crm.fsf.org/20131203/files/sites/all/modules-old/civicrm/packages/DB/mysql.php

   1 <?php
   2
   3 /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
   4
   5 /**
   6  * The PEAR DB driver for PHP's mysql extension
   7  * for interacting with MySQL databases
   8  *
   9  * PHP versions 4 and 5
  10  *
  11  * LICENSE: This source file is subject to version 3.0 of the PHP license
  12  * that is available through the world-wide-web at the following URI:
  13  * http://www.php.net/license/3_0.txt.  If you did not receive a copy of
  14  * the PHP License and are unable to obtain it through the web, please
  15  * send a note to license@php.net so we can mail you a copy immediately.
  16  *
  17  * @category   Database
  18  * @package    DB
  19  * @author     Stig Bakken <ssb@php.net>
  20  * @author     Daniel Convissor <danielc@php.net>
  21  * @copyright  1997-2007 The PHP Group
  22  * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
  23  * @version    CVS: $Id: mysql.php,v 1.126 2007/09/21 13:32:52 aharvey Exp $
  24  * @link       http://pear.php.net/package/DB
  25  */
  26
  27 /**
  28  * Obtain the DB_common class so it can be extended from
  29  */
  30 require_once 'DB/common.php';
  31
  32 /**
  33  * The methods PEAR DB uses to interact with PHP's mysql extension
  34  * for interacting with MySQL databases
  35  *
  36  * These methods overload the ones declared in DB_common.
  37  *
  38  * @category   Database
  39  * @package    DB
  40  * @author     Stig Bakken <ssb@php.net>
  41  * @author     Daniel Convissor <danielc@php.net>
  42  * @copyright  1997-2007 The PHP Group
  43  * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
  44  * @version    Release: 1.7.13
  45  * @link       http://pear.php.net/package/DB
  46  */
  47 class DB_mysql extends DB_common
  48 {
  49     // {{{ properties
  50
  51     /**
  52      * The DB driver type (mysql, oci8, odbc, etc.)
  53      * @var string
  54      */
  55     var $phptype = 'mysql';
  56
  57     /**
  58      * The database syntax variant to be used (db2, access, etc.), if any
  59      * @var string
  60      */
  61     var $dbsyntax = 'mysql';
  62
  63     /**
  64      * The capabilities of this DB implementation
  65      *
  66      * The 'new_link' element contains the PHP version that first provided
  67      * new_link support for this DBMS.  Contains false if it's unsupported.
  68      *
  69      * Meaning of the 'limit' element:
  70      *   + 'emulate' = emulate with fetch row by number
  71      *   + 'alter'   = alter the query
  72      *   + false     = skip rows
  73      *
  74      * @var array
  75      */
  76     var $features = array(
  77         'limit'         => 'alter',
  78         'new_link'      => '4.2.0',
  79         'numrows'       => true,
  80         'pconnect'      => true,
  81         'prepare'       => false,
  82         'ssl'           => false,
  83         'transactions'  => true,
  84     );
  85
  86     /**
  87      * A mapping of native error codes to DB error codes
  88      * @var array
  89      */
  90     var $errorcode_map = array(
  91         1004 => DB_ERROR_CANNOT_CREATE,
  92         1005 => DB_ERROR_CANNOT_CREATE,
  93         1006 => DB_ERROR_CANNOT_CREATE,
  94         1007 => DB_ERROR_ALREADY_EXISTS,
  95         1008 => DB_ERROR_CANNOT_DROP,
  96         1022 => DB_ERROR_ALREADY_EXISTS,
  97         1044 => DB_ERROR_ACCESS_VIOLATION,
  98         1046 => DB_ERROR_NODBSELECTED,
  99         1048 => DB_ERROR_CONSTRAINT,
 100         1049 => DB_ERROR_NOSUCHDB,
 101         1050 => DB_ERROR_ALREADY_EXISTS,
 102         1051 => DB_ERROR_NOSUCHTABLE,
 103         1054 => DB_ERROR_NOSUCHFIELD,
 104         1061 => DB_ERROR_ALREADY_EXISTS,
 105         1062 => DB_ERROR_ALREADY_EXISTS,
 106         1064 => DB_ERROR_SYNTAX,
 107         1091 => DB_ERROR_NOT_FOUND,
 108         1100 => DB_ERROR_NOT_LOCKED,
 109         1136 => DB_ERROR_VALUE_COUNT_ON_ROW,
 110         1142 => DB_ERROR_ACCESS_VIOLATION,
 111         1146 => DB_ERROR_NOSUCHTABLE,
 112         1216 => DB_ERROR_CONSTRAINT,
 113         1217 => DB_ERROR_CONSTRAINT,
 114         1356 => DB_ERROR_INVALID_VIEW,
 115         1365 => DB_ERROR_DIVZERO,
 116         1451 => DB_ERROR_CONSTRAINT,
 117         1452 => DB_ERROR_CONSTRAINT,
 118     );
 119
 120     /**
 121      * The raw database connection created by PHP
 122      * @var resource
 123      */
 124     var $connection;
 125
 126     /**
 127      * The DSN information for connecting to a database
 128      * @var array
 129      */
 130     var $dsn = array();
 131
 132
 133     /**
 134      * Should data manipulation queries be committed automatically?
 135      * @var bool
 136      * @access private
 137      */
 138     var $autocommit = true;
 139
 140     /**
 141      * The quantity of transactions begun
 142      *
 143      * {@internal  While this is private, it can't actually be designated
 144      * private in PHP 5 because it is directly accessed in the test suite.}}
 145      *
 146      * @var integer
 147      * @access private
 148      */
 149     var $transaction_opcount = 0;
 150
 151     /**
 152      * The database specified in the DSN
 153      *
 154      * It's a fix to allow calls to different databases in the same script.
 155      *
 156      * @var string
 157      * @access private
 158      */
 159     var $_db = '';
 160
 161
 162     // }}}
 163     // {{{ constructor
 164
 165     /**
 166      * This constructor calls <kbd>$this->DB_common()</kbd>
 167      *
 168      * @return void
 169      */
 170     function DB_mysql()
 171     {
 172         $this->DB_common();
 173     }
 174
 175     // }}}
 176     // {{{ connect()
 177
 178     /**
 179      * Connect to the database server, log in and open the database
 180      *
 181      * Don't call this method directly.  Use DB::connect() instead.
 182      *
 183      * PEAR DB's mysql driver supports the following extra DSN options:
 184      *   + new_link      If set to true, causes subsequent calls to connect()
 185      *                    to return a new connection link instead of the
 186      *                    existing one.  WARNING: this is not portable to
 187      *                    other DBMS's. Available since PEAR DB 1.7.0.
 188      *   + client_flags  Any combination of MYSQL_CLIENT_* constants.
 189      *                    Only used if PHP is at version 4.3.0 or greater.
 190      *                    Available since PEAR DB 1.7.0.
 191      *
 192      * @param array $dsn         the data source name
 193      * @param bool  $persistent  should the connection be persistent?
 194      *
 195      * @return int  DB_OK on success. A DB_Error object on failure.
 196      */
 197     function connect($dsn, $persistent = false)
 198     {
 199         if (!PEAR::loadExtension('mysql')) {
 200             return $this->raiseError(DB_ERROR_EXTENSION_NOT_FOUND);
 201         }
 202
 203         $this->dsn = $dsn;
 204         if ($dsn['dbsyntax']) {
 205             $this->dbsyntax = $dsn['dbsyntax'];
 206         }
 207
 208         $params = array();
 209         if ($dsn['protocol'] && $dsn['protocol'] == 'unix') {
 210             $params[0] = ':' . $dsn['socket'];
 211         } else {
 212             $params[0] = $dsn['hostspec'] ? $dsn['hostspec']
 213                          : 'localhost';
 214             if ($dsn['port']) {
 215                 $params[0] .= ':' . $dsn['port'];
 216             }
 217         }
 218         $params[] = $dsn['username'] ? $dsn['username'] : null;
 219         $params[] = $dsn['password'] ? $dsn['password'] : null;
 220
 221         if (!$persistent) {
 222             if (isset($dsn['new_link'])
 223                 && ($dsn['new_link'] == 'true' || $dsn['new_link'] === true))
 224             {
 225                 $params[] = true;
 226             } else {
 227                 $params[] = false;
 228             }
 229         }
 230         if (version_compare(phpversion(), '4.3.0', '>=')) {
 231             $params[] = isset($dsn['client_flags'])
 232                         ? $dsn['client_flags'] : null;
 233         }
 234
 235         $connect_function = $persistent ? 'mysql_pconnect' : 'mysql_connect';
 236
 237         $ini = ini_get('track_errors');
 238         $php_errormsg = '';
 239         if ($ini) {
 240             $this->connection = @call_user_func_array($connect_function,
 241                                                       $params);
 242         } else {
 243             @ini_set('track_errors', 1);
 244             $this->connection = @call_user_func_array($connect_function,
 245                                                       $params);
 246             @ini_set('track_errors', $ini);
 247         }
 248
 249         if (!$this->connection) {
 250             if (($err = @mysql_error()) != '') {
 251                 return $this->raiseError(DB_ERROR_CONNECT_FAILED,
 252                                          null, null, null,
 253                                          $err);
 254             } else {
 255                 return $this->raiseError(DB_ERROR_CONNECT_FAILED,
 256                                          null, null, null,
 257                                          $php_errormsg);
 258             }
 259         }
 260
 261         if ($dsn['database']) {
 262             if (!@mysql_select_db($dsn['database'], $this->connection)) {
 263                 return $this->mysqlRaiseError();
 264             }
 265             $this->_db = $dsn['database'];
 266         }
 267
 268         return DB_OK;
 269     }
 270
 271     // }}}
 272     // {{{ disconnect()
 273
 274     /**
 275      * Disconnects from the database server
 276      *
 277      * @return bool  TRUE on success, FALSE on failure
 278      */
 279     function disconnect()
 280     {
 281         $ret = @mysql_close($this->connection);
 282         $this->connection = null;
 283         return $ret;
 284     }
 285
 286     // }}}
 287     // {{{ simpleQuery()
 288
 289     /**
 290      * Sends a query to the database server
 291      *
 292      * Generally uses mysql_query().  If you want to use
 293      * mysql_unbuffered_query() set the "result_buffering" option to 0 using
 294      * setOptions().  This option was added in Release 1.7.0.
 295      *
 296      * @param string  the SQL query string
 297      *
 298      * @return mixed  + a PHP result resrouce for successful SELECT queries
 299      *                + the DB_OK constant for other successful queries
 300      *                + a DB_Error object on failure
 301      */
 302     function simpleQuery($query)
 303     {
 304         $ismanip = $this->_checkManip($query);
 305         $this->last_query = $query;
 306         $query = $this->modifyQuery($query);
 307         if ($this->_db) {
 308             if (!@mysql_select_db($this->_db, $this->connection)) {
 309                 return $this->mysqlRaiseError(DB_ERROR_NODBSELECTED);
 310             }
 311         }
 312         if (!$this->autocommit && $ismanip) {
 313             if ($this->transaction_opcount == 0) {
 314                 $result = @mysql_query('SET AUTOCOMMIT=0', $this->connection);
 315                 $result = @mysql_query('BEGIN', $this->connection);
 316                 if (!$result) {
 317                     return $this->mysqlRaiseError();
 318                 }
 319             }
 320             $this->transaction_opcount++;
 321         }
 322         if (!$this->options['result_buffering']) {
 323             $result = @mysql_unbuffered_query($query, $this->connection);
 324         } else {
 325             $result = @mysql_query($query, $this->connection);
 326         }
 327         if (!$result) {
 328             return $this->mysqlRaiseError();
 329         }
 330         if (is_resource($result)) {
 331             return $result;
 332         }
 333         return DB_OK;
 334     }
 335
 336     // }}}
 337     // {{{ nextResult()
 338
 339     /**
 340      * Move the internal mysql result pointer to the next available result
 341      *
 342      * This method has not been implemented yet.
 343      *
 344      * @param a valid sql result resource
 345      *
 346      * @return false
 347      */
 348     function nextResult($result)
 349     {
 350         return false;
 351     }
 352
 353     // }}}
 354     // {{{ fetchInto()
 355
 356     /**
 357      * Places a row from the result set into the given array
 358      *
 359      * Formating of the array and the data therein are configurable.
 360      * See DB_result::fetchInto() for more information.
 361      *
 362      * This method is not meant to be called directly.  Use
 363      * DB_result::fetchInto() instead.  It can't be declared "protected"
 364      * because DB_result is a separate object.
 365      *
 366      * @param resource $result    the query result resource
 367      * @param array    $arr       the referenced array to put the data in
 368      * @param int      $fetchmode how the resulting array should be indexed
 369      * @param int      $rownum    the row number to fetch (0 = first row)
 370      *
 371      * @return mixed  DB_OK on success, NULL when the end of a result set is
 372      *                 reached or on failure
 373      *
 374      * @see DB_result::fetchInto()
 375      */
 376     function fetchInto($result, &$arr, $fetchmode, $rownum = null)
 377     {
 378         if ($rownum !== null) {
 379             if (!@mysql_data_seek($result, $rownum)) {
 380                 return null;
 381             }
 382         }
 383         if ($fetchmode & DB_FETCHMODE_ASSOC) {
 384             $arr = @mysql_fetch_array($result, MYSQL_ASSOC);
 385             if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE && $arr) {
 386                 $arr = array_change_key_case($arr, CASE_LOWER);
 387             }
 388         } else {
 389             $arr = @mysql_fetch_row($result);
 390         }
 391         if (!$arr) {
 392             return null;
 393         }
 394         if ($this->options['portability'] & DB_PORTABILITY_RTRIM) {
 395             /*
 396              * Even though this DBMS already trims output, we do this because
 397              * a field might have intentional whitespace at the end that
 398              * gets removed by DB_PORTABILITY_RTRIM under another driver.
 399              */
 400             $this->_rtrimArrayValues($arr);
 401         }
 402         if ($this->options['portability'] & DB_PORTABILITY_NULL_TO_EMPTY) {
 403             $this->_convertNullArrayValuesToEmpty($arr);
 404         }
 405         return DB_OK;
 406     }
 407
 408     // }}}
 409     // {{{ freeResult()
 410
 411     /**
 412      * Deletes the result set and frees the memory occupied by the result set
 413      *
 414      * This method is not meant to be called directly.  Use
 415      * DB_result::free() instead.  It can't be declared "protected"
 416      * because DB_result is a separate object.
 417      *
 418      * @param resource $result  PHP's query result resource
 419      *
 420      * @return bool  TRUE on success, FALSE if $result is invalid
 421      *
 422      * @see DB_result::free()
 423      */
 424     function freeResult($result)
 425     {
 426         return is_resource($result) ? mysql_free_result($result) : false;
 427     }
 428
 429     // }}}
 430     // {{{ numCols()
 431
 432     /**
 433      * Gets the number of columns in a result set
 434      *
 435      * This method is not meant to be called directly.  Use
 436      * DB_result::numCols() instead.  It can't be declared "protected"
 437      * because DB_result is a separate object.
 438      *
 439      * @param resource $result  PHP's query result resource
 440      *
 441      * @return int  the number of columns.  A DB_Error object on failure.
 442      *
 443      * @see DB_result::numCols()
 444      */
 445     function numCols($result)
 446     {
 447         $cols = @mysql_num_fields($result);
 448         if (!$cols) {
 449             return $this->mysqlRaiseError();
 450         }
 451         return $cols;
 452     }
 453
 454     // }}}
 455     // {{{ numRows()
 456
 457     /**
 458      * Gets the number of rows in a result set
 459      *
 460      * This method is not meant to be called directly.  Use
 461      * DB_result::numRows() instead.  It can't be declared "protected"
 462      * because DB_result is a separate object.
 463      *
 464      * @param resource $result  PHP's query result resource
 465      *
 466      * @return int  the number of rows.  A DB_Error object on failure.
 467      *
 468      * @see DB_result::numRows()
 469      */
 470     function numRows($result)
 471     {
 472         $rows = @mysql_num_rows($result);
 473         if ($rows === null) {
 474             return $this->mysqlRaiseError();
 475         }
 476         return $rows;
 477     }
 478
 479     // }}}
 480     // {{{ autoCommit()
 481
 482     /**
 483      * Enables or disables automatic commits
 484      *
 485      * @param bool $onoff  true turns it on, false turns it off
 486      *
 487      * @return int  DB_OK on success.  A DB_Error object if the driver
 488      *               doesn't support auto-committing transactions.
 489      */
 490     function autoCommit($onoff = false)
 491     {
 492         // XXX if $this->transaction_opcount > 0, we should probably
 493         // issue a warning here.
 494         $this->autocommit = $onoff ? true : false;
 495         return DB_OK;
 496     }
 497
 498     // }}}
 499     // {{{ commit()
 500
 501     /**
 502      * Commits the current transaction
 503      *
 504      * @return int  DB_OK on success.  A DB_Error object on failure.
 505      */
 506     function commit()
 507     {
 508         if ($this->transaction_opcount > 0) {
 509             if ($this->_db) {
 510                 if (!@mysql_select_db($this->_db, $this->connection)) {
 511                     return $this->mysqlRaiseError(DB_ERROR_NODBSELECTED);
 512                 }
 513             }
 514             $result = @mysql_query('COMMIT', $this->connection);
 515             $result = @mysql_query('SET AUTOCOMMIT=1', $this->connection);
 516             $this->transaction_opcount = 0;
 517             if (!$result) {
 518                 return $this->mysqlRaiseError();
 519             }
 520         }
 521         return DB_OK;
 522     }
 523
 524     // }}}
 525     // {{{ rollback()
 526
 527     /**
 528      * Reverts the current transaction
 529      *
 530      * @return int  DB_OK on success.  A DB_Error object on failure.
 531      */
 532     function rollback()
 533     {
 534         if ($this->transaction_opcount > 0) {
 535             if ($this->_db) {
 536                 if (!@mysql_select_db($this->_db, $this->connection)) {
 537                     return $this->mysqlRaiseError(DB_ERROR_NODBSELECTED);
 538                 }
 539             }
 540             $result = @mysql_query('ROLLBACK', $this->connection);
 541             $result = @mysql_query('SET AUTOCOMMIT=1', $this->connection);
 542             $this->transaction_opcount = 0;
 543             if (!$result) {
 544                 return $this->mysqlRaiseError();
 545             }
 546         }
 547         return DB_OK;
 548     }
 549
 550     // }}}
 551     // {{{ affectedRows()
 552
 553     /**
 554      * Determines the number of rows affected by a data maniuplation query
 555      *
 556      * 0 is returned for queries that don't manipulate data.
 557      *
 558      * @return int  the number of rows.  A DB_Error object on failure.
 559      */
 560     function affectedRows()
 561     {
 562         if ($this->_last_query_manip) {
 563             return @mysql_affected_rows($this->connection);
 564         } else {
 565             return 0;
 566         }
 567      }
 568
 569     // }}}
 570     // {{{ nextId()
 571
 572     /**
 573      * Returns the next free id in a sequence
 574      *
 575      * @param string  $seq_name  name of the sequence
 576      * @param boolean $ondemand  when true, the seqence is automatically
 577      *                            created if it does not exist
 578      *
 579      * @return int  the next id number in the sequence.
 580      *               A DB_Error object on failure.
 581      *
 582      * @see DB_common::nextID(), DB_common::getSequenceName(),
 583      *      DB_mysql::createSequence(), DB_mysql::dropSequence()
 584      */
 585     function nextId($seq_name, $ondemand = true)
 586     {
 587         $seqname = $this->getSequenceName($seq_name);
 588         do {
 589             $repeat = 0;
 590             $this->pushErrorHandling(PEAR_ERROR_RETURN);
 591             $result = $this->query("UPDATE ${seqname} ".
 592                                    'SET id=LAST_INSERT_ID(id+1)');
 593             $this->popErrorHandling();
 594             if ($result === DB_OK) {
 595                 // COMMON CASE
 596                 $id = @mysql_insert_id($this->connection);
 597                 if ($id != 0) {
 598                     return $id;
 599                 }
 600                 // EMPTY SEQ TABLE
 601                 // Sequence table must be empty for some reason, so fill
 602                 // it and return 1 and obtain a user-level lock
 603                 $result = $this->getOne("SELECT GET_LOCK('${seqname}_lock',10)");
 604                 if (DB::isError($result)) {
 605                     return $this->raiseError($result);
 606                 }
 607                 if ($result == 0) {
 608                     // Failed to get the lock
 609                     return $this->mysqlRaiseError(DB_ERROR_NOT_LOCKED);
 610                 }
 611
 612                 // add the default value
 613                 $result = $this->query("REPLACE INTO ${seqname} (id) VALUES (0)");
 614                 if (DB::isError($result)) {
 615                     return $this->raiseError($result);
 616                 }
 617
 618                 // Release the lock
 619                 $result = $this->getOne('SELECT RELEASE_LOCK('
 620                                         . "'${seqname}_lock')");
 621                 if (DB::isError($result)) {
 622                     return $this->raiseError($result);
 623                 }
 624                 // We know what the result will be, so no need to try again
 625                 return 1;
 626
 627             } elseif ($ondemand && DB::isError($result) &&
 628                 $result->getCode() == DB_ERROR_NOSUCHTABLE)
 629             {
 630                 // ONDEMAND TABLE CREATION
 631                 $result = $this->createSequence($seq_name);
 632                 if (DB::isError($result)) {
 633                     return $this->raiseError($result);
 634                 } else {
 635                     $repeat = 1;
 636                 }
 637
 638             } elseif (DB::isError($result) &&
 639                       $result->getCode() == DB_ERROR_ALREADY_EXISTS)
 640             {
 641                 // BACKWARDS COMPAT
 642                 // see _BCsequence() comment
 643                 $result = $this->_BCsequence($seqname);
 644                 if (DB::isError($result)) {
 645                     return $this->raiseError($result);
 646                 }
 647                 $repeat = 1;
 648             }
 649         } while ($repeat);
 650
 651         return $this->raiseError($result);
 652     }
 653
 654     // }}}
 655     // {{{ createSequence()
 656
 657     /**
 658      * Creates a new sequence
 659      *
 660      * @param string $seq_name  name of the new sequence
 661      *
 662      * @return int  DB_OK on success.  A DB_Error object on failure.
 663      *
 664      * @see DB_common::createSequence(), DB_common::getSequenceName(),
 665      *      DB_mysql::nextID(), DB_mysql::dropSequence()
 666      */
 667     function createSequence($seq_name)
 668     {
 669         $seqname = $this->getSequenceName($seq_name);
 670         $res = $this->query('CREATE TABLE ' . $seqname
 671                             . ' (id INTEGER UNSIGNED AUTO_INCREMENT NOT NULL,'
 672                             . ' PRIMARY KEY(id))');
 673         if (DB::isError($res)) {
 674             return $res;
 675         }
 676         // insert yields value 1, nextId call will generate ID 2
 677         $res = $this->query("INSERT INTO ${seqname} (id) VALUES (0)");
 678         if (DB::isError($res)) {
 679             return $res;
 680         }
 681         // so reset to zero
 682         return $this->query("UPDATE ${seqname} SET id = 0");
 683     }
 684
 685     // }}}
 686     // {{{ dropSequence()
 687
 688     /**
 689      * Deletes a sequence
 690      *
 691      * @param string $seq_name  name of the sequence to be deleted
 692      *
 693      * @return int  DB_OK on success.  A DB_Error object on failure.
 694      *
 695      * @see DB_common::dropSequence(), DB_common::getSequenceName(),
 696      *      DB_mysql::nextID(), DB_mysql::createSequence()
 697      */
 698     function dropSequence($seq_name)
 699     {
 700         return $this->query('DROP TABLE ' . $this->getSequenceName($seq_name));
 701     }
 702
 703     // }}}
 704     // {{{ _BCsequence()
 705
 706     /**
 707      * Backwards compatibility with old sequence emulation implementation
 708      * (clean up the dupes)
 709      *
 710      * @param string $seqname  the sequence name to clean up
 711      *
 712      * @return bool  true on success.  A DB_Error object on failure.
 713      *
 714      * @access private
 715      */
 716     function _BCsequence($seqname)
 717     {
 718         // Obtain a user-level lock... this will release any previous
 719         // application locks, but unlike LOCK TABLES, it does not abort
 720         // the current transaction and is much less frequently used.
 721         $result = $this->getOne("SELECT GET_LOCK('${seqname}_lock',10)");
 722         if (DB::isError($result)) {
 723             return $result;
 724         }
 725         if ($result == 0) {
 726             // Failed to get the lock, can't do the conversion, bail
 727             // with a DB_ERROR_NOT_LOCKED error
 728             return $this->mysqlRaiseError(DB_ERROR_NOT_LOCKED);
 729         }
 730
 731         $highest_id = $this->getOne("SELECT MAX(id) FROM ${seqname}");
 732         if (DB::isError($highest_id)) {
 733             return $highest_id;
 734         }
 735         // This should kill all rows except the highest
 736         // We should probably do something if $highest_id isn't
 737         // numeric, but I'm at a loss as how to handle that...
 738         $result = $this->query('DELETE FROM ' . $seqname
 739                                . " WHERE id <> $highest_id");
 740         if (DB::isError($result)) {
 741             return $result;
 742         }
 743
 744         // If another thread has been waiting for this lock,
 745         // it will go thru the above procedure, but will have no
 746         // real effect
 747         $result = $this->getOne("SELECT RELEASE_LOCK('${seqname}_lock')");
 748         if (DB::isError($result)) {
 749             return $result;
 750         }
 751         return true;
 752     }
 753
 754     // }}}
 755     // {{{ quoteIdentifier()
 756
 757     /**
 758      * Quotes a string so it can be safely used as a table or column name
 759      * (WARNING: using names that require this is a REALLY BAD IDEA)
 760      *
 761      * WARNING:  Older versions of MySQL can't handle the backtick
 762      * character (<kbd>`</kbd>) in table or column names.
 763      *
 764      * @param string $str  identifier name to be quoted
 765      *
 766      * @return string  quoted identifier string
 767      *
 768      * @see DB_common::quoteIdentifier()
 769      * @since Method available since Release 1.6.0
 770      */
 771     function quoteIdentifier($str)
 772     {
 773         return '`' . str_replace('`', '``', $str) . '`';
 774     }
 775
 776     // }}}
 777     // {{{ quote()
 778
 779     /**
 780      * @deprecated  Deprecated in release 1.6.0
 781      */
 782     function quote($str = null)
 783     {
 784         return $this->quoteSmart($str);
 785     }
 786
 787     // }}}
 788     // {{{ escapeSimple()
 789
 790     /**
 791      * Escapes a string according to the current DBMS's standards
 792      *
 793      * @param string $str  the string to be escaped
 794      *
 795      * @return string  the escaped string
 796      *
 797      * @see DB_common::quoteSmart()
 798      * @since Method available since Release 1.6.0
 799      */
 800     function escapeSimple($str)
 801     {
 802         return @mysql_real_escape_string($str, $this->connection);
 803     }
 804
 805     // }}}
 806     // {{{ modifyQuery()
 807
 808     /**
 809      * Changes a query string for various DBMS specific reasons
 810      *
 811      * This little hack lets you know how many rows were deleted
 812      * when running a "DELETE FROM table" query.  Only implemented
 813      * if the DB_PORTABILITY_DELETE_COUNT portability option is on.
 814      *
 815      * @param string $query  the query string to modify
 816      *
 817      * @return string  the modified query string
 818      *
 819      * @access protected
 820      * @see DB_common::setOption()
 821      */
 822     function modifyQuery($query)
 823     {
 824         if ($this->options['portability'] & DB_PORTABILITY_DELETE_COUNT) {
 825             // "DELETE FROM table" gives 0 affected rows in MySQL.
 826             // This little hack lets you know how many rows were deleted.
 827             if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $query)) {
 828                 $query = preg_replace('/^\s*DELETE\s+FROM\s+(\S+)\s*$/',
 829                                       'DELETE FROM \1 WHERE 1=1', $query);
 830             }
 831         }
 832         return $query;
 833     }
 834
 835     // }}}
 836     // {{{ modifyLimitQuery()
 837
 838     /**
 839      * Adds LIMIT clauses to a query string according to current DBMS standards
 840      *
 841      * @param string $query   the query to modify
 842      * @param int    $from    the row to start to fetching (0 = the first row)
 843      * @param int    $count   the numbers of rows to fetch
 844      * @param mixed  $params  array, string or numeric data to be used in
 845      *                         execution of the statement.  Quantity of items
 846      *                         passed must match quantity of placeholders in
 847      *                         query:  meaning 1 placeholder for non-array
 848      *                         parameters or 1 placeholder per array element.
 849      *
 850      * @return string  the query string with LIMIT clauses added
 851      *
 852      * @access protected
 853      */
 854     function modifyLimitQuery($query, $from, $count, $params = array())
 855     {
 856         if (DB::isManip($query) || $this->_next_query_manip) {
 857             return $query . " LIMIT $count";
 858         } else {
 859             return $query . " LIMIT $from, $count";
 860         }
 861     }
 862
 863     // }}}
 864     // {{{ mysqlRaiseError()
 865
 866     /**
 867      * Produces a DB_Error object regarding the current problem
 868      *
 869      * @param int $errno  if the error is being manually raised pass a
 870      *                     DB_ERROR* constant here.  If this isn't passed
 871      *                     the error information gathered from the DBMS.
 872      *
 873      * @return object  the DB_Error object
 874      *
 875      * @see DB_common::raiseError(),
 876      *      DB_mysql::errorNative(), DB_common::errorCode()
 877      */
 878     function mysqlRaiseError($errno = null)
 879     {
 880         if ($errno === null) {
 881             if ($this->options['portability'] & DB_PORTABILITY_ERRORS) {
 882                 $this->errorcode_map[1022] = DB_ERROR_CONSTRAINT;
 883                 $this->errorcode_map[1048] = DB_ERROR_CONSTRAINT_NOT_NULL;
 884                 $this->errorcode_map[1062] = DB_ERROR_CONSTRAINT;
 885             } else {
 886                 // Doing this in case mode changes during runtime.
 887                 $this->errorcode_map[1022] = DB_ERROR_ALREADY_EXISTS;
 888                 $this->errorcode_map[1048] = DB_ERROR_CONSTRAINT;
 889                 $this->errorcode_map[1062] = DB_ERROR_ALREADY_EXISTS;
 890             }
 891             $errno = $this->errorCode(mysql_errno($this->connection));
 892         }
 893         return $this->raiseError($errno, null, null, null,
 894                                  @mysql_errno($this->connection) . ' ** ' .
 895                                  @mysql_error($this->connection));
 896     }
 897
 898     // }}}
 899     // {{{ errorNative()
 900
 901     /**
 902      * Gets the DBMS' native error code produced by the last query
 903      *
 904      * @return int  the DBMS' error code
 905      */
 906     function errorNative()
 907     {
 908         return @mysql_errno($this->connection);
 909     }
 910
 911     // }}}
 912     // {{{ tableInfo()
 913
 914     /**
 915      * Returns information about a table or a result set
 916      *
 917      * @param object|string  $result  DB_result object from a query or a
 918      *                                 string containing the name of a table.
 919      *                                 While this also accepts a query result
 920      *                                 resource identifier, this behavior is
 921      *                                 deprecated.
 922      * @param int            $mode    a valid tableInfo mode
 923      *
 924      * @return array  an associative array with the information requested.
 925      *                 A DB_Error object on failure.
 926      *
 927      * @see DB_common::tableInfo()
 928      */
 929     function tableInfo($result, $mode = null)
 930     {
 931         if (is_string($result)) {
 932             // Fix for bug #11580.
 933             if ($this->_db) {
 934                 if (!@mysql_select_db($this->_db, $this->connection)) {
 935                     return $this->mysqlRaiseError(DB_ERROR_NODBSELECTED);
 936                 }
 937             }
 938
 939             /*
 940              * Probably received a table name.
 941              * Create a result resource identifier.
 942              */
 943             $id = @mysql_query("SELECT * FROM $result LIMIT 0",
 944                                $this->connection);
 945             $got_string = true;
 946         } elseif (isset($result->result)) {
 947             /*
 948              * Probably received a result object.
 949              * Extract the result resource identifier.
 950              */
 951             $id = $result->result;
 952             $got_string = false;
 953         } else {
 954             /*
 955              * Probably received a result resource identifier.
 956              * Copy it.
 957              * Deprecated.  Here for compatibility only.
 958              */
 959             $id = $result;
 960             $got_string = false;
 961         }
 962
 963         if (!is_resource($id)) {
 964             return $this->mysqlRaiseError(DB_ERROR_NEED_MORE_DATA);
 965         }
 966
 967         if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
 968             $case_func = 'strtolower';
 969         } else {
 970             $case_func = 'strval';
 971         }
 972
 973         $count = @mysql_num_fields($id);
 974         $res   = array();
 975
 976         if ($mode) {
 977             $res['num_fields'] = $count;
 978         }
 979
 980         for ($i = 0; $i < $count; $i++) {
 981             $res[$i] = array(
 982                 'table' => $case_func(@mysql_field_table($id, $i)),
 983                 'name'  => $case_func(@mysql_field_name($id, $i)),
 984                 'type'  => @mysql_field_type($id, $i),
 985                 'len'   => @mysql_field_len($id, $i),
 986                 'flags' => @mysql_field_flags($id, $i),
 987             );
 988             if ($mode & DB_TABLEINFO_ORDER) {
 989                 $res['order'][$res[$i]['name']] = $i;
 990             }
 991             if ($mode & DB_TABLEINFO_ORDERTABLE) {
 992                 $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
 993             }
 994         }
 995
 996         // free the result only if we were called on a table
 997         if ($got_string) {
 998             @mysql_free_result($id);
 999         }
1000         return $res;
1001     }
1002
1003     // }}}
1004     // {{{ getSpecialQuery()
1005
1006     /**
1007      * Obtains the query string needed for listing a given type of objects
1008      *
1009      * @param string $type  the kind of objects you want to retrieve
1010      *
1011      * @return string  the SQL query string or null if the driver doesn't
1012      *                  support the object type requested
1013      *
1014      * @access protected
1015      * @see DB_common::getListOf()
1016      */
1017     function getSpecialQuery($type)
1018     {
1019         switch ($type) {
1020             case 'tables':
1021                 return 'SHOW TABLES';
1022             case 'users':
1023                 return 'SELECT DISTINCT User FROM mysql.user';
1024             case 'databases':
1025                 return 'SHOW DATABASES';
1026             default:
1027                 return null;
1028         }
1029     }
1030
1031     // }}}
1032
1033 }
1034
1035 /*
1036  * Local variables:
1037  * tab-width: 4
1038  * c-basic-offset: 4
1039  * End:
1040  */
1041
1042 ?>