includes/db/DatabaseMssql.php

   1 <?php
   2 /**
   3  * This is the MS SQL Server Native database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  * @author Joel Penner <a-joelpe at microsoft dot com>
  23  * @author Chris Pucci <a-cpucci at microsoft dot com>
  24  * @author Ryan Biesemeyer <v-ryanbi at microsoft dot com>
  25  * @author Ryan Schmidt <skizzerz at gmail dot com>
  26  */
  27
  28 /**
  29  * @ingroup Database
  30  */
  31 class DatabaseMssql extends DatabaseBase {
  32         protected $mInsertId = null;
  33         protected $mLastResult = null;
  34         protected $mAffectedRows = null;
  35         protected $mSubqueryId = 0;
  36         protected $mScrollableCursor = true;
  37         protected $mPrepareStatements = true;
  38         protected $mBinaryColumnCache = null;
  39         protected $mBitColumnCache = null;
  40         protected $mIgnoreDupKeyErrors = false;
  41
  42         protected $mPort;
  43
  44         public function cascadingDeletes() {
  45                 return true;
  46         }
  47
  48         public function cleanupTriggers() {
  49                 return false;
  50         }
  51
  52         public function strictIPs() {
  53                 return false;
  54         }
  55
  56         public function realTimestamps() {
  57                 return false;
  58         }
  59
  60         public function implicitGroupby() {
  61                 return false;
  62         }
  63
  64         public function implicitOrderby() {
  65                 return false;
  66         }
  67
  68         public function functionalIndexes() {
  69                 return true;
  70         }
  71
  72         public function unionSupportsOrderAndLimit() {
  73                 return false;
  74         }
  75
  76         /**
  77          * Usually aborts on failure
  78          * @param string $server
  79          * @param string $user
  80          * @param string $password
  81          * @param string $dbName
  82          * @throws DBConnectionError
  83          * @return bool|DatabaseBase|null
  84          */
  85         public function open( $server, $user, $password, $dbName ) {
  86                 # Test for driver support, to avoid suppressed fatal error
  87                 if ( !function_exists( 'sqlsrv_connect' ) ) {
  88                         throw new DBConnectionError(
  89                                 $this,
  90                                 "Microsoft SQL Server Native (sqlsrv) functions missing.
  91                                 You can download the driver from: http://go.microsoft.com/fwlink/?LinkId=123470\n"
  92                         );
  93                 }
  94
  95                 global $wgDBport, $wgDBWindowsAuthentication;
  96
  97                 # e.g. the class is being loaded
  98                 if ( !strlen( $user ) ) {
  99                         return null;
 100                 }
 101
 102                 $this->close();
 103                 $this->mServer = $server;
 104                 $this->mPort = $wgDBport;
 105                 $this->mUser = $user;
 106                 $this->mPassword = $password;
 107                 $this->mDBname = $dbName;
 108
 109                 $connectionInfo = array();
 110
 111                 if ( $dbName ) {
 112                         $connectionInfo['Database'] = $dbName;
 113                 }
 114
 115                 // Decide which auth scenerio to use
 116                 // if we are using Windows auth, don't add credentials to $connectionInfo
 117                 if ( !$wgDBWindowsAuthentication ) {
 118                         $connectionInfo['UID'] = $user;
 119                         $connectionInfo['PWD'] = $password;
 120                 }
 121
 122                 wfSuppressWarnings();
 123                 $this->mConn = sqlsrv_connect( $server, $connectionInfo );
 124                 wfRestoreWarnings();
 125
 126                 if ( $this->mConn === false ) {
 127                         throw new DBConnectionError( $this, $this->lastError() );
 128                 }
 129
 130                 $this->mOpened = true;
 131
 132                 return $this->mConn;
 133         }
 134
 135         /**
 136          * Closes a database connection, if it is open
 137          * Returns success, true if already closed
 138          * @return bool
 139          */
 140         protected function closeConnection() {
 141                 return sqlsrv_close( $this->mConn );
 142         }
 143
 144         /**
 145          * @param bool|MssqlResultWrapper|resource $result
 146          * @return bool|MssqlResultWrapper
 147          */
 148         public function resultObject( $result ) {
 149                 if ( empty( $result ) ) {
 150                         return false;
 151                 } elseif ( $result instanceof MssqlResultWrapper ) {
 152                         return $result;
 153                 } elseif ( $result === true ) {
 154                         // Successful write query
 155                         return $result;
 156                 } else {
 157                         return new MssqlResultWrapper( $this, $result );
 158                 }
 159         }
 160
 161         /**
 162          * @param string $sql
 163          * @return bool|MssqlResult
 164          * @throws DBUnexpectedError
 165          */
 166         protected function doQuery( $sql ) {
 167                 if ( $this->debug() ) {
 168                         wfDebug( "SQL: [$sql]\n" );
 169                 }
 170                 $this->offset = 0;
 171
 172                 // several extensions seem to think that all databases support limits
 173                 // via LIMIT N after the WHERE clause well, MSSQL uses SELECT TOP N,
 174                 // so to catch any of those extensions we'll do a quick check for a
 175                 // LIMIT clause and pass $sql through $this->LimitToTopN() which parses
 176                 // the limit clause and passes the result to $this->limitResult();
 177                 if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 178                         // massage LIMIT -> TopN
 179                         $sql = $this->LimitToTopN( $sql );
 180                 }
 181
 182                 // MSSQL doesn't have EXTRACT(epoch FROM XXX)
 183                 if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) {
 184                         // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970
 185                         $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql );
 186                 }
 187
 188                 // perform query
 189
 190                 // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is
 191                 // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED
 192                 // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty
 193                 // strings make php throw a fatal error "Severe error translating Unicode"
 194                 if ( $this->mScrollableCursor ) {
 195                         $scrollArr = array( 'Scrollable' => SQLSRV_CURSOR_STATIC );
 196                 } else {
 197                         $scrollArr = array();
 198                 }
 199
 200                 if ( $this->mPrepareStatements ) {
 201                         // we do prepare + execute so we can get its field metadata for later usage if desired
 202                         $stmt = sqlsrv_prepare( $this->mConn, $sql, array(), $scrollArr );
 203                         $success = sqlsrv_execute( $stmt );
 204                 } else {
 205                         $stmt = sqlsrv_query( $this->mConn, $sql, array(), $scrollArr );
 206                         $success = (bool)$stmt;
 207                 }
 208
 209                 if ( $this->mIgnoreDupKeyErrors ) {
 210                         // ignore duplicate key errors, but nothing else
 211                         // this emulates INSERT IGNORE in MySQL
 212                         if ( $success === false ) {
 213                                 $errors = sqlsrv_errors( SQLSRV_ERR_ERRORS );
 214                                 $success = true;
 215
 216                                 foreach ( $errors as $err ) {
 217                                         if ( $err['SQLSTATE'] == '23000' && $err['code'] == '2601' ) {
 218                                                 continue; // duplicate key error caused by unique index
 219                                         } elseif ( $err['SQLSTATE'] == '23000' && $err['code'] == '2627' ) {
 220                                                 continue; // duplicate key error caused by primary key
 221                                         } elseif ( $err['SQLSTATE'] == '01000' && $err['code'] == '3621' ) {
 222                                                 continue; // generic "the statement has been terminated" error
 223                                         }
 224
 225                                         $success = false; // getting here means we got an error we weren't expecting
 226                                         break;
 227                                 }
 228
 229                                 if ( $success ) {
 230                                         $this->mAffectedRows = 0;
 231                                         return true;
 232                                 }
 233                         }
 234                 }
 235
 236                 if ( $success === false ) {
 237                         return false;
 238                 }
 239                 // remember number of rows affected
 240                 $this->mAffectedRows = sqlsrv_rows_affected( $stmt );
 241
 242                 return $stmt;
 243         }
 244
 245         public function freeResult( $res ) {
 246                 if ( $res instanceof ResultWrapper ) {
 247                         $res = $res->result;
 248                 }
 249
 250                 sqlsrv_free_stmt( $res );
 251         }
 252
 253         /**
 254          * @param MssqlResultWrapper $res
 255          * @return stdClass
 256          */
 257         public function fetchObject( $res ) {
 258                 // $res is expected to be an instance of MssqlResultWrapper here
 259                 return $res->fetchObject();
 260         }
 261
 262         /**
 263          * @param MssqlResultWrapper $res
 264          * @return array
 265          */
 266         public function fetchRow( $res ) {
 267                 return $res->fetchRow();
 268         }
 269
 270         /**
 271          * @param mixed $res
 272          * @return int
 273          */
 274         public function numRows( $res ) {
 275                 if ( $res instanceof ResultWrapper ) {
 276                         $res = $res->result;
 277                 }
 278
 279                 return sqlsrv_num_rows( $res );
 280         }
 281
 282         /**
 283          * @param mixed $res
 284          * @return int
 285          */
 286         public function numFields( $res ) {
 287                 if ( $res instanceof ResultWrapper ) {
 288                         $res = $res->result;
 289                 }
 290
 291                 return sqlsrv_num_fields( $res );
 292         }
 293
 294         /**
 295          * @param mixed $res
 296          * @param int $n
 297          * @return int
 298          */
 299         public function fieldName( $res, $n ) {
 300                 if ( $res instanceof ResultWrapper ) {
 301                         $res = $res->result;
 302                 }
 303
 304                 $metadata = sqlsrv_field_metadata( $res );
 305                 return $metadata[$n]['Name'];
 306         }
 307
 308         /**
 309          * This must be called after nextSequenceVal
 310          * @return int|null
 311          */
 312         public function insertId() {
 313                 return $this->mInsertId;
 314         }
 315
 316         /**
 317          * @param MssqlResultWrapper $res
 318          * @param int $row
 319          * @return bool
 320          */
 321         public function dataSeek( $res, $row ) {
 322                 return $res->seek( $row );
 323         }
 324
 325         /**
 326          * @return string
 327          */
 328         public function lastError() {
 329                 $strRet = '';
 330                 $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL );
 331                 if ( $retErrors != null ) {
 332                         foreach ( $retErrors as $arrError ) {
 333                                 $strRet .= $this->formatError( $arrError ) . "\n";
 334                         }
 335                 } else {
 336                         $strRet = "No errors found";
 337                 }
 338
 339                 return $strRet;
 340         }
 341
 342         /**
 343          * @return string
 344          */
 345         private function formatError( $err ) {
 346                 return '[SQLSTATE ' . $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message'];
 347         }
 348
 349         /**
 350          * @return string
 351          */
 352         public function lastErrno() {
 353                 $err = sqlsrv_errors( SQLSRV_ERR_ALL );
 354                 if ( $err !== null && isset( $err[0] ) ) {
 355                         return $err[0]['code'];
 356                 } else {
 357                         return 0;
 358                 }
 359         }
 360
 361         /**
 362          * @return int
 363          */
 364         public function affectedRows() {
 365                 return $this->mAffectedRows;
 366         }
 367
 368         /**
 369          * SELECT wrapper
 370          *
 371          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 372          * @param mixed $vars Array or string, field name(s) to be retrieved
 373          * @param mixed $conds Array or string, condition(s) for WHERE
 374          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 375          * @param array $options Associative array of options (e.g.
 376          *   array('GROUP BY' => 'page_title')), see Database::makeSelectOptions
 377          *   code for list of supported stuff
 378          * @param array $join_conds Associative array of table join conditions
 379          *   (optional) (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 380          * @return mixed Database result resource (feed to Database::fetchObject
 381          *   or whatever), or false on failure
 382          */
 383         public function select( $table, $vars, $conds = '', $fname = __METHOD__,
 384                 $options = array(), $join_conds = array()
 385         ) {
 386                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 387                 if ( isset( $options['EXPLAIN'] ) ) {
 388                         try {
 389                                 $this->mScrollableCursor = false;
 390                                 $this->mPrepareStatements = false;
 391                                 $this->query( "SET SHOWPLAN_ALL ON" );
 392                                 $ret = $this->query( $sql, $fname );
 393                                 $this->query( "SET SHOWPLAN_ALL OFF" );
 394                         } catch ( DBQueryError $dqe ) {
 395                                 if ( isset( $options['FOR COUNT'] ) ) {
 396                                         // likely don't have privs for SHOWPLAN, so run a select count instead
 397                                         $this->query( "SET SHOWPLAN_ALL OFF" );
 398                                         unset( $options['EXPLAIN'] );
 399                                         $ret = $this->select(
 400                                                 $table,
 401                                                 'COUNT(*) AS EstimateRows',
 402                                                 $conds,
 403                                                 $fname,
 404                                                 $options,
 405                                                 $join_conds
 406                                         );
 407                                 } else {
 408                                         // someone actually wanted the query plan instead of an est row count
 409                                         // let them know of the error
 410                                         $this->mScrollableCursor = true;
 411                                         $this->mPrepareStatements = true;
 412                                         throw $dqe;
 413                                 }
 414                         }
 415                         $this->mScrollableCursor = true;
 416                         $this->mPrepareStatements = true;
 417
 418                         return $ret;
 419                 }
 420
 421                 return $this->query( $sql, $fname );
 422         }
 423
 424         /**
 425          * SELECT wrapper
 426          *
 427          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 428          * @param mixed $vars Array or string, field name(s) to be retrieved
 429          * @param mixed $conds Array or string, condition(s) for WHERE
 430          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 431          * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 432          *   see Database::makeSelectOptions code for list of supported stuff
 433          * @param array $join_conds Associative array of table join conditions (optional)
 434          *    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 435          * @return string The SQL text
 436          */
 437         public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
 438                 $options = array(), $join_conds = array()
 439         ) {
 440                 if ( isset( $options['EXPLAIN'] ) ) {
 441                         unset( $options['EXPLAIN'] );
 442                 }
 443
 444                 $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 445
 446                 // try to rewrite aggregations of bit columns (currently MAX and MIN)
 447                 if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) {
 448                         $bitColumns = array();
 449                         if ( is_array( $table ) ) {
 450                                 foreach ( $table as $t ) {
 451                                         $bitColumns += $this->getBitColumns( $this->tableName( $t ) );
 452                                 }
 453                         } else {
 454                                 $bitColumns = $this->getBitColumns( $this->tableName( $table ) );
 455                         }
 456
 457                         foreach ( $bitColumns as $col => $info ) {
 458                                 $replace = array(
 459                                         "MAX({$col})" => "MAX(CAST({$col} AS tinyint))",
 460                                         "MIN({$col})" => "MIN(CAST({$col} AS tinyint))",
 461                                 );
 462                                 $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql );
 463                         }
 464                 }
 465
 466                 return $sql;
 467         }
 468
 469         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 470                 $fname = __METHOD__
 471         ) {
 472                 $this->mScrollableCursor = false;
 473                 try {
 474                         parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname );
 475                 } catch ( Exception $e ) {
 476                         $this->mScrollableCursor = true;
 477                         throw $e;
 478                 }
 479                 $this->mScrollableCursor = true;
 480         }
 481
 482         public function delete( $table, $conds, $fname = __METHOD__ ) {
 483                 $this->mScrollableCursor = false;
 484                 try {
 485                         parent::delete( $table, $conds, $fname );
 486                 } catch ( Exception $e ) {
 487                         $this->mScrollableCursor = true;
 488                         throw $e;
 489                 }
 490                 $this->mScrollableCursor = true;
 491         }
 492
 493         /**
 494          * Estimate rows in dataset
 495          * Returns estimated count, based on SHOWPLAN_ALL output
 496          * This is not necessarily an accurate estimate, so use sparingly
 497          * Returns -1 if count cannot be found
 498          * Takes same arguments as Database::select()
 499          * @param string $table
 500          * @param string $vars
 501          * @param string $conds
 502          * @param string $fname
 503          * @param array $options
 504          * @return int
 505          */
 506         public function estimateRowCount( $table, $vars = '*', $conds = '',
 507                 $fname = __METHOD__, $options = array()
 508         ) {
 509                 // http://msdn2.microsoft.com/en-us/library/aa259203.aspx
 510                 $options['EXPLAIN'] = true;
 511                 $options['FOR COUNT'] = true;
 512                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 513
 514                 $rows = -1;
 515                 if ( $res ) {
 516                         $row = $this->fetchRow( $res );
 517
 518                         if ( isset( $row['EstimateRows'] ) ) {
 519                                 $rows = $row['EstimateRows'];
 520                         }
 521                 }
 522
 523                 return $rows;
 524         }
 525
 526         /**
 527          * Returns information about an index
 528          * If errors are explicitly ignored, returns NULL on failure
 529          * @param string $table
 530          * @param string $index
 531          * @param string $fname
 532          * @return array|bool|null
 533          */
 534         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 535                 # This does not return the same info as MYSQL would, but that's OK
 536                 # because MediaWiki never uses the returned value except to check for
 537                 # the existance of indexes.
 538                 $sql = "sp_helpindex '" . $table . "'";
 539                 $res = $this->query( $sql, $fname );
 540                 if ( !$res ) {
 541                         return null;
 542                 }
 543
 544                 $result = array();
 545                 foreach ( $res as $row ) {
 546                         if ( $row->index_name == $index ) {
 547                                 $row->Non_unique = !stristr( $row->index_description, "unique" );
 548                                 $cols = explode( ", ", $row->index_keys );
 549                                 foreach ( $cols as $col ) {
 550                                         $row->Column_name = trim( $col );
 551                                         $result[] = clone $row;
 552                                 }
 553                         } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) {
 554                                 $row->Non_unique = 0;
 555                                 $cols = explode( ", ", $row->index_keys );
 556                                 foreach ( $cols as $col ) {
 557                                         $row->Column_name = trim( $col );
 558                                         $result[] = clone $row;
 559                                 }
 560                         }
 561                 }
 562
 563                 return empty( $result ) ? false : $result;
 564         }
 565
 566         /**
 567          * INSERT wrapper, inserts an array into a table
 568          *
 569          * $arrToInsert may be a single associative array, or an array of these with numeric keys, for
 570          * multi-row insert.
 571          *
 572          * Usually aborts on failure
 573          * If errors are explicitly ignored, returns success
 574          * @param string $table
 575          * @param array $arrToInsert
 576          * @param string $fname
 577          * @param array $options
 578          * @throws DBQueryError
 579          * @return bool
 580          */
 581         public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = array() ) {
 582                 # No rows to insert, easy just return now
 583                 if ( !count( $arrToInsert ) ) {
 584                         return true;
 585                 }
 586
 587                 if ( !is_array( $options ) ) {
 588                         $options = array( $options );
 589                 }
 590
 591                 $table = $this->tableName( $table );
 592
 593                 if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row
 594                         $arrToInsert = array( 0 => $arrToInsert ); // make everything multi row compatible
 595                 }
 596
 597                 // We know the table we're inserting into, get its identity column
 598                 $identity = null;
 599                 // strip matching square brackets and the db/schema from table name
 600                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
 601                 $tableRaw = array_pop( $tableRawArr );
 602                 $res = $this->doQuery(
 603                         "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " .
 604                                 "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'"
 605                 );
 606                 if ( $res && sqlsrv_has_rows( $res ) ) {
 607                         // There is an identity for this table.
 608                         $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC );
 609                         $identity = array_pop( $identityArr );
 610                 }
 611                 sqlsrv_free_stmt( $res );
 612
 613                 // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF
 614                 $binaryColumns = $this->getBinaryColumns( $table );
 615
 616                 foreach ( $arrToInsert as $a ) {
 617                         // start out with empty identity column, this is so we can return
 618                         // it as a result of the insert logic
 619                         $sqlPre = '';
 620                         $sqlPost = '';
 621                         $identityClause = '';
 622
 623                         // if we have an identity column
 624                         if ( $identity ) {
 625                                 // iterate through
 626                                 foreach ( $a as $k => $v ) {
 627                                         if ( $k == $identity ) {
 628                                                 if ( !is_null( $v ) ) {
 629                                                         // there is a value being passed to us,
 630                                                         // we need to turn on and off inserted identity
 631                                                         $sqlPre = "SET IDENTITY_INSERT $table ON;";
 632                                                         $sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 633                                                 } else {
 634                                                         // we can't insert NULL into an identity column,
 635                                                         // so remove the column from the insert.
 636                                                         unset( $a[$k] );
 637                                                 }
 638                                         }
 639                                 }
 640
 641                                 // we want to output an identity column as result
 642                                 $identityClause = "OUTPUT INSERTED.$identity ";
 643                         }
 644
 645                         $keys = array_keys( $a );
 646
 647                         // INSERT IGNORE is not supported by SQL Server
 648                         // remove IGNORE from options list and set ignore flag to true
 649                         $ignoreClause = false;
 650                         if ( in_array( 'IGNORE', $options ) ) {
 651                                 $options = array_diff( $options, array( 'IGNORE' ) );
 652                                 $this->mIgnoreDupKeyErrors = true;
 653                         }
 654
 655                         // Build the actual query
 656                         $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) .
 657                                 " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES (";
 658
 659                         $first = true;
 660                         foreach ( $a as $key => $value ) {
 661                                 if ( isset( $binaryColumns[$key] ) ) {
 662                                         $value = new MssqlBlob( $value );
 663                                 }
 664                                 if ( $first ) {
 665                                         $first = false;
 666                                 } else {
 667                                         $sql .= ',';
 668                                 }
 669                                 if ( is_null( $value ) ) {
 670                                         $sql .= 'null';
 671                                 } elseif ( is_array( $value ) || is_object( $value ) ) {
 672                                         if ( is_object( $value ) && $value instanceof Blob ) {
 673                                                 $sql .= $this->addQuotes( $value );
 674                                         } else {
 675                                                 $sql .= $this->addQuotes( serialize( $value ) );
 676                                         }
 677                                 } else {
 678                                         $sql .= $this->addQuotes( $value );
 679                                 }
 680                         }
 681                         $sql .= ')' . $sqlPost;
 682
 683                         // Run the query
 684                         $this->mScrollableCursor = false;
 685                         try {
 686                                 $ret = $this->query( $sql );
 687                         } catch ( Exception $e ) {
 688                                 $this->mScrollableCursor = true;
 689                                 $this->mIgnoreDupKeyErrors = false;
 690                                 throw $e;
 691                         }
 692                         $this->mScrollableCursor = true;
 693                         $this->mIgnoreDupKeyErrors = false;
 694
 695                         if ( !is_null( $identity ) ) {
 696                                 // then we want to get the identity column value we were assigned and save it off
 697                                 $row = $ret->fetchObject();
 698                                 $this->mInsertId = $row->$identity;
 699                         }
 700                 }
 701
 702                 return $ret;
 703         }
 704
 705         /**
 706          * INSERT SELECT wrapper
 707          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 708          * Source items may be literals rather than field names, but strings should
 709          * be quoted with Database::addQuotes().
 710          * @param string $destTable
 711          * @param array|string $srcTable May be an array of tables.
 712          * @param array $varMap
 713          * @param array $conds May be "*" to copy the whole table.
 714          * @param string $fname
 715          * @param array $insertOptions
 716          * @param array $selectOptions
 717          * @throws DBQueryError
 718          * @return null|ResultWrapper
 719          */
 720         public function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 721                 $insertOptions = array(), $selectOptions = array()
 722         ) {
 723                 $this->mScrollableCursor = false;
 724                 try {
 725                         $ret = parent::insertSelect(
 726                                 $destTable,
 727                                 $srcTable,
 728                                 $varMap,
 729                                 $conds,
 730                                 $fname,
 731                                 $insertOptions,
 732                                 $selectOptions
 733                         );
 734                 } catch ( Exception $e ) {
 735                         $this->mScrollableCursor = true;
 736                         throw $e;
 737                 }
 738                 $this->mScrollableCursor = true;
 739
 740                 return $ret;
 741         }
 742
 743         /**
 744          * UPDATE wrapper. Takes a condition array and a SET array.
 745          *
 746          * @param string $table name of the table to UPDATE. This will be passed through
 747          *                DatabaseBase::tableName().
 748          *
 749          * @param array $values An array of values to SET. For each array element,
 750          *                the key gives the field name, and the value gives the data
 751          *                to set that field to. The data will be quoted by
 752          *                DatabaseBase::addQuotes().
 753          *
 754          * @param array $conds An array of conditions (WHERE). See
 755          *                DatabaseBase::select() for the details of the format of
 756          *                condition arrays. Use '*' to update all rows.
 757          *
 758          * @param string $fname The function name of the caller (from __METHOD__),
 759          *                for logging and profiling.
 760          *
 761          * @param array $options An array of UPDATE options, can be:
 762          *                   - IGNORE: Ignore unique key conflicts
 763          *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 764          * @return bool
 765          */
 766         function update( $table, $values, $conds, $fname = __METHOD__, $options = array() ) {
 767                 $table = $this->tableName( $table );
 768                 $binaryColumns = $this->getBinaryColumns( $table );
 769
 770                 $opts = $this->makeUpdateOptions( $options );
 771                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns );
 772
 773                 if ( $conds !== array() && $conds !== '*' ) {
 774                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns );
 775                 }
 776
 777                 $this->mScrollableCursor = false;
 778                 try {
 779                         $ret = $this->query( $sql );
 780                 } catch ( Exception $e ) {
 781                         $this->mScrollableCursor = true;
 782                         throw $e;
 783                 }
 784                 $this->mScrollableCursor = true;
 785                 return true;
 786         }
 787
 788         /**
 789          * Makes an encoded list of strings from an array
 790          * @param array $a containing the data
 791          * @param int $mode Constant
 792          *      - LIST_COMMA:          comma separated, no field names
 793          *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 794          *        the documentation for $conds in DatabaseBase::select().
 795          *      - LIST_OR:             ORed WHERE clause (without the WHERE)
 796          *      - LIST_SET:            comma separated with field names, like a SET clause
 797          *      - LIST_NAMES:          comma separated field names
 798          * @param array $binaryColumns Contains a list of column names that are binary types
 799          *      This is a custom parameter only present for MS SQL.
 800          *
 801          * @throws MWException|DBUnexpectedError
 802          * @return string
 803          */
 804         public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = array() ) {
 805                 if ( !is_array( $a ) ) {
 806                         throw new DBUnexpectedError( $this,
 807                                 'DatabaseBase::makeList called with incorrect parameters' );
 808                 }
 809
 810                 $first = true;
 811                 $list = '';
 812
 813                 foreach ( $a as $field => $value ) {
 814                         if ( $mode != LIST_NAMES && isset( $binaryColumns[$field] ) ) {
 815                                 if ( is_array( $value ) ) {
 816                                         foreach ( $value as &$v ) {
 817                                                 $v = new MssqlBlob( $v );
 818                                         }
 819                                 } else {
 820                                         $value = new MssqlBlob( $value );
 821                                 }
 822                         }
 823
 824                         if ( !$first ) {
 825                                 if ( $mode == LIST_AND ) {
 826                                         $list .= ' AND ';
 827                                 } elseif ( $mode == LIST_OR ) {
 828                                         $list .= ' OR ';
 829                                 } else {
 830                                         $list .= ',';
 831                                 }
 832                         } else {
 833                                 $first = false;
 834                         }
 835
 836                         if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
 837                                 $list .= "($value)";
 838                         } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
 839                                 $list .= "$value";
 840                         } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
 841                                 if ( count( $value ) == 0 ) {
 842                                         throw new MWException( __METHOD__ . ": empty input for field $field" );
 843                                 } elseif ( count( $value ) == 1 ) {
 844                                         // Special-case single values, as IN isn't terribly efficient
 845                                         // Don't necessarily assume the single key is 0; we don't
 846                                         // enforce linear numeric ordering on other arrays here.
 847                                         $value = array_values( $value );
 848                                         $list .= $field . " = " . $this->addQuotes( $value[0] );
 849                                 } else {
 850                                         $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
 851                                 }
 852                         } elseif ( $value === null ) {
 853                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
 854                                         $list .= "$field IS ";
 855                                 } elseif ( $mode == LIST_SET ) {
 856                                         $list .= "$field = ";
 857                                 }
 858                                 $list .= 'NULL';
 859                         } else {
 860                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
 861                                         $list .= "$field = ";
 862                                 }
 863                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
 864                         }
 865                 }
 866
 867                 return $list;
 868         }
 869
 870         /**
 871          * @param string $table
 872          * @param string $field
 873          * @return int Returns the size of a text field, or -1 for "unlimited"
 874          */
 875         public function textFieldSize( $table, $field ) {
 876                 $table = $this->tableName( $table );
 877                 $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns
 878                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'";
 879                 $res = $this->query( $sql );
 880                 $row = $this->fetchRow( $res );
 881                 $size = -1;
 882                 if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) {
 883                         $size = $row['CHARACTER_MAXIMUM_LENGTH'];
 884                 }
 885
 886                 return $size;
 887         }
 888
 889         /**
 890          * Construct a LIMIT query with optional offset
 891          * This is used for query pages
 892          *
 893          * @param string $sql SQL query we will append the limit too
 894          * @param int $limit The SQL limit
 895          * @param bool|int $offset The SQL offset (default false)
 896          * @return array|string
 897          */
 898         public function limitResult( $sql, $limit, $offset = false ) {
 899                 if ( $offset === false || $offset == 0 ) {
 900                         if ( strpos( $sql, "SELECT" ) === false ) {
 901                                 return "TOP {$limit} " . $sql;
 902                         } else {
 903                                 return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi',
 904                                         'SELECT$1 TOP ' . $limit, $sql, 1 );
 905                         }
 906                 } else {
 907                         // This one is fun, we need to pull out the select list as well as any ORDER BY clause
 908                         $select = $orderby = array();
 909                         $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select );
 910                         $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby );
 911                         $overOrder = $postOrder = '';
 912                         $first = $offset + 1;
 913                         $last = $offset + $limit;
 914                         $sub1 = 'sub_' . $this->mSubqueryId;
 915                         $sub2 = 'sub_' . ( $this->mSubqueryId + 1 );
 916                         $this->mSubqueryId += 2;
 917                         if ( !$s1 ) {
 918                                 // wat
 919                                 throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" );
 920                         }
 921                         if ( !$s2 ) {
 922                                 // no ORDER BY
 923                                 $overOrder = 'ORDER BY 1';
 924                         } else {
 925                                 if ( !isset( $orderby[2] ) || !$orderby[2] ) {
 926                                         // don't need to strip it out if we're using a FOR XML clause
 927                                         $sql = str_replace( $orderby[1], '', $sql );
 928                                 }
 929                                 $overOrder = $orderby[1];
 930                                 $postOrder = ' ' . $overOrder;
 931                         }
 932                         $sql = "SELECT {$select[1]}
 933                                         FROM (
 934                                                 SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, *
 935                                                 FROM ({$sql}) {$sub1}
 936                                         ) {$sub2}
 937                                         WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}";
 938
 939                         return $sql;
 940                 }
 941         }
 942
 943         /**
 944          * If there is a limit clause, parse it, strip it, and pass the remaining
 945          * SQL through limitResult() with the appropriate parameters. Not the
 946          * prettiest solution, but better than building a whole new parser. This
 947          * exists becase there are still too many extensions that don't use dynamic
 948          * sql generation.
 949          *
 950          * @param string $sql
 951          * @return array|mixed|string
 952          */
 953         public function LimitToTopN( $sql ) {
 954                 // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset}
 955                 $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i';
 956                 if ( preg_match( $pattern, $sql, $matches ) ) {
 957                         // row_count = $matches[4]
 958                         $row_count = $matches[4];
 959                         // offset = $matches[3] OR $matches[6]
 960                         $offset = $matches[3] or
 961                         $offset = $matches[6] or
 962                         $offset = false;
 963
 964                         // strip the matching LIMIT clause out
 965                         $sql = str_replace( $matches[0], '', $sql );
 966
 967                         return $this->limitResult( $sql, $row_count, $offset );
 968                 }
 969
 970                 return $sql;
 971         }
 972
 973         /**
 974          * @return string Wikitext of a link to the server software's web site
 975          */
 976         public function getSoftwareLink() {
 977                 return "[{{int:version-db-mssql-url}} MS SQL Server]";
 978         }
 979
 980         /**
 981          * @return string Version information from the database
 982          */
 983         public function getServerVersion() {
 984                 $server_info = sqlsrv_server_info( $this->mConn );
 985                 $version = 'Error';
 986                 if ( isset( $server_info['SQLServerVersion'] ) ) {
 987                         $version = $server_info['SQLServerVersion'];
 988                 }
 989
 990                 return $version;
 991         }
 992
 993         /**
 994          * @param string $table
 995          * @param string $fname
 996          * @return bool
 997          */
 998         public function tableExists( $table, $fname = __METHOD__ ) {
 999                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1000
1001                 if ( $db !== false ) {
1002                         // remote database
1003                         wfDebug( "Attempting to call tableExists on a remote table" );
1004                         return false;
1005                 }
1006
1007                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.TABLES
1008                         WHERE TABLE_TYPE = 'BASE TABLE'
1009                         AND TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table'" );
1010
1011                 if ( $res->numRows() ) {
1012                         return true;
1013                 } else {
1014                         return false;
1015                 }
1016         }
1017
1018         /**
1019          * Query whether a given column exists in the mediawiki schema
1020          * @param string $table
1021          * @param string $field
1022          * @param string $fname
1023          * @return bool
1024          */
1025         public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1026                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1027
1028                 if ( $db !== false ) {
1029                         // remote database
1030                         wfDebug( "Attempting to call fieldExists on a remote table" );
1031                         return false;
1032                 }
1033
1034                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS
1035                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1036
1037                 if ( $res->numRows() ) {
1038                         return true;
1039                 } else {
1040                         return false;
1041                 }
1042         }
1043
1044         public function fieldInfo( $table, $field ) {
1045                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1046
1047                 if ( $db !== false ) {
1048                         // remote database
1049                         wfDebug( "Attempting to call fieldInfo on a remote table" );
1050                         return false;
1051                 }
1052
1053                 $res = $this->query( "SELECT * FROM INFORMATION_SCHEMA.COLUMNS
1054                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1055
1056                 $meta = $res->fetchRow();
1057                 if ( $meta ) {
1058                         return new MssqlField( $meta );
1059                 }
1060
1061                 return false;
1062         }
1063
1064         /**
1065          * Begin a transaction, committing any previously open transaction
1066          */
1067         protected function doBegin( $fname = __METHOD__ ) {
1068                 sqlsrv_begin_transaction( $this->mConn );
1069                 $this->mTrxLevel = 1;
1070         }
1071
1072         /**
1073          * End a transaction
1074          */
1075         protected function doCommit( $fname = __METHOD__ ) {
1076                 sqlsrv_commit( $this->mConn );
1077                 $this->mTrxLevel = 0;
1078         }
1079
1080         /**
1081          * Rollback a transaction.
1082          * No-op on non-transactional databases.
1083          */
1084         protected function doRollback( $fname = __METHOD__ ) {
1085                 sqlsrv_rollback( $this->mConn );
1086                 $this->mTrxLevel = 0;
1087         }
1088
1089         /**
1090          * Escapes a identifier for use inm SQL.
1091          * Throws an exception if it is invalid.
1092          * Reference: http://msdn.microsoft.com/en-us/library/aa224033%28v=SQL.80%29.aspx
1093          * @param string $identifier
1094          * @throws MWException
1095          * @return string
1096          */
1097         private function escapeIdentifier( $identifier ) {
1098                 if ( strlen( $identifier ) == 0 ) {
1099                         throw new MWException( "An identifier must not be empty" );
1100                 }
1101                 if ( strlen( $identifier ) > 128 ) {
1102                         throw new MWException( "The identifier '$identifier' is too long (max. 128)" );
1103                 }
1104                 if ( ( strpos( $identifier, '[' ) !== false )
1105                         || ( strpos( $identifier, ']' ) !== false )
1106                 ) {
1107                         // It may be allowed if you quoted with double quotation marks, but
1108                         // that would break if QUOTED_IDENTIFIER is OFF
1109                         throw new MWException( "Square brackets are not allowed in '$identifier'" );
1110                 }
1111
1112                 return "[$identifier]";
1113         }
1114
1115         /**
1116          * @param string $s
1117          * @return string
1118          */
1119         public function strencode( $s ) { # Should not be called by us
1120                 return str_replace( "'", "''", $s );
1121         }
1122
1123         /**
1124          * @param string $s
1125          * @return string
1126          */
1127         public function addQuotes( $s ) {
1128                 if ( $s instanceof MssqlBlob ) {
1129                         return $s->fetch();
1130                 } elseif ( $s instanceof Blob ) {
1131                         // this shouldn't really ever be called, but it's here if needed
1132                         // (and will quite possibly make the SQL error out)
1133                         $blob = new MssqlBlob( $s->fetch() );
1134                         return $blob->fetch();
1135                 } else {
1136                         if ( is_bool( $s ) ) {
1137                                 $s = $s ? 1 : 0;
1138                         }
1139                         return parent::addQuotes( $s );
1140                 }
1141         }
1142
1143         /**
1144          * @param string $s
1145          * @return string
1146          */
1147         public function addIdentifierQuotes( $s ) {
1148                 // http://msdn.microsoft.com/en-us/library/aa223962.aspx
1149                 return '[' . $s . ']';
1150         }
1151
1152         /**
1153          * @param string $name
1154          * @return bool
1155          */
1156         public function isQuotedIdentifier( $name ) {
1157                 return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']';
1158         }
1159
1160         /**
1161          * @param string $db
1162          * @return bool
1163          */
1164         public function selectDB( $db ) {
1165                 try {
1166                         $this->mDBname = $db;
1167                         $this->query( "USE $db" );
1168                         return true;
1169                 } catch ( Exception $e ) {
1170                         return false;
1171                 }
1172         }
1173
1174         /**
1175          * @param array $options an associative array of options to be turned into
1176          *   an SQL query, valid keys are listed in the function.
1177          * @return array
1178          */
1179         public function makeSelectOptions( $options ) {
1180                 $tailOpts = '';
1181                 $startOpts = '';
1182
1183                 $noKeyOptions = array();
1184                 foreach ( $options as $key => $option ) {
1185                         if ( is_numeric( $key ) ) {
1186                                 $noKeyOptions[$option] = true;
1187                         }
1188                 }
1189
1190                 $tailOpts .= $this->makeGroupByWithHaving( $options );
1191
1192                 $tailOpts .= $this->makeOrderBy( $options );
1193
1194                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1195                         $startOpts .= 'DISTINCT';
1196                 }
1197
1198                 if ( isset( $noKeyOptions['FOR XML'] ) ) {
1199                         // used in group concat field emulation
1200                         $tailOpts .= " FOR XML PATH('')";
1201                 }
1202
1203                 // we want this to be compatible with the output of parent::makeSelectOptions()
1204                 return array( $startOpts, '', $tailOpts, '' );
1205         }
1206
1207         /**
1208          * Get the type of the DBMS, as it appears in $wgDBtype.
1209          * @return string
1210          */
1211         public function getType() {
1212                 return 'mssql';
1213         }
1214
1215         /**
1216          * @param array $stringList
1217          * @return string
1218          */
1219         public function buildConcat( $stringList ) {
1220                 return implode( ' + ', $stringList );
1221         }
1222
1223         /**
1224          * Build a GROUP_CONCAT or equivalent statement for a query.
1225          * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty)
1226          *
1227          * This is useful for combining a field for several rows into a single string.
1228          * NULL values will not appear in the output, duplicated values will appear,
1229          * and the resulting delimiter-separated values have no defined sort order.
1230          * Code using the results may need to use the PHP unique() or sort() methods.
1231          *
1232          * @param string $delim Glue to bind the results together
1233          * @param string|array $table Table name
1234          * @param string $field Field name
1235          * @param string|array $conds Conditions
1236          * @param string|array $join_conds Join conditions
1237          * @return string SQL text
1238          * @since 1.23
1239          */
1240         public function buildGroupConcatField( $delim, $table, $field, $conds = '',
1241                 $join_conds = array()
1242         ) {
1243                 $gcsq = 'gcsq_' . $this->mSubqueryId;
1244                 $this->mSubqueryId++;
1245
1246                 $delimLen = strlen( $delim );
1247                 $fld = "{$field} + {$this->addQuotes( $delim )}";
1248                 $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM ("
1249                         . $this->selectSQLText( $table, $fld, $conds, null, array( 'FOR XML' ), $join_conds )
1250                         . ") {$gcsq} ({$field}))";
1251
1252                 return $sql;
1253         }
1254
1255         /**
1256          * @return string
1257          */
1258         public function getSearchEngine() {
1259                 return "SearchMssql";
1260         }
1261
1262         /**
1263          * Returns an associative array for fields that are of type varbinary, binary, or image
1264          * $table can be either a raw table name or passed through tableName() first
1265          * @param string $table
1266          * @return array
1267          */
1268         private function getBinaryColumns( $table ) {
1269                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1270                 $tableRaw = array_pop( $tableRawArr );
1271
1272                 if ( $this->mBinaryColumnCache === null ) {
1273                         $this->populateColumnCaches();
1274                 }
1275
1276                 return isset( $this->mBinaryColumnCache[$tableRaw] )
1277                         ? $this->mBinaryColumnCache[$tableRaw]
1278                         : array();
1279         }
1280
1281         /**
1282          * @param string $table
1283          * @return array
1284          */
1285         private function getBitColumns( $table ) {
1286                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1287                 $tableRaw = array_pop( $tableRawArr );
1288
1289                 if ( $this->mBitColumnCache === null ) {
1290                         $this->populateColumnCaches();
1291                 }
1292
1293                 return isset( $this->mBitColumnCache[$tableRaw] )
1294                         ? $this->mBitColumnCache[$tableRaw]
1295                         : array();
1296         }
1297
1298         /**
1299          * @void
1300          */
1301         private function populateColumnCaches() {
1302                 $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*',
1303                         array(
1304                                 'TABLE_CATALOG' => $this->mDBname,
1305                                 'TABLE_SCHEMA' => $this->mSchema,
1306                                 'DATA_TYPE' => array( 'varbinary', 'binary', 'image', 'bit' )
1307                         ) );
1308
1309                 $this->mBinaryColumnCache = array();
1310                 $this->mBitColumnCache = array();
1311                 foreach ( $res as $row ) {
1312                         if ( $row->DATA_TYPE == 'bit' ) {
1313                                 $this->mBitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1314                         } else {
1315                                 $this->mBinaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1316                         }
1317                 }
1318         }
1319
1320         /**
1321          * @param string $name
1322          * @param string $format
1323          * @return string
1324          */
1325         function tableName( $name, $format = 'quoted' ) {
1326                 # Replace reserved words with better ones
1327                 switch ( $name ) {
1328                         case 'user':
1329                                 return $this->realTableName( 'mwuser', $format );
1330                         default:
1331                                 return $this->realTableName( $name, $format );
1332                 }
1333         }
1334
1335         /**
1336          * call this instead of tableName() in the updater when renaming tables
1337          * @param string $name
1338          * @param string $format One of quoted, raw, or split
1339          * @return string
1340          */
1341         function realTableName( $name, $format = 'quoted' ) {
1342                 $table = parent::tableName( $name, $format );
1343                 if ( $format == 'split' ) {
1344                         // Used internally, we want the schema split off from the table name and returned
1345                         // as a list with 3 elements (database, schema, table)
1346                         $table = explode( '.', $table );
1347                         if ( count( $table ) == 2 ) {
1348                                 array_unshift( $table, false );
1349                         }
1350                 }
1351                 return $table;
1352         }
1353
1354         /**
1355          * Called in the installer and updater.
1356          * Probably doesn't need to be called anywhere else in the codebase.
1357          * @param bool|null $value
1358          * @return bool|null
1359          */
1360         public function prepareStatements( $value = null ) {
1361                 return wfSetVar( $this->mPrepareStatements, $value );
1362         }
1363
1364         /**
1365          * Called in the installer and updater.
1366          * Probably doesn't need to be called anywhere else in the codebase.
1367          * @param bool|null $value
1368          * @return bool|null
1369          */
1370         public function scrollableCursor( $value = null ) {
1371                 return wfSetVar( $this->mScrollableCursor, $value );
1372         }
1373 } // end DatabaseMssql class
1374
1375 /**
1376  * Utility class.
1377  *
1378  * @ingroup Database
1379  */
1380 class MssqlField implements Field {
1381         private $name, $tableName, $default, $max_length, $nullable, $type;
1382
1383         function __construct( $info ) {
1384                 $this->name = $info['COLUMN_NAME'];
1385                 $this->tableName = $info['TABLE_NAME'];
1386                 $this->default = $info['COLUMN_DEFAULT'];
1387                 $this->max_length = $info['CHARACTER_MAXIMUM_LENGTH'];
1388                 $this->nullable = !( strtolower( $info['IS_NULLABLE'] ) == 'no' );
1389                 $this->type = $info['DATA_TYPE'];
1390         }
1391
1392         function name() {
1393                 return $this->name;
1394         }
1395
1396         function tableName() {
1397                 return $this->tableName;
1398         }
1399
1400         function defaultValue() {
1401                 return $this->default;
1402         }
1403
1404         function maxLength() {
1405                 return $this->max_length;
1406         }
1407
1408         function isNullable() {
1409                 return $this->nullable;
1410         }
1411
1412         function type() {
1413                 return $this->type;
1414         }
1415 }
1416
1417 class MssqlBlob extends Blob {
1418         public function __construct( $data ) {
1419                 if ( $data instanceof MssqlBlob ) {
1420                         return $data;
1421                 } elseif ( $data instanceof Blob ) {
1422                         $this->mData = $data->fetch();
1423                 } elseif ( is_array( $data ) && is_object( $data ) ) {
1424                         $this->mData = serialize( $data );
1425                 } else {
1426                         $this->mData = $data;
1427                 }
1428         }
1429
1430         /**
1431          * Returns an unquoted hex representation of a binary string
1432          * for insertion into varbinary-type fields
1433          * @return string
1434          */
1435         public function fetch() {
1436                 if ( $this->mData === null ) {
1437                         return 'null';
1438                 }
1439
1440                 $ret = '0x';
1441                 $dataLength = strlen( $this->mData );
1442                 for ( $i = 0; $i < $dataLength; $i++ ) {
1443                         $ret .= bin2hex( pack( 'C', ord( $this->mData[$i] ) ) );
1444                 }
1445
1446                 return $ret;
1447         }
1448 }
1449
1450 class MssqlResultWrapper extends ResultWrapper {
1451         private $mSeekTo = null;
1452
1453         /**
1454          * @return stdClass|bool
1455          */
1456         public function fetchObject() {
1457                 $res = $this->result;
1458
1459                 if ( $this->mSeekTo !== null ) {
1460                         $result = sqlsrv_fetch_object( $res, 'stdClass', array(),
1461                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1462                         $this->mSeekTo = null;
1463                 } else {
1464                         $result = sqlsrv_fetch_object( $res );
1465                 }
1466
1467                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1468                 if ( $result === null ) {
1469                         return false;
1470                 }
1471
1472                 return $result;
1473         }
1474
1475         /**
1476          * @return array|bool
1477          */
1478         public function fetchRow() {
1479                 $res = $this->result;
1480
1481                 if ( $this->mSeekTo !== null ) {
1482                         $result = sqlsrv_fetch_array( $res, SQLSRV_FETCH_BOTH,
1483                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1484                         $this->mSeekTo = null;
1485                 } else {
1486                         $result = sqlsrv_fetch_array( $res );
1487                 }
1488
1489                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1490                 if ( $result === null ) {
1491                         return false;
1492                 }
1493
1494                 return $result;
1495         }
1496
1497         /**
1498          * @param int $row
1499          * @return bool
1500          */
1501         public function seek( $row ) {
1502                 $res = $this->result;
1503
1504                 // check bounds
1505                 $numRows = $this->db->numRows( $res );
1506                 $row = intval( $row );
1507
1508                 if ( $numRows === 0 ) {
1509                         return false;
1510                 } elseif ( $row < 0 || $row > $numRows - 1 ) {
1511                         return false;
1512                 }
1513
1514                 // Unlike MySQL, the seek actually happens on the next access
1515                 $this->mSeekTo = $row;
1516                 return true;
1517         }
1518 }