Merge upstream branch

1 files changed, 152 insertions, 225 deletions

diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 5f435e363..025441f90 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * Database Driver Class
  *
@@ -42,54 +40,44 @@
  */
 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 $limit_used;
-	
-
-	/**
-	 * Constructor.  Accepts one parameter containing the database
-	 * connection settings.
-	 *
-	 * @param array
-	 */
-	function __construct($params)
+	public $dsn;
+	public $username;
+	public $password;
+	public $hostname;
+	public $database;
+	public $dbdriver		= 'mysql';
+	public $dbprefix		= '';
+	public $char_set		= 'utf8';
+	public $dbcollat		= 'utf8_general_ci';
+	public $autoinit		= TRUE; // Whether to automatically initialize the DB
+	public $swap_pre		= '';
+	public $port			= '';
+	public $pconnect		= FALSE;
+	public $conn_id			= FALSE;
+	public $result_id		= FALSE;
+	public $db_debug		= FALSE;
+	public $benchmark		= 0;
+	public $query_count		= 0;
+	public $bind_marker		= '?';
+	public $save_queries		= TRUE;
+	public $queries			= array();
+	public $query_times		= array();
+	public $data_cache		= array();
+
+	public $trans_enabled		= TRUE;
+	public $trans_strict		= TRUE;
+	protected $_trans_depth		= 0;
+	protected $_trans_status	= TRUE; // Used with transactions to determine if a rollback should occur
+
+	public $cache_on		= FALSE;
+	public $cachedir		= '';
+	public $cache_autodel		= FALSE;
+	public $CACHE; // The cache class object
+
+	protected $_protect_identifiers		= TRUE;
+	protected $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
+
+	public function __construct($params)
 	{
 		if (is_array($params))
 		{
@@ -211,10 +199,9 @@ class CI_DB_driver {
 	/**
 	 * The name of the platform in use (mysql, mssql, etc...)
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function platform()
+	public function platform()
 	{
 		return $this->dbdriver;
 	}
@@ -222,36 +209,40 @@ class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Database Version Number.  Returns a string containing the
-	 * version of the database being used
+	 * Database version number
+	 *
+	 * Returns a string containing the version of the database being used.
+	 * Most drivers will override this method.
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function version()
+	public function version()
 	{
-		if (FALSE === ($sql = $this->_version()))
+		if (isset($this->data_cache['version']))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return $this->data_cache['version'];
 		}
 
-		// Some DBs have functions that return the version, and don't run special
-		// SQL queries per se. In these instances, just return the result.
-		$driver_version_exceptions = array('oci8', 'sqlite', 'cubrid', 'pdo', 'mysqli');
-
-		if (in_array($this->dbdriver, $driver_version_exceptions))
-		{
-			return $sql;
-		}
-		else
+		if (FALSE === ($sql = $this->_version()))
 		{
-			$query = $this->query($sql);
-			return $query->row('ver');
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
+
+		$query = $this->query($sql);
+		$query = $query->row();
+		return $this->data_cache['version'] = $query->ver;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Version number query string
+	 *
+	 * @return	string
+	 */
+	protected function _version()
+	{
+		return 'SELECT VERSION() AS ver';
 	}
 
 	// --------------------------------------------------------------------
@@ -260,17 +251,16 @@ class CI_DB_driver {
 	 * 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
+	 * 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, $return_object = TRUE)
+	public function query($sql, $binds = FALSE, $return_object = TRUE)
 	{
 		if ($sql == '')
 		{
@@ -289,7 +279,13 @@ class CI_DB_driver {
 			$sql = preg_replace("/(\W)".$this->swap_pre."(\S+?)/", "\\1".$this->dbprefix."\\2", $sql);
 		}
 
-		// Is query caching enabled?  If the query is a "read type"
+		// Compile binds if needed
+		if ($binds !== FALSE)
+		{
+			$sql = $this->compile_binds($sql, $binds);
+		}
+
+		// Is query caching enabled? If the query is a "read type"
 		// we will load the caching class and return the previously
 		// cached query if it exists
 		if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))
@@ -304,12 +300,6 @@ class CI_DB_driver {
 			}
 		}
 
-		// Compile binds if needed
-		if ($binds !== FALSE)
-		{
-			$sql = $this->compile_binds($sql, $binds);
-		}
-
 		// Save the  query for debugging
 		if ($this->save_queries == TRUE)
 		{
@@ -330,30 +320,28 @@ class CI_DB_driver {
 			// This will trigger a rollback if transactions are being used
 			$this->_trans_status = FALSE;
 
-			// 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();
+			// Grab the error now, as we might run some additional queries before displaying the error
+			$error = $this->error();
 
 			// Log errors
-			log_message('error', 'Query error: '.$error_msg);
+			log_message('error', 'Query error: '.$error['message']);
 
 			if ($this->db_debug)
 			{
 				// We call this function in order to roll-back queries
-				// if transactions are enabled.  If we don't call this here
+				// 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();
 
 				// Display errors
 				return $this->display_error(
-										array(
-												'Error Number: '.$error_no,
-												$error_msg,
-												$sql
-											)
-										);
+								array(
+									'Error Number: '.$error['code'],
+									$error['message'],
+									$sql
+								)
+							);
 			}
 
 			return FALSE;
@@ -394,21 +382,9 @@ class CI_DB_driver {
 		}
 
 		// Load and instantiate the result driver
+		$driver		= $this->load_rdriver();
+		$RES		= new $driver($this);
 
-		$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
@@ -441,10 +417,9 @@ class CI_DB_driver {
 	/**
 	 * Load the result drivers
 	 *
-	 * @access	public
 	 * @return	string	the name of the result class
 	 */
-	function load_rdriver()
+	public function load_rdriver()
 	{
 		$driver = 'CI_DB_'.$this->dbdriver.'_result';
 
@@ -461,15 +436,14 @@ class CI_DB_driver {
 
 	/**
 	 * Simple Query
-	 * This is a simplified version of the query() function.  Internally
+	 * 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($sql)
+	public function simple_query($sql)
 	{
 		if ( ! $this->conn_id)
 		{
@@ -485,10 +459,9 @@ class CI_DB_driver {
 	 * Disable Transactions
 	 * This permits transactions to be disabled at run-time.
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function trans_off()
+	public function trans_off()
 	{
 		$this->trans_enabled = FALSE;
 	}
@@ -502,10 +475,9 @@ class CI_DB_driver {
 	 * If strict mode is disabled, each group is treated autonomously, meaning
 	 * a failure of one group will not affect any others
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function trans_strict($mode = TRUE)
+	public function trans_strict($mode = TRUE)
 	{
 		$this->trans_strict = is_bool($mode) ? $mode : TRUE;
 	}
@@ -515,10 +487,9 @@ class CI_DB_driver {
 	/**
 	 * Start Transaction
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function trans_start($test_mode = FALSE)
+	public function trans_start($test_mode = FALSE)
 	{
 		if ( ! $this->trans_enabled)
 		{
@@ -541,10 +512,9 @@ class CI_DB_driver {
 	/**
 	 * Complete Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_complete()
+	public function trans_complete()
 	{
 		if ( ! $this->trans_enabled)
 		{
@@ -588,10 +558,9 @@ class CI_DB_driver {
 	/**
 	 * Lets you retrieve the transaction flag to determine if it has failed
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_status()
+	public function trans_status()
 	{
 		return $this->_trans_status;
 	}
@@ -601,12 +570,11 @@ class CI_DB_driver {
 	/**
 	 * Compile Bindings
 	 *
-	 * @access	public
 	 * @param	string	the sql statement
 	 * @param	array	an array of bind data
 	 * @return	string
 	 */
-	function compile_binds($sql, $binds)
+	public function compile_binds($sql, $binds)
 	{
 		if (strpos($sql, $this->bind_marker) === FALSE)
 		{
@@ -649,7 +617,7 @@ class CI_DB_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|OPTIMIZE)\s+/i', $sql);
+		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|OPTIMIZE|REINDEX)\s+/i', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -657,11 +625,10 @@ class CI_DB_driver {
 	/**
 	 * Calculate the aggregate query elapsed time
 	 *
-	 * @access	public
-	 * @param	integer	The number of decimal places
-	 * @return	integer
+	 * @param	int	The number of decimal places
+	 * @return	int
 	 */
-	function elapsed_time($decimals = 6)
+	public function elapsed_time($decimals = 6)
 	{
 		return number_format($this->benchmark, $decimals);
 	}
@@ -671,10 +638,9 @@ class CI_DB_driver {
 	/**
 	 * Returns the total number of queries
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function total_queries()
+	public function total_queries()
 	{
 		return $this->query_count;
 	}
@@ -684,10 +650,9 @@ class CI_DB_driver {
 	/**
 	 * Returns the last query that was executed
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	string
 	 */
-	function last_query()
+	public function last_query()
 	{
 		return end($this->queries);
 	}
@@ -700,11 +665,10 @@ class CI_DB_driver {
 	 * Escapes data based on type
 	 * Sets boolean and null types
 	 *
-	 * @access	public
 	 * @param	string
 	 * @return	mixed
 	 */
-	function escape($str)
+	public function escape($str)
 	{
 		if (is_string($str))
 		{
@@ -730,11 +694,10 @@ class CI_DB_driver {
 	 * Calls the individual driver for platform
 	 * specific escaping for LIKE conditions
 	 *
-	 * @access	public
 	 * @param	string
 	 * @return	mixed
 	 */
-	function escape_like_str($str)
+	public function escape_like_str($str)
 	{
 		return $this->escape_str($str, TRUE);
 	}
@@ -744,14 +707,13 @@ class CI_DB_driver {
 	/**
 	 * Primary
 	 *
-	 * Retrieves the primary key.  It assumes that the row in the first
+	 * 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($table = '')
+	public function primary($table = '')
 	{
 		$fields = $this->list_fields($table);
 
@@ -768,10 +730,9 @@ class CI_DB_driver {
 	/**
 	 * Returns an array of table names
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function list_tables($constrain_by_prefix = FALSE)
+	public function list_tables($constrain_by_prefix = FALSE)
 	{
 		// Is there a cached result?
 		if (isset($this->data_cache['table_names']))
@@ -809,7 +770,7 @@ class CI_DB_driver {
 		}
 
 		$this->data_cache['table_names'] = $retval;
-		
+
 		return $this->data_cache['table_names'];
 	}
 
@@ -817,12 +778,12 @@ class CI_DB_driver {
 
 	/**
 	 * Determine if a particular table exists
-	 * @access	public
-	 * @return	boolean
+	 *
+	 * @return	bool
 	 */
-	function table_exists($table_name)
+	public function table_exists($table_name)
 	{
-		return ( ! in_array($this->_protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables())) ? FALSE : TRUE;
+		return in_array($this->protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables());
 	}
 
 	// --------------------------------------------------------------------
@@ -830,11 +791,10 @@ class CI_DB_driver {
 	/**
 	 * Fetch MySQL Field Names
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	array
 	 */
-	function list_fields($table = '')
+	public function list_fields($table = '')
 	{
 		// Is there a cached result?
 		if (isset($this->data_cache['field_names'][$table]))
@@ -883,12 +843,12 @@ class CI_DB_driver {
 
 	/**
 	 * Determine if a particular field exists
-	 * @access	public
+	 *
 	 * @param	string
 	 * @param	string
-	 * @return	boolean
+	 * @return	bool
 	 */
-	function field_exists($field_name, $table_name)
+	public function field_exists($field_name, $table_name)
 	{
 		return ( ! in_array($field_name, $this->list_fields($table_name))) ? FALSE : TRUE;
 	}
@@ -898,11 +858,10 @@ class CI_DB_driver {
 	/**
 	 * Returns an object with field data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	object
 	 */
-	function field_data($table = '')
+	public function field_data($table = '')
 	{
 		if ($table == '')
 		{
@@ -913,7 +872,7 @@ class CI_DB_driver {
 			return FALSE;
 		}
 
-		$query = $this->query($this->_field_data($this->_protect_identifiers($table, TRUE, NULL, FALSE)));
+		$query = $this->query($this->_field_data($this->protect_identifiers($table, TRUE, NULL, FALSE)));
 
 		return $query->field_data();
 	}
@@ -923,12 +882,11 @@ class CI_DB_driver {
 	/**
 	 * Generate an insert string
 	 *
-	 * @access	public
 	 * @param	string	the table upon which the query will be performed
 	 * @param	array	an associative array data of key/values
 	 * @return	string
 	 */
-	function insert_string($table, $data)
+	public function insert_string($table, $data)
 	{
 		$fields = array();
 		$values = array();
@@ -939,7 +897,7 @@ class CI_DB_driver {
 			$values[] = $this->escape($val);
 		}
 
-		return $this->_insert($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);
+		return $this->_insert($this->protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -947,23 +905,22 @@ class CI_DB_driver {
 	/**
 	 * 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, $where)
+	public function update_string($table, $data, $where)
 	{
 		if ($where == '')
 		{
-			return false;
+			return FALSE;
 		}
 
 		$fields = array();
 		foreach ($data as $key => $val)
 		{
-			$fields[$this->_protect_identifiers($key)] = $this->escape($val);
+			$fields[$this->protect_identifiers($key)] = $this->escape($val);
 		}
 
 		if ( ! is_array($where))
@@ -976,7 +933,7 @@ class CI_DB_driver {
 			foreach ($where as $key => $val)
 			{
 				$prefix = (count($dest) == 0) ? '' : ' AND ';
-				$key = $this->_protect_identifiers($key);
+				$key = $this->protect_identifiers($key);
 
 				if ($val !== '')
 				{
@@ -992,7 +949,7 @@ class CI_DB_driver {
 			}
 		}
 
-		return $this->_update($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $dest);
+		return $this->_update($this->protect_identifiers($table, TRUE, NULL, FALSE), $fields, $dest);
 	}
 
 	// --------------------------------------------------------------------
@@ -1000,11 +957,10 @@ class CI_DB_driver {
 	/**
 	 * Tests whether the string has an SQL operator
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	bool
 	 */
-	function _has_operator($str)
+	protected function _has_operator($str)
 	{
 		$str = trim($str);
 		if ( ! preg_match("/(\s|<|>|!|=|is null|is not null)/i", $str))
@@ -1020,12 +976,11 @@ class CI_DB_driver {
 	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
-	 * @access	public
 	 * @param	string	the function name
 	 * @param	mixed	any parameters needed by the function
 	 * @return	mixed
 	 */
-	function call_function($function)
+	public function call_function($function)
 	{
 		$driver = ($this->dbdriver == 'postgre') ? 'pg_' : $this->dbdriver.'_';
 
@@ -1062,11 +1017,10 @@ class CI_DB_driver {
 	/**
 	 * Set Cache Directory Path
 	 *
-	 * @access	public
 	 * @param	string	the path to the cache directory
 	 * @return	void
 	 */
-	function cache_set_path($path = '')
+	public function cache_set_path($path = '')
 	{
 		$this->cachedir = $path;
 	}
@@ -1076,10 +1030,9 @@ class CI_DB_driver {
 	/**
 	 * Enable Query Caching
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool	cache_on value
 	 */
-	function cache_on()
+	public function cache_on()
 	{
 		$this->cache_on = TRUE;
 		return TRUE;
@@ -1090,10 +1043,9 @@ class CI_DB_driver {
 	/**
 	 * Disable Query Caching
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool	cache_on value
 	 */
-	function cache_off()
+	public function cache_off()
 	{
 		$this->cache_on = FALSE;
 		return FALSE;
@@ -1105,10 +1057,9 @@ class CI_DB_driver {
 	/**
 	 * Delete the cache files associated with a particular URI
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool
 	 */
-	function cache_delete($segment_one = '', $segment_two = '')
+	public function cache_delete($segment_one = '', $segment_two = '')
 	{
 		if ( ! $this->_cache_init())
 		{
@@ -1122,10 +1073,9 @@ class CI_DB_driver {
 	/**
 	 * Delete All cache files
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool
 	 */
-	function cache_delete_all()
+	public function cache_delete_all()
 	{
 		if ( ! $this->_cache_init())
 		{
@@ -1140,10 +1090,9 @@ class CI_DB_driver {
 	/**
 	 * Initialize the Cache Class
 	 *
-	 * @access	private
-	 * @return	void
+	 * @return	bool
 	 */
-	function _cache_init()
+	protected function _cache_init()
 	{
 		if (is_object($this->CACHE) AND class_exists('CI_DB_Cache'))
 		{
@@ -1167,10 +1116,9 @@ class CI_DB_driver {
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function close()
+	public function close()
 	{
 		if (is_resource($this->conn_id) OR is_object($this->conn_id))
 		{
@@ -1184,13 +1132,12 @@ class CI_DB_driver {
 	/**
 	 * Display an error message
 	 *
-	 * @access	public
 	 * @param	string	the error message
 	 * @param	string	any "swap" values
-	 * @param	boolean	whether to localize the message
+	 * @param	bool	whether to localize the message
 	 * @return	string	sends the application/error_db.php template
 	 */
-	function display_error($error = '', $swap = '', $native = FALSE)
+	public function display_error($error = '', $swap = '', $native = FALSE)
 	{
 		$LANG =& load_class('Lang', 'core');
 		$LANG->load('db');
@@ -1234,27 +1181,11 @@ class CI_DB_driver {
 	/**
 	 * Protect Identifiers
 	 *
-	 * This function adds backticks if appropriate based on db type
-	 *
-	 * @access	private
-	 * @param	mixed	the item to escape
-	 * @return	mixed	the item with backticks
-	 */
-	function protect_identifiers($item, $prefix_single = FALSE)
-	{
-		return $this->_protect_identifiers($item, $prefix_single);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Protect Identifiers
-	 *
 	 * This function is used extensively by the Active Record class, and by
 	 * a couple functions in this class.
 	 * It takes a column or table name (optionally with an alias) and inserts
 	 * the table prefix onto it.  Some logic is necessary in order to deal with
-	 * column names that include the path.  Consider a query like this:
+	 * column names that include the path. Consider a query like this:
 	 *
 	 * SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
 	 *
@@ -1267,14 +1198,13 @@ class CI_DB_driver {
 	 * insert the table prefix (if it exists) in the proper position, and escape only
 	 * the correct identifiers.
 	 *
-	 * @access	private
 	 * @param	string
 	 * @param	bool
 	 * @param	mixed
 	 * @param	bool
 	 * @return	string
 	 */
-	function _protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
+	public function protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
 	{
 		if ( ! is_bool($protect_identifiers))
 		{
@@ -1284,10 +1214,9 @@ class CI_DB_driver {
 		if (is_array($item))
 		{
 			$escaped_array = array();
-
 			foreach ($item as $k => $v)
 			{
-				$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v);
+				$escaped_array[$this->protect_identifiers($k)] = $this->protect_identifiers($v);
 			}
 
 			return $escaped_array;
@@ -1307,7 +1236,7 @@ class CI_DB_driver {
 
 		// 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
+		// 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)
 		{
@@ -1322,7 +1251,7 @@ class CI_DB_driver {
 			$parts	= explode('.', $item);
 
 			// Does the first segment of the exploded item match
-			// one of the aliases previously identified?  If so,
+			// 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))
 			{
@@ -1341,7 +1270,7 @@ class CI_DB_driver {
 				return $item.$alias;
 			}
 
-			// Is there a table prefix defined in the config file?  If not, no need to do anything
+			// 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.
@@ -1395,7 +1324,7 @@ class CI_DB_driver {
 			return $item.$alias;
 		}
 
-		// Is there a table prefix?  If not, no need to insert it
+		// Is there a table prefix? If not, no need to insert it
 		if ($this->dbprefix != '')
 		{
 			// Verify table prefix and replace if necessary
@@ -1418,7 +1347,7 @@ class CI_DB_driver {
 
 		return $item.$alias;
 	}
-	
+
 	// --------------------------------------------------------------------
 
 	/**
@@ -1426,12 +1355,10 @@ class CI_DB_driver {
 	 *
 	 * This function is used extensively by every db driver.
 	 *
-	 * @access	private
 	 * @return	void
 	 */
 	protected function _reset_select()
 	{
-	
 	}
 
 }