1542         }
1543
1544         /**
1545          * DELETE where the condition is a join
1546          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1547          *
1548          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1549          * join condition matches, set $conds='*'
1550          *
1551          * DO NOT put the join condition in $conds
1552          *
1553          * @param string $delTable The table to delete from.
1554          * @param string $joinTable The other table.
1555          * @param string $delVar The variable to join on, in the first table.
1556          * @param string $joinVar The variable to join on, in the second table.
1557          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1558          */
1559         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1560                 if ( !$conds ) {
1561                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1562                 }
1563
1564                 $delTable = $this->tableName( $delTable );
1565                 $joinTable = $this->tableName( $joinTable );
1566                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1567                 if ( $conds != '*' ) {
1568                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1569                 }
1570
1571                 return $this->query( $sql, $fname );
1572         }
1573
1574         /**
1575          * Returns the size of a text field, or -1 for "unlimited"
1576          */
1577         function textFieldSize( $table, $field ) {
1578                 $table = $this->tableName( $table );
1579                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1580                 $res = $this->query( $sql, 'Database::textFieldSize' );
1581                 $row = $this->fetchObject( $res );
1582                 $this->freeResult( $res );
1583
1584                 $m = array();
1585                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1586                         $size = $m[1];
1587                 } else {
1588                         $size = -1;
1589                 }
1590                 return $size;
1591         }
1592
1593         /**
1594          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1595          */
1596         function lowPriorityOption() {
1597                 return 'LOW_PRIORITY';
1598         }
1599
1600         /**
1601          * DELETE query wrapper
1602          *
1603          * Use $conds == "*" to delete all rows
1604          */
1605         function delete( $table, $conds, $fname = 'Database::delete' ) {
1606                 if ( !$conds ) {
1607                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1608                 }
1609                 $table = $this->tableName( $table );
1610                 $sql = "DELETE FROM $table";
1611                 if ( $conds != '*' ) {
1612                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1613                 }
1614                 return $this->query( $sql, $fname );
1615         }
1616
1617         /**
1618          * INSERT SELECT wrapper
1619          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1620          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1621          * $conds may be "*" to copy the whole table
1622          * srcTable may be an array of tables.
1623          */
1624         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1625                 $insertOptions = array(), $selectOptions = array() )
1626         {
1627                 $destTable = $this->tableName( $destTable );
1628                 if ( is_array( $insertOptions ) ) {
1629                         $insertOptions = implode( ' ', $insertOptions );
1630                 }
1631                 if( !is_array( $selectOptions ) ) {
1632                         $selectOptions = array( $selectOptions );
1633                 }
1634                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1635                 if( is_array( $srcTable ) ) {
1636                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1637                 } else {
1638                         $srcTable = $this->tableName( $srcTable );
1639                 }
1640                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1641                         " SELECT $startOpts " . implode( ',', $varMap ) .
1642                         " FROM $srcTable $useIndex ";
1643                 if ( $conds != '*' ) {
1644                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1645                 }
1646                 $sql .= " $tailOpts";
1647                 return $this->query( $sql, $fname );
1648         }
1649
1650         /**
1651          * Construct a LIMIT query with optional offset
1652          * This is used for query pages
1653          * $sql string SQL query we will append the limit too
1654          * $limit integer the SQL limit
1655          * $offset integer the SQL offset (default false)
1656          */
1657         function limitResult($sql, $limit, $offset=false) {
1658                 if( !is_numeric($limit) ) {
1659                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1660                 }
1661                 return " $sql LIMIT "
1662                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1663                                 . "{$limit} ";
1664         }
1665         function limitResultForUpdate($sql, $num) {
1666                 return $this->limitResult($sql, $num, 0);
1667         }
1668
1669         /**
1670          * Returns an SQL expression for a simple conditional.
1671          * Uses IF on MySQL.
1672          *
1673          * @param string $cond SQL expression which will result in a boolean value
1674          * @param string $trueVal SQL expression to return if true
1675          * @param string $falseVal SQL expression to return if false
1676          * @return string SQL fragment
1677          */
1678         function conditional( $cond, $trueVal, $falseVal ) {
1679                 return " IF($cond, $trueVal, $falseVal) ";
1680         }
1681
1682         /**
1683          * Determines if the last failure was due to a deadlock
1684          */
1685         function wasDeadlock() {
1686                 return $this->lastErrno() == 1213;
1687         }
1688
1689         /**
1690          * Perform a deadlock-prone transaction.
1691          *
1692          * This function invokes a callback function to perform a set of write
1693          * queries. If a deadlock occurs during the processing, the transaction
1694          * will be rolled back and the callback function will be called again.
1695          *
1696          * Usage:
1697          *   $dbw->deadlockLoop( callback, ... );
1698          *
1699          * Extra arguments are passed through to the specified callback function.
1700          *
1701          * Returns whatever the callback function returned on its successful,
1702          * iteration, or false on error, for example if the retry limit was
1703          * reached.
1704          */
1705         function deadlockLoop() {
1706                 $myFname = 'Database::deadlockLoop';
1707
1708                 $this->begin();
1709                 $args = func_get_args();
1710                 $function = array_shift( $args );
1711                 $oldIgnore = $this->ignoreErrors( true );
1712                 $tries = DEADLOCK_TRIES;
1713                 if ( is_array( $function ) ) {
1714                         $fname = $function[0];
1715                 } else {
1716                         $fname = $function;
1717                 }
1718                 do {
1719                         $retVal = call_user_func_array( $function, $args );
1720                         $error = $this->lastError();
1721                         $errno = $this->lastErrno();
1722                         $sql = $this->lastQuery();
1723
1724                         if ( $errno ) {
1725                                 if ( $this->wasDeadlock() ) {
1726                                         # Retry
1727                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1728                                 } else {
1729                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1730                                 }
1731                         }
1732                 } while( $this->wasDeadlock() && --$tries > 0 );
1733                 $this->ignoreErrors( $oldIgnore );
1734                 if ( $tries <= 0 ) {
1735                         $this->query( 'ROLLBACK', $myFname );
1736                         $this->reportQueryError( $error, $errno, $sql, $fname );
1737                         return false;
1738                 } else {
1739                         $this->query( 'COMMIT', $myFname );
1740                         return $retVal;
1741                 }
1742         }
1743
1744         /**
1745          * Do a SELECT MASTER_POS_WAIT()
1746          *
1747          * @param string $file the binlog file
1748          * @param string $pos the binlog position
1749          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1750          */
1751         function masterPosWait( $file, $pos, $timeout ) {
1752                 $fname = 'Database::masterPosWait';
1753                 wfProfileIn( $fname );
1754
1755
1756                 # Commit any open transactions
1757                 $this->immediateCommit();
1758
1759                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1760                 $encFile = $this->strencode( $file );
1761                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1762                 $res = $this->doQuery( $sql );
1763                 if ( $res && $row = $this->fetchRow( $res ) ) {
1764                         $this->freeResult( $res );
1765                         wfProfileOut( $fname );
1766                         return $row[0];
1767                 } else {
1768                         wfProfileOut( $fname );
1769                         return false;
1770                 }
1771         }
1772
1773         /**
1774          * Get the position of the master from SHOW SLAVE STATUS
1775          */
1776         function getSlavePos() {
1777                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1778                 $row = $this->fetchObject( $res );
1779                 if ( $row ) {
1780                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1781                 } else {
1782                         return array( false, false );
1783                 }
1784         }
1785
1786         /**
1787          * Get the position of the master from SHOW MASTER STATUS
1788          */
1789         function getMasterPos() {
1790                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1791                 $row = $this->fetchObject( $res );
1792                 if ( $row ) {
1793                         return array( $row->File, $row->Position );
1794                 } else {
1795                         return array( false, false );
1796                 }
1797         }
1798
1799         /**
1800          * Begin a transaction, committing any previously open transaction
1801          */
1802         function begin( $fname = 'Database::begin' ) {
1803                 $this->query( 'BEGIN', $fname );
1804                 $this->mTrxLevel = 1;
1805         }
1806
1807         /**
1808          * End a transaction
1809          */
1810         function commit( $fname = 'Database::commit' ) {
1811                 $this->query( 'COMMIT', $fname );
1812                 $this->mTrxLevel = 0;
1813         }
1814
1815         /**
1816          * Rollback a transaction
1817          */
1818         function rollback( $fname = 'Database::rollback' ) {
1819                 $this->query( 'ROLLBACK', $fname );
1820                 $this->mTrxLevel = 0;
1821         }
1822
1823         /**
1824          * Begin a transaction, committing any previously open transaction
1825          * @deprecated use begin()
1826          */
1827         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1828                 $this->begin();
1829         }
1830
1831         /**
1832          * Commit transaction, if one is open
1833          * @deprecated use commit()
1834          */
1835         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1836                 $this->commit();
1837         }
1838
1839         /**
1840          * Return MW-style timestamp used for MySQL schema
1841          */
1842         function timestamp( $ts=0 ) {
1843                 return wfTimestamp(TS_MW,$ts);
1844         }
1845
1846         /**
1847          * Local database timestamp format or null
1848          */
1849         function timestampOrNull( $ts = null ) {
1850                 if( is_null( $ts ) ) {
1851                         return null;
1852                 } else {
1853                         return $this->timestamp( $ts );
1854                 }
1855         }
1856
1857         /**
1858          * @todo document
1859          */
1860         function resultObject( $result ) {
1861                 if( empty( $result ) ) {
1862                         return NULL;
1863                 } else {
1864                         return new ResultWrapper( $this, $result );
1865                 }
1866         }
1867
1868         /**
1869          * Return aggregated value alias
1870          */
1871         function aggregateValue ($valuedata,$valuename='value') {
1872                 return $valuename;
1873         }
1874
1875         /**
1876          * @return string wikitext of a link to the server software's web site
1877          */
1878         function getSoftwareLink() {
1879                 return "[http://www.mysql.com/ MySQL]";
1880         }
1881
1882         /**
1883          * @return string Version information from the database
1884          */
1885         function getServerVersion() {
1886                 return mysql_get_server_info( $this->mConn );
1887         }
1888
1889         /**
1890          * Ping the server and try to reconnect if it there is no connection
1891          */
1892         function ping() {
1893                 if( function_exists( 'mysql_ping' ) ) {
1894                         return mysql_ping( $this->mConn );
1895                 } else {
1896                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
1897                         return true;
1898                 }
1899         }
1900
1901         /**
1902          * Get slave lag.
1903          * At the moment, this will only work if the DB user has the PROCESS privilege
1904          */
1905         function getLag() {
1906                 $res = $this->query( 'SHOW PROCESSLIST' );
1907                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
1908                 # dubious, but unfortunately there's no easy rigorous way
1909                 while ( $row = $this->fetchObject( $res ) ) {
1910                         /* This should work for most situations - when default db
1911                          * for thread is not specified, it had no events executed,
1912                          * and therefore it doesn't know yet how lagged it is.
1913                          *
1914                          * Relay log I/O thread does not select databases.
1915                          */
1916                         if ( $row->User == 'system user' &&
1917                                 $row->State != 'Waiting for master to send event' &&
1918                                 $row->State != 'Connecting to master' &&
1919                                 $row->State != 'Queueing master event to the relay log' &&
1920                                 $row->State != 'Waiting for master update' &&
1921                                 $row->State != 'Requesting binlog dump'
1922                                 ) {
1923                                 # This is it, return the time (except -ve)
1924                                 if ( $row->Time > 0x7fffffff ) {
1925                                         return false;
1926                                 } else {
1927                                         return $row->Time;
1928                                 }
1929                         }
1930                 }
1931                 return false;
1932         }
1933
1934         /**
1935          * Get status information from SHOW STATUS in an associative array
1936          */
1937         function getStatus($which="%") {
1938                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1939                 $status = array();
1940                 while ( $row = $this->fetchObject( $res ) ) {
1941                         $status[$row->Variable_name] = $row->Value;
1942                 }
1943                 return $status;
1944         }
1945
1946         /**
1947          * Return the maximum number of items allowed in a list, or 0 for unlimited.
1948          */
1949         function maxListLen() {
1950                 return 0;
1951         }
1952
1953         function encodeBlob($b) {
1954                 return $b;
1955         }
1956
1957         function decodeBlob($b) {
1958                 return $b;
1959         }
1960
1961         /**
1962          * Read and execute SQL commands from a file.
1963          * Returns true on success, error string on failure
1964          */
1965         function sourceFile( $filename ) {
1966                 $fp = fopen( $filename, 'r' );
1967                 if ( false === $fp ) {
1968                         return "Could not open \"{$filename}\".\n";
1969                 }
1970
1971                 $cmd = "";
1972                 $done = false;
1973                 $dollarquote = false;
1974
1975                 while ( ! feof( $fp ) ) {
1976                         $line = trim( fgets( $fp, 1024 ) );
1977                         $sl = strlen( $line ) - 1;
1978
1979                         if ( $sl < 0 ) { continue; }
1980                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
1981
1982                         ## Allow dollar quoting for function declarations
1983                         if (substr($line,0,4) == '$mw$') {
1984                                 if ($dollarquote) {
1985                                         $dollarquote = false;
1986                                         $done = true;
1987                                 }
1988                                 else {
1989                                         $dollarquote = true;
1990                                 }
1991                         }
1992                         else if (!$dollarquote) {
1993                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
1994                                         $done = true;
1995                                         $line = substr( $line, 0, $sl );
1996                                 }
1997                         }
1998
1999                         if ( '' != $cmd ) { $cmd .= ' '; }
2000                         $cmd .= "$line\n";
2001
2002                         if ( $done ) {
2003                                 $cmd = str_replace(';;', ";", $cmd);
2004                                 $cmd = $this->replaceVars( $cmd );
2005                                 $res = $this->query( $cmd, 'dbsource', true );
2006
2007                                 if ( false === $res ) {
2008                                         $err = $this->lastError();
2009                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2010                                 }
2011
2012                                 $cmd = '';
2013                                 $done = false;
2014                         }
2015                 }
2016                 fclose( $fp );
2017                 return true;
2018         }
2019
2020         /**
2021          * Replace variables in sourced SQL
2022          */
2023         protected function replaceVars( $ins ) {
2024                 $varnames = array(
2025                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2026                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2027                         'wgDBadminuser', 'wgDBadminpassword',
2028                 );
2029
2030                 // Ordinary variables
2031                 foreach ( $varnames as $var ) {
2032                         if( isset( $GLOBALS[$var] ) ) {
2033                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2034                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2035                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2036                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2037                         }
2038                 }
2039
2040                 // Table prefixes
2041                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2042                         array( &$this, 'tableNameCallback' ), $ins );
2043                 return $ins;
2044         }
2045
2046         /**
2047          * Table name callback
2048          * @private
2049          */
2050         protected function tableNameCallback( $matches ) {
2051                 return $this->tableName( $matches[1] );
2052         }
2053
2054 }
2055
2056 /**
2057  * Database abstraction object for mySQL
2058  * Inherit all methods and properties of Database::Database()
2059  *
2060  * @see Database
2061  */
2062 class DatabaseMysql extends Database {
2063         # Inherit all
2064 }
2065
2066
2067 /**
2068  * Result wrapper for grabbing data queried by someone else
2069  *
2070  */
2071 class ResultWrapper {
2072         var $db, $result;
2073
2074         /**
2075          * @todo document
2076          */
2077         function ResultWrapper( &$database, $result ) {
2078                 $this->db =& $database;
2079                 $this->result =& $result;
2080         }
2081
2082         /**
2083          * @todo document
2084          */
2085         function numRows() {
2086                 return $this->db->numRows( $this->result );
2087         }
2088
2089         /**
2090          * @todo document
2091          */
2092         function fetchObject() {
2093                 return $this->db->fetchObject( $this->result );
2094         }
2095
2096         /**
2097          * @todo document
2098          */
2099         function fetchRow() {
2100                 return $this->db->fetchRow( $this->result );
2101         }
2102
2103         /**
2104          * @todo document
2105          */
2106         function free() {
2107                 $this->db->freeResult( $this->result );
2108                 unset( $this->result );
2109                 unset( $this->db );
2110         }
2111
2112         function seek( $row ) {
2113                 $this->db->dataSeek( $this->result, $row );
2114         }
2115
2116 }
2117
2118 ?>