includes/Database.php

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