includes/db/DatabaseIbm_db2.php

   1 <?php
   2 /**
   3  * This is the IBM DB2 database abstraction layer.
   4  * See maintenance/ibm_db2/README for development notes and other specific information
   5  *
   6  * @file
   7  * @ingroup Database
   8  * @author leo.petr+mediawiki@gmail.com
   9  */
  10
  11 /**
  12  * This represents a column in a DB2 database
  13  * @ingroup Database
  14  */
  15 class IBM_DB2Field {
  16         private $name = '';
  17         private $tablename = '';
  18         private $type = '';
  19         private $nullable = false;
  20         private $max_length = 0;
  21
  22         /**
  23          * Builder method for the class
  24          * @param $db DatabaseIbm_db2: Database interface
  25          * @param $table String: table name
  26          * @param $field String: column name
  27          * @return IBM_DB2Field
  28          */
  29         static function fromText($db, $table, $field) {
  30                 global $wgDBmwschema;
  31
  32                 $q = <<<SQL
  33 SELECT
  34 lcase(coltype) AS typname,
  35 nulls AS attnotnull, length AS attlen
  36 FROM sysibm.syscolumns
  37 WHERE tbcreator=%s AND tbname=%s AND name=%s;
  38 SQL;
  39                 $res = $db->query(sprintf($q,
  40                                 $db->addQuotes($wgDBmwschema),
  41                                 $db->addQuotes($table),
  42                                 $db->addQuotes($field)));
  43                 $row = $db->fetchObject($res);
  44                 if (!$row)
  45                         return null;
  46                 $n = new IBM_DB2Field;
  47                 $n->type = $row->typname;
  48                 $n->nullable = ($row->attnotnull == 'N');
  49                 $n->name = $field;
  50                 $n->tablename = $table;
  51                 $n->max_length = $row->attlen;
  52                 return $n;
  53         }
  54         /**
  55          * Get column name
  56          * @return string column name
  57          */
  58         function name() { return $this->name; }
  59         /**
  60          * Get table name
  61          * @return string table name
  62          */
  63         function tableName() { return $this->tablename; }
  64         /**
  65          * Get column type
  66          * @return string column type
  67          */
  68         function type() { return $this->type; }
  69         /**
  70          * Can column be null?
  71          * @return bool true or false
  72          */
  73         function nullable() { return $this->nullable; }
  74         /**
  75          * How much can you fit in the column per row?
  76          * @return int length
  77          */
  78         function maxLength() { return $this->max_length; }
  79 }
  80
  81 /**
  82  * Wrapper around binary large objects
  83  * @ingroup Database
  84  */
  85 class IBM_DB2Blob {
  86         private $mData;
  87
  88         public function __construct($data) {
  89                 $this->mData = $data;
  90         }
  91
  92         public function getData() {
  93                 return $this->mData;
  94         }
  95
  96         public function __toString()
  97     {
  98         return $this->mData;
  99     }
 100 }
 101
 102 /**
 103  * Primary database interface
 104  * @ingroup Database
 105  */
 106 class DatabaseIbm_db2 extends DatabaseBase {
 107         /*
 108          * Inherited members
 109         protected $mLastQuery = '';
 110         protected $mPHPError = false;
 111
 112         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
 113         protected $mOut, $mOpened = false;
 114
 115         protected $mFailFunction;
 116         protected $mTablePrefix;
 117         protected $mFlags;
 118         protected $mTrxLevel = 0;
 119         protected $mErrorCount = 0;
 120         protected $mLBInfo = array();
 121         protected $mFakeSlaveLag = null, $mFakeMaster = false;
 122          *
 123          */
 124
 125         /// Server port
 126         protected $mPort = null;
 127         /// Schema for tables, stored procedures, triggers
 128         protected $mSchema = null;
 129         /// Whether the schema has been applied in this session
 130         protected $mSchemaSet = false;
 131         /// Result of last query
 132         protected $mLastResult = null;
 133         /// Number of rows affected by last INSERT/UPDATE/DELETE
 134         protected $mAffectedRows = null;
 135         /// Number of rows returned by last SELECT
 136         protected $mNumRows = null;
 137
 138         /// Connection config options - see constructor
 139         public $mConnOptions = array();
 140         /// Statement config options -- see constructor
 141         public $mStmtOptions = array();
 142
 143
 144         const USE_GLOBAL = "get from global";
 145
 146         const NONE_OPTION = 0x00;
 147         const CONN_OPTION = 0x01;
 148         const STMT_OPTION = 0x02;
 149
 150         const REGULAR_MODE = 'regular';
 151         const INSTALL_MODE = 'install';
 152
 153         // Whether this is regular operation or the initial installation
 154         protected $mMode = self::REGULAR_MODE;
 155
 156         /// Last sequence value used for a primary key
 157         protected $mInsertId = null;
 158
 159         /*
 160          * These can be safely inherited
 161          *
 162          * Getter/Setter: (18)
 163          * failFunction
 164          * bufferResults
 165          * ignoreErrors
 166          * trxLevel
 167          * errorCount
 168          * getLBInfo
 169          * setLBInfo
 170          * lastQuery
 171          * isOpen
 172          * setFlag
 173          * clearFlag
 174          * getFlag
 175          * getProperty
 176          * getDBname
 177          * getServer
 178          * tableNameCallback
 179          * tablePrefix
 180          *
 181          * Administrative: (8)
 182          * debug
 183          * installErrorHandler
 184          * restoreErrorHandler
 185          * connectionErrorHandler
 186          * reportConnectionError
 187          * sourceFile
 188          * sourceStream
 189          * replaceVars
 190          *
 191          * Database: (5)
 192          * query
 193          * set
 194          * selectField
 195          * generalizeSQL
 196          * update
 197          * strreplace
 198          * deadlockLoop
 199          *
 200          * Prepared Statement: 6
 201          * prepare
 202          * freePrepared
 203          * execute
 204          * safeQuery
 205          * fillPrepared
 206          * fillPreparedArg
 207          *
 208          * Slave/Master: (4)
 209          * masterPosWait
 210          * getSlavePos
 211          * getMasterPos
 212          * getLag
 213          * setFakeMaster
 214          *
 215          * Generation: (9)
 216          * tableNames
 217          * tableNamesN
 218          * tableNamesWithUseIndexOrJOIN
 219          * escapeLike
 220          * delete
 221          * insertSelect
 222          * timestampOrNull
 223          * resultObject
 224          * aggregateValue
 225          * selectSQLText
 226          * selectRow
 227          * makeUpdateOptions
 228          *
 229          * Reflection: (1)
 230          * indexExists
 231          */
 232
 233         /*
 234          * These have been implemented
 235          *
 236          * Administrative: 7 / 7
 237          * constructor [Done]
 238          * open [Done]
 239          * openCataloged [Done]
 240          * close [Done]
 241          * newFromParams [Done]
 242          * openUncataloged [Done]
 243          * setup_database [Done]
 244          *
 245          * Getter/Setter: 13 / 13
 246          * cascadingDeletes [Done]
 247          * cleanupTriggers  [Done]
 248          * strictIPs  [Done]
 249          * realTimestamps  [Done]
 250          * impliciGroupby  [Done]
 251          * implicitOrderby  [Done]
 252          * searchableIPs  [Done]
 253          * functionalIndexes  [Done]
 254          * getWikiID  [Done]
 255          * isOpen [Done]
 256          * getServerVersion [Done]
 257          * getSoftwareLink [Done]
 258          * getSearchEngine [Done]
 259          *
 260          * Database driver wrapper: 23 / 23
 261          * lastError [Done]
 262          * lastErrno [Done]
 263          * doQuery [Done]
 264          * tableExists [Done]
 265          * fetchObject [Done]
 266          * fetchRow [Done]
 267          * freeResult [Done]
 268          * numRows [Done]
 269          * numFields [Done]
 270          * fieldName [Done]
 271          * insertId [Done]
 272          * dataSeek [Done]
 273          * affectedRows [Done]
 274          * selectDB [Done]
 275          * strencode [Done]
 276          * conditional [Done]
 277          * wasDeadlock [Done]
 278          * ping [Done]
 279          * getStatus [Done]
 280          * setTimeout [Done]
 281          * lock [Done]
 282          * unlock [Done]
 283          * insert [Done]
 284          * select [Done]
 285          *
 286          * Slave/master: 2 / 2
 287          * setFakeSlaveLag [Done] - Where??
 288          *
 289          * Reflection: 5 / 5
 290          * indexInfo [Done]
 291          * fieldInfo [Done]
 292          * fieldType [Done]
 293          * indexUnique [Done]
 294          * textFieldSize [Done]
 295          *
 296          * Generation: 16 / 16
 297          * tableName [Done]
 298          * addQuotes [Done]
 299          * makeList [Done]
 300          * makeSelectOptions [Done]
 301          * estimateRowCount [Done]
 302          * nextSequenceValue [Done]
 303          * useIndexClause [Done]
 304          * replace [Done]
 305          * deleteJoin [Done]
 306          * lowPriorityOption [Done]
 307          * limitResult [Done]
 308          * limitResultForUpdate [Done]
 309          * timestamp [Done]
 310          * encodeBlob [Done]
 311          * decodeBlob [Done]
 312          * buildConcat [Done]
 313          */
 314
 315         ######################################
 316         # Getters and Setters
 317         ######################################
 318
 319         /**
 320          * Returns true if this database supports (and uses) cascading deletes
 321          */
 322         function cascadingDeletes() {
 323                 return true;
 324         }
 325
 326         /**
 327          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 328          */
 329         function cleanupTriggers() {
 330                 return true;
 331         }
 332
 333         /**
 334          * Returns true if this database is strict about what can be put into an IP field.
 335          * Specifically, it uses a NULL value instead of an empty string.
 336          */
 337         function strictIPs() {
 338                 return true;
 339         }
 340
 341         /**
 342          * Returns true if this database uses timestamps rather than integers
 343         */
 344         function realTimestamps() {
 345                 return true;
 346         }
 347
 348         /**
 349          * Returns true if this database does an implicit sort when doing GROUP BY
 350          */
 351         function implicitGroupby() {
 352                 return false;
 353         }
 354
 355         /**
 356          * Returns true if this database does an implicit order by when the column has an index
 357          * For example: SELECT page_title FROM page LIMIT 1
 358          */
 359         function implicitOrderby() {
 360                 return false;
 361         }
 362
 363         /**
 364          * Returns true if this database can do a native search on IP columns
 365          * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
 366          */
 367         function searchableIPs() {
 368                 return true;
 369         }
 370
 371         /**
 372          * Returns true if this database can use functional indexes
 373          */
 374         function functionalIndexes() {
 375                 return true;
 376         }
 377
 378         /**
 379          * Returns a unique string representing the wiki on the server
 380          */
 381         function getWikiID() {
 382                 if( $this->mSchema ) {
 383                         return "{$this->mDBname}-{$this->mSchema}";
 384                 } else {
 385                         return $this->mDBname;
 386                 }
 387         }
 388
 389         function getType() {
 390                 return 'ibm_db2';
 391         }
 392
 393         ######################################
 394         # Setup
 395         ######################################
 396
 397
 398         /**
 399          *
 400          * @param $server String: hostname of database server
 401          * @param $user String: username
 402          * @param $password String: password
 403          * @param $dbName String: database name on the server
 404          * @param $failFunction Callback (optional)
 405          * @param $flags Integer: database behaviour flags (optional, unused)
 406          * @param $schema String
 407          */
 408         public function DatabaseIbm_db2($server = false, $user = false, $password = false,
 409                                                         $dbName = false, $failFunction = false, $flags = 0,
 410                                                         $schema = self::USE_GLOBAL )
 411         {
 412
 413                 global $wgOut, $wgDBmwschema;
 414                 # Can't get a reference if it hasn't been set yet
 415                 if ( !isset( $wgOut ) ) {
 416                         $wgOut = null;
 417                 }
 418                 $this->mOut =& $wgOut;
 419                 $this->mFailFunction = $failFunction;
 420                 $this->mFlags = DBO_TRX | $flags;
 421
 422                 if ( $schema == self::USE_GLOBAL ) {
 423                         $this->mSchema = $wgDBmwschema;
 424                 }
 425                 else {
 426                         $this->mSchema = $schema;
 427                 }
 428
 429                 // configure the connection and statement objects
 430                 $this->setDB2Option('db2_attr_case', 'DB2_CASE_LOWER', self::CONN_OPTION | self::STMT_OPTION);
 431                 $this->setDB2Option('deferred_prepare', 'DB2_DEFERRED_PREPARE_ON', self::STMT_OPTION);
 432                 $this->setDB2Option('rowcount', 'DB2_ROWCOUNT_PREFETCH_ON', self::STMT_OPTION);
 433
 434                 $this->open( $server, $user, $password, $dbName);
 435         }
 436
 437         /**
 438          * Enables options only if the ibm_db2 extension version supports them
 439          * @param $name String: name of the option in the options array
 440          * @param $const String: name of the constant holding the right option value
 441          * @param $type Integer: whether this is a Connection or Statement otion
 442          */
 443         private function setDB2Option($name, $const, $type) {
 444                 if (defined($const)) {
 445                         if ($type & self::CONN_OPTION) $this->mConnOptions[$name] = constant($const);
 446                         if ($type & self::STMT_OPTION) $this->mStmtOptions[$name] = constant($const);
 447                 }
 448                 else {
 449                         $this->installPrint("$const is not defined. ibm_db2 version is likely too low.");
 450                 }
 451         }
 452
 453         /**
 454          * Outputs debug information in the appropriate place
 455          * @param $string String: the relevant debug message
 456          */
 457         private function installPrint($string) {
 458                 wfDebug("$string\n");
 459                 if ($this->mMode == self::INSTALL_MODE) {
 460                         print "<li><pre>$string</pre></li>";
 461                         flush();
 462                 }
 463         }
 464
 465         /**
 466          * Opens a database connection and returns it
 467          * Closes any existing connection
 468          * @return a fresh connection
 469          * @param $server String: hostname
 470          * @param $user String
 471          * @param $password String
 472          * @param $dbName String: database name
 473          */
 474         public function open( $server, $user, $password, $dbName )
 475         {
 476                 // Load the port number
 477                 global $wgDBport;
 478                 wfProfileIn( __METHOD__ );
 479
 480                 // Load IBM DB2 driver if missing
 481                 wfDl( 'ibm_db2' );
 482
 483                 // Test for IBM DB2 support, to avoid suppressed fatal error
 484                 if ( !function_exists( 'db2_connect' ) ) {
 485                         $error = "DB2 functions missing, have you enabled the ibm_db2 extension for PHP?\n";
 486                         $this->installPrint($error);
 487                         $this->reportConnectionError($error);
 488                 }
 489
 490                 if (!strlen($user)) { // Copied from Postgres
 491                         return null;
 492                 }
 493
 494                 // Close existing connection
 495                 $this->close();
 496                 // Cache conn info
 497                 $this->mServer = $server;
 498                 $this->mPort = $port = $wgDBport;
 499                 $this->mUser = $user;
 500                 $this->mPassword = $password;
 501                 $this->mDBname = $dbName;
 502
 503                 $this->openUncataloged($dbName, $user, $password, $server, $port);
 504
 505                 // Apply connection config
 506                 db2_set_option($this->mConn, $this->mConnOptions, 1);
 507                 // Not all MediaWiki code is transactional
 508                 // Rather, turn autocommit off in the begin function and turn on after a commit
 509                 db2_autocommit($this->mConn, DB2_AUTOCOMMIT_ON);
 510
 511                 if ( !$this->mConn ) {
 512                         $this->installPrint( "DB connection error\n" );
 513                         $this->installPrint( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 514                         $this->installPrint( $this->lastError()."\n" );
 515                         return null;
 516                 }
 517
 518                 $this->mOpened = true;
 519                 $this->applySchema();
 520
 521                 wfProfileOut( __METHOD__ );
 522                 return $this->mConn;
 523         }
 524
 525         /**
 526          * Opens a cataloged database connection, sets mConn
 527          */
 528         protected function openCataloged( $dbName, $user, $password )
 529         {
 530                 @$this->mConn = db2_pconnect($dbName, $user, $password);
 531         }
 532
 533         /**
 534          * Opens an uncataloged database connection, sets mConn
 535          */
 536         protected function openUncataloged( $dbName, $user, $password, $server, $port )
 537         {
 538                 $str = "DRIVER={IBM DB2 ODBC DRIVER};";
 539                 $str .= "DATABASE=$dbName;";
 540                 $str .= "HOSTNAME=$server;";
 541                 if ($port) $str .= "PORT=$port;";
 542                 $str .= "PROTOCOL=TCPIP;";
 543                 $str .= "UID=$user;";
 544                 $str .= "PWD=$password;";
 545
 546                 @$this->mConn = db2_pconnect($str, $user, $password);
 547         }
 548
 549         /**
 550          * Closes a database connection, if it is open
 551          * Returns success, true if already closed
 552          */
 553         public function close() {
 554                 $this->mOpened = false;
 555                 if ( $this->mConn ) {
 556                         if ($this->trxLevel() > 0) {
 557                                 $this->commit();
 558                         }
 559                         return db2_close( $this->mConn );
 560                 }
 561                 else {
 562                         return true;
 563                 }
 564         }
 565
 566         /**
 567          * Returns a fresh instance of this class
 568          *
 569          * @param $server String: hostname of database server
 570          * @param $user String: username
 571          * @param $password String
 572          * @param $dbName String: database name on the server
 573          * @param $failFunction Callback (optional)
 574          * @param $flags Integer: database behaviour flags (optional, unused)
 575          * @return DatabaseIbm_db2 object
 576          */
 577         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0)
 578         {
 579                 return new DatabaseIbm_db2( $server, $user, $password, $dbName, $failFunction, $flags );
 580         }
 581
 582         /**
 583          * Retrieves the most current database error
 584          * Forces a database rollback
 585          */
 586         public function lastError() {
 587                 $connerr = db2_conn_errormsg();
 588                 if ($connerr) {
 589                         //$this->rollback();
 590                         return $connerr;
 591                 }
 592                 $stmterr = db2_stmt_errormsg();
 593                 if ($stmterr) {
 594                         //$this->rollback();
 595                         return $stmterr;
 596                 }
 597
 598                 return false;
 599         }
 600
 601         /**
 602          * Get the last error number
 603          * Return 0 if no error
 604          * @return integer
 605          */
 606         public function lastErrno() {
 607                 $connerr = db2_conn_error();
 608                 if ($connerr) return $connerr;
 609                 $stmterr = db2_stmt_error();
 610                 if ($stmterr) return $stmterr;
 611                 return 0;
 612         }
 613
 614         /**
 615          * Is a database connection open?
 616          * @return
 617          */
 618         public function isOpen() { return $this->mOpened; }
 619
 620         /**
 621          * The DBMS-dependent part of query()
 622          * @param  $sql String: SQL query.
 623          * @return object Result object to feed to fetchObject, fetchRow, ...; or false on failure
 624          * @access private
 625          */
 626         /*private*/
 627         public function doQuery( $sql ) {
 628                 $this->applySchema();
 629
 630                 $ret = db2_exec( $this->mConn, $sql, $this->mStmtOptions );
 631                 if( $ret == FALSE ) {
 632                         $error = db2_stmt_errormsg();
 633                         $this->installPrint("<pre>$sql</pre>");
 634                         $this->installPrint($error);
 635                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( $error ) );
 636                 }
 637                 $this->mLastResult = $ret;
 638                 $this->mAffectedRows = null;    // Not calculated until asked for
 639                 return $ret;
 640         }
 641
 642         /**
 643          * @return string Version information from the database
 644          */
 645         public function getServerVersion() {
 646                 $info = db2_server_info( $this->mConn );
 647                 return $info->DBMS_VER;
 648         }
 649
 650         /**
 651          * Queries whether a given table exists
 652          * @return boolean
 653          */
 654         public function tableExists( $table ) {
 655                 $schema = $this->mSchema;
 656                 $sql = <<< EOF
 657 SELECT COUNT(*) FROM SYSIBM.SYSTABLES ST
 658 WHERE ST.NAME = '$table' AND ST.CREATOR = '$schema'
 659 EOF;
 660                 $res = $this->query( $sql );
 661                 if (!$res) return false;
 662
 663                 // If the table exists, there should be one of it
 664                 @$row = $this->fetchRow($res);
 665                 $count = $row[0];
 666                 if ($count == '1' or $count == 1) {
 667                         return true;
 668                 }
 669
 670                 return false;
 671         }
 672
 673         /**
 674          * Fetch the next row from the given result object, in object form.
 675          * Fields can be retrieved with $row->fieldname, with fields acting like
 676          * member variables.
 677          *
 678          * @param $res SQL result object as returned from Database::query(), etc.
 679          * @return DB2 row object
 680          * @throws DBUnexpectedError Thrown if the database returns an error
 681          */
 682         public function fetchObject( $res ) {
 683                 if ( $res instanceof ResultWrapper ) {
 684                         $res = $res->result;
 685                 }
 686                 @$row = db2_fetch_object( $res );
 687                 if( $this->lastErrno() ) {
 688                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 689                 }
 690                 return $row;
 691         }
 692
 693         /**
 694          * Fetch the next row from the given result object, in associative array
 695          * form.  Fields are retrieved with $row['fieldname'].
 696          *
 697          * @param $res SQL result object as returned from Database::query(), etc.
 698          * @return DB2 row object
 699          * @throws DBUnexpectedError Thrown if the database returns an error
 700          */
 701         public function fetchRow( $res ) {
 702                 if ( $res instanceof ResultWrapper ) {
 703                         $res = $res->result;
 704                 }
 705                 @$row = db2_fetch_array( $res );
 706                 if ( $this->lastErrno() ) {
 707                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 708                 }
 709                 return $row;
 710         }
 711
 712         /**
 713          * Override if introduced to base Database class
 714          */
 715         public function initial_setup() {
 716                 // do nothing
 717         }
 718
 719         /**
 720          * Create tables, stored procedures, and so on
 721          */
 722         public function setup_database() {
 723                 // Timeout was being changed earlier due to mysterious crashes
 724                 // Changing it now may cause more problems than not changing it
 725                 //set_time_limit(240);
 726                 try {
 727                         // TODO: switch to root login if available
 728
 729                         // Switch into the correct namespace
 730                         $this->applySchema();
 731                         $this->begin();
 732
 733                         $res = $this->sourceFile( "../maintenance/ibm_db2/tables.sql" );
 734                         if ($res !== true) {
 735                                 print " <b>FAILED</b>: " . htmlspecialchars( $res ) . "</li>";
 736                         } else {
 737                                 print " done</li>";
 738                         }
 739                         $res = $this->sourceFile( "../maintenance/ibm_db2/foreignkeys.sql" );
 740                         if ($res !== true) {
 741                                 print " <b>FAILED</b>: " . htmlspecialchars( $res ) . "</li>";
 742                         } else {
 743                                 print "<li>Foreign keys done</li>";
 744                         }
 745                         $res = null;
 746
 747                         // TODO: populate interwiki links
 748
 749                         if ($this->lastError()) {
 750                                 print "<li>Errors encountered during table creation -- rolled back</li>\n";
 751                                 print "<li>Please install again</li>\n";
 752                                 $this->rollback();
 753                         }
 754                         else {
 755                                 $this->commit();
 756                         }
 757                 }
 758                 catch (MWException $mwe)
 759                 {
 760                         print "<br><pre>$mwe</pre><br>";
 761                 }
 762         }
 763
 764         /**
 765          * Escapes strings
 766          * Doesn't escape numbers
 767          * @param $s String: string to escape
 768          * @return escaped string
 769          */
 770         public function addQuotes( $s ) {
 771                 //$this->installPrint("DB2::addQuotes($s)\n");
 772                 if ( is_null( $s ) ) {
 773                         return "NULL";
 774                 } else if ($s instanceof Blob) {
 775                         return "'".$s->fetch($s)."'";
 776                 } else if ($s instanceof IBM_DB2Blob) {
 777                         return "'".$this->decodeBlob($s)."'";
 778                 }
 779                 $s = $this->strencode($s);
 780                 if ( is_numeric($s) ) {
 781                         return $s;
 782                 }
 783                 else {
 784                         return "'$s'";
 785                 }
 786         }
 787
 788         /**
 789          * Verifies that a DB2 column/field type is numeric
 790          * @return bool true if numeric
 791          * @param $type String: DB2 column type
 792          */
 793         public function is_numeric_type( $type ) {
 794                 switch (strtoupper($type)) {
 795                 case 'SMALLINT':
 796                 case 'INTEGER':
 797                 case 'INT':
 798                 case 'BIGINT':
 799                 case 'DECIMAL':
 800                 case 'REAL':
 801                 case 'DOUBLE':
 802                 case 'DECFLOAT':
 803                         return true;
 804                 }
 805                 return false;
 806         }
 807
 808         /**
 809          * Alias for addQuotes()
 810          * @param $s String: string to escape
 811          * @return escaped string
 812          */
 813         public function strencode( $s ) {
 814                 // Bloody useless function
 815                 //  Prepends backslashes to \x00, \n, \r, \, ', " and \x1a.
 816                 //  But also necessary
 817                 $s = db2_escape_string($s);
 818                 // Wide characters are evil -- some of them look like '
 819                 $s = utf8_encode($s);
 820                 // Fix its stupidity
 821                 $from = array("\\\\",   "\\'",  '\\n',  '\\t',  '\\"',  '\\r');
 822                 $to =   array("\\",             "''",   "\n",   "\t",   '"',    "\r");
 823                 $s = str_replace($from, $to, $s); // DB2 expects '', not \' escaping
 824                 return $s;
 825         }
 826
 827         /**
 828          * Switch into the database schema
 829          */
 830         protected function applySchema() {
 831                 if ( !($this->mSchemaSet) ) {
 832                         $this->mSchemaSet = true;
 833                         $this->begin();
 834                         $this->doQuery("SET SCHEMA = $this->mSchema");
 835                         $this->commit();
 836                 }
 837         }
 838
 839         /**
 840          * Start a transaction (mandatory)
 841          */
 842         public function begin( $fname = 'DatabaseIbm_db2::begin' ) {
 843                 // turn off auto-commit
 844                 db2_autocommit($this->mConn, DB2_AUTOCOMMIT_OFF);
 845                 $this->mTrxLevel = 1;
 846         }
 847
 848         /**
 849          * End a transaction
 850          * Must have a preceding begin()
 851          */
 852         public function commit( $fname = 'DatabaseIbm_db2::commit' ) {
 853                 db2_commit($this->mConn);
 854                 // turn auto-commit back on
 855                 db2_autocommit($this->mConn, DB2_AUTOCOMMIT_ON);
 856                 $this->mTrxLevel = 0;
 857         }
 858
 859         /**
 860          * Cancel a transaction
 861          */
 862         public function rollback( $fname = 'DatabaseIbm_db2::rollback' ) {
 863                 db2_rollback($this->mConn);
 864                 // turn auto-commit back on
 865                 // not sure if this is appropriate
 866                 db2_autocommit($this->mConn, DB2_AUTOCOMMIT_ON);
 867                 $this->mTrxLevel = 0;
 868         }
 869
 870         /**
 871          * Makes an encoded list of strings from an array
 872          * $mode:
 873          *        LIST_COMMA         - comma separated, no field names
 874          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
 875          *        LIST_OR            - ORed WHERE clause (without the WHERE)
 876          *        LIST_SET           - comma separated with field names, like a SET clause
 877          *        LIST_NAMES         - comma separated field names
 878          *        LIST_SET_PREPARED  - like LIST_SET, except with ? tokens as values
 879          */
 880         function makeList( $a, $mode = LIST_COMMA ) {
 881                 if ( !is_array( $a ) ) {
 882                         throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
 883                 }
 884
 885                 // if this is for a prepared UPDATE statement
 886                 // (this should be promoted to the parent class
 887                 //  once other databases use prepared statements)
 888                 if ($mode == LIST_SET_PREPARED) {
 889                         $first = true;
 890                         $list = '';
 891                         foreach ( $a as $field => $value ) {
 892                                 if (!$first) {
 893                                         $list .= ", $field = ?";
 894                                 }
 895                                 else {
 896                                         $list .= "$field = ?";
 897                                   $first = false;
 898                                 }
 899                         }
 900                         $list .= '';
 901
 902                         return $list;
 903                 }
 904
 905                 // otherwise, call the usual function
 906                 return parent::makeList( $a, $mode );
 907         }
 908
 909         /**
 910          * Construct a LIMIT query with optional offset
 911          * This is used for query pages
 912          * @param $sql string SQL query we will append the limit too
 913          * @param $limit integer the SQL limit
 914          * @param $offset integer the SQL offset (default false)
 915          */
 916         public function limitResult($sql, $limit, $offset=false) {
 917                 if( !is_numeric($limit) ) {
 918                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
 919                 }
 920                 if( $offset ) {
 921                         //$this->installPrint("Offset parameter not supported in limitResult()\n");
 922                         if ( stripos($sql, 'where') === false ) {
 923                                 return "$sql AND (ROWNUM BETWEEN $offset AND $offset+$limit)";
 924                         }
 925                         else {
 926                                 return "$sql WHERE (ROWNUM BETWEEN $offset AND $offset+$limit)";
 927                         }
 928                 }
 929                 return "$sql FETCH FIRST $limit ROWS ONLY ";
 930         }
 931
 932         /**
 933          * Handle reserved keyword replacement in table names
 934          * @return
 935          * @param $name Object
 936          */
 937         public function tableName( $name ) {
 938                 # Replace reserved words with better ones
 939 //              switch( $name ) {
 940 //                      case 'user':
 941 //                              return 'mwuser';
 942 //                      case 'text':
 943 //                              return 'pagecontent';
 944 //                      default:
 945 //                              return $name;
 946 //              }
 947                 // we want maximum compatibility with MySQL schema
 948                 return $name;
 949         }
 950
 951         /**
 952          * Generates a timestamp in an insertable format
 953          * @return string timestamp value
 954          * @param $ts timestamp
 955          */
 956         public function timestamp( $ts=0 ) {
 957                 // TS_MW cannot be easily distinguished from an integer
 958                 return wfTimestamp(TS_DB2,$ts);
 959         }
 960
 961         /**
 962          * Return the next in a sequence, save the value for retrieval via insertId()
 963          * @param $seqName String: name of a defined sequence in the database
 964          * @return next value in that sequence
 965          */
 966         public function nextSequenceValue( $seqName ) {
 967                 // Not using sequences in the primary schema to allow for easy third-party migration scripts
 968                 // Emulating MySQL behaviour of using NULL to signal that sequences aren't used
 969                 /*
 970                 $safeseq = preg_replace( "/'/", "''", $seqName );
 971                 $res = $this->query( "VALUES NEXTVAL FOR $safeseq" );
 972                 $row = $this->fetchRow( $res );
 973                 $this->mInsertId = $row[0];
 974                 return $this->mInsertId;
 975                 */
 976                 return null;
 977         }
 978
 979         /**
 980          * This must be called after nextSequenceVal
 981          * @return Last sequence value used as a primary key
 982          */
 983         public function insertId() {
 984                 return $this->mInsertId;
 985         }
 986
 987         /**
 988          * Updates the mInsertId property with the value of the last insert into a generated column
 989          * @param $table      String: sanitized table name
 990          * @param $primaryKey Mixed: string name of the primary key or a bool if this call is a do-nothing
 991          * @param $stmt       Resource: prepared statement resource
 992          *  of the SELECT primary_key FROM FINAL TABLE ( INSERT ... ) form
 993          */
 994         private function calcInsertId($table, $primaryKey, $stmt) {
 995                 if ($primaryKey) {
 996                         $this->mInsertId = db2_last_insert_id($this->mConn);
 997                         //$this->installPrint("Last $primaryKey for $table was $this->mInsertId");
 998                 }
 999         }
1000
1001         /**
1002          * INSERT wrapper, inserts an array into a table
1003          *
1004          * $args may be a single associative array, or an array of these with numeric keys,
1005          * for multi-row insert
1006          *
1007          * @param $table   String: Name of the table to insert to.
1008          * @param $args    Array: Items to insert into the table.
1009          * @param $fname   String: Name of the function, for profiling
1010          * @param $options String or Array. Valid options: IGNORE
1011          *
1012          * @return bool Success of insert operation. IGNORE always returns true.
1013          */
1014         public function insert( $table, $args, $fname = 'DatabaseIbm_db2::insert', $options = array() ) {
1015                 if ( !count( $args ) ) {
1016                         return true;
1017                 }
1018                 // get database-specific table name (not used)
1019                 $table = $this->tableName( $table );
1020                 // format options as an array
1021                 $options = IBM_DB2Helper::makeArray($options);
1022                 // format args as an array of arrays
1023                 if ( !( isset( $args[0] ) && is_array( $args[0] ) ) ) {
1024                         $args = array($args);
1025                 }
1026
1027                 // prevent insertion of NULL into primary key columns
1028                 list($args, $primaryKeys) = $this->removeNullPrimaryKeys($table, $args);
1029                 // if there's only one primary key
1030                 // we'll be able to read its value after insertion
1031                 $primaryKey = false;
1032                 if (count($primaryKeys) == 1) {
1033                         $primaryKey = $primaryKeys[0];
1034                 }
1035
1036                 // get column names
1037                 $keys = array_keys( $args[0] );
1038                 $key_count = count($keys);
1039
1040                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
1041                 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
1042
1043                 // assume success
1044                 $res = true;
1045                 // If we are not in a transaction, we need to be for savepoint trickery
1046                 if (! $this->mTrxLevel) {
1047                         $this->begin();
1048                 }
1049
1050                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1051                 if ($key_count == 1) {
1052                         $sql .= '(?)';
1053                 } else {
1054                         $sql .= '(?' . str_repeat(',?', $key_count-1) . ')';
1055                 }
1056                 //$this->installPrint("Preparing the following SQL:");
1057                 //$this->installPrint("$sql");
1058                 //$this->installPrint(print_r($args, true));
1059                 $stmt = $this->prepare($sql);
1060
1061                 // start a transaction/enter transaction mode
1062                 $this->begin();
1063
1064                 if ( !$ignore ) {
1065                         //$first = true;
1066                         foreach ( $args as $row ) {
1067                                 //$this->installPrint("Inserting " . print_r($row, true));
1068                                 // insert each row into the database
1069                                 $res = $res & $this->execute($stmt, $row);
1070                                 if (!$res) {
1071                                         $this->installPrint("Last error:");
1072                                         $this->installPrint($this->lastError());
1073                                 }
1074                                 // get the last inserted value into a generated column
1075                                 $this->calcInsertId($table, $primaryKey, $stmt);
1076                         }
1077                 }
1078                 else {
1079                         $olde = error_reporting( 0 );
1080                         // For future use, we may want to track the number of actual inserts
1081                         // Right now, insert (all writes) simply return true/false
1082                         $numrowsinserted = 0;
1083
1084                         // always return true
1085                         $res = true;
1086
1087                         foreach ( $args as $row ) {
1088                                 $overhead = "SAVEPOINT $ignore ON ROLLBACK RETAIN CURSORS";
1089                                 db2_exec($this->mConn, $overhead, $this->mStmtOptions);
1090                                 //$this->installPrint("Inserting " . print_r($row, true));
1091
1092                                 $this->execute($stmt, $row);
1093                                 //$this->installPrint(wfGetAllCallers());
1094                                 if (!$res2) {
1095                                         $this->installPrint("Last error:");
1096                                         $this->installPrint($this->lastError());
1097                                 }
1098                                 // get the last inserted value into a generated column
1099                                 $this->calcInsertId($table, $primaryKey, $stmt);
1100
1101                                 $errNum = $this->lastErrno();
1102                                 if ($errNum) {
1103                                         db2_exec( $this->mConn, "ROLLBACK TO SAVEPOINT $ignore", $this->mStmtOptions );
1104                                 }
1105                                 else {
1106                                         db2_exec( $this->mConn, "RELEASE SAVEPOINT $ignore", $this->mStmtOptions );
1107                                         $numrowsinserted++;
1108                                 }
1109                         }
1110
1111                         $olde = error_reporting( $olde );
1112                         // Set the affected row count for the whole operation
1113                         $this->mAffectedRows = $numrowsinserted;
1114                 }
1115                 // commit either way
1116                 $this->commit();
1117                 $this->freePrepared($stmt);
1118
1119                 return $res;
1120         }
1121
1122         /**
1123          * Given a table name and a hash of columns with values
1124          * Removes primary key columns from the hash where the value is NULL
1125          *
1126          * @param $table String: name of the table
1127          * @param $args Array of hashes of column names with values
1128          * @return Array: tuple containing filtered array of columns, array of primary keys
1129          */
1130         private function removeNullPrimaryKeys($table, $args) {
1131                 $schema = $this->mSchema;
1132                 // find out the primary keys
1133                 $keyres = db2_primary_keys($this->mConn, null, strtoupper($schema), strtoupper($table));
1134                 $keys = array();
1135                 for ($row = $this->fetchObject($keyres); $row != null; $row = $this->fetchRow($keyres)) {
1136                         $keys[] = strtolower($row->column_name);
1137                 }
1138                 // remove primary keys
1139                 foreach ($args as $ai => $row) {
1140                         foreach ($keys as $ki => $key) {
1141                                 if ($row[$key] == null) {
1142                                         unset($row[$key]);
1143                                 }
1144                         }
1145                         $args[$ai] = $row;
1146                 }
1147                 // return modified hash
1148                 return array($args, $keys);
1149         }
1150
1151         /**
1152          * UPDATE wrapper, takes a condition array and a SET array
1153          *
1154          * @param $table  String: The table to UPDATE
1155          * @param $values An array of values to SET
1156          * @param $conds  An array of conditions (WHERE). Use '*' to update all rows.
1157          * @param $fname  String: The Class::Function calling this function
1158          *                (for the log)
1159          * @param $options An array of UPDATE options, can be one or
1160          *                 more of IGNORE, LOW_PRIORITY
1161          * @return Boolean
1162          */
1163         public function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1164                 $table = $this->tableName( $table );
1165                 $opts = $this->makeUpdateOptions( $options );
1166                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET_PREPARED );
1167                 if ( $conds != '*' ) {
1168                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1169                 }
1170                 $stmt = $this->prepare( $sql );
1171                 $this->installPrint("UPDATE: " . print_r($values, TRUE));
1172                 // assuming for now that an array with string keys will work
1173                 // if not, convert to simple array first
1174                 $result = $this->execute( $stmt, $values );
1175                 $this->freePrepared( $stmt );
1176                 //$result = $this->query( $sql, $fname );
1177                 // commit regardless of state
1178                 //$this->commit();
1179                 return $result;
1180         }
1181
1182         /**
1183          * DELETE query wrapper
1184          *
1185          * Use $conds == "*" to delete all rows
1186          */
1187         public function delete( $table, $conds, $fname = 'Database::delete' ) {
1188                 if ( !$conds ) {
1189                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1190                 }
1191                 $table = $this->tableName( $table );
1192                 $sql = "DELETE FROM $table";
1193                 if ( $conds != '*' ) {
1194                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1195                 }
1196                 $result = $this->query( $sql, $fname );
1197                 // commit regardless
1198                 //$this->commit();
1199                 return $result;
1200         }
1201
1202         /**
1203          * Returns the number of rows affected by the last query or 0
1204          * @return Integer: the number of rows affected by the last query
1205          */
1206         public function affectedRows() {
1207                 if ( !is_null( $this->mAffectedRows ) ) {
1208                         // Forced result for simulated queries
1209                         return $this->mAffectedRows;
1210                 }
1211                 if( empty( $this->mLastResult ) )
1212                         return 0;
1213                 return db2_num_rows( $this->mLastResult );
1214         }
1215
1216         /**
1217          * Simulates REPLACE with a DELETE followed by INSERT
1218          * @param $table Object
1219          * @param $uniqueIndexes Array consisting of indexes and arrays of indexes
1220          * @param $rows Array: rows to insert
1221          * @param $fname String: name of the function for profiling
1222          * @return nothing
1223          */
1224         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseIbm_db2::replace' ) {
1225                 $table = $this->tableName( $table );
1226
1227                 if (count($rows)==0) {
1228                         return;
1229                 }
1230
1231                 # Single row case
1232                 if ( !is_array( reset( $rows ) ) ) {
1233                         $rows = array( $rows );
1234                 }
1235
1236                 foreach( $rows as $row ) {
1237                         # Delete rows which collide
1238                         if ( $uniqueIndexes ) {
1239                                 $sql = "DELETE FROM $table WHERE ";
1240                                 $first = true;
1241                                 foreach ( $uniqueIndexes as $index ) {
1242                                         if ( $first ) {
1243                                                 $first = false;
1244                                                 $sql .= "(";
1245                                         } else {
1246                                                 $sql .= ') OR (';
1247                                         }
1248                                         if ( is_array( $index ) ) {
1249                                                 $first2 = true;
1250                                                 foreach ( $index as $col ) {
1251                                                         if ( $first2 ) {
1252                                                                 $first2 = false;
1253                                                         } else {
1254                                                                 $sql .= ' AND ';
1255                                                         }
1256                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
1257                                                 }
1258                                         } else {
1259                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
1260                                         }
1261                                 }
1262                                 $sql .= ')';
1263                                 $this->query( $sql, $fname );
1264                         }
1265
1266                         # Now insert the row
1267                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
1268                                 $this->makeList( $row, LIST_COMMA ) . ')';
1269                         $this->query( $sql, $fname );
1270                 }
1271         }
1272
1273         /**
1274          * Returns the number of rows in the result set
1275          * Has to be called right after the corresponding select query
1276          * @param $res Object result set
1277          * @return Integer: number of rows
1278          */
1279         public function numRows( $res ) {
1280                 if ( $res instanceof ResultWrapper ) {
1281                         $res = $res->result;
1282                 }
1283                 if ( $this->mNumRows ) {
1284                         return $this->mNumRows;
1285                 }
1286                 else {
1287                         return 0;
1288                 }
1289         }
1290
1291         /**
1292          * Moves the row pointer of the result set
1293          * @param $res Object: result set
1294          * @param $row Integer: row number
1295          * @return success or failure
1296          */
1297         public function dataSeek( $res, $row ) {
1298                 if ( $res instanceof ResultWrapper ) {
1299                         $res = $res->result;
1300                 }
1301                 return db2_fetch_row( $res, $row );
1302         }
1303
1304         ###
1305         # Fix notices in Block.php
1306         ###
1307
1308         /**
1309          * Frees memory associated with a statement resource
1310          * @param $res Object: statement resource to free
1311          * @return Boolean success or failure
1312          */
1313         public function freeResult( $res ) {
1314                 if ( $res instanceof ResultWrapper ) {
1315                         $res = $res->result;
1316                 }
1317                 if ( !@db2_free_result( $res ) ) {
1318                         throw new DBUnexpectedError($this,  "Unable to free DB2 result\n" );
1319                 }
1320         }
1321
1322         /**
1323          * Returns the number of columns in a resource
1324          * @param $res Object: statement resource
1325          * @return Number of fields/columns in resource
1326          */
1327         public function numFields( $res ) {
1328                 if ( $res instanceof ResultWrapper ) {
1329                         $res = $res->result;
1330                 }
1331                 return db2_num_fields( $res );
1332         }
1333
1334         /**
1335          * Returns the nth column name
1336          * @param $res Object: statement resource
1337          * @param $n Integer: Index of field or column
1338          * @return String name of nth column
1339          */
1340         public function fieldName( $res, $n ) {
1341                 if ( $res instanceof ResultWrapper ) {
1342                         $res = $res->result;
1343                 }
1344                 return db2_field_name( $res, $n );
1345         }
1346
1347         /**
1348          * SELECT wrapper
1349          *
1350          * @param $table   Array or string, table name(s) (prefix auto-added)
1351          * @param $vars    Array or string, field name(s) to be retrieved
1352          * @param $conds   Array or string, condition(s) for WHERE
1353          * @param $fname   String: calling function name (use __METHOD__) for logs/profiling
1354          * @param $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1355          *                 see Database::makeSelectOptions code for list of supported stuff
1356          * @param $join_conds Associative array of table join conditions (optional)
1357          *                    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1358          * @return Mixed: database result resource (feed to Database::fetchObject or whatever), or false on failure
1359          */
1360         public function select( $table, $vars, $conds='', $fname = 'DatabaseIbm_db2::select', $options = array(), $join_conds = array() )
1361         {
1362                 $res = parent::select( $table, $vars, $conds, $fname, $options, $join_conds );
1363
1364                 // We must adjust for offset
1365                 if ( isset( $options['LIMIT'] ) ) {
1366                         if ( isset ($options['OFFSET'] ) ) {
1367                                 $limit = $options['LIMIT'];
1368                                 $offset = $options['OFFSET'];
1369                         }
1370                 }
1371
1372
1373                 // DB2 does not have a proper num_rows() function yet, so we must emulate it
1374                 // DB2 9.5.3/9.5.4 and the corresponding ibm_db2 driver will introduce a working one
1375                 // Yay!
1376
1377                 // we want the count
1378                 $vars2 = array('count(*) as num_rows');
1379                 // respecting just the limit option
1380                 $options2 = array();
1381                 if ( isset( $options['LIMIT'] ) ) $options2['LIMIT'] = $options['LIMIT'];
1382                 // but don't try to emulate for GROUP BY
1383                 if ( isset( $options['GROUP BY'] ) ) return $res;
1384
1385                 $res2 = parent::select( $table, $vars2, $conds, $fname, $options2, $join_conds );
1386                 $obj = $this->fetchObject($res2);
1387                 $this->mNumRows = $obj->num_rows;
1388
1389
1390                 return $res;
1391         }
1392
1393         /**
1394          * Handles ordering, grouping, and having options ('GROUP BY' => colname)
1395          * Has limited support for per-column options (colnum => 'DISTINCT')
1396          *
1397          * @private
1398          *
1399          * @param $options Associative array of options to be turned into
1400          *              an SQL query, valid keys are listed in the function.
1401          * @return Array
1402          */
1403         function makeSelectOptions( $options ) {
1404                 $preLimitTail = $postLimitTail = '';
1405                 $startOpts = '';
1406
1407                 $noKeyOptions = array();
1408                 foreach ( $options as $key => $option ) {
1409                         if ( is_numeric( $key ) ) {
1410                                 $noKeyOptions[$option] = true;
1411                         }
1412                 }
1413
1414                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1415                 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
1416                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1417
1418                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1419
1420                 return array( $startOpts, '', $preLimitTail, $postLimitTail );
1421         }
1422
1423         /**
1424          * Returns link to IBM DB2 free download
1425          * @return string wikitext of a link to the server software's web site
1426          */
1427         public static function getSoftwareLink() {
1428                 return "[http://www.ibm.com/software/data/db2/express/?s_cmp=ECDDWW01&s_tact=MediaWiki IBM DB2]";
1429         }
1430
1431         /**
1432          * Get search engine class. All subclasses of this
1433          * need to implement this if they wish to use searching.
1434          *
1435          * @return String
1436          */
1437         public function getSearchEngine() {
1438                 return "SearchIBM_DB2";
1439         }
1440
1441         /**
1442          * Did the last database access fail because of deadlock?
1443          * @return Boolean
1444          */
1445         public function wasDeadlock() {
1446                 // get SQLSTATE
1447                 $err = $this->lastErrno();
1448                 switch($err) {
1449                         case '40001':   // sql0911n, Deadlock or timeout, rollback
1450                         case '57011':   // sql0904n, Resource unavailable, no rollback
1451                         case '57033':   // sql0913n, Deadlock or timeout, no rollback
1452                         $this->installPrint("In a deadlock because of SQLSTATE $err");
1453                         return true;
1454                 }
1455                 return false;
1456         }
1457
1458         /**
1459          * Ping the server and try to reconnect if it there is no connection
1460          * The connection may be closed and reopened while this happens
1461          * @return Boolean: whether the connection exists
1462          */
1463         public function ping() {
1464                 // db2_ping() doesn't exist
1465                 // Emulate
1466                 $this->close();
1467                 $this->mConn = $this->openUncataloged($this->mDBName, $this->mUser, $this->mPassword, $this->mServer, $this->mPort);
1468
1469                 return false;
1470         }
1471         ######################################
1472         # Unimplemented and not applicable
1473         ######################################
1474         /**
1475          * Not implemented
1476          * @return string ''
1477          */
1478         public function getStatus( $which="%" ) { $this->installPrint('Not implemented for DB2: getStatus()'); return ''; }
1479         /**
1480          * Not implemented
1481          * @return string $sql
1482          */
1483         public function limitResultForUpdate($sql, $num) { $this->installPrint('Not implemented for DB2: limitResultForUpdate()'); return $sql; }
1484
1485         /**
1486          * Only useful with fake prepare like in base Database class
1487          * @return      string
1488          */
1489         public function fillPreparedArg( $matches ) { $this->installPrint('Not useful for DB2: fillPreparedArg()'); return ''; }
1490
1491         ######################################
1492         # Reflection
1493         ######################################
1494
1495         /**
1496          * Returns information about an index
1497          * If errors are explicitly ignored, returns NULL on failure
1498          * @param $table String: table name
1499          * @param $index String: index name
1500          * @param $fname String: function name for logging and profiling
1501          * @return Object query row in object form
1502          */
1503         public function indexInfo( $table, $index, $fname = 'DatabaseIbm_db2::indexExists' ) {
1504                 $table = $this->tableName( $table );
1505                 $sql = <<<SQL
1506 SELECT name as indexname
1507 FROM sysibm.sysindexes si
1508 WHERE si.name='$index' AND si.tbname='$table' AND sc.tbcreator='$this->mSchema'
1509 SQL;
1510                 $res = $this->query( $sql, $fname );
1511                 if ( !$res ) {
1512                         return null;
1513                 }
1514                 $row = $this->fetchObject( $res );
1515                 if ($row != null) return $row;
1516                 else return false;
1517         }
1518
1519         /**
1520          * Returns an information object on a table column
1521          * @param $table String: table name
1522          * @param $field String: column name
1523          * @return IBM_DB2Field
1524          */
1525         public function fieldInfo( $table, $field ) {
1526                 return IBM_DB2Field::fromText($this, $table, $field);
1527         }
1528
1529         /**
1530          * db2_field_type() wrapper
1531          * @param $res Object: result of executed statement
1532          * @param $index Mixed: number or name of the column
1533          * @return String column type
1534          */
1535         public function fieldType( $res, $index ) {
1536                 if ( $res instanceof ResultWrapper ) {
1537                         $res = $res->result;
1538                 }
1539                 return db2_field_type( $res, $index );
1540         }
1541
1542         /**
1543          * Verifies that an index was created as unique
1544          * @param $table String: table name
1545          * @param $index String: index name
1546          * @param $fname function name for profiling
1547          * @return Bool
1548          */
1549         public function indexUnique ($table, $index, $fname = 'Database::indexUnique' ) {
1550                 $table = $this->tableName( $table );
1551                 $sql = <<<SQL
1552 SELECT si.name as indexname
1553 FROM sysibm.sysindexes si
1554 WHERE si.name='$index' AND si.tbname='$table' AND sc.tbcreator='$this->mSchema'
1555 AND si.uniquerule IN ('U', 'P')
1556 SQL;
1557                 $res = $this->query( $sql, $fname );
1558                 if ( !$res ) {
1559                         return null;
1560                 }
1561                 if ($this->fetchObject( $res )) {
1562                         return true;
1563                 }
1564                 return false;
1565
1566         }
1567
1568         /**
1569          * Returns the size of a text field, or -1 for "unlimited"
1570          * @param $table String: table name
1571          * @param $field String: column name
1572          * @return Integer: length or -1 for unlimited
1573          */
1574         public function textFieldSize( $table, $field ) {
1575                 $table = $this->tableName( $table );
1576                 $sql = <<<SQL
1577 SELECT length as size
1578 FROM sysibm.syscolumns sc
1579 WHERE sc.name='$field' AND sc.tbname='$table' AND sc.tbcreator='$this->mSchema'
1580 SQL;
1581                 $res = $this->query($sql);
1582                 $row = $this->fetchObject($res);
1583                 $size = $row->size;
1584                 return $size;
1585         }
1586
1587         /**
1588          * DELETE where the condition is a join
1589          * @param $delTable String: deleting from this table
1590          * @param $joinTable String: using data from this table
1591          * @param $delVar String: variable in deleteable table
1592          * @param $joinVar String: variable in data table
1593          * @param $conds Array: conditionals for join table
1594          * @param $fname String: function name for profiling
1595          */
1596         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "DatabaseIbm_db2::deleteJoin" ) {
1597                 if ( !$conds ) {
1598                         throw new DBUnexpectedError($this,  'Database::deleteJoin() called with empty $conds' );
1599                 }
1600
1601                 $delTable = $this->tableName( $delTable );
1602                 $joinTable = $this->tableName( $joinTable );
1603                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
1604                 if ( $conds != '*' ) {
1605                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
1606                 }
1607                 $sql .= ')';
1608
1609                 $this->query( $sql, $fname );
1610         }
1611
1612         /**
1613          * Description is left as an exercise for the reader
1614          * @param $b Mixed: data to be encoded
1615          * @return IBM_DB2Blob
1616          */
1617         public function encodeBlob($b) {
1618                 return new IBM_DB2Blob($b);
1619         }
1620
1621         /**
1622          * Description is left as an exercise for the reader
1623          * @param $b IBM_DB2Blob: data to be decoded
1624          * @return mixed
1625          */
1626         public function decodeBlob($b) {
1627                 return "$b";
1628         }
1629
1630         /**
1631          * Convert into a list of string being concatenated
1632          * @param $stringList Array: strings that need to be joined together by the SQL engine
1633          * @return String: joined by the concatenation operator
1634          */
1635         public function buildConcat( $stringList ) {
1636                 // || is equivalent to CONCAT
1637                 // Sample query: VALUES 'foo' CONCAT 'bar' CONCAT 'baz'
1638                 return implode( ' || ', $stringList );
1639         }
1640
1641         /**
1642          * Generates the SQL required to convert a DB2 timestamp into a Unix epoch
1643          * @param $column String: name of timestamp column
1644          * @return String: SQL code
1645          */
1646         public function extractUnixEpoch( $column ) {
1647                 // TODO
1648                 // see SpecialAncientpages
1649         }
1650
1651         ######################################
1652         # Prepared statements
1653         ######################################
1654
1655         /**
1656          * Intended to be compatible with the PEAR::DB wrapper functions.
1657          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1658          *
1659          * ? = scalar value, quoted as necessary
1660          * ! = raw SQL bit (a function for instance)
1661          * & = filename; reads the file and inserts as a blob
1662          *     (we don't use this though...)
1663          * @param $sql String: SQL statement with appropriate markers
1664          * @param $func String: Name of the function, for profiling
1665          * @return resource a prepared DB2 SQL statement
1666          */
1667         public function prepare( $sql, $func = 'DB2::prepare' ) {
1668                 $stmt = db2_prepare($this->mConn, $sql, $this->mStmtOptions);
1669                 return $stmt;
1670         }
1671
1672         /**
1673          * Frees resources associated with a prepared statement
1674          * @return Boolean success or failure
1675          */
1676         public function freePrepared( $prepared ) {
1677                 return db2_free_stmt($prepared);
1678         }
1679
1680         /**
1681          * Execute a prepared query with the various arguments
1682          * @param $prepared String: the prepared sql
1683          * @param $args Mixed: either an array here, or put scalars as varargs
1684          * @return Resource: results object
1685          */
1686         public function execute( $prepared, $args = null ) {
1687                 if( !is_array( $args ) ) {
1688                         # Pull the var args
1689                         $args = func_get_args();
1690                         array_shift( $args );
1691                 }
1692                 $res = db2_execute($prepared, $args);
1693                 if ( !$res ) {
1694                         $this->installPrint(db2_stmt_errormsg());
1695                 }
1696                 return $res;
1697         }
1698
1699         /**
1700          * Prepare & execute an SQL statement, quoting and inserting arguments
1701          * in the appropriate places.
1702          * @param $query String
1703          * @param $args ...
1704          */
1705         public function safeQuery( $query, $args = null ) {
1706                 // copied verbatim from Database.php
1707                 $prepared = $this->prepare( $query, 'DB2::safeQuery' );
1708                 if( !is_array( $args ) ) {
1709                         # Pull the var args
1710                         $args = func_get_args();
1711                         array_shift( $args );
1712                 }
1713                 $retval = $this->execute( $prepared, $args );
1714                 $this->freePrepared( $prepared );
1715                 return $retval;
1716         }
1717
1718         /**
1719          * For faking prepared SQL statements on DBs that don't support
1720          * it directly.
1721          * @param $preparedQuery String: a 'preparable' SQL statement
1722          * @param $args Array of arguments to fill it with
1723          * @return String: executable statement
1724          */
1725         public function fillPrepared( $preparedQuery, $args ) {
1726                 reset( $args );
1727                 $this->preparedArgs =& $args;
1728
1729                 foreach ($args as $i => $arg) {
1730                         db2_bind_param($preparedQuery, $i+1, $args[$i]);
1731                 }
1732
1733                 return $preparedQuery;
1734         }
1735
1736         /**
1737          * Switches module between regular and install modes
1738          */
1739         public function setMode($mode) {
1740                 $old =  $this->mMode;
1741                 $this->mMode = $mode;
1742                 return $old;
1743         }
1744
1745         /**
1746          * Bitwise negation of a column or value in SQL
1747          * Same as (~field) in C
1748          * @param $field String
1749          * @return String
1750          */
1751         function bitNot($field) {
1752                 //expecting bit-fields smaller than 4bytes
1753                 return 'BITNOT('.$field.')';
1754         }
1755
1756         /**
1757          * Bitwise AND of two columns or values in SQL
1758          * Same as (fieldLeft & fieldRight) in C
1759          * @param $fieldLeft String
1760          * @param $fieldRight String
1761          * @return String
1762          */
1763         function bitAnd($fieldLeft, $fieldRight) {
1764                 return 'BITAND('.$fieldLeft.', '.$fieldRight.')';
1765         }
1766
1767         /**
1768          * Bitwise OR of two columns or values in SQL
1769          * Same as (fieldLeft | fieldRight) in C
1770          * @param $fieldLeft String
1771          * @param $fieldRight String
1772          * @return String
1773          */
1774         function bitOr($fieldLeft, $fieldRight) {
1775                 return 'BITOR('.$fieldLeft.', '.$fieldRight.')';
1776         }
1777 }
1778
1779 class IBM_DB2Helper {
1780         public static function makeArray($maybeArray) {
1781                 if ( !is_array( $maybeArray ) ) $maybeArray = array( $maybeArray );
1782
1783                 return $maybeArray;
1784         }
1785 }