Initial commit

Signed-off-by: Florian Pritz <bluewind@xssn.at>

1 files changed, 1366 insertions, 0 deletions

diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
new file mode 100644
index 000000000..014dfd44e
--- /dev/null
+++ b/system/database/DB_driver.php
@@ -0,0 +1,1366 @@
+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		ExpressionEngine Dev Team
+ * @copyright	Copyright (c) 2008 - 2009, EllisLab, Inc.
+ * @license		http://codeigniter.com/user_guide/license.html
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * Database Driver Class
+ *
+ * This is the platform-independent base DB implementation class.
+ * This class will not be called directly. Rather, the adapter
+ * class for the specific database will extend and instantiate it.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Drivers
+ * @category	Database
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_driver {
+
+	var $username;
+	var $password;
+	var $hostname;
+	var $database;
+	var $dbdriver		= 'mysql';
+	var $dbprefix		= '';
+	var $char_set		= 'utf8';
+	var $dbcollat		= 'utf8_general_ci';
+	var $autoinit		= TRUE; // Whether to automatically initialize the DB
+	var $swap_pre		= '';
+	var $port			= '';
+	var $pconnect		= FALSE;
+	var $conn_id		= FALSE;
+	var $result_id		= FALSE;
+	var $db_debug		= FALSE;
+	var $benchmark		= 0;
+	var $query_count	= 0;
+	var $bind_marker	= '?';
+	var $save_queries	= TRUE;
+	var $queries		= array();
+	var $query_times	= array();
+	var $data_cache		= array();
+	var $trans_enabled	= TRUE;
+	var $trans_strict	= TRUE;
+	var $_trans_depth	= 0;
+	var $_trans_status	= TRUE; // Used with transactions to determine if a rollback should occur
+	var $cache_on		= FALSE;
+	var $cachedir		= '';
+	var $cache_autodel	= FALSE;
+	var $CACHE; // The cache class object
+
+	// Private variables
+	var $_protect_identifiers	= TRUE;
+	var $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
+
+	// These are use with Oracle
+	var $stmt_id;
+	var $curs_id;
+	var $limit_used;
+
+
+	
+	/**
+	 * Constructor.  Accepts one parameter containing the database
+	 * connection settings.
+	 *
+	 * @param array
+	 */	
+	function CI_DB_driver($params)
+	{
+		if (is_array($params))
+		{
+			foreach ($params as $key => $val)
+			{
+				$this->$key = $val;
+			}
+		}
+
+		log_message('debug', 'Database Driver Class Initialized');
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Initialize Database Settings
+	 *
+	 * @access	private Called by the constructor
+	 * @param	mixed
+	 * @return	void
+	 */	
+	function initialize()
+	{
+		// If an existing connection resource is available
+		// there is no need to connect and select the database
+		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		{
+			return TRUE;
+		}
+	
+		// ----------------------------------------------------------------
+		
+		// Connect to the database and set the connection ID
+		$this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect();
+
+		// No connection resource?  Throw an error
+		if ( ! $this->conn_id)
+		{
+			log_message('error', 'Unable to connect to the database');
+			
+			if ($this->db_debug)
+			{
+				$this->display_error('db_unable_to_connect');
+			}
+			return FALSE;
+		}
+
+		// ----------------------------------------------------------------
+
+		// Select the DB... assuming a database name is specified in the config file
+		if ($this->database != '')
+		{
+			if ( ! $this->db_select())
+			{
+				log_message('error', 'Unable to select database: '.$this->database);
+			
+				if ($this->db_debug)
+				{
+					$this->display_error('db_unable_to_select', $this->database);
+				}
+				return FALSE;			
+			}
+			else
+			{
+				// We've selected the DB. Now we set the character set
+				if ( ! $this->db_set_charset($this->char_set, $this->dbcollat))
+				{
+					return FALSE;
+				}
+		
+				return TRUE;
+			}
+		}
+
+		return TRUE;
+	}
+		
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set client character set
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	resource
+	 */
+	function db_set_charset($charset, $collation)
+	{
+		if ( ! $this->_db_set_charset($this->char_set, $this->dbcollat))
+		{
+			log_message('error', 'Unable to set database connection charset: '.$this->char_set);
+		
+			if ($this->db_debug)
+			{
+				$this->display_error('db_unable_to_set_charset', $this->char_set);
+			}
+			
+			return FALSE;
+		}
+		
+		return TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * The name of the platform in use (mysql, mssql, etc...)
+	 *
+	 * @access	public
+	 * @return	string		
+	 */	
+	function platform()
+	{
+		return $this->dbdriver;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Database Version Number.  Returns a string containing the
+	 * version of the database being used
+	 *
+	 * @access	public
+	 * @return	string	
+	 */	
+	function version()
+	{
+		if (FALSE === ($sql = $this->_version()))
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_unsupported_function');
+			}
+			return FALSE;
+		}
+		
+		if ($this->dbdriver == 'oci8')
+		{
+			return $sql;
+		}
+	
+		$query = $this->query($sql);
+		return $query->row('ver');
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Execute the query
+	 *
+	 * Accepts an SQL string as input and returns a result object upon
+	 * successful execution of a "read" type query.  Returns boolean TRUE
+	 * upon successful execution of a "write" type query. Returns boolean
+	 * FALSE upon failure, and if the $db_debug variable is set to TRUE
+	 * will raise an error.
+	 *
+	 * @access	public
+	 * @param	string	An SQL query string
+	 * @param	array	An array of binding data
+	 * @return	mixed		
+	 */	
+	function query($sql, $binds = FALSE, $return_object = TRUE)
+	{
+		if ($sql == '')
+		{
+			if ($this->db_debug)
+			{
+				log_message('error', 'Invalid query: '.$sql);
+				return $this->display_error('db_invalid_query');
+			}
+			return FALSE;
+		}
+
+		// Verify table prefix and replace if necessary
+		if ( ($this->dbprefix != '' AND $this->swap_pre != '') AND ($this->dbprefix != $this->swap_pre) )
+		{			
+			$sql = preg_replace("/(\W)".$this->swap_pre."(\S+?)/", "\\1".$this->dbprefix."\\2", $sql);
+		}
+		
+		// Is query caching enabled?  If the query is a "read type"
+		// we will load the caching class and return the previously
+		// cached query if it exists
+		if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))
+		{
+			if ($this->_cache_init())
+			{
+				$this->load_rdriver();
+				if (FALSE !== ($cache = $this->CACHE->read($sql)))
+				{
+					return $cache;
+				}
+			}
+		}
+		
+		// Compile binds if needed
+		if ($binds !== FALSE)
+		{
+			$sql = $this->compile_binds($sql, $binds);
+		}
+
+		// Save the  query for debugging
+		if ($this->save_queries == TRUE)
+		{
+			$this->queries[] = $sql;
+		}
+		
+		// Start the Query Timer
+		$time_start = list($sm, $ss) = explode(' ', microtime());
+	
+		// Run the Query
+		if (FALSE === ($this->result_id = $this->simple_query($sql)))
+		{
+			if ($this->save_queries == TRUE)
+			{
+				$this->query_times[] = 0;
+			}
+		
+			// This will trigger a rollback if transactions are being used
+			$this->_trans_status = FALSE;
+
+			if ($this->db_debug)
+			{
+				// grab the error number and message now, as we might run some
+				// additional queries before displaying the error
+				$error_no = $this->_error_number();
+				$error_msg = $this->_error_message();
+				
+				// We call this function in order to roll-back queries
+				// if transactions are enabled.  If we don't call this here
+				// the error message will trigger an exit, causing the 
+				// transactions to remain in limbo.
+				$this->trans_complete();
+
+				// Log and display errors
+				log_message('error', 'Query error: '.$error_msg);
+				return $this->display_error(
+										array(
+												'Error Number: '.$error_no,
+												$error_msg,
+												$sql
+											)
+										);
+			}
+		
+			return FALSE;
+		}
+		
+		// Stop and aggregate the query time results
+		$time_end = list($em, $es) = explode(' ', microtime());
+		$this->benchmark += ($em + $es) - ($sm + $ss);
+
+		if ($this->save_queries == TRUE)
+		{
+			$this->query_times[] = ($em + $es) - ($sm + $ss);
+		}
+		
+		// Increment the query counter
+		$this->query_count++;
+		
+		// Was the query a "write" type?
+		// If so we'll simply return true
+		if ($this->is_write_type($sql) === TRUE)
+		{
+			// If caching is enabled we'll auto-cleanup any
+			// existing files related to this particular URI
+			if ($this->cache_on == TRUE AND $this->cache_autodel == TRUE AND $this->_cache_init())
+			{
+				$this->CACHE->delete();
+			}
+		
+			return TRUE;
+		}
+		
+		// Return TRUE if we don't need to create a result object
+		// Currently only the Oracle driver uses this when stored
+		// procedures are used
+		if ($return_object !== TRUE)
+		{
+			return TRUE;
+		}
+	
+		// Load and instantiate the result driver	
+		
+		$driver 		= $this->load_rdriver();
+		$RES 			= new $driver();
+		$RES->conn_id	= $this->conn_id;
+		$RES->result_id	= $this->result_id;
+
+		if ($this->dbdriver == 'oci8')
+		{
+			$RES->stmt_id		= $this->stmt_id;
+			$RES->curs_id		= NULL;
+			$RES->limit_used	= $this->limit_used;
+			$this->stmt_id		= FALSE;
+		}
+		
+		// oci8 vars must be set before calling this
+		$RES->num_rows	= $RES->num_rows();
+				
+		// Is query caching enabled?  If so, we'll serialize the
+		// result object and save it to a cache file.
+		if ($this->cache_on == TRUE AND $this->_cache_init())
+		{
+			// We'll create a new instance of the result object
+			// only without the platform specific driver since
+			// we can't use it with cached data (the query result
+			// resource ID won't be any good once we've cached the
+			// result object, so we'll have to compile the data
+			// and save it)
+			$CR = new CI_DB_result();
+			$CR->num_rows 		= $RES->num_rows();
+			$CR->result_object	= $RES->result_object();
+			$CR->result_array	= $RES->result_array();
+			
+			// Reset these since cached objects can not utilize resource IDs.
+			$CR->conn_id		= NULL;
+			$CR->result_id		= NULL;
+
+			$this->CACHE->write($sql, $CR);
+		}
+		
+		return $RES;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Load the result drivers
+	 *
+	 * @access	public
+	 * @return	string 	the name of the result class		
+	 */		
+	function load_rdriver()
+	{
+		$driver = 'CI_DB_'.$this->dbdriver.'_result';
+
+		if ( ! class_exists($driver))
+		{
+			include_once(BASEPATH.'database/DB_result'.EXT);
+			include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result'.EXT);
+		}
+		
+		return $driver;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Simple Query
+	 * This is a simplified version of the query() function.  Internally
+	 * we only use it when running transaction commands since they do
+	 * not require all the features of the main query() function.
+	 *
+	 * @access	public
+	 * @param	string	the sql query
+	 * @return	mixed		
+	 */	
+	function simple_query($sql)
+	{
+		if ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		return $this->_execute($sql);
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Disable Transactions
+	 * This permits transactions to be disabled at run-time.
+	 *
+	 * @access	public
+	 * @return	void		
+	 */	
+	function trans_off()
+	{
+		$this->trans_enabled = FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Enable/disable Transaction Strict Mode
+	 * When strict mode is enabled, if you are running multiple groups of
+	 * transactions, if one group fails all groups will be rolled back.
+	 * If strict mode is disabled, each group is treated autonomously, meaning
+	 * a failure of one group will not affect any others
+	 *
+	 * @access	public
+	 * @return	void		
+	 */	
+	function trans_strict($mode = TRUE)
+	{
+		$this->trans_strict = is_bool($mode) ? $mode : TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Start Transaction
+	 *
+	 * @access	public
+	 * @return	void		
+	 */	
+	function trans_start($test_mode = FALSE)
+	{	
+		if ( ! $this->trans_enabled)
+		{
+			return FALSE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			$this->_trans_depth += 1;
+			return;
+		}
+		
+		$this->trans_begin($test_mode);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Complete Transaction
+	 *
+	 * @access	public
+	 * @return	bool		
+	 */	
+	function trans_complete()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return FALSE;
+		}
+	
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 1)
+		{
+			$this->_trans_depth -= 1;
+			return TRUE;
+		}
+	
+		// The query() function will set this flag to FALSE in the event that a query failed
+		if ($this->_trans_status === FALSE)
+		{
+			$this->trans_rollback();
+			
+			// If we are NOT running in strict mode, we will reset
+			// the _trans_status flag so that subsequent groups of transactions
+			// will be permitted.
+			if ($this->trans_strict === FALSE)
+			{
+				$this->_trans_status = TRUE;
+			}
+
+			log_message('debug', 'DB Transaction Failure');
+			return FALSE;
+		}
+		
+		$this->trans_commit();
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Lets you retrieve the transaction flag to determine if it has failed
+	 *
+	 * @access	public
+	 * @return	bool		
+	 */	
+	function trans_status()
+	{
+		return $this->_trans_status;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Compile Bindings
+	 *
+	 * @access	public
+	 * @param	string	the sql statement
+	 * @param	array	an array of bind data
+	 * @return	string		
+	 */	
+	function compile_binds($sql, $binds)
+	{
+		if (strpos($sql, $this->bind_marker) === FALSE)
+		{
+			return $sql;
+		}
+		
+		if ( ! is_array($binds))
+		{
+			$binds = array($binds);
+		}
+		
+		// Get the sql segments around the bind markers
+		$segments = explode($this->bind_marker, $sql);
+
+		// The count of bind should be 1 less then the count of segments
+		// If there are more bind arguments trim it down
+		if (count($binds) >= count($segments)) {
+			$binds = array_slice($binds, 0, count($segments)-1);
+		}
+
+		// Construct the binded query
+		$result = $segments[0];
+		$i = 0;
+		foreach ($binds as $bind)
+		{
+			$result .= $this->escape($bind);
+			$result .= $segments[++$i];
+		}
+
+		return $result;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Determines if a query is a "write" type.
+	 *
+	 * @access	public
+	 * @param	string	An SQL query string
+	 * @return	boolean		
+	 */	
+	function is_write_type($sql)
+	{
+		if ( ! preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK)\s+/i', $sql))
+		{
+			return FALSE;
+		}
+		return TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Calculate the aggregate query elapsed time
+	 *
+	 * @access	public
+	 * @param	integer	The number of decimal places
+	 * @return	integer		
+	 */	
+	function elapsed_time($decimals = 6)
+	{
+		return number_format($this->benchmark, $decimals);
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Returns the total number of queries
+	 *
+	 * @access	public
+	 * @return	integer		
+	 */	
+	function total_queries()
+	{
+		return $this->query_count;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Returns the last query that was executed
+	 *
+	 * @access	public
+	 * @return	void		
+	 */	
+	function last_query()
+	{
+		return end($this->queries);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * "Smart" Escape String
+	 *
+	 * Escapes data based on type
+	 * Sets boolean and null types
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	mixed		
+	 */	
+	function escape($str)
+	{
+		if (is_string($str))
+		{
+			$str = "'".$this->escape_str($str)."'";
+		}
+		elseif (is_bool($str))
+		{
+			$str = ($str === FALSE) ? 0 : 1;
+		}
+		elseif (is_null($str))
+		{
+			$str = 'NULL';
+		}
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Escape LIKE String
+	 *
+	 * Calls the individual driver for platform
+	 * specific escaping for LIKE conditions
+	 * 
+	 * @access	public
+	 * @param	string
+	 * @return	mixed
+	 */
+    function escape_like_str($str)    
+    {    
+    	return $this->escape_str($str, TRUE);
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Primary
+	 *
+	 * Retrieves the primary key.  It assumes that the row in the first
+	 * position is the primary key
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	string		
+	 */	
+	function primary($table = '')
+	{	
+		$fields = $this->list_fields($table);
+		
+		if ( ! is_array($fields))
+		{
+			return FALSE;
+		}
+
+		return current($fields);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Returns an array of table names
+	 *
+	 * @access	public
+	 * @return	array		
+	 */	
+	function list_tables($constrain_by_prefix = FALSE)
+	{
+		// Is there a cached result?
+		if (isset($this->data_cache['table_names']))
+		{
+			return $this->data_cache['table_names'];
+		}
+	
+		if (FALSE === ($sql = $this->_list_tables($constrain_by_prefix)))
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_unsupported_function');
+			}
+			return FALSE;
+		}
+
+		$retval = array();
+		$query = $this->query($sql);
+		
+		if ($query->num_rows() > 0)
+		{
+			foreach($query->result_array() as $row)
+			{
+				if (isset($row['TABLE_NAME']))
+				{
+					$retval[] = $row['TABLE_NAME'];
+				}
+				else
+				{
+					$retval[] = array_shift($row);
+				}
+			}
+		}
+
+		$this->data_cache['table_names'] = $retval;
+		return $this->data_cache['table_names'];
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Determine if a particular table exists
+	 * @access	public
+	 * @return	boolean
+	 */
+	function table_exists($table_name)
+	{	
+		return ( ! in_array($this->_protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables())) ? FALSE : TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch MySQL Field Names
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	array		
+	 */
+	function list_fields($table = '')
+	{
+		// Is there a cached result?
+		if (isset($this->data_cache['field_names'][$table]))
+		{
+			return $this->data_cache['field_names'][$table];
+		}
+	
+		if ($table == '')
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_field_param_missing');
+			}
+			return FALSE;
+		}
+		
+		if (FALSE === ($sql = $this->_list_columns($this->_protect_identifiers($table, TRUE, NULL, FALSE))))
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_unsupported_function');
+			}
+			return FALSE;
+		}
+		
+		$query = $this->query($sql);
+		
+		$retval = array();
+		foreach($query->result_array() as $row)
+		{
+			if (isset($row['COLUMN_NAME']))
+			{
+				$retval[] = $row['COLUMN_NAME'];
+			}
+			else
+			{
+				$retval[] = current($row);
+			}		
+		}
+		
+		$this->data_cache['field_names'][$table] = $retval;
+		return $this->data_cache['field_names'][$table];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Determine if a particular field exists
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	boolean
+	 */
+	function field_exists($field_name, $table_name)
+	{	
+		return ( ! in_array($field_name, $this->list_fields($table_name))) ? FALSE : TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Returns an object with field data
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	object		
+	 */	
+	function field_data($table = '')
+	{
+		if ($table == '')
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_field_param_missing');
+			}
+			return FALSE;
+		}
+		
+		$query = $this->query($this->_field_data($this->_protect_identifiers($table, TRUE, NULL, FALSE)));
+
+		return $query->field_data();
+	}	
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Generate an insert string
+	 *
+	 * @access	public
+	 * @param	string	the table upon which the query will be performed
+	 * @param	array	an associative array data of key/values
+	 * @return	string		
+	 */	
+	function insert_string($table, $data)
+	{
+		$fields = array();
+		$values = array();
+		
+		foreach($data as $key => $val)
+		{
+			$fields[] = $this->_escape_identifiers($key);
+			$values[] = $this->escape($val);
+		}
+				
+		return $this->_insert($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);
+	}	
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Generate an update string
+	 *
+	 * @access	public
+	 * @param	string	the table upon which the query will be performed
+	 * @param	array	an associative array data of key/values
+	 * @param	mixed	the "where" statement
+	 * @return	string		
+	 */	
+	function update_string($table, $data, $where)
+	{
+		if ($where == '')
+		{
+			return false;
+		}
+					
+		$fields = array();
+		foreach($data as $key => $val)
+		{
+			$fields[$this->_protect_identifiers($key)] = $this->escape($val);
+		}
+
+		if ( ! is_array($where))
+		{
+			$dest = array($where);
+		}
+		else
+		{
+			$dest = array();
+			foreach ($where as $key => $val)
+			{
+				$prefix = (count($dest) == 0) ? '' : ' AND ';
+	
+				if ($val !== '')
+				{
+					if ( ! $this->_has_operator($key))
+					{
+						$key .= ' =';
+					}
+				
+					$val = ' '.$this->escape($val);
+				}
+							
+				$dest[] = $prefix.$key.$val;
+			}
+		}		
+
+		return $this->_update($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $dest);
+	}	
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Tests whether the string has an SQL operator
+	 *
+	 * @access	private
+	 * @param	string
+	 * @return	bool
+	 */
+	function _has_operator($str)
+	{
+		$str = trim($str);
+		if ( ! preg_match("/(\s|<|>|!|=|is null|is not null)/i", $str))
+		{
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
+	 *
+	 * @access	public
+	 * @param	string	the function name
+	 * @param	mixed	any parameters needed by the function
+	 * @return	mixed		
+	 */	
+	function call_function($function)
+	{
+		$driver = ($this->dbdriver == 'postgre') ? 'pg_' : $this->dbdriver.'_';
+	
+		if (FALSE === strpos($driver, $function))
+		{
+			$function = $driver.$function;
+		}
+		
+		if ( ! function_exists($function))
+		{
+			if ($this->db_debug)
+			{
+				return $this->display_error('db_unsupported_function');
+			}
+			return FALSE;
+		}
+		else
+		{
+			$args = (func_num_args() > 1) ? array_splice(func_get_args(), 1) : null;
+
+			return call_user_func_array($function, $args);
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set Cache Directory Path
+	 *
+	 * @access	public
+	 * @param	string	the path to the cache directory
+	 * @return	void
+	 */		
+	function cache_set_path($path = '')
+	{
+		$this->cachedir = $path;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Enable Query Caching
+	 *
+	 * @access	public
+	 * @return	void
+	 */		
+	function cache_on()
+	{
+		$this->cache_on = TRUE;
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Disable Query Caching
+	 *
+	 * @access	public
+	 * @return	void
+	 */	
+	function cache_off()
+	{
+		$this->cache_on = FALSE;
+		return FALSE;
+	}
+	
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete the cache files associated with a particular URI
+	 *
+	 * @access	public
+	 * @return	void
+	 */		
+	function cache_delete($segment_one = '', $segment_two = '')
+	{
+		if ( ! $this->_cache_init())
+		{
+			return FALSE;
+		}
+		return $this->CACHE->delete($segment_one, $segment_two);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete All cache files
+	 *
+	 * @access	public
+	 * @return	void
+	 */		
+	function cache_delete_all()
+	{
+		if ( ! $this->_cache_init())
+		{
+			return FALSE;
+		}
+
+		return $this->CACHE->delete_all();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Initialize the Cache Class
+	 *
+	 * @access	private
+	 * @return	void
+	 */	
+	function _cache_init()
+	{
+		if (is_object($this->CACHE) AND class_exists('CI_DB_Cache'))
+		{
+			return TRUE;
+		}
+
+		if ( ! class_exists('CI_DB_Cache'))
+		{
+			if ( ! @include(BASEPATH.'database/DB_cache'.EXT))
+			{
+				return $this->cache_off();
+			}
+		}
+
+		$this->CACHE = new CI_DB_Cache($this); // pass db object to support multiple db connections and returned db objects
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Close DB Connection
+	 *
+	 * @access	public
+	 * @return	void		
+	 */	
+	function close()
+	{
+		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		{
+			$this->_close($this->conn_id);
+		}
+		$this->conn_id = FALSE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Display an error message
+	 *
+	 * @access	public
+	 * @param	string	the error message
+	 * @param	string	any "swap" values
+	 * @param	boolean	whether to localize the message
+	 * @return	string	sends the application/error_db.php template		
+	 */	
+	function display_error($error = '', $swap = '', $native = FALSE)
+	{
+		$LANG =& load_class('Language');
+		$LANG->load('db');
+
+		$heading = $LANG->line('db_error_heading');
+
+		if ($native == TRUE)
+		{
+			$message = $error;
+		}
+		else
+		{
+			$message = ( ! is_array($error)) ? array(str_replace('%s', $swap, $LANG->line($error))) : $error;
+		}
+		
+		$error =& load_class('Exceptions');
+		echo $error->show_error($heading, $message, 'error_db');
+		exit;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Protect Identifiers
+	 *
+	 * This function adds backticks if appropriate based on db type
+	 *
+	 * @access	private
+	 * @param	mixed	the item to escape
+	 * @return	mixed	the item with backticks
+	 */
+	function protect_identifiers($item, $prefix_single = FALSE)
+	{
+		return $this->_protect_identifiers($item, $prefix_single);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Protect Identifiers
+	 *
+	 * This function is used extensively by the Active Record class, and by
+	 * a couple functions in this class. 
+	 * It takes a column or table name (optionally with an alias) and inserts
+	 * the table prefix onto it.  Some logic is necessary in order to deal with
+	 * column names that include the path.  Consider a query like this:
+	 *
+	 * SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
+	 *
+	 * Or a query with aliasing:
+	 *
+	 * SELECT m.member_id, m.member_name FROM members AS m
+	 *
+	 * Since the column name can include up to four segments (host, DB, table, column)
+	 * or also have an alias prefix, we need to do a bit of work to figure this out and
+	 * insert the table prefix (if it exists) in the proper position, and escape only
+	 * the correct identifiers.
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	bool
+	 * @param	mixed
+	 * @param	bool
+	 * @return	string
+	 */	
+	function _protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
+	{
+		if ( ! is_bool($protect_identifiers))
+		{
+			$protect_identifiers = $this->_protect_identifiers;
+		}
+
+		if (is_array($item))
+		{
+			$escaped_array = array();
+
+			foreach($item as $k => $v)
+			{
+				$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v);
+			}
+
+			return $escaped_array;
+		}
+
+		// Convert tabs or multiple spaces into single spaces
+		$item = preg_replace('/[\t ]+/', ' ', $item);
+	
+		// If the item has an alias declaration we remove it and set it aside.
+		// Basically we remove everything to the right of the first space
+		$alias = '';
+		if (strpos($item, ' ') !== FALSE)
+		{
+			$alias = strstr($item, " ");
+			$item = substr($item, 0, - strlen($alias));
+		}
+
+		// This is basically a bug fix for queries that use MAX, MIN, etc.
+		// If a parenthesis is found we know that we do not need to 
+		// escape the data or add a prefix.  There's probably a more graceful
+		// way to deal with this, but I'm not thinking of it -- Rick
+		if (strpos($item, '(') !== FALSE)
+		{
+			return $item.$alias;
+		}
+
+		// Break the string apart if it contains periods, then insert the table prefix
+		// in the correct location, assuming the period doesn't indicate that we're dealing
+		// with an alias. While we're at it, we will escape the components
+		if (strpos($item, '.') !== FALSE)
+		{
+			$parts	= explode('.', $item);
+			
+			// Does the first segment of the exploded item match
+			// one of the aliases previously identified?  If so,
+			// we have nothing more to do other than escape the item
+			if (in_array($parts[0], $this->ar_aliased_tables))
+			{
+				if ($protect_identifiers === TRUE)
+				{
+					foreach ($parts as $key => $val)
+					{
+						if ( ! in_array($val, $this->_reserved_identifiers))
+						{
+							$parts[$key] = $this->_escape_identifiers($val);
+						}
+					}
+				
+					$item = implode('.', $parts);
+				}			
+				return $item.$alias;
+			}
+			
+			// Is there a table prefix defined in the config file?  If not, no need to do anything
+			if ($this->dbprefix != '')
+			{
+				// We now add the table prefix based on some logic.
+				// Do we have 4 segments (hostname.database.table.column)?
+				// If so, we add the table prefix to the column name in the 3rd segment.
+				if (isset($parts[3]))
+				{
+					$i = 2;
+				}
+				// Do we have 3 segments (database.table.column)?
+				// If so, we add the table prefix to the column name in 2nd position
+				elseif (isset($parts[2]))
+				{
+					$i = 1;
+				}
+				// Do we have 2 segments (table.column)?
+				// If so, we add the table prefix to the column name in 1st segment
+				else
+				{
+					$i = 0;
+				}
+				
+				// This flag is set when the supplied $item does not contain a field name.
+				// This can happen when this function is being called from a JOIN.
+				if ($field_exists == FALSE)
+				{
+					$i++;
+				}
+
+				// Verify table prefix and replace if necessary
+				if ($this->swap_pre != '' && strncmp($parts[$i], $this->swap_pre, strlen($this->swap_pre)) === 0)
+				{
+					$parts[$i] = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $parts[$i]);
+				}
+								
+				// We only add the table prefix if it does not already exist
+				if (substr($parts[$i], 0, strlen($this->dbprefix)) != $this->dbprefix)
+				{
+					$parts[$i] = $this->dbprefix.$parts[$i];
+				}
+				
+				// Put the parts back together
+				$item = implode('.', $parts);
+			}
+			
+			if ($protect_identifiers === TRUE)
+			{
+				$item = $this->_escape_identifiers($item);
+			}
+			
+			return $item.$alias;
+		}
+
+		// Is there a table prefix?  If not, no need to insert it
+		if ($this->dbprefix != '')
+		{
+			// Verify table prefix and replace if necessary
+			if ($this->swap_pre != '' && strncmp($item, $this->swap_pre, strlen($this->swap_pre)) === 0)
+			{
+				$item = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $item);
+			}
+
+			// Do we prefix an item with no segments?
+			if ($prefix_single == TRUE AND substr($item, 0, strlen($this->dbprefix)) != $this->dbprefix)
+			{
+				$item = $this->dbprefix.$item;
+			}		
+		}
+
+		if ($protect_identifiers === TRUE AND ! in_array($item, $this->_reserved_identifiers))
+		{
+			$item = $this->_escape_identifiers($item);
+		}
+		
+		return $item.$alias;
+	}
+
+
+}
+
+
+/* End of file DB_driver.php */
+/* Location: ./system/database/DB_driver.php */
\ No newline at end of file