githubFork/roundcubemail.git

old mode 100755 new mode 100644

			@@ -1,375 +1,1356 @@
			<?php
			// +----------------------------------------------------------------------+
			// \| PHP versions 4 and 5 \|
			// +----------------------------------------------------------------------+
			// \| Copyright (c) 1998-2004 Manuel Lemos, Tomas V.V.Cox, \|
			// \| Stig. S. Bakken, Lukas Smith \|
			// \| All rights reserved. \|
			// +----------------------------------------------------------------------+
			// \| MDB2 is a merge of PEAR DB and Metabases that provides a unified DB \|
			// \| API as well as database abstraction for PHP applications. \|
			// \| This LICENSE is in the BSD license style. \|
			// \| \|
			// \| Redistribution and use in source and binary forms, with or without \|
			// \| modification, are permitted provided that the following conditions \|
			// \| are met: \|
			// \| \|
			// \| Redistributions of source code must retain the above copyright \|
			// \| notice, this list of conditions and the following disclaimer. \|
			// \| \|
			// \| Redistributions in binary form must reproduce the above copyright \|
			// \| notice, this list of conditions and the following disclaimer in the \|
			// \| documentation and/or other materials provided with the distribution. \|
			// \| \|
			// \| Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken, \|
			// \| Lukas Smith nor the names of his contributors may be used to endorse \|
			// \| or promote products derived from this software without specific prior\|
			// \| written permission. \|
			// \| \|
			// \| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \|
			// \| "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT \|
			// \| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS \|
			// \| FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE \|
			// \| REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, \|
			// \| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, \|
			// \| BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS\|
			// \| OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED \|
			// \| AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT \|
			// \| LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY\|
			// \| WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE \|
			// \| POSSIBILITY OF SUCH DAMAGE. \|
			// +----------------------------------------------------------------------+
			// \| Author: Lukas Smith <smith@backendmedia.com> \|
			// +----------------------------------------------------------------------+
			//
			// $Id$
			//

			require_once 'MDB2/Driver/Manager/Common.php';

			/**
			* MDB2 SQLite driver for the management modules
			*
			* @package MDB2
			* @category Database
			* @author Lukas Smith <smith@backendmedia.com>
			*/
			class MDB2_Driver_Manager_sqlite extends MDB2_Driver_Manager_Common
			{
			// {{{ createDatabase()

			/**
			* create a new database
			*
			* @param string $name name of the database that should be created
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createDatabase($name)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$database_file = $db->_getDatabaseFile($name);
			if (file_exists($database_file)) {
			return $db->raiseError(MDB2_ERROR_CANNOT_CREATE, null, null,
			'createDatabase: database already exists');
			}
			$php_errormsg = '';
			$handle = @sqlite_open($database_file, $db->dsn['mode'], $php_errormsg);
			if (!$handle) {
			return $db->raiseError(MDB2_ERROR_CANNOT_CREATE, null, null,
			'createDatabase: '.(isset($php_errormsg) ? $php_errormsg : 'could not create the database file'));
			}
			@sqlite_close($handle);
			return MDB2_OK;
			}

			// }}}
			// {{{ dropDatabase()

			/**
			* drop an existing database
			*
			* @param string $name name of the database that should be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropDatabase($name)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$database_file = $db->_getDatabaseFile($name);
			if (!@file_exists($database_file)) {
			return $db->raiseError(MDB2_ERROR_CANNOT_DROP, null, null,
			'dropDatabase: database does not exist');
			}
			$result = @unlink($database_file);
			if (!$result) {
			return $db->raiseError(MDB2_ERROR_CANNOT_DROP, null, null,
			'dropDatabase: '.(isset($php_errormsg) ? $php_errormsg : 'could not remove the database file'));
			}
			return MDB2_OK;
			}

			// }}}
			// {{{ listDatabases()

			/**
			* list all databases
			*
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listDatabases()
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			return $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
			'listDatabases: list databases is not supported');
			}

			// }}}
			// {{{ listUsers()

			/**
			* list all users
			*
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listUsers()
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			return $db->queryCol('SELECT DISTINCT USER FROM USER');
			}

			// }}}
			// {{{ listTables()

			/**
			* list all tables in the current database
			*
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listTables()
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$query = "SELECT name FROM sqlite_master WHERE type='table' AND sql NOT NULL ORDER BY name";
			$table_names = $db->queryCol($query);
			if (PEAR::isError($table_names)) {
			return $table_names;
			}
			$tables = array();
			for ($i = 0, $j = count($table_names); $i < $j; ++$i) {
			if (!$this->_isSequenceName($table_names[$i]))
			$tables[] = $table_names[$i];
			}
			return $tables;
			}

			// }}}
			// {{{ listTableFields()

			/**
			* list all fields in a tables in the current database
			*
			* @param string $table name of table that should be used in method
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listTableFields($table)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$query = "SELECT * FROM $table";
			$db->setLimit(1);
			$result = $db->query($query);
			if (PEAR::isError($result)) {
			return $result;
			}
			$columns = $result->getColumnNames();
			$result->free();
			if (PEAR::isError($columns)) {
			return $columns;
			}
			return array_flip($columns);
			}

			// }}}
			// {{{ createIndex()

			/**
			* get the stucture of a field into an array
			*
			* @param string $table name of the table on which the index is to be created
			* @param string $name name of the index to be created
			* @param array $definition associative array that defines properties of the index to be created.
			* Currently, only one property named FIELDS is supported. This property
			* is also an associative with the names of the index fields as array
			* indexes. Each entry of this array is set to another type of associative
			* array that specifies properties of the index that are specific to
			* each field.
			*
			* Currently, only the sorting property is supported. It should be used
			* to define the sorting direction of the index. It may be set to either
			* ascending or descending.
			*
			* Not all DBMS support index sorting direction configuration. The DBMS
			* drivers of those that do not support it ignore this property. Use the
			* function support() to determine whether the DBMS driver can manage indexes.

			* Example
			* array(
			* 'fields' => array(
			* 'user_name' => array(
			* 'sorting' => 'ascending'
			* ),
			* 'last_login' => array()
			* )
			* )
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createIndex($table, $name, $definition)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$query = 'CREATE '.(isset($definition['unique']) ? 'UNIQUE' : '')." INDEX $name ON $table (";
			$skipped_first = false;
			foreach ($definition['fields'] as $field_name => $field) {
			if ($skipped_first) {
			$query .= ',';
			}
			$query .= $field_name;
			$skipped_first = true;
			}
			$query .= ')';
			return $db->query($query);
			}

			// }}}
			// {{{ dropIndex()

			/**
			* drop existing index
			*
			* @param string $table name of table that should be used in method
			* @param string $name name of the index to be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropIndex($table, $name)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			return $db->query("DROP INDEX $name");
			}

			// }}}
			// {{{ listTableIndexes()

			/**
			* list all indexes in a table
			*
			* @param string $table name of table that should be used in method
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listTableIndexes($table)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$query = "SELECT name FROM sqlite_master WHERE type='index' AND tbl_name='$table' AND sql NOT NULL ORDER BY name";
			$indexes_all = $db->queryCol($query);
			if (PEAR::isError($indexes_all)) {
			return $indexes_all;
			}
			$found = $indexes = array();
			foreach ($indexes_all as $index => $index_name) {
			if ($indexes_all[$index] != 'PRIMARY' && !isset($found[$index_name])) {
			$indexes[] = $index_name;
			$found[$index_name] = true;
			}
			}
			return $indexes;
			}

			// }}}
			// {{{ createSequence()

			/**
			* create sequence
			*
			* @param string $seq_name name of the sequence to be created
			* @param string $start start value of the sequence; default is 1
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createSequence($seq_name, $start = 1)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$sequence_name = $db->getSequenceName($seq_name);
			$seqcol_name = $db->options['seqcol_name'];
			$query = "CREATE TABLE $sequence_name ($seqcol_name INTEGER PRIMARY KEY DEFAULT 0 NOT NULL)";
			$res = $db->query($query);
			if (PEAR::isError($res)) {
			return $res;
			}
			if ($start == 1) {
			return MDB2_OK;
			}
			$res = $db->query("INSERT INTO $sequence_name ($seqcol_name) VALUES (".($start-1).')');
			if (!PEAR::isError($res)) {
			return MDB2_OK;
			}
			// Handle error
			$result = $db->query("DROP TABLE $sequence_name");
			if (PEAR::isError($result)) {
			return $db->raiseError(MDB2_ERROR, null, null,
			'createSequence: could not drop inconsistent sequence table ('.
			$result->getMessage().' ('.$result->getUserinfo().'))');
			}
			return $db->raiseError(MDB2_ERROR, null, null,
			'createSequence: could not create sequence table ('.
			$res->getMessage().' ('.$res->getUserinfo().'))');
			}

			// }}}
			// {{{ dropSequence()

			/**
			* drop existing sequence
			*
			* @param string $seq_name name of the sequence to be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropSequence($seq_name)
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$sequence_name = $db->getSequenceName($seq_name);
			return $db->query("DROP TABLE $sequence_name");
			}

			// }}}
			// {{{ listSequences()

			/**
			* list all sequences in the current database
			*
			* @return mixed data array on success, a MDB2 error on failure
			* @access public
			*/
			function listSequences()
			{
			$db =& $GLOBALS['_MDB2_databases'][$this->db_index];
			$query = "SELECT name FROM sqlite_master WHERE type='table' AND sql NOT NULL ORDER BY name";
			$table_names = $db->queryCol($query);
			if (PEAR::isError($table_names)) {
			return $table_names;
			}
			$sequences = array();
			for ($i = 0, $j = count($table_names); $i < $j; ++$i) {
			if ($sqn = $this->_isSequenceName($table_names[$i]))
			$sequences[] = $sqn;
			}
			return $sequences;
			}

			// }}}
			}
			?>
			<?php
			// +----------------------------------------------------------------------+
			// \| PHP versions 4 and 5 \|
			// +----------------------------------------------------------------------+
			// \| Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox, \|
			// \| Stig. S. Bakken, Lukas Smith, Lorenzo Alberton \|
			// \| All rights reserved. \|
			// +----------------------------------------------------------------------+
			// \| MDB2 is a merge of PEAR DB and Metabases that provides a unified DB \|
			// \| API as well as database abstraction for PHP applications. \|
			// \| This LICENSE is in the BSD license style. \|
			// \| \|
			// \| Redistribution and use in source and binary forms, with or without \|
			// \| modification, are permitted provided that the following conditions \|
			// \| are met: \|
			// \| \|
			// \| Redistributions of source code must retain the above copyright \|
			// \| notice, this list of conditions and the following disclaimer. \|
			// \| \|
			// \| Redistributions in binary form must reproduce the above copyright \|
			// \| notice, this list of conditions and the following disclaimer in the \|
			// \| documentation and/or other materials provided with the distribution. \|
			// \| \|
			// \| Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken, \|
			// \| Lukas Smith nor the names of his contributors may be used to endorse \|
			// \| or promote products derived from this software without specific prior\|
			// \| written permission. \|
			// \| \|
			// \| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \|
			// \| "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT \|
			// \| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS \|
			// \| FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE \|
			// \| REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, \|
			// \| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, \|
			// \| BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS\|
			// \| OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED \|
			// \| AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT \|
			// \| LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY\|
			// \| WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE \|
			// \| POSSIBILITY OF SUCH DAMAGE. \|
			// +----------------------------------------------------------------------+
			// \| Authors: Lukas Smith <smith@pooteeweet.org> \|
			// \| Lorenzo Alberton <l.alberton@quipo.it> \|
			// +----------------------------------------------------------------------+
			//
			// $Id: sqlite.php,v 1.74 2008/03/05 11:08:53 quipo Exp $
			//

			require_once 'MDB2/Driver/Manager/Common.php';

			/**
			* MDB2 SQLite driver for the management modules
			*
			* @package MDB2
			* @category Database
			* @author Lukas Smith <smith@pooteeweet.org>
			* @author Lorenzo Alberton <l.alberton@quipo.it>
			*/
			class MDB2_Driver_Manager_sqlite extends MDB2_Driver_Manager_Common
			{
			// {{{ createDatabase()

			/**
			* create a new database
			*
			* @param string $name name of the database that should be created
			* @param array $options array with charset info
			*
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createDatabase($name, $options = array())
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$database_file = $db->_getDatabaseFile($name);
			if (file_exists($database_file)) {
			return $db->raiseError(MDB2_ERROR_ALREADY_EXISTS, null, null,
			'database already exists', __FUNCTION__);
			}
			$php_errormsg = '';
			$handle = @sqlite_open($database_file, $db->dsn['mode'], $php_errormsg);
			if (!$handle) {
			return $db->raiseError(MDB2_ERROR_CANNOT_CREATE, null, null,
			(isset($php_errormsg) ? $php_errormsg : 'could not create the database file'), __FUNCTION__);
			}
			if (!empty($options['charset'])) {
			$query = 'PRAGMA encoding = ' . $db->quote($options['charset'], 'text');
			@sqlite_query($query, $handle);
			}
			@sqlite_close($handle);
			return MDB2_OK;
			}

			// }}}
			// {{{ dropDatabase()

			/**
			* drop an existing database
			*
			* @param string $name name of the database that should be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropDatabase($name)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$database_file = $db->_getDatabaseFile($name);
			if (!@file_exists($database_file)) {
			return $db->raiseError(MDB2_ERROR_CANNOT_DROP, null, null,
			'database does not exist', __FUNCTION__);
			}
			$result = @unlink($database_file);
			if (!$result) {
			return $db->raiseError(MDB2_ERROR_CANNOT_DROP, null, null,
			(isset($php_errormsg) ? $php_errormsg : 'could not remove the database file'), __FUNCTION__);
			}
			return MDB2_OK;
			}

			// }}}
			// {{{ _getAdvancedFKOptions()

			/**
			* Return the FOREIGN KEY query section dealing with non-standard options
			* as MATCH, INITIALLY DEFERRED, ON UPDATE, ...
			*
			* @param array $definition
			* @return string
			* @access protected
			*/
			function _getAdvancedFKOptions($definition)
			{
			$query = '';
			if (!empty($definition['match'])) {
			$query .= ' MATCH '.$definition['match'];
			}
			if (!empty($definition['onupdate']) && (strtoupper($definition['onupdate']) != 'NO ACTION')) {
			$query .= ' ON UPDATE '.$definition['onupdate'];
			}
			if (!empty($definition['ondelete']) && (strtoupper($definition['ondelete']) != 'NO ACTION')) {
			$query .= ' ON DELETE '.$definition['ondelete'];
			}
			if (!empty($definition['deferrable'])) {
			$query .= ' DEFERRABLE';
			} else {
			$query .= ' NOT DEFERRABLE';
			}
			if (!empty($definition['initiallydeferred'])) {
			$query .= ' INITIALLY DEFERRED';
			} else {
			$query .= ' INITIALLY IMMEDIATE';
			}
			return $query;
			}

			// }}}
			// {{{ _getCreateTableQuery()

			/**
			* Create a basic SQL query for a new table creation
			* @param string $name Name of the database that should be created
			* @param array $fields Associative array that contains the definition of each field of the new table
			* @param array $options An associative array of table options
			* @return mixed string (the SQL query) on success, a MDB2 error on failure
			* @see createTable()
			*/
			function _getCreateTableQuery($name, $fields, $options = array())
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			if (!$name) {
			return $db->raiseError(MDB2_ERROR_CANNOT_CREATE, null, null,
			'no valid table name specified', __FUNCTION__);
			}
			if (empty($fields)) {
			return $db->raiseError(MDB2_ERROR_CANNOT_CREATE, null, null,
			'no fields specified for table "'.$name.'"', __FUNCTION__);
			}
			$query_fields = $this->getFieldDeclarationList($fields);
			if (PEAR::isError($query_fields)) {
			return $query_fields;
			}
			if (!empty($options['primary'])) {
			$query_fields.= ', PRIMARY KEY ('.implode(', ', array_keys($options['primary'])).')';
			}
			if (!empty($options['foreign_keys'])) {
			foreach ($options['foreign_keys'] as $fkname => $fkdef) {
			if (empty($fkdef)) {
			continue;
			}
			$query_fields.= ', CONSTRAINT '.$fkname.' FOREIGN KEY ('.implode(', ', array_keys($fkdef['fields'])).')';
			$query_fields.= ' REFERENCES '.$fkdef['references']['table'].' ('.implode(', ', array_keys($fkdef['references']['fields'])).')';
			$query_fields.= $this->_getAdvancedFKOptions($fkdef);
			}
			}

			$name = $db->quoteIdentifier($name, true);
			$result = 'CREATE ';
			if (!empty($options['temporary'])) {
			$result .= $this->_getTemporaryTableQuery();
			}
			$result .= " TABLE $name ($query_fields)";
			return $result;
			}

			// }}}
			// {{{ createTable()

			/**
			* create a new table
			*
			* @param string $name Name of the database that should be created
			* @param array $fields Associative array that contains the definition of each field of the new table
			* @param array $options An associative array of table options
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createTable($name, $fields, $options = array())
			{
			$result = parent::createTable($name, $fields, $options);
			if (PEAR::isError($result)) {
			return $result;
			}
			// create triggers to enforce FOREIGN KEY constraints
			if (!empty($options['foreign_keys'])) {
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}
			foreach ($options['foreign_keys'] as $fkname => $fkdef) {
			if (empty($fkdef)) {
			continue;
			}
			//set actions to 'RESTRICT' if not set
			$fkdef['onupdate'] = empty($fkdef['onupdate']) ? 'RESTRICT' : strtoupper($fkdef['onupdate']);
			$fkdef['ondelete'] = empty($fkdef['ondelete']) ? 'RESTRICT' : strtoupper($fkdef['ondelete']);

			$trigger_names = array(
			'insert' => $fkname.'_insert_trg',
			'update' => $fkname.'_update_trg',
			'pk_update' => $fkname.'_pk_update_trg',
			'pk_delete' => $fkname.'_pk_delete_trg',
			);

			//create the [insert\|update] triggers on the FK table
			$table_fields = array_keys($fkdef['fields']);
			$referenced_fields = array_keys($fkdef['references']['fields']);
			$query = 'CREATE TRIGGER %s BEFORE %s ON '.$name
			.' FOR EACH ROW BEGIN'
			.' SELECT RAISE(ROLLBACK, \'%s on table "'.$name.'" violates FOREIGN KEY constraint "'.$fkname.'"\')'
			.' WHERE (SELECT ';
			$aliased_fields = array();
			foreach ($referenced_fields as $field) {
			$aliased_fields[] = $fkdef['references']['table'] .'.'.$field .' AS '.$field;
			}
			$query .= implode(',', $aliased_fields)
			.' FROM '.$fkdef['references']['table']
			.' WHERE ';
			$conditions = array();
			for ($i=0; $i<count($table_fields); $i++) {
			$conditions[] = $referenced_fields[$i] .' = NEW.'.$table_fields[$i];
			}
			$query .= implode(' AND ', $conditions).') IS NULL; END;';
			$result = $db->exec(sprintf($query, $trigger_names['insert'], 'INSERT', 'insert'));
			if (PEAR::isError($result)) {
			return $result;
			}

			$result = $db->exec(sprintf($query, $trigger_names['update'], 'UPDATE', 'update'));
			if (PEAR::isError($result)) {
			return $result;
			}

			//create the ON [UPDATE\|DELETE] triggers on the primary table
			$restrict_action = 'SELECT RAISE(ROLLBACK, \'%s on table "'.$name.'" violates FOREIGN KEY constraint "'.$fkname.'"\')'
			.' WHERE (SELECT ';
			$aliased_fields = array();
			foreach ($table_fields as $field) {
			$aliased_fields[] = $name .'.'.$field .' AS '.$field;
			}
			$restrict_action .= implode(',', $aliased_fields)
			.' FROM '.$name
			.' WHERE ';
			$conditions = array();
			$new_values = array();
			$null_values = array();
			for ($i=0; $i<count($table_fields); $i++) {
			$conditions[] = $table_fields[$i] .' = OLD.'.$referenced_fields[$i];
			$new_values[] = $table_fields[$i] .' = NEW.'.$referenced_fields[$i];
			$null_values[] = $table_fields[$i] .' = NULL';
			}
			$restrict_action .= implode(' AND ', $conditions).') IS NOT NULL';

			$cascade_action_update = 'UPDATE '.$name.' SET '.implode(', ', $new_values) .' WHERE '.implode(' AND ', $conditions);
			$cascade_action_delete = 'DELETE FROM '.$name.' WHERE '.implode(' AND ', $conditions);
			$setnull_action = 'UPDATE '.$name.' SET '.implode(', ', $null_values).' WHERE '.implode(' AND ', $conditions);

			if ('SET DEFAULT' == $fkdef['onupdate'] \|\| 'SET DEFAULT' == $fkdef['ondelete']) {
			$db->loadModule('Reverse', null, true);
			$default_values = array();
			foreach ($table_fields as $table_field) {
			$field_definition = $db->reverse->getTableFieldDefinition($name, $field);
			if (PEAR::isError($field_definition)) {
			return $field_definition;
			}
			$default_values[] = $table_field .' = '. $field_definition[0]['default'];
			}
			$setdefault_action = 'UPDATE '.$name.' SET '.implode(', ', $default_values).' WHERE '.implode(' AND ', $conditions);
			}

			$query = 'CREATE TRIGGER %s'
			.' %s ON '.$fkdef['references']['table']
			.' FOR EACH ROW BEGIN ';

			if ('CASCADE' == $fkdef['onupdate']) {
			$sql_update = sprintf($query, $trigger_names['pk_update'], 'AFTER UPDATE', 'update') . $cascade_action_update. '; END;';
			} elseif ('SET NULL' == $fkdef['onupdate']) {
			$sql_update = sprintf($query, $trigger_names['pk_update'], 'BEFORE UPDATE', 'update') . $setnull_action. '; END;';
			} elseif ('SET DEFAULT' == $fkdef['onupdate']) {
			$sql_update = sprintf($query, $trigger_names['pk_update'], 'BEFORE UPDATE', 'update') . $setdefault_action. '; END;';
			} elseif ('NO ACTION' == $fkdef['onupdate']) {
			$sql_update = sprintf($query.$restrict_action, $trigger_names['pk_update'], 'AFTER UPDATE', 'update') . '; END;';
			} else {
			//'RESTRICT'
			$sql_update = sprintf($query.$restrict_action, $trigger_names['pk_update'], 'BEFORE UPDATE', 'update') . '; END;';
			}
			if ('CASCADE' == $fkdef['ondelete']) {
			$sql_delete = sprintf($query, $trigger_names['pk_delete'], 'AFTER DELETE', 'delete') . $cascade_action_delete. '; END;';
			} elseif ('SET NULL' == $fkdef['ondelete']) {
			$sql_delete = sprintf($query, $trigger_names['pk_delete'], 'BEFORE DELETE', 'delete') . $setnull_action. '; END;';
			} elseif ('SET DEFAULT' == $fkdef['ondelete']) {
			$sql_delete = sprintf($query, $trigger_names['pk_delete'], 'BEFORE DELETE', 'delete') . $setdefault_action. '; END;';
			} elseif ('NO ACTION' == $fkdef['ondelete']) {
			$sql_delete = sprintf($query.$restrict_action, $trigger_names['pk_delete'], 'AFTER DELETE', 'delete') . '; END;';
			} else {
			//'RESTRICT'
			$sql_delete = sprintf($query.$restrict_action, $trigger_names['pk_delete'], 'BEFORE DELETE', 'delete') . '; END;';
			}

			if (PEAR::isError($result)) {
			return $result;
			}
			$result = $db->exec($sql_delete);
			if (PEAR::isError($result)) {
			return $result;
			}
			$result = $db->exec($sql_update);
			if (PEAR::isError($result)) {
			return $result;
			}
			}
			}
			if (PEAR::isError($result)) {
			return $result;
			}
			return MDB2_OK;
			}

			// }}}
			// {{{ dropTable()

			/**
			* drop an existing table
			*
			* @param string $name name of the table that should be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropTable($name)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			//delete the triggers associated to existing FK constraints
			$constraints = $this->listTableConstraints($name);
			if (!PEAR::isError($constraints) && !empty($constraints)) {
			$db->loadModule('Reverse', null, true);
			foreach ($constraints as $constraint) {
			$definition = $db->reverse->getTableConstraintDefinition($name, $constraint);
			if (!PEAR::isError($definition) && !empty($definition['foreign'])) {
			$result = $this->_dropFKTriggers($name, $constraint, $definition['references']['table']);
			if (PEAR::isError($result)) {
			return $result;
			}
			}
			}
			}

			$name = $db->quoteIdentifier($name, true);
			return $db->exec("DROP TABLE $name");
			}

			// }}}
			// {{{ vacuum()

			/**
			* Optimize (vacuum) all the tables in the db (or only the specified table)
			* and optionally run ANALYZE.
			*
			* @param string $table table name (all the tables if empty)
			* @param array $options an array with driver-specific options:
			* - timeout [int] (in seconds) [mssql-only]
			* - analyze [boolean] [pgsql and mysql]
			* - full [boolean] [pgsql-only]
			* - freeze [boolean] [pgsql-only]
			*
			* @return mixed MDB2_OK success, a MDB2 error on failure
			* @access public
			*/
			function vacuum($table = null, $options = array())
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = 'VACUUM';
			if (!empty($table)) {
			$query .= ' '.$db->quoteIdentifier($table, true);
			}
			return $db->exec($query);
			}

			// }}}
			// {{{ alterTable()

			/**
			* alter an existing table
			*
			* @param string $name name of the table that is intended to be changed.
			* @param array $changes associative array that contains the details of each type
			* of change that is intended to be performed. The types of
			* changes that are currently supported are defined as follows:
			*
			* name
			*
			* New name for the table.
			*
			* add
			*
			* Associative array with the names of fields to be added as
			* indexes of the array. The value of each entry of the array
			* should be set to another associative array with the properties
			* of the fields to be added. The properties of the fields should
			* be the same as defined by the MDB2 parser.
			*
			*
			* remove
			*
			* Associative array with the names of fields to be removed as indexes
			* of the array. Currently the values assigned to each entry are ignored.
			* An empty array should be used for future compatibility.
			*
			* rename
			*
			* Associative array with the names of fields to be renamed as indexes
			* of the array. The value of each entry of the array should be set to
			* another associative array with the entry named name with the new
			* field name and the entry named Declaration that is expected to contain
			* the portion of the field declaration already in DBMS specific SQL code
			* as it is used in the CREATE TABLE statement.
			*
			* change
			*
			* Associative array with the names of the fields to be changed as indexes
			* of the array. Keep in mind that if it is intended to change either the
			* name of a field and any other properties, the change array entries
			* should have the new names of the fields as array indexes.
			*
			* The value of each entry of the array should be set to another associative
			* array with the properties of the fields to that are meant to be changed as
			* array entries. These entries should be assigned to the new values of the
			* respective properties. The properties of the fields should be the same
			* as defined by the MDB2 parser.
			*
			* Example
			* array(
			* 'name' => 'userlist',
			* 'add' => array(
			* 'quota' => array(
			* 'type' => 'integer',
			* 'unsigned' => 1
			* )
			* ),
			* 'remove' => array(
			* 'file_limit' => array(),
			* 'time_limit' => array()
			* ),
			* 'change' => array(
			* 'name' => array(
			* 'length' => '20',
			* 'definition' => array(
			* 'type' => 'text',
			* 'length' => 20,
			* ),
			* )
			* ),
			* 'rename' => array(
			* 'sex' => array(
			* 'name' => 'gender',
			* 'definition' => array(
			* 'type' => 'text',
			* 'length' => 1,
			* 'default' => 'M',
			* ),
			* )
			* )
			* )
			*
			* @param boolean $check indicates whether the function should just check if the DBMS driver
			* can perform the requested table alterations if the value is true or
			* actually perform them otherwise.
			* @access public
			*
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			*/
			function alterTable($name, $changes, $check, $options = array())
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			foreach ($changes as $change_name => $change) {
			switch ($change_name) {
			case 'add':
			case 'remove':
			case 'change':
			case 'name':
			case 'rename':
			break;
			default:
			return $db->raiseError(MDB2_ERROR_CANNOT_ALTER, null, null,
			'change type "'.$change_name.'" not yet supported', __FUNCTION__);
			}
			}

			if ($check) {
			return MDB2_OK;
			}

			$db->loadModule('Reverse', null, true);

			// actually sqlite 2.x supports no ALTER TABLE at all .. so we emulate it
			$fields = $db->manager->listTableFields($name);
			if (PEAR::isError($fields)) {
			return $fields;
			}

			$fields = array_flip($fields);
			foreach ($fields as $field => $value) {
			$definition = $db->reverse->getTableFieldDefinition($name, $field);
			if (PEAR::isError($definition)) {
			return $definition;
			}
			$fields[$field] = $definition[0];
			}

			$indexes = $db->manager->listTableIndexes($name);
			if (PEAR::isError($indexes)) {
			return $indexes;
			}

			$indexes = array_flip($indexes);
			foreach ($indexes as $index => $value) {
			$definition = $db->reverse->getTableIndexDefinition($name, $index);
			if (PEAR::isError($definition)) {
			return $definition;
			}
			$indexes[$index] = $definition;
			}

			$constraints = $db->manager->listTableConstraints($name);
			if (PEAR::isError($constraints)) {
			return $constraints;
			}

			if (!array_key_exists('foreign_keys', $options)) {
			$options['foreign_keys'] = array();
			}
			$constraints = array_flip($constraints);
			foreach ($constraints as $constraint => $value) {
			if (!empty($definition['primary'])) {
			if (!array_key_exists('primary', $options)) {
			$options['primary'] = $definition['fields'];
			//remove from the $constraint array, it's already handled by createTable()
			unset($constraints[$constraint]);
			}
			} else {
			$c_definition = $db->reverse->getTableConstraintDefinition($name, $constraint);
			if (PEAR::isError($c_definition)) {
			return $c_definition;
			}
			if (!empty($c_definition['foreign'])) {
			if (!array_key_exists($constraint, $options['foreign_keys'])) {
			$options['foreign_keys'][$constraint] = $c_definition;
			}
			//remove from the $constraint array, it's already handled by createTable()
			unset($constraints[$constraint]);
			} else {
			$constraints[$constraint] = $c_definition;
			}
			}
			}

			$name_new = $name;
			$create_order = $select_fields = array_keys($fields);
			foreach ($changes as $change_name => $change) {
			switch ($change_name) {
			case 'add':
			foreach ($change as $field_name => $field) {
			$fields[$field_name] = $field;
			$create_order[] = $field_name;
			}
			break;
			case 'remove':
			foreach ($change as $field_name => $field) {
			unset($fields[$field_name]);
			$select_fields = array_diff($select_fields, array($field_name));
			$create_order = array_diff($create_order, array($field_name));
			}
			break;
			case 'change':
			foreach ($change as $field_name => $field) {
			$fields[$field_name] = $field['definition'];
			}
			break;
			case 'name':
			$name_new = $change;
			break;
			case 'rename':
			foreach ($change as $field_name => $field) {
			unset($fields[$field_name]);
			$fields[$field['name']] = $field['definition'];
			$create_order[array_search($field_name, $create_order)] = $field['name'];
			}
			break;
			default:
			return $db->raiseError(MDB2_ERROR_CANNOT_ALTER, null, null,
			'change type "'.$change_name.'" not yet supported', __FUNCTION__);
			}
			}

			$data = null;
			if (!empty($select_fields)) {
			$query = 'SELECT '.implode(', ', $select_fields).' FROM '.$db->quoteIdentifier($name, true);
			$data = $db->queryAll($query, null, MDB2_FETCHMODE_ORDERED);
			}

			$result = $this->dropTable($name);
			if (PEAR::isError($result)) {
			return $result;
			}

			$result = $this->createTable($name_new, $fields, $options);
			if (PEAR::isError($result)) {
			return $result;
			}

			foreach ($indexes as $index => $definition) {
			$this->createIndex($name_new, $index, $definition);
			}

			foreach ($constraints as $constraint => $definition) {
			$this->createConstraint($name_new, $constraint, $definition);
			}

			if (!empty($select_fields) && !empty($data)) {
			$query = 'INSERT INTO '.$db->quoteIdentifier($name_new, true);
			$query.= '('.implode(', ', array_slice(array_keys($fields), 0, count($select_fields))).')';
			$query.=' VALUES (?'.str_repeat(', ?', (count($select_fields) - 1)).')';
			$stmt =& $db->prepare($query, null, MDB2_PREPARE_MANIP);
			if (PEAR::isError($stmt)) {
			return $stmt;
			}
			foreach ($data as $row) {
			$result = $stmt->execute($row);
			if (PEAR::isError($result)) {
			return $result;
			}
			}
			}
			return MDB2_OK;
			}

			// }}}
			// {{{ listDatabases()

			/**
			* list all databases
			*
			* @return mixed array of database names on success, a MDB2 error on failure
			* @access public
			*/
			function listDatabases()
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			return $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
			'list databases is not supported', __FUNCTION__);
			}

			// }}}
			// {{{ listUsers()

			/**
			* list all users
			*
			* @return mixed array of user names on success, a MDB2 error on failure
			* @access public
			*/
			function listUsers()
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			return $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
			'list databases is not supported', __FUNCTION__);
			}

			// }}}
			// {{{ listViews()

			/**
			* list all views in the current database
			*
			* @return mixed array of view names on success, a MDB2 error on failure
			* @access public
			*/
			function listViews()
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = "SELECT name FROM sqlite_master WHERE type='view' AND sql NOT NULL";
			$result = $db->queryCol($query);
			if (PEAR::isError($result)) {
			return $result;
			}
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_map(($db->options['field_case'] == CASE_LOWER ? 'strtolower' : 'strtoupper'), $result);
			}
			return $result;
			}

			// }}}
			// {{{ listTableViews()

			/**
			* list the views in the database that reference a given table
			*
			* @param string table for which all referenced views should be found
			* @return mixed array of view names on success, a MDB2 error on failure
			* @access public
			*/
			function listTableViews($table)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = "SELECT name, sql FROM sqlite_master WHERE type='view' AND sql NOT NULL";
			$views = $db->queryAll($query, array('text', 'text'), MDB2_FETCHMODE_ASSOC);
			if (PEAR::isError($views)) {
			return $views;
			}
			$result = array();
			foreach ($views as $row) {
			if (preg_match("/^create view .* \bfrom\b\s+\b{$table}\b /i", $row['sql'])) {
			if (!empty($row['name'])) {
			$result[$row['name']] = true;
			}
			}
			}

			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_change_key_case($result, $db->options['field_case']);
			}
			return array_keys($result);
			}

			// }}}
			// {{{ listTables()

			/**
			* list all tables in the current database
			*
			* @return mixed array of table names on success, a MDB2 error on failure
			* @access public
			*/
			function listTables()
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = "SELECT name FROM sqlite_master WHERE type='table' AND sql NOT NULL ORDER BY name";
			$table_names = $db->queryCol($query);
			if (PEAR::isError($table_names)) {
			return $table_names;
			}
			$result = array();
			foreach ($table_names as $table_name) {
			if (!$this->_fixSequenceName($table_name, true)) {
			$result[] = $table_name;
			}
			}
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_map(($db->options['field_case'] == CASE_LOWER ? 'strtolower' : 'strtoupper'), $result);
			}
			return $result;
			}

			// }}}
			// {{{ listTableFields()

			/**
			* list all fields in a table in the current database
			*
			* @param string $table name of table that should be used in method
			* @return mixed array of field names on success, a MDB2 error on failure
			* @access public
			*/
			function listTableFields($table)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$result = $db->loadModule('Reverse', null, true);
			if (PEAR::isError($result)) {
			return $result;
			}
			$query = "SELECT sql FROM sqlite_master WHERE type='table' AND ";
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$query.= 'LOWER(name)='.$db->quote(strtolower($table), 'text');
			} else {
			$query.= 'name='.$db->quote($table, 'text');
			}
			$sql = $db->queryOne($query);
			if (PEAR::isError($sql)) {
			return $sql;
			}
			$columns = $db->reverse->_getTableColumns($sql);
			$fields = array();
			foreach ($columns as $column) {
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			if ($db->options['field_case'] == CASE_LOWER) {
			$column['name'] = strtolower($column['name']);
			} else {
			$column['name'] = strtoupper($column['name']);
			}
			} else {
			$column = array_change_key_case($column, $db->options['field_case']);
			}
			$fields[] = $column['name'];
			}
			return $fields;
			}

			// }}}
			// {{{ listTableTriggers()

			/**
			* list all triggers in the database that reference a given table
			*
			* @param string table for which all referenced triggers should be found
			* @return mixed array of trigger names on success, a MDB2 error on failure
			* @access public
			*/
			function listTableTriggers($table = null)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = "SELECT name FROM sqlite_master WHERE type='trigger' AND sql NOT NULL";
			if (!is_null($table)) {
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$query.= ' AND LOWER(tbl_name)='.$db->quote(strtolower($table), 'text');
			} else {
			$query.= ' AND tbl_name='.$db->quote($table, 'text');
			}
			}
			$result = $db->queryCol($query);
			if (PEAR::isError($result)) {
			return $result;
			}
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_map(($db->options['field_case'] == CASE_LOWER ? 'strtolower' : 'strtoupper'), $result);
			}
			return $result;
			}

			// }}}
			// {{{ createIndex()

			/**
			* Get the stucture of a field into an array
			*
			* @param string $table name of the table on which the index is to be created
			* @param string $name name of the index to be created
			* @param array $definition associative array that defines properties of the index to be created.
			* Currently, only one property named FIELDS is supported. This property
			* is also an associative with the names of the index fields as array
			* indexes. Each entry of this array is set to another type of associative
			* array that specifies properties of the index that are specific to
			* each field.
			*
			* Currently, only the sorting property is supported. It should be used
			* to define the sorting direction of the index. It may be set to either
			* ascending or descending.
			*
			* Not all DBMS support index sorting direction configuration. The DBMS
			* drivers of those that do not support it ignore this property. Use the
			* function support() to determine whether the DBMS driver can manage indexes.

			* Example
			* array(
			* 'fields' => array(
			* 'user_name' => array(
			* 'sorting' => 'ascending'
			* ),
			* 'last_login' => array()
			* )
			* )
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createIndex($table, $name, $definition)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$table = $db->quoteIdentifier($table, true);
			$name = $db->getIndexName($name);
			$query = "CREATE INDEX $name ON $table";
			$fields = array();
			foreach ($definition['fields'] as $field_name => $field) {
			$field_string = $field_name;
			if (!empty($field['sorting'])) {
			switch ($field['sorting']) {
			case 'ascending':
			$field_string.= ' ASC';
			break;
			case 'descending':
			$field_string.= ' DESC';
			break;
			}
			}
			$fields[] = $field_string;
			}
			$query .= ' ('.implode(', ', $fields) . ')';
			return $db->exec($query);
			}

			// }}}
			// {{{ dropIndex()

			/**
			* drop existing index
			*
			* @param string $table name of table that should be used in method
			* @param string $name name of the index to be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropIndex($table, $name)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$name = $db->getIndexName($name);
			return $db->exec("DROP INDEX $name");
			}

			// }}}
			// {{{ listTableIndexes()

			/**
			* list all indexes in a table
			*
			* @param string $table name of table that should be used in method
			* @return mixed array of index names on success, a MDB2 error on failure
			* @access public
			*/
			function listTableIndexes($table)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$table = $db->quote($table, 'text');
			$query = "SELECT sql FROM sqlite_master WHERE type='index' AND ";
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$query.= 'LOWER(tbl_name)='.strtolower($table);
			} else {
			$query.= "tbl_name=$table";
			}
			$query.= " AND sql NOT NULL ORDER BY name";
			$indexes = $db->queryCol($query, 'text');
			if (PEAR::isError($indexes)) {
			return $indexes;
			}

			$result = array();
			foreach ($indexes as $sql) {
			if (preg_match("/^create index ([^ ]+) on /i", $sql, $tmp)) {
			$index = $this->_fixIndexName($tmp[1]);
			if (!empty($index)) {
			$result[$index] = true;
			}
			}
			}

			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_change_key_case($result, $db->options['field_case']);
			}
			return array_keys($result);
			}

			// }}}
			// {{{ createConstraint()

			/**
			* create a constraint on a table
			*
			* @param string $table name of the table on which the constraint is to be created
			* @param string $name name of the constraint to be created
			* @param array $definition associative array that defines properties of the constraint to be created.
			* Currently, only one property named FIELDS is supported. This property
			* is also an associative with the names of the constraint fields as array
			* constraints. Each entry of this array is set to another type of associative
			* array that specifies properties of the constraint that are specific to
			* each field.
			*
			* Example
			* array(
			* 'fields' => array(
			* 'user_name' => array(),
			* 'last_login' => array()
			* )
			* )
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createConstraint($table, $name, $definition)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			if (!empty($definition['primary'])) {
			return $db->manager->alterTable($table, array(), false, array('primary' => $definition['fields']));
			}

			if (!empty($definition['foreign'])) {
			return $db->manager->alterTable($table, array(), false, array('foreign_keys' => array($name => $definition)));
			}

			$table = $db->quoteIdentifier($table, true);
			$name = $db->getIndexName($name);
			$query = "CREATE UNIQUE INDEX $name ON $table";
			$fields = array();
			foreach ($definition['fields'] as $field_name => $field) {
			$field_string = $field_name;
			if (!empty($field['sorting'])) {
			switch ($field['sorting']) {
			case 'ascending':
			$field_string.= ' ASC';
			break;
			case 'descending':
			$field_string.= ' DESC';
			break;
			}
			}
			$fields[] = $field_string;
			}
			$query .= ' ('.implode(', ', $fields) . ')';
			return $db->exec($query);
			}

			// }}}
			// {{{ dropConstraint()

			/**
			* drop existing constraint
			*
			* @param string $table name of table that should be used in method
			* @param string $name name of the constraint to be dropped
			* @param string $primary hint if the constraint is primary
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropConstraint($table, $name, $primary = false)
			{
			if ($primary \|\| $name == 'PRIMARY') {
			return $this->alterTable($table, array(), false, array('primary' => null));
			}

			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			//is it a FK constraint? If so, also delete the associated triggers
			$db->loadModule('Reverse', null, true);
			$definition = $db->reverse->getTableConstraintDefinition($table, $name);
			if (!PEAR::isError($definition) && !empty($definition['foreign'])) {
			//first drop the FK enforcing triggers
			$result = $this->_dropFKTriggers($table, $name, $definition['references']['table']);
			if (PEAR::isError($result)) {
			return $result;
			}
			//then drop the constraint itself
			return $this->alterTable($table, array(), false, array('foreign_keys' => array($name => null)));
			}

			$name = $db->getIndexName($name);
			return $db->exec("DROP INDEX $name");
			}

			// }}}
			// {{{ _dropFKTriggers()

			/**
			* Drop the triggers created to enforce the FOREIGN KEY constraint on the table
			*
			* @param string $table table name
			* @param string $fkname FOREIGN KEY constraint name
			* @param string $referenced_table referenced table name
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access private
			*/
			function _dropFKTriggers($table, $fkname, $referenced_table)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$triggers = $this->listTableTriggers($table);
			$triggers2 = $this->listTableTriggers($referenced_table);
			if (!PEAR::isError($triggers2) && !PEAR::isError($triggers)) {
			$triggers = array_merge($triggers, $triggers2);
			$pattern = '/^'.$fkname.'(_pk)?_(insert\|update\|delete)_trg$/i';
			foreach ($triggers as $trigger) {
			if (preg_match($pattern, $trigger)) {
			$result = $db->exec('DROP TRIGGER '.$trigger);
			if (PEAR::isError($result)) {
			return $result;
			}
			}
			}
			}
			return MDB2_OK;
			}

			// }]]
			// {{{ listTableConstraints()

			/**
			* list all constraints in a table
			*
			* @param string $table name of table that should be used in method
			* @return mixed array of constraint names on success, a MDB2 error on failure
			* @access public
			*/
			function listTableConstraints($table)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$table = $db->quote($table, 'text');
			$query = "SELECT sql FROM sqlite_master WHERE type='index' AND ";
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$query.= 'LOWER(tbl_name)='.strtolower($table);
			} else {
			$query.= "tbl_name=$table";
			}
			$query.= " AND sql NOT NULL ORDER BY name";
			$indexes = $db->queryCol($query, 'text');
			if (PEAR::isError($indexes)) {
			return $indexes;
			}

			$result = array();
			foreach ($indexes as $sql) {
			if (preg_match("/^create unique index ([^ ]+) on /i", $sql, $tmp)) {
			$index = $this->_fixIndexName($tmp[1]);
			if (!empty($index)) {
			$result[$index] = true;
			}
			}
			}

			// also search in table definition for PRIMARY KEYs...
			$query = "SELECT sql FROM sqlite_master WHERE type='table' AND ";
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$query.= 'LOWER(name)='.strtolower($table);
			} else {
			$query.= "name=$table";
			}
			$query.= " AND sql NOT NULL ORDER BY name";
			$table_def = $db->queryOne($query, 'text');
			if (PEAR::isError($table_def)) {
			return $table_def;
			}
			if (preg_match("/\bPRIMARY\s+KEY\b/i", $table_def, $tmp)) {
			$result['primary'] = true;
			}

			// ...and for FOREIGN KEYs
			if (preg_match_all("/\bCONSTRAINT\b\s+([^\s]+)\s+\bFOREIGN\s+KEY/imsx", $table_def, $tmp)) {
			foreach ($tmp[1] as $fk) {
			$result[$fk] = true;
			}
			}

			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_change_key_case($result, $db->options['field_case']);
			}
			return array_keys($result);
			}

			// }}}
			// {{{ createSequence()

			/**
			* create sequence
			*
			* @param string $seq_name name of the sequence to be created
			* @param string $start start value of the sequence; default is 1
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function createSequence($seq_name, $start = 1)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$sequence_name = $db->quoteIdentifier($db->getSequenceName($seq_name), true);
			$seqcol_name = $db->quoteIdentifier($db->options['seqcol_name'], true);
			$query = "CREATE TABLE $sequence_name ($seqcol_name INTEGER PRIMARY KEY DEFAULT 0 NOT NULL)";
			$res = $db->exec($query);
			if (PEAR::isError($res)) {
			return $res;
			}
			if ($start == 1) {
			return MDB2_OK;
			}
			$res = $db->exec("INSERT INTO $sequence_name ($seqcol_name) VALUES (".($start-1).')');
			if (!PEAR::isError($res)) {
			return MDB2_OK;
			}
			// Handle error
			$result = $db->exec("DROP TABLE $sequence_name");
			if (PEAR::isError($result)) {
			return $db->raiseError($result, null, null,
			'could not drop inconsistent sequence table', __FUNCTION__);
			}
			return $db->raiseError($res, null, null,
			'could not create sequence table', __FUNCTION__);
			}

			// }}}
			// {{{ dropSequence()

			/**
			* drop existing sequence
			*
			* @param string $seq_name name of the sequence to be dropped
			* @return mixed MDB2_OK on success, a MDB2 error on failure
			* @access public
			*/
			function dropSequence($seq_name)
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$sequence_name = $db->quoteIdentifier($db->getSequenceName($seq_name), true);
			return $db->exec("DROP TABLE $sequence_name");
			}

			// }}}
			// {{{ listSequences()

			/**
			* list all sequences in the current database
			*
			* @return mixed array of sequence names on success, a MDB2 error on failure
			* @access public
			*/
			function listSequences()
			{
			$db =& $this->getDBInstance();
			if (PEAR::isError($db)) {
			return $db;
			}

			$query = "SELECT name FROM sqlite_master WHERE type='table' AND sql NOT NULL ORDER BY name";
			$table_names = $db->queryCol($query);
			if (PEAR::isError($table_names)) {
			return $table_names;
			}
			$result = array();
			foreach ($table_names as $table_name) {
			if ($sqn = $this->_fixSequenceName($table_name, true)) {
			$result[] = $sqn;
			}
			}
			if ($db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$result = array_map(($db->options['field_case'] == CASE_LOWER ? 'strtolower' : 'strtoupper'), $result);
			}
			return $result;
			}

			// }}}
			}
			?>