3 * This is the IBM DB2 database abstraction layer.
4 * See maintenance/ibm_db2/README for development notes
5 * and other specific information
9 * @author leo.petr+mediawiki@gmail.com
13 * This represents a column in a DB2 database
16 class IBM_DB2Field implements Field {
18 private $tablename = '';
20 private $nullable = false;
21 private $max_length = 0;
24 * Builder method for the class
25 * @param $db DatabaseIbm_db2: Database interface
26 * @param $table String: table name
27 * @param $field String: column name
28 * @return IBM_DB2Field
30 static function fromText( $db, $table, $field ) {
35 lcase( coltype ) AS typname,
36 nulls AS attnotnull, length AS attlen
37 FROM sysibm.syscolumns
38 WHERE tbcreator=%s AND tbname=%s AND name=%s;
42 $db->addQuotes( $wgDBmwschema ),
43 $db->addQuotes( $table ),
44 $db->addQuotes( $field )
47 $row = $db->fetchObject( $res );
51 $n = new IBM_DB2Field;
52 $n->type = $row->typname;
53 $n->nullable = ( $row->attnotnull == 'N' );
55 $n->tablename = $table;
56 $n->max_length = $row->attlen;
61 * @return string column name
63 function name() { return $this->name; }
66 * @return string table name
68 function tableName() { return $this->tablename; }
71 * @return string column type
73 function type() { return $this->type; }
76 * @return bool true or false
78 function isNullable() { return $this->nullable; }
80 * How much can you fit in the column per row?
83 function maxLength() { return $this->max_length; }
87 * Wrapper around binary large objects
93 public function __construct( $data ) {
97 public function getData() {
101 public function __toString() {
107 * Primary database interface
110 class DatabaseIbm_db2 extends DatabaseBase {
113 protected $mLastQuery = '';
114 protected $mPHPError = false;
116 protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
117 protected $mOut, $mOpened = false;
119 protected $mTablePrefix;
121 protected $mTrxLevel = 0;
122 protected $mErrorCount = 0;
123 protected $mLBInfo = array();
124 protected $mFakeSlaveLag = null, $mFakeMaster = false;
128 /** Database server port */
129 protected $mPort = null;
130 /** Schema for tables, stored procedures, triggers */
131 protected $mSchema = null;
132 /** Whether the schema has been applied in this session */
133 protected $mSchemaSet = false;
134 /** Result of last query */
135 protected $mLastResult = null;
136 /** Number of rows affected by last INSERT/UPDATE/DELETE */
137 protected $mAffectedRows = null;
138 /** Number of rows returned by last SELECT */
139 protected $mNumRows = null;
141 /** Connection config options - see constructor */
142 public $mConnOptions = array();
143 /** Statement config options -- see constructor */
144 public $mStmtOptions = array();
146 /** Default schema */
147 const USE_GLOBAL = 'mediawiki';
149 /** Option that applies to nothing */
150 const NONE_OPTION = 0x00;
151 /** Option that applies to connection objects */
152 const CONN_OPTION = 0x01;
153 /** Option that applies to statement objects */
154 const STMT_OPTION = 0x02;
156 /** Regular operation mode -- minimal debug messages */
157 const REGULAR_MODE = 'regular';
158 /** Installation mode -- lots of debug messages */
159 const INSTALL_MODE = 'install';
161 /** Controls the level of debug message output */
162 protected $mMode = self::REGULAR_MODE;
164 /** Last sequence value used for a primary key */
165 protected $mInsertId = null;
167 ######################################
168 # Getters and Setters
169 ######################################
172 * Returns true if this database supports (and uses) cascading deletes
174 function cascadingDeletes() {
179 * Returns true if this database supports (and uses) triggers (e.g. on the
182 function cleanupTriggers() {
187 * Returns true if this database is strict about what can be put into an
189 * Specifically, it uses a NULL value instead of an empty string.
191 function strictIPs() {
196 * Returns true if this database uses timestamps rather than integers
198 function realTimestamps() {
203 * Returns true if this database does an implicit sort when doing GROUP BY
205 function implicitGroupby() {
210 * Returns true if this database does an implicit order by when the column
212 * For example: SELECT page_title FROM page LIMIT 1
214 function implicitOrderby() {
219 * Returns true if this database can do a native search on IP columns
220 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
222 function searchableIPs() {
227 * Returns true if this database can use functional indexes
229 function functionalIndexes() {
234 * Returns a unique string representing the wiki on the server
236 function getWikiID() {
237 if( $this->mSchema ) {
238 return "{$this->mDBname}-{$this->mSchema}";
240 return $this->mDBname;
250 * @param $server String: hostname of database server
251 * @param $user String: username
252 * @param $password String: password
253 * @param $dbName String: database name on the server
254 * @param $flags Integer: database behaviour flags (optional, unused)
255 * @param $schema String
257 public function __construct( $server = false, $user = false,
259 $dbName = false, $flags = 0,
260 $schema = self::USE_GLOBAL )
262 global $wgDBmwschema;
264 if ( $schema == self::USE_GLOBAL ) {
265 $this->mSchema = $wgDBmwschema;
267 $this->mSchema = $schema;
270 // configure the connection and statement objects
271 $this->setDB2Option( 'db2_attr_case', 'DB2_CASE_LOWER',
272 self::CONN_OPTION | self::STMT_OPTION );
273 $this->setDB2Option( 'deferred_prepare', 'DB2_DEFERRED_PREPARE_ON',
275 $this->setDB2Option( 'rowcount', 'DB2_ROWCOUNT_PREFETCH_ON',
278 parent::__construct( $server, $user, $password, $dbName, DBO_TRX | $flags );
282 * Enables options only if the ibm_db2 extension version supports them
283 * @param $name String: name of the option in the options array
284 * @param $const String: name of the constant holding the right option value
285 * @param $type Integer: whether this is a Connection or Statement otion
287 private function setDB2Option( $name, $const, $type ) {
288 if ( defined( $const ) ) {
289 if ( $type & self::CONN_OPTION ) {
290 $this->mConnOptions[$name] = constant( $const );
292 if ( $type & self::STMT_OPTION ) {
293 $this->mStmtOptions[$name] = constant( $const );
297 "$const is not defined. ibm_db2 version is likely too low." );
302 * Outputs debug information in the appropriate place
303 * @param $string String: the relevant debug message
305 private function installPrint( $string ) {
306 wfDebug( "$string\n" );
307 if ( $this->mMode == self::INSTALL_MODE ) {
308 print "<li><pre>$string</pre></li>";
314 * Opens a database connection and returns it
315 * Closes any existing connection
317 * @param $server String: hostname
318 * @param $user String
319 * @param $password String
320 * @param $dbName String: database name
321 * @return a fresh connection
323 public function open( $server, $user, $password, $dbName ) {
324 // Load the port number
326 wfProfileIn( __METHOD__ );
328 // Load IBM DB2 driver if missing
331 // Test for IBM DB2 support, to avoid suppressed fatal error
332 if ( !function_exists( 'db2_connect' ) ) {
334 DB2 functions missing, have you enabled the ibm_db2 extension for PHP?
337 $this->installPrint( $error );
338 $this->reportConnectionError( $error );
341 if ( strlen( $user ) < 1 ) {
342 wfProfileOut( __METHOD__ );
346 // Close existing connection
349 $this->mServer = $server;
350 $this->mPort = $port = $wgDBport;
351 $this->mUser = $user;
352 $this->mPassword = $password;
353 $this->mDBname = $dbName;
355 $this->openUncataloged( $dbName, $user, $password, $server, $port );
357 // Apply connection config
358 db2_set_option( $this->mConn, $this->mConnOptions, 1 );
359 // Some MediaWiki code is still transaction-less (?).
360 // The strategy is to keep AutoCommit on for that code
361 // but switch it off whenever a transaction is begun.
362 db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
364 if ( !$this->mConn ) {
365 $this->installPrint( "DB connection error\n" );
367 "Server: $server, Database: $dbName, User: $user, Password: "
368 . substr( $password, 0, 3 ) . "...\n" );
369 $this->installPrint( $this->lastError() . "\n" );
371 wfProfileOut( __METHOD__ );
375 $this->mOpened = true;
376 $this->applySchema();
378 wfProfileOut( __METHOD__ );
383 * Opens a cataloged database connection, sets mConn
385 protected function openCataloged( $dbName, $user, $password ) {
386 @$this->mConn = db2_pconnect( $dbName, $user, $password );
390 * Opens an uncataloged database connection, sets mConn
392 protected function openUncataloged( $dbName, $user, $password, $server, $port )
394 $str = "DRIVER={IBM DB2 ODBC DRIVER};";
395 $str .= "DATABASE=$dbName;";
396 $str .= "HOSTNAME=$server;";
397 // port was formerly validated to not be 0
398 $str .= "PORT=$port;";
399 $str .= "PROTOCOL=TCPIP;";
400 $str .= "UID=$user;";
401 $str .= "PWD=$password;";
403 @$this->mConn = db2_pconnect( $str, $user, $password );
407 * Closes a database connection, if it is open
408 * Returns success, true if already closed
410 public function close() {
411 $this->mOpened = false;
412 if ( $this->mConn ) {
413 if ( $this->trxLevel() > 0 ) {
416 return db2_close( $this->mConn );
423 * Returns a fresh instance of this class
425 * @param $server String: hostname of database server
426 * @param $user String: username
427 * @param $password String
428 * @param $dbName String: database name on the server
429 * @param $flags Integer: database behaviour flags (optional, unused)
430 * @return DatabaseIbm_db2 object
432 static function newFromParams( $server, $user, $password, $dbName,
435 return new DatabaseIbm_db2( $server, $user, $password, $dbName,
440 * Retrieves the most current database error
441 * Forces a database rollback
443 public function lastError() {
444 $connerr = db2_conn_errormsg();
449 $stmterr = db2_stmt_errormsg();
459 * Get the last error number
460 * Return 0 if no error
463 public function lastErrno() {
464 $connerr = db2_conn_error();
468 $stmterr = db2_stmt_error();
476 * Is a database connection open?
479 public function isOpen() { return $this->mOpened; }
482 * The DBMS-dependent part of query()
483 * @param $sql String: SQL query.
484 * @return object Result object for fetch functions or false on failure
488 public function doQuery( $sql ) {
489 $this->applySchema();
491 $ret = db2_exec( $this->mConn, $sql, $this->mStmtOptions );
492 if( $ret == false ) {
493 $error = db2_stmt_errormsg();
494 $this->installPrint( "<pre>$sql</pre>" );
495 $this->installPrint( $error );
496 throw new DBUnexpectedError( $this, 'SQL error: '
497 . htmlspecialchars( $error ) );
499 $this->mLastResult = $ret;
500 $this->mAffectedRows = null; // Not calculated until asked for
505 * @return string Version information from the database
507 public function getServerVersion() {
508 $info = db2_server_info( $this->mConn );
509 return $info->DBMS_VER;
513 * Queries whether a given table exists
516 public function tableExists( $table ) {
517 $schema = $this->mSchema;
519 SELECT COUNT( * ) FROM SYSIBM.SYSTABLES ST
520 WHERE ST.NAME = '$table' AND ST.CREATOR = '$schema'
522 $res = $this->query( $sql );
527 // If the table exists, there should be one of it
528 @$row = $this->fetchRow( $res );
530 if ( $count == '1' || $count == 1 ) {
538 * Fetch the next row from the given result object, in object form.
539 * Fields can be retrieved with $row->fieldname, with fields acting like
542 * @param $res SQL result object as returned from Database::query(), etc.
543 * @return DB2 row object
544 * @throws DBUnexpectedError Thrown if the database returns an error
546 public function fetchObject( $res ) {
547 if ( $res instanceof ResultWrapper ) {
550 @$row = db2_fetch_object( $res );
551 if( $this->lastErrno() ) {
552 throw new DBUnexpectedError( $this, 'Error in fetchObject(): '
553 . htmlspecialchars( $this->lastError() ) );
559 * Fetch the next row from the given result object, in associative array
560 * form. Fields are retrieved with $row['fieldname'].
562 * @param $res SQL result object as returned from Database::query(), etc.
563 * @return DB2 row object
564 * @throws DBUnexpectedError Thrown if the database returns an error
566 public function fetchRow( $res ) {
567 if ( $res instanceof ResultWrapper ) {
570 @$row = db2_fetch_array( $res );
571 if ( $this->lastErrno() ) {
572 throw new DBUnexpectedError( $this, 'Error in fetchRow(): '
573 . htmlspecialchars( $this->lastError() ) );
579 * Create tables, stored procedures, and so on
581 public function setup_database() {
583 // TODO: switch to root login if available
585 // Switch into the correct namespace
586 $this->applySchema();
589 $res = $this->sourceFile( "../maintenance/ibm_db2/tables.sql" );
590 if ( $res !== true ) {
591 print ' <b>FAILED</b>: ' . htmlspecialchars( $res ) . '</li>';
595 $res = $this->sourceFile( "../maintenance/ibm_db2/foreignkeys.sql" );
596 if ( $res !== true ) {
597 print ' <b>FAILED</b>: ' . htmlspecialchars( $res ) . '</li>';
599 print '<li>Foreign keys done</li>';
602 // TODO: populate interwiki links
604 if ( $this->lastError() ) {
606 'Errors encountered during table creation -- rolled back' );
607 $this->installPrint( 'Please install again' );
612 } catch ( MWException $mwe ) {
613 print "<br><pre>$mwe</pre><br>";
619 * Doesn't escape numbers
621 * @param $s String: string to escape
622 * @return escaped string
624 public function addQuotes( $s ) {
625 //$this->installPrint( "DB2::addQuotes( $s )\n" );
626 if ( is_null( $s ) ) {
628 } elseif ( $s instanceof Blob ) {
629 return "'" . $s->fetch( $s ) . "'";
630 } elseif ( $s instanceof IBM_DB2Blob ) {
631 return "'" . $this->decodeBlob( $s ) . "'";
633 $s = $this->strencode( $s );
634 if ( is_numeric( $s ) ) {
642 * Verifies that a DB2 column/field type is numeric
644 * @param $type String: DB2 column type
645 * @return Boolean: true if numeric
647 public function is_numeric_type( $type ) {
648 switch ( strtoupper( $type ) ) {
663 * Alias for addQuotes()
664 * @param $s String: string to escape
665 * @return escaped string
667 public function strencode( $s ) {
668 // Bloody useless function
669 // Prepends backslashes to \x00, \n, \r, \, ', " and \x1a.
670 // But also necessary
671 $s = db2_escape_string( $s );
672 // Wide characters are evil -- some of them look like '
673 $s = utf8_encode( $s );
675 $from = array( "\\\\", "\\'", '\\n', '\\t', '\\"', '\\r' );
676 $to = array( "\\", "''", "\n", "\t", '"', "\r" );
677 $s = str_replace( $from, $to, $s ); // DB2 expects '', not \' escaping
682 * Switch into the database schema
684 protected function applySchema() {
685 if ( !( $this->mSchemaSet ) ) {
686 $this->mSchemaSet = true;
688 $this->doQuery( "SET SCHEMA = $this->mSchema" );
694 * Start a transaction (mandatory)
696 public function begin( $fname = 'DatabaseIbm_db2::begin' ) {
697 // BEGIN is implicit for DB2
698 // However, it requires that AutoCommit be off.
700 // Some MediaWiki code is still transaction-less (?).
701 // The strategy is to keep AutoCommit on for that code
702 // but switch it off whenever a transaction is begun.
703 db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_OFF );
705 $this->mTrxLevel = 1;
710 * Must have a preceding begin()
712 public function commit( $fname = 'DatabaseIbm_db2::commit' ) {
713 db2_commit( $this->mConn );
715 // Some MediaWiki code is still transaction-less (?).
716 // The strategy is to keep AutoCommit on for that code
717 // but switch it off whenever a transaction is begun.
718 db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
720 $this->mTrxLevel = 0;
724 * Cancel a transaction
726 public function rollback( $fname = 'DatabaseIbm_db2::rollback' ) {
727 db2_rollback( $this->mConn );
728 // turn auto-commit back on
729 // not sure if this is appropriate
730 db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
731 $this->mTrxLevel = 0;
735 * Makes an encoded list of strings from an array
737 * LIST_COMMA - comma separated, no field names
738 * LIST_AND - ANDed WHERE clause (without the WHERE)
739 * LIST_OR - ORed WHERE clause (without the WHERE)
740 * LIST_SET - comma separated with field names, like a SET clause
741 * LIST_NAMES - comma separated field names
742 * LIST_SET_PREPARED - like LIST_SET, except with ? tokens as values
744 function makeList( $a, $mode = LIST_COMMA ) {
745 if ( !is_array( $a ) ) {
746 throw new DBUnexpectedError( $this,
747 'DatabaseIbm_db2::makeList called with incorrect parameters' );
750 // if this is for a prepared UPDATE statement
751 // (this should be promoted to the parent class
752 // once other databases use prepared statements)
753 if ( $mode == LIST_SET_PREPARED ) {
756 foreach ( $a as $field => $value ) {
758 $list .= ", $field = ?";
760 $list .= "$field = ?";
769 // otherwise, call the usual function
770 return parent::makeList( $a, $mode );
774 * Construct a LIMIT query with optional offset
775 * This is used for query pages
777 * @param $sql string SQL query we will append the limit too
778 * @param $limit integer the SQL limit
779 * @param $offset integer the SQL offset (default false)
781 public function limitResult( $sql, $limit, $offset=false ) {
782 if( !is_numeric( $limit ) ) {
783 throw new DBUnexpectedError( $this,
784 "Invalid non-numeric limit passed to limitResult()\n" );
787 if ( stripos( $sql, 'where' ) === false ) {
788 return "$sql AND ( ROWNUM BETWEEN $offset AND $offset+$limit )";
790 return "$sql WHERE ( ROWNUM BETWEEN $offset AND $offset+$limit )";
793 return "$sql FETCH FIRST $limit ROWS ONLY ";
797 * Handle reserved keyword replacement in table names
799 * @param $name Object
802 public function tableName( $name ) {
803 // we want maximum compatibility with MySQL schema
808 * Generates a timestamp in an insertable format
810 * @param $ts timestamp
811 * @return String: timestamp value
813 public function timestamp( $ts = 0 ) {
814 // TS_MW cannot be easily distinguished from an integer
815 return wfTimestamp( TS_DB2, $ts );
819 * Return the next in a sequence, save the value for retrieval via insertId()
820 * @param $seqName String: name of a defined sequence in the database
821 * @return next value in that sequence
823 public function nextSequenceValue( $seqName ) {
824 // Not using sequences in the primary schema to allow for easier migration
826 // Emulating MySQL behaviour of using NULL to signal that sequences
829 $safeseq = preg_replace( "/'/", "''", $seqName );
830 $res = $this->query( "VALUES NEXTVAL FOR $safeseq" );
831 $row = $this->fetchRow( $res );
832 $this->mInsertId = $row[0];
833 return $this->mInsertId;
839 * This must be called after nextSequenceVal
840 * @return Last sequence value used as a primary key
842 public function insertId() {
843 return $this->mInsertId;
847 * Updates the mInsertId property with the value of the last insert
848 * into a generated column
850 * @param $table String: sanitized table name
851 * @param $primaryKey Mixed: string name of the primary key
852 * @param $stmt Resource: prepared statement resource
853 * of the SELECT primary_key FROM FINAL TABLE ( INSERT ... ) form
855 private function calcInsertId( $table, $primaryKey, $stmt ) {
857 $this->mInsertId = db2_last_insert_id( $this->mConn );
862 * INSERT wrapper, inserts an array into a table
864 * $args may be a single associative array, or an array of arrays
865 * with numeric keys, for multi-row insert
867 * @param $table String: Name of the table to insert to.
868 * @param $args Array: Items to insert into the table.
869 * @param $fname String: Name of the function, for profiling
870 * @param $options String or Array. Valid options: IGNORE
872 * @return bool Success of insert operation. IGNORE always returns true.
874 public function insert( $table, $args, $fname = 'DatabaseIbm_db2::insert',
877 if ( !count( $args ) ) {
880 // get database-specific table name (not used)
881 $table = $this->tableName( $table );
882 // format options as an array
883 $options = IBM_DB2Helper::makeArray( $options );
884 // format args as an array of arrays
885 if ( !( isset( $args[0] ) && is_array( $args[0] ) ) ) {
886 $args = array( $args );
889 // prevent insertion of NULL into primary key columns
890 list( $args, $primaryKeys ) = $this->removeNullPrimaryKeys( $table, $args );
891 // if there's only one primary key
892 // we'll be able to read its value after insertion
894 if ( count( $primaryKeys ) == 1 ) {
895 $primaryKey = $primaryKeys[0];
899 $keys = array_keys( $args[0] );
900 $key_count = count( $keys );
902 // If IGNORE is set, we use savepoints to emulate mysql's behavior
903 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
907 // If we are not in a transaction, we need to be for savepoint trickery
908 if ( !$this->mTrxLevel ) {
912 $sql = "INSERT INTO $table ( " . implode( ',', $keys ) . ' ) VALUES ';
913 if ( $key_count == 1 ) {
916 $sql .= '( ?' . str_repeat( ',?', $key_count-1 ) . ' )';
918 //$this->installPrint( "Preparing the following SQL:" );
919 //$this->installPrint( "$sql" );
920 //$this->installPrint( print_r( $args, true ));
921 $stmt = $this->prepare( $sql );
923 // start a transaction/enter transaction mode
928 foreach ( $args as $row ) {
929 //$this->installPrint( "Inserting " . print_r( $row, true ));
930 // insert each row into the database
931 $res = $res & $this->execute( $stmt, $row );
933 $this->installPrint( 'Last error:' );
934 $this->installPrint( $this->lastError() );
936 // get the last inserted value into a generated column
937 $this->calcInsertId( $table, $primaryKey, $stmt );
940 $olde = error_reporting( 0 );
941 // For future use, we may want to track the number of actual inserts
942 // Right now, insert (all writes) simply return true/false
943 $numrowsinserted = 0;
945 // always return true
948 foreach ( $args as $row ) {
949 $overhead = "SAVEPOINT $ignore ON ROLLBACK RETAIN CURSORS";
950 db2_exec( $this->mConn, $overhead, $this->mStmtOptions );
952 $res2 = $this->execute( $stmt, $row );
955 $this->installPrint( 'Last error:' );
956 $this->installPrint( $this->lastError() );
958 // get the last inserted value into a generated column
959 $this->calcInsertId( $table, $primaryKey, $stmt );
961 $errNum = $this->lastErrno();
963 db2_exec( $this->mConn, "ROLLBACK TO SAVEPOINT $ignore",
964 $this->mStmtOptions );
966 db2_exec( $this->mConn, "RELEASE SAVEPOINT $ignore",
967 $this->mStmtOptions );
972 $olde = error_reporting( $olde );
973 // Set the affected row count for the whole operation
974 $this->mAffectedRows = $numrowsinserted;
978 $this->freePrepared( $stmt );
984 * Given a table name and a hash of columns with values
985 * Removes primary key columns from the hash where the value is NULL
987 * @param $table String: name of the table
988 * @param $args Array of hashes of column names with values
989 * @return Array: tuple( filtered array of columns, array of primary keys )
991 private function removeNullPrimaryKeys( $table, $args ) {
992 $schema = $this->mSchema;
993 // find out the primary keys
994 $keyres = db2_primary_keys( $this->mConn, null, strtoupper( $schema ),
999 $row = $this->fetchObject( $keyres );
1001 $row = $this->fetchObject( $keyres )
1004 $keys[] = strtolower( $row->column_name );
1006 // remove primary keys
1007 foreach ( $args as $ai => $row ) {
1008 foreach ( $keys as $key ) {
1009 if ( $row[$key] == null ) {
1010 unset( $row[$key] );
1015 // return modified hash
1016 return array( $args, $keys );
1020 * UPDATE wrapper, takes a condition array and a SET array
1022 * @param $table String: The table to UPDATE
1023 * @param $values An array of values to SET
1024 * @param $conds An array of conditions ( WHERE ). Use '*' to update all rows.
1025 * @param $fname String: The Class::Function calling this function
1027 * @param $options An array of UPDATE options, can be one or
1028 * more of IGNORE, LOW_PRIORITY
1031 public function update( $table, $values, $conds, $fname = 'DatabaseIbm_db2::update',
1032 $options = array() )
1034 $table = $this->tableName( $table );
1035 $opts = $this->makeUpdateOptions( $options );
1036 $sql = "UPDATE $opts $table SET "
1037 . $this->makeList( $values, LIST_SET_PREPARED );
1038 if ( $conds != '*' ) {
1039 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1041 $stmt = $this->prepare( $sql );
1042 $this->installPrint( 'UPDATE: ' . print_r( $values, true ) );
1043 // assuming for now that an array with string keys will work
1044 // if not, convert to simple array first
1045 $result = $this->execute( $stmt, $values );
1046 $this->freePrepared( $stmt );
1052 * DELETE query wrapper
1054 * Use $conds == "*" to delete all rows
1056 public function delete( $table, $conds, $fname = 'DatabaseIbm_db2::delete' ) {
1058 throw new DBUnexpectedError( $this,
1059 'DatabaseIbm_db2::delete() called with no conditions' );
1061 $table = $this->tableName( $table );
1062 $sql = "DELETE FROM $table";
1063 if ( $conds != '*' ) {
1064 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1066 $result = $this->query( $sql, $fname );
1072 * Returns the number of rows affected by the last query or 0
1073 * @return Integer: the number of rows affected by the last query
1075 public function affectedRows() {
1076 if ( !is_null( $this->mAffectedRows ) ) {
1077 // Forced result for simulated queries
1078 return $this->mAffectedRows;
1080 if( empty( $this->mLastResult ) ) {
1083 return db2_num_rows( $this->mLastResult );
1087 * Simulates REPLACE with a DELETE followed by INSERT
1088 * @param $table Object
1089 * @param $uniqueIndexes Array consisting of indexes and arrays of indexes
1090 * @param $rows Array: rows to insert
1091 * @param $fname String: name of the function for profiling
1094 function replace( $table, $uniqueIndexes, $rows,
1095 $fname = 'DatabaseIbm_db2::replace' )
1097 $table = $this->tableName( $table );
1099 if ( count( $rows )==0 ) {
1104 if ( !is_array( reset( $rows ) ) ) {
1105 $rows = array( $rows );
1108 foreach( $rows as $row ) {
1109 # Delete rows which collide
1110 if ( $uniqueIndexes ) {
1111 $sql = "DELETE FROM $table WHERE ";
1113 foreach ( $uniqueIndexes as $index ) {
1120 if ( is_array( $index ) ) {
1122 foreach ( $index as $col ) {
1128 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
1131 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
1135 $this->query( $sql, $fname );
1138 # Now insert the row
1139 $sql = "INSERT INTO $table ( "
1140 . $this->makeList( array_keys( $row ), LIST_NAMES )
1141 .' ) VALUES ( ' . $this->makeList( $row, LIST_COMMA ) . ' )';
1142 $this->query( $sql, $fname );
1147 * Returns the number of rows in the result set
1148 * Has to be called right after the corresponding select query
1149 * @param $res Object result set
1150 * @return Integer: number of rows
1152 public function numRows( $res ) {
1153 if ( $res instanceof ResultWrapper ) {
1154 $res = $res->result;
1156 if ( $this->mNumRows ) {
1157 return $this->mNumRows;
1164 * Moves the row pointer of the result set
1165 * @param $res Object: result set
1166 * @param $row Integer: row number
1167 * @return success or failure
1169 public function dataSeek( $res, $row ) {
1170 if ( $res instanceof ResultWrapper ) {
1171 $res = $res->result;
1173 return db2_fetch_row( $res, $row );
1177 # Fix notices in Block.php
1181 * Frees memory associated with a statement resource
1182 * @param $res Object: statement resource to free
1183 * @return Boolean success or failure
1185 public function freeResult( $res ) {
1186 if ( $res instanceof ResultWrapper ) {
1187 $res = $res->result;
1189 if ( !@db2_free_result( $res ) ) {
1190 throw new DBUnexpectedError( $this, "Unable to free DB2 result\n" );
1195 * Returns the number of columns in a resource
1196 * @param $res Object: statement resource
1197 * @return Number of fields/columns in resource
1199 public function numFields( $res ) {
1200 if ( $res instanceof ResultWrapper ) {
1201 $res = $res->result;
1203 return db2_num_fields( $res );
1207 * Returns the nth column name
1208 * @param $res Object: statement resource
1209 * @param $n Integer: Index of field or column
1210 * @return String name of nth column
1212 public function fieldName( $res, $n ) {
1213 if ( $res instanceof ResultWrapper ) {
1214 $res = $res->result;
1216 return db2_field_name( $res, $n );
1222 * @param $table Array or string, table name(s) (prefix auto-added)
1223 * @param $vars Array or string, field name(s) to be retrieved
1224 * @param $conds Array or string, condition(s) for WHERE
1225 * @param $fname String: calling function name (use __METHOD__)
1226 * for logs/profiling
1227 * @param $options Associative array of options
1228 * (e.g. array('GROUP BY' => 'page_title')),
1229 * see Database::makeSelectOptions code for list of
1231 * @param $join_conds Associative array of table join conditions (optional)
1232 * (e.g. array( 'page' => array('LEFT JOIN',
1233 * 'page_latest=rev_id') )
1234 * @return Mixed: database result resource for fetch functions or false
1237 public function select( $table, $vars, $conds = '', $fname = 'DatabaseIbm_db2::select', $options = array(), $join_conds = array() )
1239 $res = parent::select( $table, $vars, $conds, $fname, $options,
1242 // We must adjust for offset
1243 if ( isset( $options['LIMIT'] ) && isset ( $options['OFFSET'] ) ) {
1244 $limit = $options['LIMIT'];
1245 $offset = $options['OFFSET'];
1248 // DB2 does not have a proper num_rows() function yet, so we must emulate
1249 // DB2 9.5.4 and the corresponding ibm_db2 driver will introduce
1253 // we want the count
1254 $vars2 = array( 'count( * ) as num_rows' );
1255 // respecting just the limit option
1256 $options2 = array();
1257 if ( isset( $options['LIMIT'] ) ) {
1258 $options2['LIMIT'] = $options['LIMIT'];
1260 // but don't try to emulate for GROUP BY
1261 if ( isset( $options['GROUP BY'] ) ) {
1265 $res2 = parent::select( $table, $vars2, $conds, $fname, $options2,
1267 $obj = $this->fetchObject( $res2 );
1268 $this->mNumRows = $obj->num_rows;
1274 * Handles ordering, grouping, and having options ('GROUP BY' => colname)
1275 * Has limited support for per-column options (colnum => 'DISTINCT')
1279 * @param $options Associative array of options to be turned into
1280 * an SQL query, valid keys are listed in the function.
1283 function makeSelectOptions( $options ) {
1284 $preLimitTail = $postLimitTail = '';
1287 $noKeyOptions = array();
1288 foreach ( $options as $key => $option ) {
1289 if ( is_numeric( $key ) ) {
1290 $noKeyOptions[$option] = true;
1294 if ( isset( $options['GROUP BY'] ) ) {
1295 $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1297 if ( isset( $options['HAVING'] ) ) {
1298 $preLimitTail .= " HAVING {$options['HAVING']}";
1300 if ( isset( $options['ORDER BY'] ) ) {
1301 $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1304 if ( isset( $noKeyOptions['DISTINCT'] )
1305 || isset( $noKeyOptions['DISTINCTROW'] ) )
1307 $startOpts .= 'DISTINCT';
1310 return array( $startOpts, '', $preLimitTail, $postLimitTail );
1314 * Returns link to IBM DB2 free download
1315 * @return String: wikitext of a link to the server software's web site
1317 public static function getSoftwareLink() {
1318 return '[http://www.ibm.com/db2/express/ IBM DB2]';
1322 * Get search engine class. All subclasses of this
1323 * need to implement this if they wish to use searching.
1327 public function getSearchEngine() {
1328 return 'SearchIBM_DB2';
1332 * Did the last database access fail because of deadlock?
1335 public function wasDeadlock() {
1337 $err = $this->lastErrno();
1339 // This is literal port of the MySQL logic and may be wrong for DB2
1340 case '40001': // sql0911n, Deadlock or timeout, rollback
1341 case '57011': // sql0904n, Resource unavailable, no rollback
1342 case '57033': // sql0913n, Deadlock or timeout, no rollback
1343 $this->installPrint( "In a deadlock because of SQLSTATE $err" );
1350 * Ping the server and try to reconnect if it there is no connection
1351 * The connection may be closed and reopened while this happens
1352 * @return Boolean: whether the connection exists
1354 public function ping() {
1355 // db2_ping() doesn't exist
1358 $this->mConn = $this->openUncataloged( $this->mDBName, $this->mUser,
1359 $this->mPassword, $this->mServer, $this->mPort );
1363 ######################################
1364 # Unimplemented and not applicable
1365 ######################################
1370 public function getStatus( $which = '%' ) {
1371 $this->installPrint( 'Not implemented for DB2: getStatus()' );
1376 * @return string $sql
1378 public function limitResultForUpdate( $sql, $num ) {
1379 $this->installPrint( 'Not implemented for DB2: limitResultForUpdate()' );
1384 * Only useful with fake prepare like in base Database class
1387 public function fillPreparedArg( $matches ) {
1388 $this->installPrint( 'Not useful for DB2: fillPreparedArg()' );
1392 ######################################
1394 ######################################
1397 * Returns information about an index
1398 * If errors are explicitly ignored, returns NULL on failure
1399 * @param $table String: table name
1400 * @param $index String: index name
1401 * @param $fname String: function name for logging and profiling
1402 * @return Object query row in object form
1404 public function indexInfo( $table, $index,
1405 $fname = 'DatabaseIbm_db2::indexExists' )
1407 $table = $this->tableName( $table );
1409 SELECT name as indexname
1410 FROM sysibm.sysindexes si
1411 WHERE si.name='$index' AND si.tbname='$table'
1412 AND sc.tbcreator='$this->mSchema'
1414 $res = $this->query( $sql, $fname );
1418 $row = $this->fetchObject( $res );
1419 if ( $row != null ) {
1427 * Returns an information object on a table column
1428 * @param $table String: table name
1429 * @param $field String: column name
1430 * @return IBM_DB2Field
1432 public function fieldInfo( $table, $field ) {
1433 return IBM_DB2Field::fromText( $this, $table, $field );
1437 * db2_field_type() wrapper
1438 * @param $res Object: result of executed statement
1439 * @param $index Mixed: number or name of the column
1440 * @return String column type
1442 public function fieldType( $res, $index ) {
1443 if ( $res instanceof ResultWrapper ) {
1444 $res = $res->result;
1446 return db2_field_type( $res, $index );
1450 * Verifies that an index was created as unique
1451 * @param $table String: table name
1452 * @param $index String: index name
1453 * @param $fname function name for profiling
1456 public function indexUnique ( $table, $index,
1457 $fname = 'DatabaseIbm_db2::indexUnique' )
1459 $table = $this->tableName( $table );
1461 SELECT si.name as indexname
1462 FROM sysibm.sysindexes si
1463 WHERE si.name='$index' AND si.tbname='$table'
1464 AND sc.tbcreator='$this->mSchema'
1465 AND si.uniquerule IN ( 'U', 'P' )
1467 $res = $this->query( $sql, $fname );
1471 if ( $this->fetchObject( $res ) ) {
1479 * Returns the size of a text field, or -1 for "unlimited"
1480 * @param $table String: table name
1481 * @param $field String: column name
1482 * @return Integer: length or -1 for unlimited
1484 public function textFieldSize( $table, $field ) {
1485 $table = $this->tableName( $table );
1487 SELECT length as size
1488 FROM sysibm.syscolumns sc
1489 WHERE sc.name='$field' AND sc.tbname='$table'
1490 AND sc.tbcreator='$this->mSchema'
1492 $res = $this->query( $sql );
1493 $row = $this->fetchObject( $res );
1499 * DELETE where the condition is a join
1500 * @param $delTable String: deleting from this table
1501 * @param $joinTable String: using data from this table
1502 * @param $delVar String: variable in deleteable table
1503 * @param $joinVar String: variable in data table
1504 * @param $conds Array: conditionals for join table
1505 * @param $fname String: function name for profiling
1507 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar,
1508 $conds, $fname = "DatabaseIbm_db2::deleteJoin" )
1511 throw new DBUnexpectedError( $this,
1512 'DatabaseIbm_db2::deleteJoin() called with empty $conds' );
1515 $delTable = $this->tableName( $delTable );
1516 $joinTable = $this->tableName( $joinTable );
1518 DELETE FROM $delTable
1520 SELECT $joinVar FROM $joinTable
1523 if ( $conds != '*' ) {
1524 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
1528 $this->query( $sql, $fname );
1532 * Description is left as an exercise for the reader
1533 * @param $b Mixed: data to be encoded
1534 * @return IBM_DB2Blob
1536 public function encodeBlob( $b ) {
1537 return new IBM_DB2Blob( $b );
1541 * Description is left as an exercise for the reader
1542 * @param $b IBM_DB2Blob: data to be decoded
1545 public function decodeBlob( $b ) {
1550 * Convert into a list of string being concatenated
1551 * @param $stringList Array: strings that need to be joined together
1553 * @return String: joined by the concatenation operator
1555 public function buildConcat( $stringList ) {
1556 // || is equivalent to CONCAT
1557 // Sample query: VALUES 'foo' CONCAT 'bar' CONCAT 'baz'
1558 return implode( ' || ', $stringList );
1562 * Generates the SQL required to convert a DB2 timestamp into a Unix epoch
1563 * @param $column String: name of timestamp column
1564 * @return String: SQL code
1566 public function extractUnixEpoch( $column ) {
1568 // see SpecialAncientpages
1571 ######################################
1572 # Prepared statements
1573 ######################################
1576 * Intended to be compatible with the PEAR::DB wrapper functions.
1577 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1579 * ? = scalar value, quoted as necessary
1580 * ! = raw SQL bit (a function for instance)
1581 * & = filename; reads the file and inserts as a blob
1582 * (we don't use this though...)
1583 * @param $sql String: SQL statement with appropriate markers
1584 * @param $func String: Name of the function, for profiling
1585 * @return resource a prepared DB2 SQL statement
1587 public function prepare( $sql, $func = 'DB2::prepare' ) {
1588 $stmt = db2_prepare( $this->mConn, $sql, $this->mStmtOptions );
1593 * Frees resources associated with a prepared statement
1594 * @return Boolean success or failure
1596 public function freePrepared( $prepared ) {
1597 return db2_free_stmt( $prepared );
1601 * Execute a prepared query with the various arguments
1602 * @param $prepared String: the prepared sql
1603 * @param $args Mixed: either an array here, or put scalars as varargs
1604 * @return Resource: results object
1606 public function execute( $prepared, $args = null ) {
1607 if( !is_array( $args ) ) {
1609 $args = func_get_args();
1610 array_shift( $args );
1612 $res = db2_execute( $prepared, $args );
1614 $this->installPrint( db2_stmt_errormsg() );
1620 * Prepare & execute an SQL statement, quoting and inserting arguments
1621 * in the appropriate places.
1622 * @param $query String
1625 public function safeQuery( $query, $args = null ) {
1626 // copied verbatim from Database.php
1627 $prepared = $this->prepare( $query, 'DB2::safeQuery' );
1628 if( !is_array( $args ) ) {
1630 $args = func_get_args();
1631 array_shift( $args );
1633 $retval = $this->execute( $prepared, $args );
1634 $this->freePrepared( $prepared );
1639 * For faking prepared SQL statements on DBs that don't support
1641 * @param $preparedQuery String: a 'preparable' SQL statement
1642 * @param $args Array of arguments to fill it with
1643 * @return String: executable statement
1645 public function fillPrepared( $preparedQuery, $args ) {
1647 $this->preparedArgs =& $args;
1649 foreach ( $args as $i => $arg ) {
1650 db2_bind_param( $preparedQuery, $i+1, $args[$i] );
1653 return $preparedQuery;
1657 * Switches module between regular and install modes
1659 public function setMode( $mode ) {
1660 $old = $this->mMode;
1661 $this->mMode = $mode;
1666 * Bitwise negation of a column or value in SQL
1667 * Same as (~field) in C
1668 * @param $field String
1671 function bitNot( $field ) {
1672 // expecting bit-fields smaller than 4bytes
1673 return "BITNOT( $field )";
1677 * Bitwise AND of two columns or values in SQL
1678 * Same as (fieldLeft & fieldRight) in C
1679 * @param $fieldLeft String
1680 * @param $fieldRight String
1683 function bitAnd( $fieldLeft, $fieldRight ) {
1684 return "BITAND( $fieldLeft, $fieldRight )";
1688 * Bitwise OR of two columns or values in SQL
1689 * Same as (fieldLeft | fieldRight) in C
1690 * @param $fieldLeft String
1691 * @param $fieldRight String
1694 function bitOr( $fieldLeft, $fieldRight ) {
1695 return "BITOR( $fieldLeft, $fieldRight )";
1699 class IBM_DB2Helper {
1700 public static function makeArray( $maybeArray ) {
1701 if ( !is_array( $maybeArray ) ) {
1702 return array( $maybeArray );