Merge branch 'develop' of git://github.com/EllisLab/CodeIgniter into develop

Conflicts:
	system/core/Loader.php
	system/database/DB_query_builder.php
	system/database/drivers/cubrid/cubrid_driver.php
	system/database/drivers/mssql/mssql_driver.php
	system/database/drivers/mysql/mysql_driver.php
	system/database/drivers/mysqli/mysqli_driver.php
	system/database/drivers/oci8/oci8_driver.php
	system/database/drivers/odbc/odbc_driver.php
	system/database/drivers/pdo/pdo_driver.php
	system/database/drivers/postgre/postgre_driver.php
	system/database/drivers/sqlite/sqlite_driver.php
	user_guide_src/source/changelog.rst
	user_guide_src/source/database/query_builder.rst

1 files changed, 120 insertions, 358 deletions

diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 83a9c31ca..f4c3a7438 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_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
+ * An open source application development framework for PHP 5.2.4 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
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * PDO Database Adapter Class
  *
@@ -42,28 +40,28 @@
  */
 class CI_DB_pdo_driver extends CI_DB {
 
-	var $dbdriver = 'pdo';
+	public $dbdriver = 'pdo';
 
 	// the character used to excape - not necessary for PDO
-	var $_escape_char = '';
+	protected $_escape_char = '';
 
 	// clause and character used for LIKE escape sequences
-	var $_like_escape_str;
-	var $_like_escape_chr;
+	protected $_like_escape_str = " ESCAPE '%s' ";
+	protected $_like_escape_chr = '!';
 
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
 	 * used for the count_all() and count_all_results() functions.
 	 */
-	var $_count_string = "SELECT COUNT(*) AS ";
-	var $_random_keyword;
+	protected $_count_string = 'SELECT COUNT(*) AS ';
+	protected $_random_keyword;
 
 	// need to track the pdo driver and options
-	var $pdodriver;
-	var $options = array();
+	public $pdodriver;
+	public $options = array();
 
-	function __construct($params)
+	public function __construct($params)
 	{
 		parent::__construct($params);
 
@@ -83,32 +81,30 @@ class CI_DB_pdo_driver extends CI_DB {
 		// this one depends on the driver being used
 		if ($this->pdodriver == 'mysql')
 		{
+			$this->_escape_char = '`';
 			$this->_like_escape_str = '';
 			$this->_like_escape_chr = '';
 		}
 		elseif ($this->pdodriver == 'odbc')
 		{
 			$this->_like_escape_str = " {escape '%s'} ";
-			$this->_like_escape_chr = '!';
 		}
-		else
+		elseif ( ! in_array($this->pdodriver, array('sqlsrv', 'mssql', 'dblib', 'sybase')))
 		{
-			$this->_like_escape_str = " ESCAPE '%s' ";
-			$this->_like_escape_chr = '!';
+			$this->_escape_char = '"';
 		}
-		
-		$this->trans_enabled   = FALSE;
+
+		$this->trans_enabled = FALSE;
 		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
 	}
 
 	/**
 	 * Connection String
 	 *
-	 * @access	private
 	 * @param	array
 	 * @return	void
 	 */
-	function _connect_string($params)
+	protected function _connect_string($params)
 	{
 		if (strpos($this->hostname, ':'))
 		{
@@ -138,7 +134,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			$this->dsn = $this->pdodriver.':';
 
 			// Add hostname to the DSN for databases that need it
-			if ( ! empty($this->hostname) 
+			if ( ! empty($this->hostname)
 				&& strpos($this->hostname, ':') === FALSE
 				&& in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'sybase', 'mssql', 'dblib', 'cubrid')))
 			{
@@ -153,7 +149,7 @@ class CI_DB_pdo_driver extends CI_DB {
 		}
 
 		// Add the database name to the DSN, if needed
-	    if (stripos($this->dsn, 'dbname') === FALSE 
+	    if (stripos($this->dsn, 'dbname') === FALSE
 	       && in_array($this->pdodriver, array('4D', 'pgsql', 'mysql', 'firebird', 'sybase', 'mssql', 'dblib', 'cubrid')))
 	    {
 	        $this->dsn .= 'dbname='.$this->database.';';
@@ -187,17 +183,16 @@ class CI_DB_pdo_driver extends CI_DB {
 	    }
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @return	object
 	 */
-	function db_connect()
+	public function db_connect()
 	{
-		$this->options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_SILENT;
-
-		return $this->pdo_connect();
+		return $this->_pdo_connect();
 	}
 
 	// --------------------------------------------------------------------
@@ -205,15 +200,11 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Persistent database connection
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @return	object
 	 */
-	function db_pconnect()
+	public function db_pconnect()
 	{
-		$this->options[PDO::ATTR_ERRMODE]    = PDO::ERRMODE_SILENT;
-		$this->options[PDO::ATTR_PERSISTENT] = TRUE;
-	
-		return $this->pdo_connect();
+		return $this->_pdo_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
@@ -221,23 +212,31 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * PDO connection
 	 *
-	 * @access	private called by the PDO driver class
-	 * @return	resource
+	 * @param	bool
+	 * @return	object
 	 */
-	function pdo_connect()
+	protected function _pdo_connect($persistent = FALSE)
 	{
-		// Refer : http://php.net/manual/en/ref.pdo-mysql.connection.php
-		if ($this->pdodriver == 'mysql' && is_php('5.3.6'))
+		$this->options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_SILENT;
+		$persistent === FALSE OR $this->options[PDO::ATTR_PERSISTENT] = TRUE;
+
+		/* Prior to PHP 5.3.6, even if the charset was supplied in the DSN
+		 * on connect - it was ignored. This is a work-around for the issue.
+		 *
+		 * Reference: http://www.php.net/manual/en/ref.pdo-mysql.connection.php
+		 */
+		if ($this->subdriver === 'mysql' && ! is_php('5.3.6') && ! empty($this->char_set))
 		{
-			$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = "SET NAMES $this->char_set COLLATE '$this->dbcollat'";
+			$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES '.$this->char_set
+					.( ! empty($this->db_collat) ? " COLLATE '".$this->dbcollat."'" : '');
 		}
 
 		// Connecting...
-		try 
+		try
 		{
-			$db = new PDO($this->dsn, $this->username, $this->password, $this->options);
-		} 
-		catch (PDOException $e) 
+			return new PDO($this->dsn, $this->username, $this->password, $this->options);
+		}
+		catch (PDOException $e)
 		{
 			if ($this->db_debug && empty($this->failover))
 			{
@@ -246,43 +245,6 @@ class CI_DB_pdo_driver extends CI_DB {
 
 			return FALSE;
 		}
-
-		return $db;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Reconnect
-	 *
-	 * Keep / reestablish the db connection if no queries have been
-	 * sent for a length of time exceeding the server's idle timeout
-	 *
-	 * @access	public
-	 * @return	void
-	 */
-	function reconnect()
-	{
-		if ($this->db->db_debug)
-		{
-			return $this->db->display_error('db_unsuported_feature');
-		}
-
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Select the database
-	 *
-	 * @access	private called by the base class
-	 * @return	resource
-	 */
-	function db_select()
-	{
-		// Not needed for PDO
-		return TRUE;
 	}
 
 	// --------------------------------------------------------------------
@@ -304,53 +266,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @access	private called by the base class
-	 * @param	string	an SQL query
-	 * @return	object
-	 */
-	function _execute($sql)
-	{
-		$sql = $this->_prep_query($sql);
-
-		$result_id = $this->conn_id->query($sql);
-		
-		if (is_object($result_id))
-		{
-			$this->affect_rows = $result_id->rowCount();
-		}
-		else
-		{
-			$this->affect_rows = 0;
-		}
-		
-		return $result_id;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Prep the query
-	 *
-	 * If needed, each database adapter can prep the query string
-	 *
-	 * @access	private called by execute()
 	 * @param	string	an SQL query
-	 * @return	string
+	 * @return	mixed
 	 */
-	function _prep_query($sql)
+	protected function _execute($sql)
 	{
-		if ($this->pdodriver === 'pgsql')
-		{
-			// Change the backtick(s) for Postgre
-			$sql = str_replace('`', '"', $sql);
-		}
-		elseif ($this->pdodriver === 'sqlite')
-		{
-			// Change the backtick(s) for SQLite
-			$sql = str_replace('`', '', $sql);
-		}
-
-		return $sql;
+		return $this->conn_id->query($sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -358,18 +279,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_begin($test_mode = FALSE)
+	public function trans_begin($test_mode = FALSE)
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -377,7 +292,7 @@ class CI_DB_pdo_driver extends CI_DB {
 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
-		$this->_trans_failure = (bool) ($test_mode === TRUE);
+		$this->_trans_failure = ($test_mode === TRUE);
 
 		return $this->conn_id->beginTransaction();
 	}
@@ -387,25 +302,17 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Commit Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_commit()
+	public function trans_commit()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		$ret = $this->conn->commit();
-		
-		return $ret;
+		return $this->conn_id->commit();
 	}
 
 	// --------------------------------------------------------------------
@@ -413,25 +320,17 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Rollback Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_rollback()
+	public function trans_rollback()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		$ret = $this->conn_id->rollBack();
-
-		return $ret;
+		return $this->conn_id->rollBack();
 	}
 
 	// --------------------------------------------------------------------
@@ -439,12 +338,11 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	bool	whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
-	function escape_str($str, $like = FALSE)
+	public function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
@@ -455,24 +353,22 @@ class CI_DB_pdo_driver extends CI_DB {
 
 			return $str;
 		}
-		
-		//Escape the string
+
+		// Escape the string
 		$str = $this->conn_id->quote($str);
-		
-		//If there are duplicated quotes, trim them away
+
+		// If there are duplicated quotes, trim them away
 		if (strpos($str, "'") === 0)
 		{
 			$str = substr($str, 1, -1);
 		}
-		
+
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(	array('%', '_', $this->_like_escape_chr),
-								array($this->_like_escape_chr.'%', 
-								      $this->_like_escape_chr.'_', 
-								      $this->_like_escape_chr.$this->_like_escape_chr),
-								$str);
+			return str_replace(array($this->_like_escape_chr, '%', '_'),
+						array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
+						$str);
 		}
 
 		return $str;
@@ -483,12 +379,11 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Affected Rows
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function affected_rows()
+	public function affected_rows()
 	{
-		return $this->affect_rows;
+		return is_object($this->result_id) ? $this->result_id->rowCount() : 0;
 	}
 
 	// --------------------------------------------------------------------
@@ -496,6 +391,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Insert ID
 	 *
+	 * @param	string
 	 * @return	int
 	 */
 	public function insert_id($name = NULL)
@@ -518,11 +414,10 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * Generates a platform-specific query string that counts all records in
 	 * the specified database
 	 *
-	 * @access	public
 	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	public function count_all($table = '')
 	{
 		if ($table == '')
 		{
@@ -550,25 +445,29 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
-	 * @param	boolean
+	 * @param	bool
 	 * @return	string
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
 		if ($this->pdodriver == 'pgsql')
 		{
 			// Analog function to show all tables in postgre
 			$sql = "SELECT * FROM information_schema.tables WHERE table_schema = 'public'";
 		}
+		elseif ($this->pdodriver == 'sqlite')
+		{
+			// Analog function to show all tables in sqlite
+			$sql = "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'";
+		}
 		else
 		{
-			$sql = "SHOW TABLES FROM `".$this->database."`";
+			$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 		}
 
 		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
 		{
-			return FALSE; 
+			return FALSE;
 		}
 
 		return $sql;
@@ -581,13 +480,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
-		return 'SHOW COLUMNS FROM '.$this->_from_tables($table);
+		return 'SHOW COLUMNS FROM '.$this->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -597,13 +495,28 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	string
 	 */
-	function _field_data($table)
+	protected function _field_data($table)
 	{
-		return 'SELECT TOP 1 FROM '.$this->_from_tables($table);
+		if ($this->pdodriver == 'mysql' or $this->pdodriver == 'pgsql')
+		{
+			// Analog function for mysql and postgre
+			return 'SELECT * FROM '.$this->escape_identifiers($table).' LIMIT 1';
+		}
+		elseif ($this->pdodriver == 'oci')
+		{
+			// Analog function for oci
+			return 'SELECT * FROM '.$this->escape_identifiers($table).' WHERE ROWNUM <= 1';
+		}
+		elseif ($this->pdodriver == 'sqlite')
+		{
+			// Analog function for sqlite
+			return 'PRAGMA table_info('.$this->escape_identifiers($table).')';
+		}
+
+		return 'SELECT TOP 1 FROM '.$this->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -638,150 +551,37 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @access	private
-	 * @param	string
-	 * @return	string
-	 */
-	function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str  = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-			$str .= $this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
 	 * about operator precedence in harmony with SQL standards
 	 *
-	 * @access	public
-	 * @param	type
-	 * @return	type
+	 * @param	array
+	 * @return	string
 	 */
-	function _from_tables($tables)
+	protected function _from_tables($tables)
 	{
 		if ( ! is_array($tables))
 		{
 			$tables = array($tables);
 		}
 
-		return (count($tables) == 1) ? '`'.$tables[0].'`' : '('.implode(', ', $tables).')';
+		return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$this->_from_tables($table).' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-	
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @access  public
-	 * @param   string  the table name
-	 * @param   array   the insert keys
-	 * @param   array   the insert values
-	 * @return  string
-	 */
-	function _insert_batch($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$this->_from_tables($table).' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit   = ( ! $limit) ? '' : ' LIMIT '.$limit;
-		$orderby = (count($orderby) >= 1) ? ' ORDER BY '.implode(', ', $orderby) : '';
-
-		$sql  = 'UPDATE '.$this->_from_tables($table).' SET '.implode(', ', $valstr);
-		$sql .= ($where != '' && count($where) >= 1) ? ' WHERE '.implode(' ', $where) : '';
-		$sql .= $orderby.$limit;
-
-		return $sql;
-	}
-	
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
 	 * @return	string
 	 */
-	function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index, $where = NULL)
 	{
 		$ids   = array();
 		$where = ($where != '' && count($where) >=1) ? implode(" ", $where).' AND ' : '';
@@ -799,7 +599,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			}
 		}
 
-		$sql   = 'UPDATE '.$this->_from_tables($table).' SET ';
+		$sql   = 'UPDATE '.$table.' SET ';
 		$cases = '';
 
 		foreach ($final as $k => $v)
@@ -820,58 +620,22 @@ class CI_DB_pdo_driver extends CI_DB {
 		return $sql;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
-	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	function _truncate($table)
-	{
-		return $this->_delete($table);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete statement
 	 *
-	 * Generates a platform-specific delete string from the supplied data
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _truncate($table)
 	{
-		$conditions = '';
-
-		if (count($where) > 0 OR count($like) > 0)
-		{
-			$conditions  = "\nWHERE ";
-			$conditions .= implode("\n", $this->qb_where);
-
-			if (count($where) > 0 && count($like) > 0)
-			{
-				$conditions .= " AND ";
-			}
-
-			$conditions .= implode("\n", $like);
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		return 'DELETE FROM '.$this->_from_tables($table).$conditions.$limit;
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
@@ -881,13 +645,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @access	public
 	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _limit($sql, $limit, $offset)
 	{
 		if ($this->pdodriver == 'cubrid' OR $this->pdodriver == 'sqlite')
 		{
@@ -899,7 +662,7 @@ class CI_DB_pdo_driver extends CI_DB {
 		{
 			$sql .= 'LIMIT '.$limit;
 			$sql .= ($offset > 0) ? ' OFFSET '.$offset : '';
-			
+
 			return $sql;
 		}
 	}
@@ -909,13 +672,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
-	 * @param	resource
+	 * @param	object
 	 * @return	void
 	 */
-	function _close($conn_id)
+	protected function _close($conn_id)
 	{
-		$this->conn_id = null;
+		$this->conn_id = NULL;
 	}
 
 }