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