githubFork/roundcubemail.git

			@@ -4,8 +4,8 @@
			+-----------------------------------------------------------------------+
			\| program/include/rcube_mdb2.php \|
			\| \|
			\| This file is part of the RoundCube Webmail client \|
			\| Copyright (C) 2005-2009, RoundCube Dev. - Switzerland \|
			\| This file is part of the Roundcube Webmail client \|
			\| Copyright (C) 2005-2009, Roundcube Dev. - Switzerland \|
			\| Licensed under the GNU GPL \|
			\| \|
			\| PURPOSE: \|
			@@ -30,679 +30,706 @@
			* @author David Saez Padros <david@ols.es>
			* @author Thomas Bruederli <roundcube@gmail.com>
			* @author Lukas Kahwe Smith <smith@pooteeweet.org>
			* @version 1.16
			* @version 1.17
			* @link http://pear.php.net/package/MDB2
			*/
			class rcube_mdb2
			{
			var $db_dsnw; // DSN for write operations
			var $db_dsnr; // DSN for read operations
			var $db_connected = false; // Already connected ?
			var $db_mode = ''; // Connection mode
			var $db_handle = 0; // Connection handle
			var $db_error = false;
			var $db_error_msg = '';
			var $debug_mode = false;
			{
			var $db_dsnw; // DSN for write operations
			var $db_dsnr; // DSN for read operations
			var $db_connected = false; // Already connected ?
			var $db_mode = ''; // Connection mode
			var $db_handle = 0; // Connection handle
			var $db_error = false;
			var $db_error_msg = '';

			var $a_query_results = array('dummy');
			var $last_res_id = 0;
			private $debug_mode = false;
			private $a_query_results = array('dummy');
			private $last_res_id = 0;
			private $tables;


			/**
			* Object constructor
			*
			* @param string DSN for read/write operations
			* @param string Optional DSN for read only operations
			*/
			function __construct($db_dsnw, $db_dsnr='', $pconn=false)
			/**
			* Object constructor
			*
			* @param string DSN for read/write operations
			* @param string Optional DSN for read only operations
			*/
			function __construct($db_dsnw, $db_dsnr='', $pconn=false)
			{
			if ($db_dsnr=='')
			$db_dsnr=$db_dsnw;
			if ($db_dsnr == '')
			$db_dsnr = $db_dsnw;

			$this->db_dsnw = $db_dsnw;
			$this->db_dsnr = $db_dsnr;
			$this->db_pconn = $pconn;

			$dsn_array = MDB2::parseDSN($db_dsnw);
			$this->db_provider = $dsn_array['phptype'];
			$this->db_dsnw = $db_dsnw;
			$this->db_dsnr = $db_dsnr;
			$this->db_pconn = $pconn;

			$dsn_array = MDB2::parseDSN($db_dsnw);
			$this->db_provider = $dsn_array['phptype'];
			}


			/**
			* Connect to specific database
			*
			* @param string DSN for DB connections
			* @return object PEAR database handle
			* @access private
			*/
			function dsn_connect($dsn)
			/**
			* Connect to specific database
			*
			* @param string DSN for DB connections
			* @return object PEAR database handle
			* @access private
			*/
			private function dsn_connect($dsn)
			{
			// Use persistent connections if available
			$db_options = array(
			'persistent' => $this->db_pconn,
			'emulate_prepared' => $this->debug_mode,
			'debug' => $this->debug_mode,
			'debug_handler' => 'mdb2_debug_handler',
			'portability' => MDB2_PORTABILITY_ALL ^ MDB2_PORTABILITY_EMPTY_TO_NULL);
			// Use persistent connections if available
			$db_options = array(
			'persistent' => $this->db_pconn,
			'emulate_prepared' => $this->debug_mode,
			'debug' => $this->debug_mode,
			'debug_handler' => 'mdb2_debug_handler',
			'portability' => MDB2_PORTABILITY_ALL ^ MDB2_PORTABILITY_EMPTY_TO_NULL);

			if ($this->db_provider == 'pgsql') {
			$db_options['disable_smart_seqname'] = true;
			$db_options['seqname_format'] = '%s';
			}

			$dbh = MDB2::connect($dsn, $db_options);

			if (MDB2::isError($dbh))
			{
			$this->db_error = TRUE;
			$this->db_error_msg = $dbh->getMessage();

			raise_error(array('code' => 500, 'type' => 'db', 'line' => __LINE__,
			'file' => __FILE__, 'message' => $dbh->getUserInfo()), TRUE, FALSE);
			}
			else if ($this->db_provider=='sqlite')
			{
			$dsn_array = MDB2::parseDSN($dsn);
			if (!filesize($dsn_array['database']) && !empty($this->sqlite_initials))
			$this->_sqlite_create_database($dbh, $this->sqlite_initials);
			}
			else
			$dbh->setCharset('utf8');

			return $dbh;
			}


			/**
			* Connect to appropiate databse
			* depending on the operation
			*
			* @param string Connection mode (r\|w)
			* @access public
			*/
			function db_connect($mode)
			{
			$this->db_mode = $mode;

			// Already connected
			if ($this->db_connected)
			{
			// no replication, current connection is ok
			if ($this->db_dsnw==$this->db_dsnr)
			return;

			// connected to master, current connection is ok
			if ($this->db_mode=='w')
			return;

			// Same mode, current connection is ok
			if ($this->db_mode==$mode)
			return;
			}

			if ($mode=='r')
			$dsn = $this->db_dsnr;
			else
			$dsn = $this->db_dsnw;

			$this->db_handle = $this->dsn_connect($dsn);
			$this->db_connected = true;
			}


			/**
			* Activate/deactivate debug mode
			*
			* @param boolean True if SQL queries should be logged
			*/
			function set_debug($dbg = true)
			{
			$this->debug_mode = $dbg;
			if ($this->db_connected)
			{
			$this->db_handle->setOption('debug', $dbg);
			$this->db_handle->setOption('emulate_prepared', $dbg);
			}
			}


			/**
			* Getter for error state
			*
			* @param boolean True on error
			*/
			function is_error()
			{
			return $this->db_error ? $this->db_error_msg : FALSE;
			}


			/**
			* Connection state checker
			*
			* @param boolean True if in connected state
			*/
			function is_connected()
			{
			return PEAR::isError($this->db_handle) ? false : true;
			}


			/**
			* Execute a SQL query
			*
			* @param string SQL query to execute
			* @param mixed Values to be inserted in query
			* @return number Query handle identifier
			* @access public
			*/
			function query()
			{
			if (!$this->is_connected())
			return NULL;

			$params = func_get_args();
			$query = array_shift($params);

			return $this->_query($query, 0, 0, $params);
			}


			/**
			* Execute a SQL query with limits
			*
			* @param string SQL query to execute
			* @param number Offset for LIMIT statement
			* @param number Number of rows for LIMIT statement
			* @param mixed Values to be inserted in query
			* @return number Query handle identifier
			* @access public
			*/
			function limitquery()
			{
			$params = func_get_args();
			$query = array_shift($params);
			$offset = array_shift($params);
			$numrows = array_shift($params);

			return $this->_query($query, $offset, $numrows, $params);
			}


			/**
			* Execute a SQL query with limits
			*
			* @param string SQL query to execute
			* @param number Offset for LIMIT statement
			* @param number Number of rows for LIMIT statement
			* @param array Values to be inserted in query
			* @return number Query handle identifier
			* @access private
			*/
			function _query($query, $offset, $numrows, $params)
			{
			// Read or write ?
			if (strtolower(substr(trim($query),0,6))=='select')
			$mode='r';
			else
			$mode='w';

			$this->db_connect($mode);

			if ($this->db_provider == 'sqlite')
			$this->_sqlite_prepare();

			if ($numrows \|\| $offset)
			$result = $this->db_handle->setLimit($numrows,$offset);

			if (empty($params))
			$result = $this->db_handle->query($query);
			else
			{
			$params = (array)$params;
			$q = $this->db_handle->prepare($query);
			if ($this->db_handle->isError($q))
			{
			$this->db_error = TRUE;
			$this->db_error_msg = $q->userinfo;

			raise_error(array('code' => 500, 'type' => 'db', 'line' => __LINE__, 'file' => __FILE__,
			'message' => $this->db_error_msg), TRUE, TRUE);
			if ($this->db_provider == 'pgsql') {
			$db_options['disable_smart_seqname'] = true;
			$db_options['seqname_format'] = '%s';
			}
			else
			{
			$result = $q->execute($params);
			$q->free();

			$dbh = MDB2::connect($dsn, $db_options);

			if (MDB2::isError($dbh)) {
			$this->db_error = true;
			$this->db_error_msg = $dbh->getMessage();

			raise_error(array('code' => 500, 'type' => 'db',
			'line' => __LINE__, 'file' => __FILE__,
			'message' => $dbh->getUserInfo()), true, false);
			}
			}
			else if ($this->db_provider == 'sqlite') {
			$dsn_array = MDB2::parseDSN($dsn);
			if (!filesize($dsn_array['database']) && !empty($this->sqlite_initials))
			$this->_sqlite_create_database($dbh, $this->sqlite_initials);
			}
			else if ($this->db_provider!='mssql' && $this->db_provider!='sqlsrv')
			$dbh->setCharset('utf8');

			// add result, even if it's an error
			return $this->_add_result($result);
			return $dbh;
			}


			/**
			* Get number of rows for a SQL query
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Number of rows or FALSE on failure
			* @access public
			*/
			function num_rows($res_id=NULL)
			/**
			* Connect to appropiate database depending on the operation
			*
			* @param string Connection mode (r\|w)
			* @access public
			*/
			function db_connect($mode)
			{
			if (!$this->db_handle)
			return FALSE;
			// Already connected
			if ($this->db_connected) {
			// no replication, current connection is ok for read and write
			if (empty($this->db_dsnr) \|\| $this->db_dsnw == $this->db_dsnr) {
			$this->db_mode = 'w';
			return;
			}

			if ($result = $this->_get_result($res_id))
			return $result->numRows();
			else
			return FALSE;
			// connected to read-write db, current connection is ok
			if ($this->db_mode == 'w')
			return;

			// Same mode, current connection is ok
			if ($this->db_mode == $mode)
			return;
			}

			$dsn = ($mode == 'r') ? $this->db_dsnr : $this->db_dsnw;

			$this->db_handle = $this->dsn_connect($dsn);
			$this->db_connected = !PEAR::isError($this->db_handle);
			$this->db_mode = $mode;
			}


			/**
			* Get number of affected rows for the last query
			*
			* @param number Optional query handle identifier
			* @return mixed Number of rows or FALSE on failure
			* @access public
			*/
			function affected_rows($res_id = null)
			/**
			* Activate/deactivate debug mode
			*
			* @param boolean True if SQL queries should be logged
			* @access public
			*/
			function set_debug($dbg = true)
			{
			if (!$this->db_handle)
			return FALSE;

			return (int) $this->_get_result($res_id);
			$this->debug_mode = $dbg;
			if ($this->db_connected) {
			$this->db_handle->setOption('debug', $dbg);
			$this->db_handle->setOption('emulate_prepared', $dbg);
			}
			}


			/**
			* Get last inserted record ID
			* For Postgres databases, a sequence name is required
			*
			* @param string Sequence name for increment
			* @return mixed ID or FALSE on failure
			* @access public
			*/
			function insert_id($sequence = '')
			/**
			* Getter for error state
			*
			* @param boolean True on error
			* @access public
			*/
			function is_error()
			{
			if (!$this->db_handle \|\| $this->db_mode=='r')
			return FALSE;

			return $this->db_handle->lastInsertID($sequence);
			return $this->db_error ? $this->db_error_msg : false;
			}


			/**
			* Get an associative array for one row
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Array with col values or FALSE on failure
			* @access public
			*/
			function fetch_assoc($res_id=NULL)
			/**
			* Connection state checker
			*
			* @param boolean True if in connected state
			* @access public
			*/
			function is_connected()
			{
			$result = $this->_get_result($res_id);
			return $this->_fetch_row($result, MDB2_FETCHMODE_ASSOC);
			return PEAR::isError($this->db_handle) ? false : $this->db_connected;
			}


			/**
			* Get an index array for one row
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Array with col values or FALSE on failure
			* @access public
			*/
			function fetch_array($res_id=NULL)
			/**
			* Execute a SQL query
			*
			* @param string SQL query to execute
			* @param mixed Values to be inserted in query
			* @return number Query handle identifier
			* @access public
			*/
			function query()
			{
			$result = $this->_get_result($res_id);
			return $this->_fetch_row($result, MDB2_FETCHMODE_ORDERED);
			$params = func_get_args();
			$query = array_shift($params);

			return $this->_query($query, 0, 0, $params);
			}


			/**
			* Get col values for a result row
			*
			* @param object Query result handle
			* @param number Fetch mode identifier
			* @return mixed Array with col values or FALSE on failure
			* @access private
			*/
			function _fetch_row($result, $mode)
			/**
			* Execute a SQL query with limits
			*
			* @param string SQL query to execute
			* @param number Offset for LIMIT statement
			* @param number Number of rows for LIMIT statement
			* @param mixed Values to be inserted in query
			* @return number Query handle identifier
			* @access public
			*/
			function limitquery()
			{
			if ($result === FALSE \|\| PEAR::isError($result) \|\| !$this->is_connected())
			return FALSE;
			$params = func_get_args();
			$query = array_shift($params);
			$offset = array_shift($params);
			$numrows = array_shift($params);

			return $result->fetchRow($mode);
			return $this->_query($query, $offset, $numrows, $params);
			}


			/**
			* Formats input so it can be safely used in a query
			*
			* @param mixed Value to quote
			* @return string Quoted/converted string for use in query
			* @access public
			*/
			function quote($input, $type = null)
			/**
			* Execute a SQL query with limits
			*
			* @param string SQL query to execute
			* @param number Offset for LIMIT statement
			* @param number Number of rows for LIMIT statement
			* @param array Values to be inserted in query
			* @return number Query handle identifier
			* @access private
			*/
			private function _query($query, $offset, $numrows, $params)
			{
			// create DB handle if not available
			if (!$this->db_handle)
			$this->db_connect('r');
			// Read or write ?
			$mode = (strtolower(substr(trim($query),0,6)) == 'select') ? 'r' : 'w';

			// escape pear identifier chars
			$rep_chars = array('?' => '\?',
			'!' => '\!',
			'&' => '\&');
			$this->db_connect($mode);

			return $this->db_handle->quote($input, $type);
			// check connection before proceeding
			if (!$this->is_connected())
			return null;

			if ($this->db_provider == 'sqlite')
			$this->_sqlite_prepare();

			if ($numrows \|\| $offset)
			$result = $this->db_handle->setLimit($numrows,$offset);

			if (empty($params))
			$result = $mode == 'r' ? $this->db_handle->query($query) : $this->db_handle->exec($query);
			else {
			$params = (array)$params;
			$q = $this->db_handle->prepare($query, null, $mode=='w' ? MDB2_PREPARE_MANIP : null);
			if ($this->db_handle->isError($q)) {
			$this->db_error = true;
			$this->db_error_msg = $q->userinfo;

			raise_error(array('code' => 500, 'type' => 'db',
			'line' => __LINE__, 'file' => __FILE__,
			'message' => $this->db_error_msg), true, true);
			}
			else {
			$result = $q->execute($params);
			$q->free();
			}
			}

			// add result, even if it's an error
			return $this->_add_result($result);
			}


			/**
			* Quotes a string so it can be safely used as a table or column name
			*
			* @param string Value to quote
			* @return string Quoted string for use in query
			* @deprecated Replaced by rcube_MDB2::quote_identifier
			* @see rcube_mdb2::quote_identifier
			* @access public
			*/
			function quoteIdentifier($str)
			/**
			* Get number of rows for a SQL query
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Number of rows or false on failure
			* @access public
			*/
			function num_rows($res_id=null)
			{
			return $this->quote_identifier($str);
			if (!$this->db_handle)
			return false;

			if ($result = $this->_get_result($res_id))
			return $result->numRows();
			else
			return false;
			}


			/**
			* Quotes a string so it can be safely used as a table or column name
			*
			* @param string Value to quote
			* @return string Quoted string for use in query
			* @access public
			*/
			function quote_identifier($str)
			/**
			* Get number of affected rows for the last query
			*
			* @param number Optional query handle identifier
			* @return mixed Number of rows or false on failure
			* @access public
			*/
			function affected_rows($res_id = null)
			{
			if (!$this->db_handle)
			$this->db_connect('r');
			if (!$this->db_handle)
			return false;

			return $this->db_handle->quoteIdentifier($str);
			return (int) $this->_get_result($res_id);
			}

			/**
			* Escapes a string
			*
			* @param string The string to be escaped
			* @return string The escaped string
			* @access public
			* @since 0.1.1
			*/
			function escapeSimple($str)

			/**
			* Get last inserted record ID
			* For Postgres databases, a sequence name is required
			*
			* @param string Table name (to find the incremented sequence)
			* @return mixed ID or false on failure
			* @access public
			*/
			function insert_id($table = '')
			{
			if (!$this->db_handle)
			$this->db_connect('r');

			return $this->db_handle->escape($str);
			if (!$this->db_handle \|\| $this->db_mode == 'r')
			return false;

			if ($table) {
			if ($this->db_provider == 'pgsql')
			// find sequence name
			$table = get_sequence_name($table);
			else
			// resolve table name
			$table = get_table_name($table);
			}

			$id = $this->db_handle->lastInsertID($table);

			return $this->db_handle->isError($id) ? null : $id;
			}


			/**
			* Return SQL function for current time and date
			*
			* @return string SQL function to use in query
			* @access public
			*/
			function now()
			/**
			* Get an associative array for one row
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Array with col values or false on failure
			* @access public
			*/
			function fetch_assoc($res_id=null)
			{
			switch($this->db_provider)
			{
			case 'mssql':
			return "getdate()";

			default:
			return "now()";
			}
			$result = $this->_get_result($res_id);
			return $this->_fetch_row($result, MDB2_FETCHMODE_ASSOC);
			}


			/**
			* Return list of elements for use with SQL's IN clause
			*
			* @param string Input array
			* @return string Elements list string
			* @access public
			*/
			function array2list($arr, $type=null)
			/**
			* Get an index array for one row
			* If no query handle is specified, the last query will be taken as reference
			*
			* @param number Optional query handle identifier
			* @return mixed Array with col values or false on failure
			* @access public
			*/
			function fetch_array($res_id=null)
			{
			if (!is_array($arr))
			return $this->quote($arr, $type);

			$res = array();
			foreach ($arr as $item)
			$res[] = $this->quote($item, $type);

			return implode(',', $res);
			$result = $this->_get_result($res_id);
			return $this->_fetch_row($result, MDB2_FETCHMODE_ORDERED);
			}


			/**
			* Return SQL statement to convert a field value into a unix timestamp
			*
			* @param string Field name
			* @return string SQL statement to use in query
			* @access public
			*/
			function unixtimestamp($field)
			/**
			* Get col values for a result row
			*
			* @param object Query result handle
			* @param number Fetch mode identifier
			* @return mixed Array with col values or false on failure
			* @access private
			*/
			private function _fetch_row($result, $mode)
			{
			switch($this->db_provider)
			{
			case 'pgsql':
			return "EXTRACT (EPOCH FROM $field)";
			break;
			if ($result === false \|\| PEAR::isError($result) \|\| !$this->is_connected())
			return false;

			case 'mssql':
			return "datediff(s, '1970-01-01 00:00:00', $field)";

			default:
			return "UNIX_TIMESTAMP($field)";
			}
			return $result->fetchRow($mode);
			}


			/**
			* Return SQL statement to convert from a unix timestamp
			*
			* @param string Field name
			* @return string SQL statement to use in query
			* @access public
			*/
			function fromunixtime($timestamp)
			/**
			* Wrapper for the SHOW TABLES command
			*
			* @return array List of all tables of the current database
			* @access public
			* @since 0.4-beta
			*/
			function list_tables()
			{
			switch($this->db_provider)
			{
			case 'mysqli':
			case 'mysql':
			case 'sqlite':
			return sprintf("FROM_UNIXTIME(%d)", $timestamp);
			// get tables if not cached
			if (!$this->tables) {
			$this->db_handle->loadModule('Manager');
			if (!PEAR::isError($result = $this->db_handle->listTables()))
			$this->tables = $result;
			else
			$this->tables = array();
			}

			default:
			return date("'Y-m-d H:i:s'", $timestamp);
			}
			return $this->tables;
			}


			/**
			* Return SQL statement for case insensitive LIKE
			*
			* @param string Field name
			* @param string Search value
			* @return string SQL statement to use in query
			* @access public
			*/
			function ilike($column, $value)
			/**
			* Formats input so it can be safely used in a query
			*
			* @param mixed Value to quote
			* @param string Type of data
			* @return string Quoted/converted string for use in query
			* @access public
			*/
			function quote($input, $type = null)
			{
			// TODO: use MDB2's matchPattern() function
			switch($this->db_provider)
			{
			case 'pgsql':
			return $this->quote_identifier($column).' ILIKE '.$this->quote($value);
			default:
			return $this->quote_identifier($column).' LIKE '.$this->quote($value);
			}
			// handle int directly for better performance
			if ($type == 'integer')
			return intval($input);

			// create DB handle if not available
			if (!$this->db_handle)
			$this->db_connect('r');

			return $this->db_handle->quote($input, $type);
			}


			/**
			* Encodes non-UTF-8 characters in string/array/object (recursive)
			*
			* @param mixed Data to fix
			* @return mixed Properly UTF-8 encoded data
			* @access public
			*/
			function encode($input)
			/**
			* Quotes a string so it can be safely used as a table or column name
			*
			* @param string Value to quote
			* @return string Quoted string for use in query
			* @deprecated Replaced by rcube_MDB2::quote_identifier
			* @see rcube_mdb2::quote_identifier
			* @access public
			*/
			function quoteIdentifier($str)
			{
			if (is_object($input)) {
			foreach (get_object_vars($input) as $idx => $value)
			$input->$idx = $this->encode($value);
			return $input;
			}
			else if (is_array($input)) {
			foreach ($input as $idx => $value)
			$input[$idx] = $this->encode($value);
			return $input;
			}

			return utf8_encode($input);
			return $this->quote_identifier($str);
			}


			/**
			* Decodes encoded UTF-8 string/object/array (recursive)
			*
			* @param mixed Input data
			* @return mixed Decoded data
			* @access public
			*/
			function decode($input)
			/**
			* Quotes a string so it can be safely used as a table or column name
			*
			* @param string Value to quote
			* @return string Quoted string for use in query
			* @access public
			*/
			function quote_identifier($str)
			{
			if (is_object($input)) {
			foreach (get_object_vars($input) as $idx => $value)
			$input->$idx = $this->decode($value);
			return $input;
			}
			else if (is_array($input)) {
			foreach ($input as $idx => $value)
			$input[$idx] = $this->decode($value);
			return $input;
			}
			if (!$this->db_handle)
			$this->db_connect('r');

			return utf8_decode($input);
			return $this->db_handle->quoteIdentifier($str);
			}


			/**
			* Adds a query result and returns a handle ID
			*
			* @param object Query handle
			* @return mixed Handle ID
			* @access private
			*/
			function _add_result($res)
			/**
			* Escapes a string
			*
			* @param string The string to be escaped
			* @return string The escaped string
			* @access public
			* @since 0.1.1
			*/
			function escapeSimple($str)
			{
			// sql error occured
			if (PEAR::isError($res))
			{
			$this->db_error = TRUE;
			$this->db_error_msg = $res->getMessage();
			raise_error(array('code' => 500, 'type' => 'db', 'line' => __LINE__, 'file' => __FILE__,
			'message' => $res->getMessage() . " Query: "
			. substr(preg_replace('/[\r\n]+\s*/', ' ', $res->userinfo), 0, 512)),
			TRUE, FALSE);
			}

			$res_id = sizeof($this->a_query_results);
			$this->last_res_id = $res_id;
			$this->a_query_results[$res_id] = $res;
			return $res_id;
			if (!$this->db_handle)
			$this->db_connect('r');

			return $this->db_handle->escape($str);
			}


			/**
			* Resolves a given handle ID and returns the according query handle
			* If no ID is specified, the last resource handle will be returned
			*
			* @param number Handle ID
			* @return mixed Resource handle or FALSE on failure
			* @access private
			*/
			function _get_result($res_id=NULL)
			/**
			* Return SQL function for current time and date
			*
			* @return string SQL function to use in query
			* @access public
			*/
			function now()
			{
			if ($res_id==NULL)
			$res_id = $this->last_res_id;
			switch($this->db_provider) {
			case 'mssql':
			case 'sqlsrv':
			return "getdate()";

			if (isset($this->a_query_results[$res_id]))
			if (!PEAR::isError($this->a_query_results[$res_id]))
			return $this->a_query_results[$res_id];

			return FALSE;
			default:
			return "now()";
			}
			}


			/**
			* Create a sqlite database from a file
			*
			* @param object SQLite database handle
			* @param string File path to use for DB creation
			* @access private
			*/
			function _sqlite_create_database($dbh, $file_name)
			/**
			* Return list of elements for use with SQL's IN clause
			*
			* @param array Input array
			* @param string Type of data
			* @return string Comma-separated list of quoted values for use in query
			* @access public
			*/
			function array2list($arr, $type = null)
			{
			if (empty($file_name) \|\| !is_string($file_name))
			return;
			if (!is_array($arr))
			return $this->quote($arr, $type);

			$data = file_get_contents($file_name);
			foreach ($arr as $idx => $item)
			$arr[$idx] = $this->quote($item, $type);

			if (strlen($data))
			if (!sqlite_exec($dbh->connection, $data, $error) \|\| MDB2::isError($dbh))
			raise_error(array('code' => 500, 'type' => 'db',
			'line' => __LINE__, 'file' => __FILE__, 'message' => $error), TRUE, FALSE);
			return implode(',', $arr);
			}


			/**
			* Add some proprietary database functions to the current SQLite handle
			* in order to make it MySQL compatible
			*
			* @access private
			*/
			function _sqlite_prepare()
			/**
			* Return SQL statement to convert a field value into a unix timestamp
			*
			* @param string Field name
			* @return string SQL statement to use in query
			* @access public
			*/
			function unixtimestamp($field)
			{
			include_once('include/rcube_sqlite.inc');
			switch($this->db_provider) {
			case 'pgsql':
			return "EXTRACT (EPOCH FROM $field)";

			// we emulate via callback some missing MySQL function
			sqlite_create_function($this->db_handle->connection, "from_unixtime", "rcube_sqlite_from_unixtime");
			sqlite_create_function($this->db_handle->connection, "unix_timestamp", "rcube_sqlite_unix_timestamp");
			sqlite_create_function($this->db_handle->connection, "now", "rcube_sqlite_now");
			sqlite_create_function($this->db_handle->connection, "md5", "rcube_sqlite_md5");
			case 'mssql':
			case 'sqlsrv':
			return "DATEDIFF(second, '19700101', $field) + DATEDIFF(second, GETDATE(), GETUTCDATE())";

			default:
			return "UNIX_TIMESTAMP($field)";
			}
			}


			} // end class rcube_db
			/**
			* Return SQL statement to convert from a unix timestamp
			*
			* @param string Field name
			* @return string SQL statement to use in query
			* @access public
			*/
			function fromunixtime($timestamp)
			{
			switch($this->db_provider) {
			case 'mysqli':
			case 'mysql':
			case 'sqlite':
			return sprintf("FROM_UNIXTIME(%d)", $timestamp);

			default:
			return date("'Y-m-d H:i:s'", $timestamp);
			}
			}


			/**
			* Return SQL statement for case insensitive LIKE
			*
			* @param string Field name
			* @param string Search value
			* @return string SQL statement to use in query
			* @access public
			*/
			function ilike($column, $value)
			{
			// TODO: use MDB2's matchPattern() function
			switch($this->db_provider) {
			case 'pgsql':
			return $this->quote_identifier($column).' ILIKE '.$this->quote($value);
			default:
			return $this->quote_identifier($column).' LIKE '.$this->quote($value);
			}
			}


			/**
			* Encodes non-UTF-8 characters in string/array/object (recursive)
			*
			* @param mixed Data to fix
			* @return mixed Properly UTF-8 encoded data
			* @access public
			*/
			function encode($input)
			{
			if (is_object($input)) {
			foreach (get_object_vars($input) as $idx => $value)
			$input->$idx = $this->encode($value);
			return $input;
			}
			else if (is_array($input)) {
			foreach ($input as $idx => $value)
			$input[$idx] = $this->encode($value);
			return $input;
			}

			return utf8_encode($input);
			}


			/**
			* Decodes encoded UTF-8 string/object/array (recursive)
			*
			* @param mixed Input data
			* @return mixed Decoded data
			* @access public
			*/
			function decode($input)
			{
			if (is_object($input)) {
			foreach (get_object_vars($input) as $idx => $value)
			$input->$idx = $this->decode($value);
			return $input;
			}
			else if (is_array($input)) {
			foreach ($input as $idx => $value)
			$input[$idx] = $this->decode($value);
			return $input;
			}

			return utf8_decode($input);
			}


			/**
			* Adds a query result and returns a handle ID
			*
			* @param object Query handle
			* @return mixed Handle ID
			* @access private
			*/
			private function _add_result($res)
			{
			// sql error occured
			if (PEAR::isError($res)) {
			$this->db_error = true;
			$this->db_error_msg = $res->getMessage();
			raise_error(array('code' => 500, 'type' => 'db',
			'line' => __LINE__, 'file' => __FILE__,
			'message' => $res->getMessage() . " Query: "
			. substr(preg_replace('/[\r\n]+\s*/', ' ', $res->userinfo), 0, 512)),
			true, false);
			}

			$res_id = sizeof($this->a_query_results);
			$this->last_res_id = $res_id;
			$this->a_query_results[$res_id] = $res;
			return $res_id;
			}


			/**
			* Resolves a given handle ID and returns the according query handle
			* If no ID is specified, the last resource handle will be returned
			*
			* @param number Handle ID
			* @return mixed Resource handle or false on failure
			* @access private
			*/
			private function _get_result($res_id = null)
			{
			if ($res_id == null)
			$res_id = $this->last_res_id;

			if (isset($this->a_query_results[$res_id]))
			if (!PEAR::isError($this->a_query_results[$res_id]))
			return $this->a_query_results[$res_id];

			return false;
			}


			/**
			* Create a sqlite database from a file
			*
			* @param object SQLite database handle
			* @param string File path to use for DB creation
			* @access private
			*/
			private function _sqlite_create_database($dbh, $file_name)
			{
			if (empty($file_name) \|\| !is_string($file_name))
			return;

			$data = file_get_contents($file_name);

			if (strlen($data))
			if (!sqlite_exec($dbh->connection, $data, $error) \|\| MDB2::isError($dbh))
			raise_error(array('code' => 500, 'type' => 'db',
			'line' => __LINE__, 'file' => __FILE__,
			'message' => $error), true, false);
			}


			/**
			* Add some proprietary database functions to the current SQLite handle
			* in order to make it MySQL compatible
			*
			* @access private
			*/
			private function _sqlite_prepare()
			{
			include_once('include/rcube_sqlite.inc');

			// we emulate via callback some missing MySQL function
			sqlite_create_function($this->db_handle->connection,
			'from_unixtime', 'rcube_sqlite_from_unixtime');
			sqlite_create_function($this->db_handle->connection,
			'unix_timestamp', 'rcube_sqlite_unix_timestamp');
			sqlite_create_function($this->db_handle->connection,
			'now', 'rcube_sqlite_now');
			sqlite_create_function($this->db_handle->connection,
			'md5', 'rcube_sqlite_md5');
			}

			} // end class rcube_db


			/* this is our own debug handler for the MDB2 connection */
			function mdb2_debug_handler(&$db, $scope, $message, $context = array())
			{
			if ($scope != 'prepare')
			{
			$debug_output = $scope . '('.$db->db_index.'): ';
			$debug_output .= $message . $db->getOption('log_line_break');
			write_log('sqllog', $debug_output);
			}
			if ($scope != 'prepare') {
			$debug_output = sprintf('%s(%d): %s;',
			$scope, $db->db_index, rtrim($message, ';'));
			write_log('sql', $debug_output);
			}
			}