Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	user_guide_src/source/changelog.rst

Signed-off-by: Jonathon Hill <jhill@brandmovers.com>

162 files changed, 7927 insertions, 2854 deletions

diff --git a/system/core/Benchmark.php b/system/core/Benchmark.php
index f94db2721..e80ee54dd 100644
--- a/system/core/Benchmark.php
+++ b/system/core/Benchmark.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Benchmark Class
diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index f27086386..89081b572 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * System Initialization File
@@ -255,23 +256,22 @@
  *  Security check
  * ------------------------------------------------------
  *
- *  None of the functions in the app controller or the
+ *  None of the methods in the app controller or the
  *  loader class can be called via the URI, nor can
- *  controller functions that begin with an underscore
+ *  controller functions that begin with an underscore.
  */
 	$class  = $RTR->fetch_class();
 	$method = $RTR->fetch_method();
 
-	if ( ! class_exists($class)
-		OR strpos($method, '_') === 0
-		OR in_array(strtolower($method), array_map('strtolower', get_class_methods('CI_Controller')))
-		)
+	if ( ! class_exists($class) OR $method[0] === '_' OR method_exists('CI_Controller', $method))
 	{
 		if ( ! empty($RTR->routes['404_override']))
 		{
-			$x = explode('/', $RTR->routes['404_override'], 2);
-			$class = $x[0];
-			$method = isset($x[1]) ? $x[1] : 'index';
+			if (sscanf($RTR->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
+
 			if ( ! class_exists($class))
 			{
 				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
@@ -288,6 +288,42 @@
 		}
 	}
 
+	if (method_exists($class, '_remap'))
+	{
+		$params = array($method, array_slice($URI->rsegments, 2));
+		$method = '_remap';
+	}
+	else
+	{
+		// WARNING: It appears that there are issues with is_callable() even in PHP 5.2!
+		// Furthermore, there are bug reports and feature/change requests related to it
+		// that make it unreliable to use in this context. Please, DO NOT change this
+		// work-around until a better alternative is available.
+		if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($class)), TRUE))
+		{
+			if (empty($RTR->routes['404_override']))
+			{
+				show_404($class.'/'.$method);
+			}
+			elseif (sscanf($RTR->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
+
+			if ( ! class_exists($class))
+			{
+				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
+				{
+					show_404($class.'/'.$method);
+				}
+
+				include_once(APPPATH.'controllers/'.$class.'.php');
+			}
+		}
+
+		$params = array_slice($URI->rsegments, 2);
+	}
+
 /*
  * ------------------------------------------------------
  *  Is there a "pre_controller" hook?
@@ -317,45 +353,7 @@
  *  Call the requested method
  * ------------------------------------------------------
  */
-	// Is there a "remap" function? If so, we call it instead
-	if (method_exists($CI, '_remap'))
-	{
-		$CI->_remap($method, array_slice($URI->rsegments, 2));
-	}
-	else
-	{
-		// is_callable() returns TRUE on some versions of PHP 5 for private and protected
-		// methods, so we'll use this workaround for consistent behavior
-		if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($CI))))
-		{
-			// Check and see if we are using a 404 override and use it.
-			if ( ! empty($RTR->routes['404_override']))
-			{
-				$x = explode('/', $RTR->routes['404_override'], 2);
-				$class = $x[0];
-				$method = isset($x[1]) ? $x[1] : 'index';
-				if ( ! class_exists($class))
-				{
-					if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
-					{
-						show_404($class.'/'.$method);
-					}
-
-					include_once(APPPATH.'controllers/'.$class.'.php');
-					unset($CI);
-					$CI = new $class();
-				}
-			}
-			else
-			{
-				show_404($class.'/'.$method);
-			}
-		}
-
-		// Call the requested method.
-		// Any URI segments present (besides the class/function) will be passed to the method for convenience
-		call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2));
-	}
+	call_user_func_array(array(&$CI, $method), $params);
 
 	// Mark a benchmark end point
 	$BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_end');
diff --git a/system/core/Common.php b/system/core/Common.php
index 2dd31d3e9..7feb16bfd 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Common Functions
@@ -419,7 +420,7 @@ if ( ! function_exists('log_message'))
 			return;
 		}
 
-		$_log =& load_class('Log');
+		$_log =& load_class('Log', 'core');
 		$_log->write_log($level, $message, $php_error);
 	}
 }
@@ -650,5 +651,52 @@ if ( ! function_exists('_stringify_attributes'))
 	}
 }
 
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('function_usable'))
+{
+	/**
+	 * Function usable
+	 *
+	 * Executes a function_exists() check, and if the Suhosin PHP
+	 * extension is loaded - checks whether the function that is
+	 * checked might be disabled in there as well.
+	 *
+	 * This is useful as function_exists() will return FALSE for
+	 * functions disabled via the *disable_functions* php.ini
+	 * setting, but not for *suhosin.executor.func.blacklist* and
+	 * *suhosin.executor.disable_eval*. These settings will just
+	 * terminate script execution if a disabled function is executed.
+	 *
+	 * @link	http://www.hardened-php.net/suhosin/
+	 * @param	string	$function_name	Function to check for
+	 * @return	bool	TRUE if the function exists and is safe to call,
+	 *			FALSE otherwise.
+	 */
+	function function_usable($function_name)
+	{
+		static $_suhosin_func_blacklist;
+
+		if (function_exists($function_name))
+		{
+			if ( ! isset($_suhosin_func_blacklist))
+			{
+				$_suhosin_func_blacklist = extension_loaded('suhosin')
+					? array()
+					: explode(',', trim(@ini_get('suhosin.executor.func.blacklist')));
+
+				if ( ! in_array('eval', $_suhosin_func_blacklist, TRUE) && @ini_get('suhosin.executor.disable_eval'))
+				{
+					$_suhosin_func_blacklist[] = 'eval';
+				}
+			}
+
+			return in_array($function_name, $_suhosin_func_blacklist, TRUE);
+		}
+
+		return FALSE;
+	}
+}
+
 /* End of file Common.php */
 /* Location: ./system/core/Common.php */
\ No newline at end of file
diff --git a/system/core/Config.php b/system/core/Config.php
index 642cee798..8250b5b1a 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Config Class
diff --git a/system/core/Controller.php b/system/core/Controller.php
index 8c2ba893e..ee6fec8d5 100644
--- a/system/core/Controller.php
+++ b/system/core/Controller.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Application Controller Class
diff --git a/system/core/Exceptions.php b/system/core/Exceptions.php
index 556257729..ced65ece4 100644
--- a/system/core/Exceptions.php
+++ b/system/core/Exceptions.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Exceptions Class
diff --git a/system/core/Hooks.php b/system/core/Hooks.php
index d60e9ac5d..3c28ec9ba 100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Hooks Class
diff --git a/system/core/Input.php b/system/core/Input.php
index f6213c34e..adc5f7ac0 100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Input Class
@@ -99,6 +100,16 @@ class CI_Input {
 	protected $headers = array();
 
 	/**
+	 * Input stream data
+	 *
+	 * Parsed from php://input at runtime
+	 *
+	 * @see	CI_Input::input_stream()
+	 * @var	array
+	 */
+	protected $_input_stream = NULL;
+
+	/**
 	 * Class constructor
 	 *
 	 * Determines whether to globally enable the XSS processing
@@ -256,6 +267,37 @@ class CI_Input {
 	// ------------------------------------------------------------------------
 
 	/**
+	 * Fetch an item from the php://input stream
+	 *
+	 * Useful when you need to access PUT, DELETE or PATCH request data.
+	 *
+	 * @param	string	$index		Index for item to be fetched
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
+	public function input_stream($index = '', $xss_clean = FALSE)
+	{
+		// The input stream can only be read once, so we'll need to check
+		// if we have already done that first.
+		if (is_array($this->_input_stream))
+		{
+			return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
+		}
+
+		// Parse the input stream in our cache var
+		parse_str(file_get_contents('php://input'), $this->_input_stream);
+		if ( ! is_array($this->_input_stream))
+		{
+			$this->_input_stream = array();
+			return NULL;
+		}
+
+		return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
 	 * Set cookie
 	 *
 	 * Accepts an arbitrary number of parameters (up to 7) or an associative
@@ -355,11 +397,7 @@ class CI_Input {
 					// Some proxies typically list the whole chain of IP
 					// addresses through which the client has reached us.
 					// e.g. client_ip, proxy_ip1, proxy_ip2, etc.
-					if (strpos($spoof, ',') !== FALSE)
-					{
-						$spoof = explode(',', $spoof, 2);
-						$spoof = $spoof[0];
-					}
+					sscanf($spoof, '%[^,]', $spoof);
 
 					if ( ! $this->valid_ip($spoof))
 					{
@@ -429,7 +467,7 @@ class CI_Input {
 					}
 
 					// Split the netmask length off the network address
-					list($netaddr, $masklen) = explode('/', $proxy_ips[$i], 2);
+					sscanf($proxy_ips[$i], '%[^/]/%d', $netaddr, $masklen);
 
 					// Again, an IPv6 address is most likely in a compressed form
 					if ($separator === ':')
@@ -694,7 +732,7 @@ class CI_Input {
 	 */
 	protected function _clean_input_keys($str)
 	{
-		if ( ! preg_match('/^[a-z0-9:_\/-]+$/i', $str))
+		if ( ! preg_match('/^[a-z0-9:_\/|-]+$/i', $str))
 		{
 			set_status_header(503);
 			exit('Disallowed Key Characters.');
diff --git a/system/core/Lang.php b/system/core/Lang.php
index 251cf6ef1..896385134 100644
--- a/system/core/Lang.php
+++ b/system/core/Lang.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Language Class
diff --git a/system/core/Loader.php b/system/core/Loader.php
index db56ab3ae..1e6eafe8a 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Loader Class
@@ -129,7 +130,7 @@ class CI_Loader {
 	/**
 	 * Class constructor
 	 *
-	 * Sets component load paths gets the initial output buffering level.
+	 * Sets component load paths, gets the initial output buffering level.
 	 *
 	 * @return	void
 	 */
@@ -147,21 +148,18 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Initialize the Loader
+	 * Initializer
 	 *
-	 * @used-by	CI_Controller
+	 * @todo	Figure out a way to move this to the constructor
+	 *		without breaking *package_path*() methods.
 	 * @uses	CI_Loader::_ci_autoloader()
-	 * @return 	object	$this
+	 * @used-by	CI_Controller::__construct()
+	 * @return	void
 	 */
 	public function initialize()
 	{
-		$this->_ci_classes = array();
-		$this->_ci_loaded_files = array();
-		$this->_ci_models = array();
 		$this->_base_classes =& is_loaded();
-
 		$this->_ci_autoloader();
-		return $this;
 	}
 
 	// --------------------------------------------------------------------
@@ -354,26 +352,30 @@ class CI_Loader {
 	/**
 	 * Load the Database Utilities Class
 	 *
-	 * @return	void
+	 * @param	object	$db	Database object
+	 * @param	bool	$return	Whether to return the DB Forge class object or not
+	 * @return	void|object
 	 */
-	public function dbutil()
+	public function dbutil($db = NULL, $return = FALSE)
 	{
-		if ( ! class_exists('CI_DB'))
-		{
-			$this->database();
-		}
-
 		$CI =& get_instance();
 
-		// for backwards compatibility, load dbforge so we can extend dbutils off it
-		// this use is deprecated and strongly discouraged
-		$CI->load->dbforge();
+		if ( ! is_object($db) OR ! ($db instanceof CI_DB))
+		{
+			class_exists('CI_DB', FALSE) OR $this->database();
+			$db =& $CI->db;
+		}
 
 		require_once(BASEPATH.'database/DB_utility.php');
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_utility.php');
-		$class = 'CI_DB_'.$CI->db->dbdriver.'_utility';
+		require_once(BASEPATH.'database/drivers/'.$db->dbdriver.'/'.$db->dbdriver.'_utility.php');
+		$class = 'CI_DB_'.$db->dbdriver.'_utility';
 
-		$CI->dbutil = new $class();
+		if ($return === TRUE)
+		{
+			return new $class($db);
+		}
+
+		$CI->dbutil = new $class($db);
 	}
 
 	// --------------------------------------------------------------------
@@ -381,22 +383,42 @@ class CI_Loader {
 	/**
 	 * Load the Database Forge Class
 	 *
-	 * @return	void
+	 * @param	object	$db	Database object
+	 * @param	bool	$return	Whether to return the DB Forge class object or not
+	 * @return	void|object
 	 */
-	public function dbforge()
+	public function dbforge($db = NULL, $return = FALSE)
 	{
-		if ( ! class_exists('CI_DB'))
+		$CI =& get_instance();
+		if ( ! is_object($db) OR ! ($db instanceof CI_DB))
 		{
-			$this->database();
+			class_exists('CI_DB', FALSE) OR $this->database();
+			$db =& $CI->db;
 		}
 
-		$CI =& get_instance();
-
 		require_once(BASEPATH.'database/DB_forge.php');
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_forge.php');
-		$class = 'CI_DB_'.$CI->db->dbdriver.'_forge';
+		require_once(BASEPATH.'database/drivers/'.$db->dbdriver.'/'.$db->dbdriver.'_forge.php');
 
-		$CI->dbforge = new $class();
+		if ( ! empty($db->subdriver))
+		{
+			$driver_path = BASEPATH.'database/drivers/'.$db->dbdriver.'/subdrivers/'.$db->dbdriver.'_'.$db->subdriver.'_forge.php';
+			if (file_exists($driver_path))
+			{
+				require_once($driver_path);
+				$class = 'CI_DB_'.$db->dbdriver.'_'.$db->subdriver.'_forge';
+			}
+		}
+		else
+		{
+			$class = 'CI_DB_'.$db->dbdriver.'_forge';
+		}
+
+		if ($return === TRUE)
+		{
+			return new $class($db);
+		}
+
+		$CI->dbforge = new $class($db);
 	}
 
 	// --------------------------------------------------------------------
@@ -510,27 +532,34 @@ class CI_Loader {
 				continue;
 			}
 
-			$ext_helper = APPPATH.'helpers/'.config_item('subclass_prefix').$helper.'.php';
-
 			// Is this a helper extension request?
-			if (file_exists($ext_helper))
+			$ext_helper = config_item('subclass_prefix').$helper;
+			$ext_loaded = FALSE;
+			foreach ($this->_ci_helper_paths as $path)
 			{
-				$base_helper = BASEPATH.'helpers/'.$helper.'.php';
+				if (file_exists($path.'helpers/'.$ext_helper.'.php'))
+				{
+					include_once($path.'helpers/'.$ext_helper.'.php');
+					$ext_loaded = TRUE;
+				}
+			}
 
+			// If we have loaded extensions - check if the base one is here
+			if ($ext_loaded === TRUE)
+			{
+				$base_helper = BASEPATH.'helpers/'.$helper.'.php';
 				if ( ! file_exists($base_helper))
 				{
 					show_error('Unable to load the requested file: helpers/'.$helper.'.php');
 				}
 
-				include_once($ext_helper);
 				include_once($base_helper);
-
 				$this->_ci_helpers[$helper] = TRUE;
 				log_message('debug', 'Helper loaded: '.$helper);
 				continue;
 			}
 
-			// Try to load the helper
+			// No extensions found ... try loading regular helpers and/or overrides
 			foreach ($this->_ci_helper_paths as $path)
 			{
 				if (file_exists($path.'helpers/'.$helper.'.php'))
@@ -849,7 +878,9 @@ class CI_Loader {
 		// If the PHP installation does not support short tags we'll
 		// do a little string replacement, changing the short tags
 		// to standard PHP echo statements.
-		if ( ! is_php('5.4') && (bool) @ini_get('short_open_tag') === FALSE && config_item('rewrite_short_tags') === TRUE)
+		if ( ! is_php('5.4') && (bool) @ini_get('short_open_tag') === FALSE
+			&& config_item('rewrite_short_tags') === TRUE && function_usable('eval')
+		)
 		{
 			echo eval('?>'.preg_replace('/;*\s*\?>/', '; ?>', str_replace('<?=', '<?php echo ', file_get_contents($_ci_path))));
 		}
diff --git a/system/libraries/Log.php b/system/core/Log.php
index baac80121..e66270840 100644
--- a/system/libraries/Log.php
+++ b/system/core/Log.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Logging Class
@@ -151,7 +152,7 @@ class CI_Log {
 		if ( ! file_exists($filepath))
 		{
 			$newfile = TRUE;
-			$message .= '<'."?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); ?".">\n\n";
+			$message .= '<'."?php defined('BASEPATH') OR exit('No direct script access allowed'); ?".">\n\n";
 		}
 
 		if ( ! $fp = @fopen($filepath, FOPEN_WRITE_CREATE))
diff --git a/system/core/Model.php b/system/core/Model.php
index 5a87ab153..28fdfbb69 100644
--- a/system/core/Model.php
+++ b/system/core/Model.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Model Class
diff --git a/system/core/Output.php b/system/core/Output.php
index 3bb8f8dc0..9300df356 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Output Class
diff --git a/system/core/Router.php b/system/core/Router.php
index a5e29f1a3..01f44bc83 100644
--- a/system/core/Router.php
+++ b/system/core/Router.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Router Class
@@ -53,13 +54,6 @@ class CI_Router {
 	public $routes =	array();
 
 	/**
-	 * List of error routes
-	 *
-	 * @var	array
-	 */
-	public $error_routes =	array();
-
-	/**
 	 * Current class name
 	 *
 	 * @var	string
@@ -148,12 +142,12 @@ class CI_Router {
 			include(APPPATH.'config/routes.php');
 		}
 
-		$this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route;
+		$this->routes = (isset($route) && is_array($route)) ? $route : array();
 		unset($route);
 
 		// Set the default controller so we can display it in the event
 		// the URI doesn't correlated to a valid controller.
-		$this->default_controller = empty($this->routes['default_controller']) ? FALSE : strtolower($this->routes['default_controller']);
+		$this->default_controller = empty($this->routes['default_controller']) ? FALSE : $this->routes['default_controller'];
 
 		// Were there any query string segments? If so, we'll validate them and bail out since we're done.
 		if (count($segments) > 0)
@@ -185,25 +179,21 @@ class CI_Router {
 	 */
 	protected function _set_default_controller()
 	{
-		if ($this->default_controller === FALSE)
+		if (empty($this->default_controller))
 		{
 			show_error('Unable to determine what should be displayed. A default route has not been specified in the routing file.');
 		}
+
 		// Is the method being specified?
-		if (strpos($this->default_controller, '/') !== FALSE)
-		{
-			$x = explode('/', $this->default_controller);
-			$this->set_class($x[0]);
-			$this->set_method($x[1]);
-			$this->_set_request($x);
-		}
-		else
+		if (sscanf($this->default_controller, '%[^/]/%s', $class, $method) !== 2)
 		{
-			$this->set_class($this->default_controller);
-			$this->set_method('index');
-			$this->_set_request(array($this->default_controller, 'index'));
+			$method = 'index';
 		}
 
+		$this->set_class($class);
+		$this->set_method($method);
+		$this->_set_request(array($class, $method));
+
 		// re-index the routed segments array so it starts with 1 rather than 0
 		$this->uri->_reindex_segments();
 
@@ -232,17 +222,8 @@ class CI_Router {
 
 		$this->set_class($segments[0]);
 
-		if (isset($segments[1]))
-		{
-			// A standard method request
-			$this->set_method($segments[1]);
-		}
-		else
-		{
-			// This lets the "routed" segment array identify that the default
-			// index method is being used.
-			$segments[1] = 'index';
-		}
+		isset($segments[1]) OR $segments[1] = 'index';
+		$this->set_method($segments[1]);
 
 		// Update our "routed" segment array to contain the segments.
 		// Note: If there is no custom routing, this array will be
@@ -267,9 +248,13 @@ class CI_Router {
 			return $segments;
 		}
 
+		$temp = str_replace('-', '_', $segments[0]);
+
 		// Does the requested controller exist in the root folder?
-		if (file_exists(APPPATH.'controllers/'.$segments[0].'.php'))
+		if (file_exists(APPPATH.'controllers/'.$temp.'.php'))
 		{
+			$segments[0] = $temp;
+			empty($segments[1]) OR $segments[1] = str_replace('-', '_', $segments[1]);
 			return $segments;
 		}
 
@@ -277,22 +262,19 @@ class CI_Router {
 		if (is_dir(APPPATH.'controllers/'.$segments[0]))
 		{
 			// Set the directory and remove it from the segment array
-			$this->set_directory($segments[0]);
-			$segments = array_slice($segments, 1);
-
+			$this->set_directory(array_shift($segments));
 			if (count($segments) > 0)
 			{
+				$segments[0] = str_replace('-', '_', $segments[0]);
+				empty($segments[1]) OR $segments[1] = str_replace('-', '_', $segments[1]);
+
 				// Does the requested controller exist in the sub-folder?
 				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))
 				{
 					if ( ! empty($this->routes['404_override']))
 					{
-						$x = explode('/', $this->routes['404_override']);
-						$this->set_directory('');
-						$this->set_class($x[0]);
-						$this->set_method(isset($x[1]) ? $x[1] : 'index');
-
-						return $x;
+						$this->directory = '';
+						return explode('/', $this->routes['404_override'], 2);
 					}
 					else
 					{
@@ -303,40 +285,26 @@ class CI_Router {
 			else
 			{
 				// Is the method being specified in the route?
-				if (strpos($this->default_controller, '/') !== FALSE)
-				{
-					$x = explode('/', $this->default_controller);
-					$this->set_class($x[0]);
-					$this->set_method($x[1]);
-				}
-				else
-				{
-					$this->set_class($this->default_controller);
-					$this->set_method('index');
-				}
-
-				// Does the default controller exist in the sub-folder?
-				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.'.php'))
+				$segments = explode('/', $this->default_controller);
+				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))
 				{
 					$this->directory = '';
-					return array();
 				}
-
 			}
 
 			return $segments;
 		}
 
-
 		// If we've gotten this far it means that the URI does not correlate to a valid
 		// controller class. We will now see if there is an override
 		if ( ! empty($this->routes['404_override']))
 		{
-			$x = explode('/', $this->routes['404_override']);
-			$this->set_class($x[0]);
-			$this->set_method(isset($x[1]) ? $x[1] : 'index');
+			if (sscanf($this->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
 
-			return $x;
+			return array($class, $method);
 		}
 
 		// Nothing else to do at this point but show a 404
@@ -359,7 +327,7 @@ class CI_Router {
 		$uri = implode('/', $this->uri->segments);
 
 		// Is there a literal match?  If so we're done
-		if (isset($this->routes[$uri]))
+		if (isset($this->routes[$uri]) && is_string($this->routes[$uri]))
 		{
 			return $this->_set_request(explode('/', $this->routes[$uri]));
 		}
@@ -371,10 +339,48 @@ class CI_Router {
 			$key = str_replace(array(':any', ':num'), array('[^/]+', '[0-9]+'), $key);
 
 			// Does the RegEx match?
-			if (preg_match('#^'.$key.'$#', $uri))
+			if (preg_match('#^'.$key.'$#', $uri, $matches))
 			{
-				// Do we have a back-reference?
-				if (strpos($val, '$') !== FALSE && strpos($key, '(') !== FALSE)
+				// Are we using callbacks to process back-references?
+				if ( ! is_string($val) && is_callable($val))
+				{
+					// Remove the original string from the matches array.
+					array_shift($matches);
+
+					// Get the match count.
+					$match_count = count($matches);
+
+					// Determine how many parameters the callback has.
+					$reflection = new ReflectionFunction($val);
+					$param_count = $reflection->getNumberOfParameters();
+
+					// Are there more parameters than matches?
+					if ($param_count > $match_count)
+					{
+						// Any params without matches will be set to an empty string.
+						$matches = array_merge($matches, array_fill($match_count, $param_count - $match_count, ''));
+
+						$match_count = $param_count;
+					}
+
+					// Get the parameters so we can use their default values.
+					$params = $reflection->getParameters();
+
+					for ($m = 0; $m < $match_count; $m++)
+					{
+						// Is the match empty and does a default value exist?
+						if (empty($matches[$m]) && $params[$m]->isDefaultValueAvailable())
+						{
+							// Substitute the empty match for the default value.
+							$matches[$m] = $params[$m]->getDefaultValue();
+						}
+					}
+
+					// Execute the callback using the values in matches as its parameters.
+					$val = call_user_func_array($val, $matches);
+				}
+				// Are we using the default routing method for back-references?
+				elseif (strpos($val, '$') !== FALSE && strpos($key, '(') !== FALSE)
 				{
 					$val = preg_replace('#^'.$key.'$#', $val, $uri);
 				}
@@ -493,7 +499,7 @@ class CI_Router {
 
 		if (isset($routing['function']))
 		{
-			$routing['function'] = ($routing['function'] == '') ? 'index' : $routing['function'];
+			$routing['function'] = empty($routing['function']) ? 'index' : $routing['function'];
 			$this->set_method($routing['function']);
 		}
 	}
diff --git a/system/core/Security.php b/system/core/Security.php
index 50d0ce052..b8e66c087 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Security Class
diff --git a/system/core/URI.php b/system/core/URI.php
index d67a35d4b..91740254c 100644
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * URI Class
@@ -98,31 +99,28 @@ class CI_URI {
 			// Is the request coming from the command line?
 			if ($this->_is_cli_request())
 			{
-				$this->_set_uri_string($this->_parse_cli_args());
+				$this->_set_uri_string($this->_parse_argv());
 				return;
 			}
 
-			// Let's try the REQUEST_URI first, this will work in most situations
-			if ($uri = $this->_detect_uri())
+			// Is there a PATH_INFO variable? This should be the easiest solution.
+			if (isset($_SERVER['PATH_INFO']))
 			{
-				$this->_set_uri_string($uri);
+				$this->_set_uri_string($_SERVER['PATH_INFO']);
 				return;
 			}
 
-			// Is there a PATH_INFO variable?
-			// Note: some servers seem to have trouble with getenv() so we'll test it two ways
-			$path = isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : @getenv('PATH_INFO');
-			if (trim($path, '/') !== '' && $path !== '/'.SELF)
+			// Let's try REQUEST_URI then, this will work in most situations
+			if (($uri = $this->_parse_request_uri()) !== '')
 			{
-				$this->_set_uri_string($path);
+				$this->_set_uri_string($uri);
 				return;
 			}
 
-			// No PATH_INFO?... What about QUERY_STRING?
-			$path = isset($_SERVER['QUERY_STRING']) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING');
-			if (trim($path, '/') !== '')
+			// No REQUEST_URI either?... What about QUERY_STRING?
+			if (($uri = $this->_parse_query_string()) !== '')
 			{
-				$this->_set_uri_string($path);
+				$this->_set_uri_string($uri);
 				return;
 			}
 
@@ -140,19 +138,19 @@ class CI_URI {
 
 		$uri = strtoupper($this->config->item('uri_protocol'));
 
-		if ($uri === 'REQUEST_URI')
+		if ($uri === 'CLI')
 		{
-			$this->_set_uri_string($this->_detect_uri());
+			$this->_set_uri_string($this->_parse_argv());
 			return;
 		}
-		elseif ($uri === 'CLI')
+		elseif (method_exists($this, ($method = '_parse_'.strtolower($uri))))
 		{
-			$this->_set_uri_string($this->_parse_cli_args());
+			$this->_set_uri_string($this->$method());
 			return;
 		}
 
-		$path = isset($_SERVER[$uri]) ? $_SERVER[$uri] : @getenv($uri);
-		$this->_set_uri_string($path);
+		$uri = isset($_SERVER[$uri]) ? $_SERVER[$uri] : @getenv($uri);
+		$this->_set_uri_string($uri);
 	}
 
 	// --------------------------------------------------------------------
@@ -172,59 +170,54 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Detects URI
+	 * Parse REQUEST_URI
 	 *
-	 * Will detect the URI automatically and fix the query string if necessary.
+	 * Will parse REQUEST_URI and automatically detect the URI from it,
+	 * while fixing the query string if necessary.
 	 *
+	 * @used-by	CI_URI::_fetch_uri_string()
 	 * @return	string
 	 */
-	protected function _detect_uri()
+	protected function _parse_request_uri()
 	{
 		if ( ! isset($_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME']))
 		{
 			return '';
 		}
 
-		if (strpos($_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME']) === 0)
-		{
-			$uri = substr($_SERVER['REQUEST_URI'], strlen($_SERVER['SCRIPT_NAME']));
-		}
-		elseif (strpos($_SERVER['REQUEST_URI'], dirname($_SERVER['SCRIPT_NAME'])) === 0)
+		$uri = parse_url($_SERVER['REQUEST_URI']);
+		$query = isset($uri['query']) ? $uri['query'] : '';
+		$uri = isset($uri['path']) ? rawurldecode($uri['path']) : '';
+
+		if (strpos($uri, $_SERVER['SCRIPT_NAME']) === 0)
 		{
-			$uri = substr($_SERVER['REQUEST_URI'], strlen(dirname($_SERVER['SCRIPT_NAME'])));
+			$uri = (string) substr($uri, strlen($_SERVER['SCRIPT_NAME']));
 		}
-		else
+		elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0)
 		{
-			$uri = $_SERVER['REQUEST_URI'];
+			$uri = (string) substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));
 		}
 
 		// This section ensures that even on servers that require the URI to be in the query string (Nginx) a correct
 		// URI is found, and also fixes the QUERY_STRING server var and $_GET array.
-		if (strpos($uri, '?/') === 0)
+		if (trim($uri, '/') === '' && strncmp($query, '/', 1) === 0)
 		{
-			$uri = substr($uri, 2);
-		}
-
-		$parts = explode('?', $uri, 2);
-		$uri = $parts[0];
-		if (isset($parts[1]))
-		{
-			$_SERVER['QUERY_STRING'] = $parts[1];
-			parse_str($_SERVER['QUERY_STRING'], $_GET);
+			$query = explode('?', $query, 2);
+			$uri = rawurldecode($query[0]);
+			$_SERVER['QUERY_STRING'] = isset($query[1]) ? $query[1] : '';
 		}
 		else
 		{
-			$_SERVER['QUERY_STRING'] = '';
-			$_GET = array();
+			$_SERVER['QUERY_STRING'] = $query;
 		}
 
+		parse_str($_SERVER['QUERY_STRING'], $_GET);
+
 		if ($uri === '/' OR $uri === '')
 		{
 			return '/';
 		}
 
-		$uri = parse_url('pseudo://hostname/'.$uri, PHP_URL_PATH);
-
 		// Do some final cleaning of the URI and return it
 		return str_replace(array('//', '../'), '/', trim($uri, '/'));
 	}
@@ -232,6 +225,36 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Parse QUERY_STRING
+	 *
+	 * Will parse QUERY_STRING and automatically detect the URI from it.
+	 *
+	 * @used-by	CI_URI::_fetch_uri_string()
+	 * @return	string
+	 */
+	protected function _parse_query_string()
+	{
+		$uri = isset($_SERVER['QUERY_STRING']) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING');
+
+		if (trim($uri, '/') === '')
+		{
+			return '';
+		}
+		elseif (strncmp($uri, '/', 1) === 0)
+		{
+			$uri = explode('?', $uri, 2);
+			$_SERVER['QUERY_STRING'] = isset($uri[1]) ? $uri[1] : '';
+			$uri = rawurldecode($uri[0]);
+		}
+
+		parse_str($_SERVER['QUERY_STRING'], $_GET);
+
+		return str_replace(array('//', '../'), '/', trim($uri, '/'));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Is CLI Request?
 	 *
 	 * Duplicate of method from the Input class to test to see if
@@ -255,10 +278,10 @@ class CI_URI {
 	 *
 	 * @return	string
 	 */
-	protected function _parse_cli_args()
+	protected function _parse_argv()
 	{
 		$args = array_slice($_SERVER['argv'], 1);
-		return $args ? '/'.implode('/', $args) : '';
+		return $args ? implode('/', $args) : '';
 	}
 
 	// --------------------------------------------------------------------
@@ -278,7 +301,7 @@ class CI_URI {
 		{
 			// preg_quote() in PHP 5.3 escapes -, so the str_replace() and addition of - to preg_quote() is to maintain backwards
 			// compatibility as many are unaware of how characters in the permitted_uri_chars will be parsed as a regex pattern
-			if ( ! preg_match('|^['.str_replace(array('\\-', '\-'), '-', preg_quote($this->config->item('permitted_uri_chars'), '-')).']+$|i', urldecode($str)))
+			if ( ! preg_match('|^['.str_replace(array('\\-', '\-'), '-', preg_quote($this->config->item('permitted_uri_chars'), '-')).']+$|i', $str))
 			{
 				show_error('The URI you submitted has disallowed characters.', 400);
 			}
@@ -673,7 +696,14 @@ class CI_URI {
 	 */
 	public function ruri_string()
 	{
-		return implode('/', $this->rsegment_array());
+		global $RTR;
+
+		if (($dir = $RTR->fetch_directory()) === '/')
+		{
+			$dir = '';
+		}
+
+		return $dir.implode('/', $this->rsegment_array());
 	}
 
 }
diff --git a/system/core/Utf8.php b/system/core/Utf8.php
index efe3c10dc..5bc2dd5c9 100644
--- a/system/core/Utf8.php
+++ b/system/core/Utf8.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Utf8 Class
diff --git a/system/database/DB.php b/system/database/DB.php
index d751325ce..f4062fa73 100644
--- a/system/database/DB.php
+++ b/system/database/DB.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Initialize the database
@@ -31,8 +32,10 @@
  * @category	Database
  * @author	EllisLab Dev Team
  * @link	http://codeigniter.com/user_guide/database/
- * @param 	string
- * @param 	bool	Determines if query builder should be used or not
+ *
+ * @param 	string|string[]	$params
+ * @param 	bool		$query_builder_override
+ *				Determines if query builder should be used or not
  */
 function &DB($params = '', $query_builder_override = NULL)
 {
@@ -47,18 +50,18 @@ function &DB($params = '', $query_builder_override = NULL)
 		}
 
 		include($file_path);
-		//make packages contain database config files
-		foreach(get_instance()->load->get_package_paths() as $path)
+		// Make packages contain database config files
+		foreach (get_instance()->load->get_package_paths() as $path)
 		{
 			if ($path !== APPPATH)
 			{
-				if (file_exists ($file_path = $path.'config/'.ENVIRONMENT.'/database.php'))
+				if (file_exists($file_path = $path.'config/'.ENVIRONMENT.'/database.php'))
 				{
-					include ($file_path);
+					include($file_path);
 				}
-				elseif ( file_exists ($file_path = $path.'config/database.php'))
+				elseif (file_exists($file_path = $path.'config/database.php'))
 				{
-					include ($file_path);
+					include($file_path);
 				}
 			}
 		}
@@ -82,12 +85,12 @@ function &DB($params = '', $query_builder_override = NULL)
 	}
 	elseif (is_string($params))
 	{
-
-		/* parse the URL from the DSN string
-		 *  Database settings can be passed as discreet
-		 *  parameters or as a data source name in the first
-		 *  parameter. DSNs must have this prototype:
-		 *  $dsn = 'driver://username:password@hostname/database';
+		/**
+		 * Parse the URL from the DSN string
+		 * Database settings can be passed as discreet
+		 * parameters or as a data source name in the first
+		 * parameter. DSNs must have this prototype:
+		 * $dsn = 'driver://username:password@hostname/database';
 		 */
 		if (($dsn = @parse_url($params)) === FALSE)
 		{
@@ -103,7 +106,7 @@ function &DB($params = '', $query_builder_override = NULL)
 				'database'	=> isset($dsn['path']) ? rawurldecode(substr($dsn['path'], 1)) : ''
 			);
 
-		// were additional config items set?
+		// Were additional config items set?
 		if (isset($dsn['query']))
 		{
 			parse_str($dsn['query'], $extra);
@@ -148,11 +151,22 @@ function &DB($params = '', $query_builder_override = NULL)
 		require_once(BASEPATH.'database/DB_query_builder.php');
 		if ( ! class_exists('CI_DB'))
 		{
+			/**
+			 * CI_DB
+			 *
+			 * Acts as an alias for both CI_DB_driver and CI_DB_query_builder.
+			 *
+			 * @see	CI_DB_query_builder
+			 * @see	CI_DB_driver
+			 */
 			class CI_DB extends CI_DB_query_builder { }
 		}
 	}
 	elseif ( ! class_exists('CI_DB'))
 	{
+		/**
+	 	 * @ignore
+		 */
 		class CI_DB extends CI_DB_driver { }
 	}
 
diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
index d07c755c6..1be80c5c7 100644
--- a/system/database/DB_cache.php
+++ b/system/database/DB_cache.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Cache Class
@@ -34,8 +35,24 @@
  */
 class CI_DB_Cache {
 
+	/**
+	 * CI Singleton
+	 *
+	 * @var	object
+	 */
 	public $CI;
-	public $db;	// allows passing of db object so that multiple database connections and returned db objects can be supported
+
+	/**
+	 * Database object
+	 *
+	 * Allows passing of DB object so that multiple database connections
+	 * and returned DB objects can be supported.
+	 *
+	 * @var	object
+	 */
+	public $db;
+
+	// --------------------------------------------------------------------
 
 	/**
 	 * Constructor
@@ -58,7 +75,7 @@ class CI_DB_Cache {
 	/**
 	 * Set Cache Directory Path
 	 *
-	 * @param	string	the path to the cache directory
+	 * @param	string	$path	Path to the cache directory
 	 * @return	bool
 	 */
 	public function check_path($path = '')
@@ -94,7 +111,7 @@ class CI_DB_Cache {
 	 * Retrieve a cached query
 	 *
 	 * The URI being requested will become the name of the cache sub-folder.
-	 * An MD5 hash of the SQL statement will become the cache file name
+	 * An MD5 hash of the SQL statement will become the cache file name.
 	 *
 	 * @param	string	$sql
 	 * @return	string
@@ -153,8 +170,8 @@ class CI_DB_Cache {
 	/**
 	 * Delete cache files within a particular directory
 	 *
-	 * @param	string	$segment_one = ''
-	 * @param	string	$segment_two = ''
+	 * @param	string	$segment_one
+	 * @param	string	$segment_two
 	 * @return	void
 	 */
 	public function delete($segment_one = '', $segment_two = '')
@@ -182,7 +199,7 @@ class CI_DB_Cache {
 	 */
 	public function delete_all()
 	{
-		delete_files($this->db->cachedir, TRUE, 0, TRUE);
+		delete_files($this->db->cachedir, TRUE, TRUE);
 	}
 
 }
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index e8286aaa1..dfaf0e0c1 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Driver Class
@@ -40,60 +41,314 @@
  */
 abstract class CI_DB_driver {
 
+	/**
+	 * Data Source Name / Connect string
+	 *
+	 * @var	string
+	 */
 	public $dsn;
+
+	/**
+	 * Username
+	 *
+	 * @var	string
+	 */
 	public $username;
+
+	/**
+	 * Password
+	 *
+	 * @var	string
+	 */
 	public $password;
+
+	/**
+	 * Hostname
+	 *
+	 * @var	string
+	 */
 	public $hostname;
+
+	/**
+	 * Database name
+	 *
+	 * @var	string
+	 */
 	public $database;
+
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver		= 'mysqli';
+
+	/**
+	 * Sub-driver
+	 *
+	 * @used-by	CI_DB_pdo_driver
+	 * @var	string
+	 */
 	public $subdriver;
+
+	/**
+	 * Table prefix
+	 *
+	 * @var	string
+	 */
 	public $dbprefix		= '';
+
+	/**
+	 * Character set
+	 *
+	 * @var	string
+	 */
 	public $char_set		= 'utf8';
+
+	/**
+	 * Collation
+	 *
+	 * @var	string
+	 */
 	public $dbcollat		= 'utf8_general_ci';
-	public $autoinit		= TRUE; // Whether to automatically initialize the DB
+
+	/**
+	 * Auto-init flag
+	 *
+	 * Whether to automatically initialize the DB connection.
+	 *
+	 * @var	bool
+	 */
+	public $autoinit		= TRUE;
+
+	/**
+	 * Encryption flag/data
+	 *
+	 * @var	mixed
+	 */
 	public $encrypt			= FALSE;
+
+	/**
+	 * Swap Prefix
+	 *
+	 * @var	string
+	 */
 	public $swap_pre		= '';
+
+	/**
+	 * Database port
+	 *
+	 * @var	int
+	 */
 	public $port			= '';
+
+	/**
+	 * Persistent connection flag
+	 *
+	 * @var	bool
+	 */
 	public $pconnect		= FALSE;
+
+	/**
+	 * Connection ID
+	 *
+	 * @var	object|resource
+	 */
 	public $conn_id			= FALSE;
+
+	/**
+	 * Result ID
+	 *
+	 * @var	object|resource
+	 */
 	public $result_id		= FALSE;
+
+	/**
+	 * Debug flag
+	 *
+	 * Whether to display error messages.
+	 *
+	 * @var	bool
+	 */
 	public $db_debug		= FALSE;
+
+	/**
+	 * Benchmark time
+	 *
+	 * @var	int
+	 */
 	public $benchmark		= 0;
+
+	/**
+	 * Executed queries count
+	 *
+	 * @var	int
+	 */
 	public $query_count		= 0;
+
+	/**
+	 * Bind marker
+	 *
+	 * Character used to identify values in a prepared statement.
+	 *
+	 * @var	string
+	 */
 	public $bind_marker		= '?';
+
+	/**
+	 * Save queries flag
+	 *
+	 * Whether to keep an in-memory history of queries for debugging purposes.
+	 *
+	 * @var	bool
+	 */
 	public $save_queries		= TRUE;
+
+	/**
+	 * Queries list
+	 *
+	 * @see	CI_DB_driver::$save_queries
+	 * @var	string[]
+	 */
 	public $queries			= array();
+
+	/**
+	 * Query times
+	 *
+	 * A list of times that queries took to execute.
+	 *
+	 * @var	array
+	 */
 	public $query_times		= array();
+
+	/**
+	 * Data cache
+	 *
+	 * An internal generic value cache.
+	 *
+	 * @var	array
+	 */
 	public $data_cache		= array();
 
+	/**
+	 * Transaction enabled flag
+	 *
+	 * @var	bool
+	 */
 	public $trans_enabled		= TRUE;
+
+	/**
+	 * Strict transaction mode flag
+	 *
+	 * @var	bool
+	 */
 	public $trans_strict		= TRUE;
+
+	/**
+	 * Transaction depth level
+	 *
+	 * @var	int
+	 */
 	protected $_trans_depth		= 0;
-	protected $_trans_status	= TRUE; // Used with transactions to determine if a rollback should occur
 
+	/**
+	 * Transaction status flag
+	 *
+	 * Used with transactions to determine if a rollback should occur.
+	 *
+	 * @var	bool
+	 */
+	protected $_trans_status	= TRUE;
+
+	/**
+	 * Cache On flag
+	 *
+	 * @var	bool
+	 */
 	public $cache_on		= FALSE;
+
+	/**
+	 * Cache directory path
+	 *
+	 * @var	bool
+	 */
 	public $cachedir		= '';
+
+	/**
+	 * Cache auto-delete flag
+	 *
+	 * @var	bool
+	 */
 	public $cache_autodel		= FALSE;
-	public $CACHE; // The cache class object
 
+	/**
+	 * DB Cache object
+	 *
+	 * @see	CI_DB_cache
+	 * @var	object
+	 */
+	public $CACHE;
+
+	/**
+	 * Protect identifiers flag
+	 *
+	 * @var	bool
+	 */
 	protected $_protect_identifiers		= TRUE;
-	protected $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
 
-	// clause and character used for LIKE escape sequences
+	/**
+	 * List of reserved identifiers
+	 *
+	 * Identifiers that must NOT be escaped.
+	 *
+	 * @var	string[]
+	 */
+	protected $_reserved_identifiers	= array('*');
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '"';
+
+	/**
+	 * ESCAPE statement string
+	 *
+	 * @var	string
+	 */
 	protected $_like_escape_str = " ESCAPE '%s' ";
+
+	/**
+	 * ESCAPE character
+	 *
+	 * @var	string
+	 */
 	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.
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
+	protected $_random_keyword = ' RAND()';
+
+	/**
+	 * COUNT string
+	 *
+	 * @used-by	CI_DB_driver::count_all()
+	 * @used-by	CI_DB_query_builder::count_all_results()
+	 *
+	 * @var	string
 	 */
 	protected $_count_string = 'SELECT COUNT(*) AS ';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -981,7 +1236,7 @@ abstract class CI_DB_driver {
 	 */
 	public function escape_identifiers($item)
 	{
-		if ($this->_escape_char === '' OR empty($item))
+		if ($this->_escape_char === '' OR empty($item) OR in_array($item, $this->_reserved_identifiers))
 		{
 			return $item;
 		}
@@ -1080,43 +1335,19 @@ abstract class CI_DB_driver {
 	 */
 	public function update_string($table, $data, $where)
 	{
-		if ($where === '')
+		if (empty($where))
 		{
 			return FALSE;
 		}
 
+		$this->where($where);
+
 		$fields = array();
 		foreach ($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 ';
-				$key = $this->protect_identifiers($key);
-
-				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);
 	}
 
@@ -1198,8 +1429,7 @@ abstract class CI_DB_driver {
 	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
-	 * @param	string	$function	the function name
-	 * @param	mixed	$param,...	optional parameters needed by the function
+	 * @param	string	$function	Function name
 	 * @return	mixed
 	 */
 	public function call_function($function)
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 119d78d38..21046012a 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Forge Class
@@ -34,27 +35,127 @@
  */
 abstract class CI_DB_forge {
 
+	/**
+	 * Database object
+	 *
+	 * @var	object
+	 */
+	protected $db;
+
+	/**
+	 * Fields data
+	 *
+	 * @var	array
+	 */
 	public $fields		= array();
+
+	/**
+	 * Keys data
+	 *
+	 * @var	array
+	 */
 	public $keys		= array();
+
+	/**
+	 * Primary Keys data
+	 *
+	 * @var	array
+	 */
 	public $primary_keys	= array();
+
+	/**
+	 * Database character set
+	 *
+	 * @var	string
+	 */
 	public $db_char_set	= '';
 
-	// Platform specific SQL strings
+	// --------------------------------------------------------------------
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= 'CREATE DATABASE %s';
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_drop_database	= 'DROP DATABASE %s';
-	protected $_drop_table		= 'DROP TABLE IF EXISTS %s';
-	protected $_rename_table	= 'ALTER TABLE %s RENAME TO %s';
 
 	/**
-	 * Constructor
+	 * CREATE TABLE statement
 	 *
+	 * @var	string
+	 */
+	protected $_create_table	= "%s %s (%s\n)";
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+
+	/**
+	 * CREATE TABLE keys flag
+	 *
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
+	 */
+	protected $_create_table_keys	= FALSE;
+
+	/**
+	 * DROP TABLE IF EXISTS statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * RENAME TABLE statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= 'ALTER TABLE %s RENAME TO %s;';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= TRUE;
+
+	/**
+	 * NULL value representatin in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= '';
+
+	/**
+	 * DEFAULT value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_default		= ' DEFAULT ';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
 	 * @return	void
 	 */
-	public function __construct()
+	public function __construct(&$db)
 	{
-		// Assign the main database object to $this->db
-		$CI =& get_instance();
-		$this->db =& $CI->db;
+		$this->db =& $db;
 		log_message('debug', 'Database Forge Class Initialized');
 	}
 
@@ -63,14 +164,14 @@ abstract class CI_DB_forge {
 	/**
 	 * Create database
 	 *
-	 * @param	string	the database name
+	 * @param	string	$db_name
 	 * @return	bool
 	 */
 	public function create_database($db_name)
 	{
 		if ($this->_create_database === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 		elseif ( ! $this->db->query(sprintf($this->_create_database, $db_name, $this->db->char_set, $this->db->dbcollat)))
 		{
@@ -90,7 +191,7 @@ abstract class CI_DB_forge {
 	/**
 	 * Drop database
 	 *
-	 * @param	string	the database name
+	 * @param	string	$db_name
 	 * @return	bool
 	 */
 	public function drop_database($db_name)
@@ -102,7 +203,7 @@ abstract class CI_DB_forge {
 		}
 		elseif ($this->_drop_database === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 		elseif ( ! $this->db->query(sprintf($this->_drop_database, $db_name)))
 		{
@@ -126,25 +227,25 @@ abstract class CI_DB_forge {
 	/**
 	 * Add Key
 	 *
-	 * @param	string	key
-	 * @param	string	type
+	 * @param	string	$key
+	 * @param	bool	$primary
 	 * @return	object
 	 */
 	public function add_key($key = '', $primary = FALSE)
 	{
-		if (is_array($key))
+		if (empty($key))
+		{
+			show_error('Key information is required for that operation.');
+		}
+
+		if ($primary === TRUE && is_array($key))
 		{
 			foreach ($key as $one)
 			{
 				$this->add_key($one, $primary);
 			}
 
-			return;
-		}
-
-		if ($key === '')
-		{
-			show_error('Key information is required for that operation.');
+			return $this;
 		}
 
 		if ($primary === TRUE)
@@ -164,12 +265,12 @@ abstract class CI_DB_forge {
 	/**
 	 * Add Field
 	 *
-	 * @param	string	collation
+	 * @param	array	$field
 	 * @return	object
 	 */
 	public function add_field($field = '')
 	{
-		if ($field === '')
+		if (empty($field))
 		{
 			show_error('Field information is required.');
 		}
@@ -211,8 +312,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Create Table
 	 *
-	 * @param	string	$table = ''
-	 * @param	bool	$if_not_exists = FALSE
+	 * @param	string	$table		Table name
+	 * @param	bool	$if_not_exists	Whether to add IF NOT EXISTS condition
 	 * @return	bool
 	 */
 	public function create_table($table = '', $if_not_exists = FALSE)
@@ -221,51 +322,129 @@ abstract class CI_DB_forge {
 		{
 			show_error('A table name is required for that operation.');
 		}
+		else
+		{
+			$table = $this->db->dbprefix.$table;
+		}
 
 		if (count($this->fields) === 0)
 		{
 			show_error('Field information is required.');
 		}
 
-		$sql = $this->_create_table($this->db->dbprefix.$table, $this->fields, $this->primary_keys, $this->keys, $if_not_exists);
-		$this->_reset();
+		$sql = $this->_create_table($table, $if_not_exists);
 
 		if (is_bool($sql))
 		{
-			return $sql;
+			$this->_reset();
+			if ($sql === FALSE)
+			{
+				return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+			}
 		}
 
-		if (($result = $this->db->query($sql)) !== FALSE && ! empty($this->db->data_cache['table_names']))
+		if (($result = $this->db->query($sql)) !== FALSE)
 		{
-			$this->db->data_cache['table_names'][] = $this->db->dbprefix.$table;
+			empty($this->db->data_cache['table_names']) OR $this->db->data_cache['table_names'][] = $table;
+
+			// Most databases don't support creating indexes from within the CREATE TABLE statement
+			if ( ! empty($this->keys))
+			{
+				for ($i = 0, $sqls = $this->_process_indexes($table), $c = count($sqls); $i < $c; $i++)
+				{
+					$this->db->query($sqls[$i]);
+				}
+			}
 		}
 
+		$this->_reset();
 		return $result;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
+	 * Create Table
+	 *
+	 * @param	string	$table		Table name
+	 * @param	bool	$if_not_exists	Whether to add 'IF NOT EXISTS' condition
+	 * @return	mixed
+	 */
+	protected function _create_table($table, $if_not_exists)
+	{
+		if ($if_not_exists === TRUE && $this->_create_table_if === FALSE)
+		{
+			if ($this->db->table_exists($table))
+			{
+				return TRUE;
+			}
+			else
+			{
+				$if_not_exists = FALSE;
+			}
+		}
+
+		$sql = ($if_not_exists)
+			? sprintf($this->_create_table_if, $this->db->escape_identifiers($table))
+			: 'CREATE TABLE';
+
+		$columns = $this->_process_fields(TRUE);
+		for ($i = 0, $c = count($columns); $i < $c; $i++)
+		{
+			$columns[$i] = ($columns[$i]['_literal'] !== FALSE)
+					? "\n\t".$columns[$i]['_literal']
+					: "\n\t".$this->_process_column($columns[$i]);
+		}
+
+		$columns = implode(',', $columns)
+				.$this->_process_primary_keys($table);
+
+		// Are indexes created from within the CREATE TABLE statement? (e.g. in MySQL)
+		if ($this->_create_table_keys === TRUE)
+		{
+			$columns .= $this->_process_indexes();
+		}
+
+		// _create_table will usually have the following format: "%s %s (%s\n)"
+		$sql = sprintf($this->_create_table.';',
+			$sql,
+			$this->db->escape_identifiers($table),
+			$columns
+		);
+
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Drop Table
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table_name	Table name
+	 * @param	bool	$if_exists	Whether to add an IF EXISTS condition
 	 * @return	bool
 	 */
-	public function drop_table($table_name)
+	public function drop_table($table_name, $if_exists = FALSE)
 	{
 		if ($table_name === '')
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_table_name_required') : FALSE;
 		}
-		elseif ($this->_drop_table === FALSE)
+
+		$query = $this->_drop_table($this->db->dbprefix.$table_name, $if_exists);
+		if ($query === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		}
+		elseif ($query === TRUE)
+		{
+			return TRUE;
 		}
 
-		$result = $this->db->query(sprintf($this->_drop_table, $this->db->escape_identifiers($this->db->dbprefix.$table_name)));
+		$query = $this->db->query($query);
 
 		// Update table list cache
-		if ($result && ! empty($this->db->data_cache['table_names']))
+		if ($query && ! empty($this->db->data_cache['table_names']))
 		{
 			$key = array_search(strtolower($this->db->dbprefix.$table_name), array_map('strtolower', $this->db->data_cache['table_names']), TRUE);
 			if ($key !== FALSE)
@@ -274,7 +453,40 @@ abstract class CI_DB_forge {
 			}
 		}
 
-		return $result;
+		return $query;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Drop Table
+	 *
+	 * Generates a platform-specific DROP TABLE string
+	 *
+	 * @param	string	$table		Table name
+	 * @param	bool	$if_exists	Whether to add an IF EXISTS condition
+	 * @return	string
+	 */
+	protected function _drop_table($table, $if_exists)
+	{
+		$sql = 'DROP TABLE';
+
+		if ($if_exists)
+		{
+			if ($this->_drop_table_if === FALSE)
+			{
+				if ( ! $this->db->table_exists($table))
+				{
+					return TRUE;
+				}
+			}
+			else
+			{
+				$sql = sprintf($this->_drop_table_if, $this->db->escape_identifiers($table));
+			}
+		}
+
+		return $sql.' '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -282,8 +494,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Rename Table
 	 *
-	 * @param	string	the old table name
-	 * @param	string	the new table name
+	 * @param	string	$table_name	Old table name
+	 * @param	string	$new_table_name	New table name
 	 * @return	bool
 	 */
 	public function rename_table($table_name, $new_table_name)
@@ -295,7 +507,7 @@ abstract class CI_DB_forge {
 		}
 		elseif ($this->_rename_table === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 
 		$result = $this->db->query(sprintf($this->_rename_table,
@@ -320,33 +532,46 @@ abstract class CI_DB_forge {
 	/**
 	 * Column Add
 	 *
-	 * @param	string	the table name
-	 * @param	string	the column name
-	 * @param	string	the column definition
+	 * @todo	Remove deprecated $_after option in 3.1+
+	 * @param	string	$table	Table name
+	 * @param	array	$field	Column definition
+	 * @param	string	$_after	Column for AFTER clause (deprecated)
 	 * @return	bool
 	 */
-	public function add_column($table = '', $field = array(), $after_field = '')
+	public function add_column($table = '', $field = array(), $_after = NULL)
 	{
 		if ($table === '')
 		{
 			show_error('A table name is required for that operation.');
 		}
 
-		// add field info into field array, but we can only do one at a time
-		// so we cycle through
-		foreach (array_keys($field) as $k)
+		// Work-around for literal column definitions
+		if ( ! is_array($field))
 		{
-			$this->add_field(array($k => $field[$k]));
+			$field = array($field);
+		}
 
-			if (count($this->fields) === 0)
+		foreach (array_keys($field) as $k)
+		{
+			// Backwards-compatibility work-around for MySQL/CUBRID AFTER clause (remove in 3.1+)
+			if ($_after !== NULL && is_array($field[$k]) && ! isset($field[$k]['after']))
 			{
-				show_error('Field information is required.');
+				$field[$k]['after'] = $_after;
 			}
 
-			$sql = $this->_alter_table('ADD', $this->db->dbprefix.$table, $this->fields, $after_field);
-			$this->_reset();
+			$this->add_field(array($k => $field[$k]));
+		}
+
+		$sqls = $this->_alter_table('ADD', $this->db->dbprefix.$table, $this->_process_fields());
+		$this->_reset();
+		if ($sqls === FALSE)
+		{
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		}
 
-			if ($this->db->query($sql) === FALSE)
+		for ($i = 0, $c = count($sqls); $i < $c; $i++)
+		{
+			if ($this->db->query($sqls[$i]) === FALSE)
 			{
 				return FALSE;
 			}
@@ -360,8 +585,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Column Drop
 	 *
-	 * @param	string	the table name
-	 * @param	string	the column name
+	 * @param	string	$table		Table name
+	 * @param	string	$column_name	Column name
 	 * @return	bool
 	 */
 	public function drop_column($table = '', $column_name = '')
@@ -376,7 +601,13 @@ abstract class CI_DB_forge {
 			show_error('A column name is required for that operation.');
 		}
 
-		return $this->db->query($this->_alter_table('DROP', $this->db->dbprefix.$table, $column_name));
+		$sql = $this->_alter_table('DROP', $this->db->dbprefix.$table, $column_name);
+		if ($sql === FALSE)
+		{
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		}
+
+		return $this->db->query($sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -384,8 +615,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Column Modify
 	 *
-	 * @param	string	$table = ''
-	 * @param	string	$field = array()	column definition
+	 * @param	string	$table	Table name
+	 * @param	string	$field	Column definition
 	 * @return	bool
 	 */
 	public function modify_column($table = '', $field = array())
@@ -395,32 +626,363 @@ abstract class CI_DB_forge {
 			show_error('A table name is required for that operation.');
 		}
 
-		// add field info into field array, but we can only do one at a time
-		// so we cycle through
+		// Work-around for literal column definitions
+		if ( ! is_array($field))
+		{
+			$field = array($field);
+		}
+
 		foreach (array_keys($field) as $k)
 		{
-			// If no name provided, use the current name
-			if ( ! isset($field[$k]['name']))
+			$this->add_field(array($k => $field[$k]));
+		}
+
+		if (count($this->fields) === 0)
+		{
+			show_error('Field information is required.');
+		}
+
+		$sqls = $this->_alter_table('CHANGE', $this->db->dbprefix.$table, $this->fields);
+		$this->_reset();
+		if ($sqls === FALSE)
+		{
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		}
+
+		for ($i = 0, $c = count($sqls); $i < $c; $i++)
+		{
+			if ($this->db->query($sqls[$i]) === FALSE)
 			{
-				$field[$k]['name'] = $k;
+				return FALSE;
 			}
+		}
 
-			$this->add_field(array($k => $field[$k]));
-			if (count($this->fields) === 0)
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' ';
+
+		// DROP has everything it needs now.
+		if ($alter_type === 'DROP')
+		{
+			return $sql.'DROP COLUMN '.$this->db->escape_identifiers($field);
+		}
+
+		$sqls = array();
+		for ($i = 0, $c = count($field), $sql .= $alter_type.' COLUMN '; $i < $c; $i++)
+		{
+			$sqls[] = $sql
+				.($field[$i]['_literal'] !== FALSE ? $field[$i]['_literal'] : $this->_process_column($field[$i]));
+		}
+
+		return $sqls;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process fields
+	 *
+	 * @param	bool	$create_table
+	 * @return	array
+	 */
+	protected function _process_fields($create_table = FALSE)
+	{
+		$fields = array();
+
+		foreach ($this->fields as $key => $attributes)
+		{
+			if (is_int($key) && ! is_array($attributes))
 			{
-				show_error('Field information is required.');
+				$fields[] = array('_literal' => $attributes);
+				continue;
 			}
 
-			$sql = $this->_alter_table('CHANGE', $this->db->dbprefix.$table, $this->fields);
-			$this->_reset();
+			$attributes = array_change_key_case($attributes, CASE_UPPER);
 
-			if ($this->db->query($sql) === FALSE)
+			if ($create_table === TRUE && empty($attributes['TYPE']))
 			{
-				return FALSE;
+				continue;
+			}
+
+			if (isset($attributes['TYPE']))
+			{
+				$this->_attr_type($attributes);
+				$this->_attr_unsigned($attributes, $field);
 			}
+
+			$field = array(
+					'name'			=> $key,
+					'new_name'		=> isset($attributes['NAME']) ? $attributes['NAME'] : NULL,
+					'type'			=> isset($attributes['TYPE']) ? $attributes['TYPE'] : NULL,
+					'length'		=> '',
+					'unsigned'		=> '',
+					'null'			=> '',
+					'unique'		=> '',
+					'default'		=> '',
+					'auto_increment'	=> '',
+					'_literal'		=> FALSE
+			);
+
+			$this->_attr_default($attributes, $field);
+
+			if (isset($attributes['NULL']))
+			{
+				if ($attributes['NULL'] === TRUE)
+				{
+					$field['null'] = empty($this->_null) ? '' : ' '.$this->_null;
+				}
+				elseif ($create_table === TRUE)
+				{
+					$field['null'] = ' NOT NULL';
+				}
+			}
+
+			$this->_attr_auto_increment($attributes, $field);
+			$this->_attr_unique($attributes, $field);
+
+			if (isset($attributes['TYPE']) && ! empty($attributes['CONSTRAINT']))
+			{
+				switch (strtoupper($attributes['TYPE']))
+				{
+					case 'ENUM':
+					case 'SET':
+						$attributes['CONSTRAINT'] = $this->db->escape($attributes['CONSTRAINT']);
+					default:
+						$field['length'] = is_array($attributes['CONSTRAINT'])
+								? '('.implode(',', $attributes['CONSTRAINT']).')'
+								: '('.$attributes['CONSTRAINT'].')';
+						break;
+				}
+			}
+
+			$fields[] = $field;
 		}
 
-		return TRUE;
+		return $fields;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['default']
+			.$field['null']
+			.$field['auto_increment']
+			.$field['unique'];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		// Usually overriden by drivers
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute UNSIGNED
+	 *
+	 * Depending on the _unsigned property value:
+	 *
+	 *	- TRUE will always set $field['unsigned'] to 'UNSIGNED'
+	 *	- FALSE will always set $field['unsigned'] to ''
+	 *	- array(TYPE) will set $field['unsigned'] to 'UNSIGNED',
+	 *		if $attributes['TYPE'] is found in the array
+	 *	- array(TYPE => UTYPE) will change $field['type'],
+	 *		from TYPE to UTYPE in case of a match
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_unsigned(&$attributes, &$field)
+	{
+		if (empty($attributes['UNSIGNED']) OR $attributes['UNSIGNED'] !== TRUE)
+		{
+			return;
+		}
+
+		// Reset the attribute in order to avoid issues if we do type conversion
+		$attributes['UNSIGNED'] = FALSE;
+
+		if (is_array($this->_unsigned))
+		{
+			foreach (array_keys($this->_unsigned) as $key)
+			{
+				if (is_int($key) && strcasecmp($attributes['TYPE'], $this->_unsigned[$key]) === 0)
+				{
+					$field['unsigned'] = ' UNSIGNED';
+					return;
+				}
+				elseif (is_string($key) && strcasecmp($attributes['TYPE'], $key) === 0)
+				{
+					$field['type'] = $key;
+					return;
+				}
+			}
+
+			return;
+		}
+
+		$field['unsigned'] = ($this->_unsigned === TRUE) ? ' UNSIGNED' : '';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute DEFAULT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_default(&$attributes, &$field)
+	{
+		if ($this->_default === FALSE)
+		{
+			return;
+		}
+
+		if (array_key_exists('DEFAULT', $attributes))
+		{
+			if ($attributes['DEFAULT'] === NULL)
+			{
+				$field['default'] = empty($this->_null) ? '' : $this->_default.$this->_null;
+
+				// Override the NULL attribute if that's our default
+				$attributes['NULL'] = NULL;
+				$field['null'] = empty($this->_null) ? '' : ' '.$this->_null;
+			}
+			else
+			{
+				$field['default'] = $this->_default.$this->db->escape($attributes['DEFAULT']);
+			}
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute UNIQUE
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_unique(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
+		{
+			$field['unique'] = ' UNIQUE';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['auto_increment'] = ' AUTO_INCREMENT';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process primary keys
+	 *
+	 * @param	string	$table	Table name
+	 * @return	string
+	 */
+	protected function _process_primary_keys($table)
+	{
+		$sql = '';
+
+		for ($i = 0, $c = count($this->primary_keys); $i < $c; $i++)
+		{
+			if ( ! isset($this->fields[$this->primary_keys[$i]]))
+			{
+				unset($this->primary_keys[$i]);
+			}
+		}
+
+		if (count($this->primary_keys) > 0)
+		{
+			$sql .= ",\n\tCONSTRAINT ".$this->db->escape_identifiers('pk_'.$table)
+				.' PRIMARY KEY('.implode(', ', $this->db->escape_identifiers($this->primary_keys)).')';
+		}
+
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
+	 *
+	 * @param	string	$table
+	 * @return	string
+	 */
+	protected function _process_indexes($table = NULL)
+	{
+		$table = $this->db->escape_identifiers($table);
+		$sqls = array();
+
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
+		{
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sqls[] = 'CREATE INDEX '.$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ON '.$this->db->escape_identifiers($table)
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).');';
+		}
+
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index a3585586e..364397721 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Query Builder Class
@@ -39,42 +40,213 @@
 
 abstract class CI_DB_query_builder extends CI_DB_driver {
 
+	/**
+	 * Return DELETE SQL flag
+	 *
+	 * @var	bool
+	 */
 	protected $return_delete_sql		= FALSE;
+
+	/**
+	 * Reset DELETE data flag
+	 *
+	 * @var	bool
+	 */
 	protected $reset_delete_data		= FALSE;
 
+	/**
+	 * QB SELECT data
+	 *
+	 * @var	array
+	 */
 	protected $qb_select			= array();
+
+	/**
+	 * QB DISTINCT flag
+	 *
+	 * @var	bool
+	 */
 	protected $qb_distinct			= FALSE;
+
+	/**
+	 * QB FROM data
+	 *
+	 * @var	array
+	 */
 	protected $qb_from			= array();
+
+	/**
+	 * QB JOIN data
+	 *
+	 * @var	array
+	 */
 	protected $qb_join			= array();
+
+	/**
+	 * QB WHERE data
+	 *
+	 * @var	array
+	 */
 	protected $qb_where			= array();
+
+	/**
+	 * QB GROUP BY data
+	 *
+	 * @var	array
+	 */
 	protected $qb_groupby			= array();
+
+	/**
+	 * QB HAVING data
+	 *
+	 * @var	array
+	 */
 	protected $qb_having			= array();
+
+	/**
+	 * QB keys
+	 *
+	 * @var	array
+	 */
 	protected $qb_keys			= array();
+
+	/**
+	 * QB LIMIT data
+	 *
+	 * @var	int
+	 */
 	protected $qb_limit			= FALSE;
+
+	/**
+	 * QB OFFSET data
+	 *
+	 * @var	int
+	 */
 	protected $qb_offset			= FALSE;
+
+	/**
+	 * QB ORDER BY data
+	 *
+	 * @var	array
+	 */
 	protected $qb_orderby			= array();
+
+	/**
+	 * QB data sets
+	 *
+	 * @var	array
+	 */
 	protected $qb_set			= array();
+
+	/**
+	 * QB aliased tables list
+	 *
+	 * @var	array
+	 */
 	protected $qb_aliased_tables		= array();
-	protected $qb_store_array		= array();
+
+	/**
+	 * QB WHERE group started flag
+	 *
+	 * @var	bool
+	 */
 	protected $qb_where_group_started	= FALSE;
+
+	/**
+	 * QB WHERE group count
+	 *
+	 * @var	int
+	 */
 	protected $qb_where_group_count		= 0;
 
 	// Query Builder Caching variables
+
+	/**
+	 * QB Caching flag
+	 *
+	 * @var	bool
+	 */
 	protected $qb_caching				= FALSE;
+
+	/**
+	 * QB Cache exists list
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_exists			= array();
+
+	/**
+	 * QB Cache SELECT data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_select			= array();
+
+	/**
+	 * QB Cache FROM data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_from			= array();
+
+	/**
+	 * QB Cache JOIN data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_join			= array();
+
+	/**
+	 * QB Cache WHERE data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_where			= array();
-	protected $qb_cache_like			= array();
+
+	/**
+	 * QB Cache GROUP BY data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_groupby			= array();
+
+	/**
+	 * QB Cache HAVING data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_having			= array();
+
+	/**
+	 * QB Cache ORDER BY data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_orderby			= array();
+
+	/**
+	 * QB Cache data sets
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_set				= array();
 
+	/**
+	 * QB No Escape data
+	 *
+	 * @var	array
+	 */
 	protected $qb_no_escape 			= array();
+
+	/**
+	 * QB Cache No Escape data
+	 *
+	 * @var	array
+	 */
 	protected $qb_cache_no_escape			= array();
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Select
 	 *
@@ -182,17 +354,16 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Processing Function for the following functions:
-	 *
-	 *	select_max()
-	 *	select_min()
-	 *	select_avg()
-	 *	select_sum()
+	 * SELECT [MAX|MIN|AVG|SUM]()
 	 *
+	 * @used-by	select_max()
+	 * @used-by	select_min()
+	 * @used-by	select_avg()
+	 * @used-by	select_sum()
 	 *
-	 * @param	string	$select = ''	field name
-	 * @param	string	$alias = ''
-	 * @param	string	$type = 'MAX'
+	 * @param	string	$select	Field name
+	 * @param	string	$alias
+	 * @param	string	$type
 	 * @return	object
 	 */
 	protected function _max_min_avg_sum($select = '', $alias = '', $type = 'MAX')
@@ -233,7 +404,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Determines the alias name based on the table
 	 *
-	 * @param	string
+	 * @param	string	$item
 	 * @return	string
 	 */
 	protected function _create_alias_from_table($item)
@@ -254,7 +425,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Sets a flag which tells the query string compiler to add DISTINCT
 	 *
-	 * @param	bool
+	 * @param	bool	$val
 	 * @return	object
 	 */
 	public function distinct($val = TRUE)
@@ -270,7 +441,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Generates the FROM portion of the query
 	 *
-	 * @param	mixed	can be a string or array
+	 * @param	mixed	$from	can be a string or array
 	 * @return	object
 	 */
 	public function from($from)
@@ -317,7 +488,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Join
+	 * JOIN
 	 *
 	 * Generates the JOIN portion of the query
 	 *
@@ -405,10 +576,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where
+	 * WHERE
 	 *
-	 * Generates the WHERE portion of the query. Separates
-	 * multiple calls with AND
+	 * Generates the WHERE portion of the query.
+	 * Separates multiple calls with 'AND'.
 	 *
 	 * @param	mixed
 	 * @param	mixed
@@ -423,10 +594,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * OR Where
+	 * OR WHERE
 	 *
-	 * Generates the WHERE portion of the query. Separates
-	 * multiple calls with OR
+	 * Generates the WHERE portion of the query.
+	 * Separates multiple calls with 'OR'.
 	 *
 	 * @param	mixed
 	 * @param	mixed
@@ -443,13 +614,16 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * WHERE, HAVING
 	 *
-	 * Called by where(), or_where(), having(), or_having()
+	 * @used-by	where()
+	 * @used-by	or_where()
+	 * @used-by	having()
+	 * @used-by	or_having()
 	 *
-	 * @param	string	'qb_where' or 'qb_having'
-	 * @param	mixed
-	 * @param	mixed
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$qb_key	'qb_where' or 'qb_having'
+	 * @param	mixed	$key
+	 * @param	mixed	$value
+	 * @param	string	$type
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	protected function _wh($qb_key, $key, $value = NULL, $type = 'AND ', $escape = NULL)
@@ -504,14 +678,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where_in
+	 * WHERE IN
 	 *
-	 * Generates a WHERE field IN('item', 'item') SQL query joined with
-	 * AND if appropriate
+	 * Generates a WHERE field IN('item', 'item') SQL query,
+	 * joined with 'AND' if appropriate.
 	 *
-	 * @param	string	$key = NULL	The field to search
-	 * @param	array	$values = NULL	The values searched on
-	 * @param	bool	$escape = NULL
+	 * @param	string	$key	The field to search
+	 * @param	array	$values	The values searched on
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function where_in($key = NULL, $values = NULL, $escape = NULL)
@@ -522,14 +696,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Or_where_in
+	 * OR WHERE IN
 	 *
-	 * Generates a WHERE field IN('item', 'item') SQL query joined with
-	 * OR if appropriate
+	 * Generates a WHERE field IN('item', 'item') SQL query,
+	 * joined with 'OR' if appropriate.
 	 *
-	 * @param	string	$key = NULL	The field to search
-	 * @param	array	$values = NULL	The values searched on
-	 * @param	bool	$escape = NULL
+	 * @param	string	$key	The field to search
+	 * @param	array	$values	The values searched on
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function or_where_in($key = NULL, $values = NULL, $escape = NULL)
@@ -540,14 +714,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where_not_in
+	 * WHERE NOT IN
 	 *
-	 * Generates a WHERE field NOT IN('item', 'item') SQL query joined
-	 * with AND if appropriate
+	 * Generates a WHERE field NOT IN('item', 'item') SQL query,
+	 * joined with 'AND' if appropriate.
 	 *
-	 * @param	string	$key = NULL	The field to search
-	 * @param	array	$values = NULL	The values searched on
-	 * @param	bool	$escape = NULL
+	 * @param	string	$key	The field to search
+	 * @param	array	$values	The values searched on
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function where_not_in($key = NULL, $values = NULL, $escape = NULL)
@@ -558,14 +732,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Or_where_not_in
+	 * OR WHERE NOT IN
 	 *
-	 * Generates a WHERE field NOT IN('item', 'item') SQL query joined
-	 * with OR if appropriate
+	 * Generates a WHERE field NOT IN('item', 'item') SQL query,
+	 * joined with 'OR' if appropriate.
 	 *
-	 * @param	string	$key = NULL	The field to search
-	 * @param	array	$values = NULL	The values searched on
-	 * @param	bool	$escape = NULL
+	 * @param	string	$key	The field to search
+	 * @param	array	$values	The values searched on
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function or_where_not_in($key = NULL, $values = NULL, $escape = NULL)
@@ -576,15 +750,18 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where_in
+	 * Internal WHERE IN
 	 *
-	 * Called by where_in(), or_where_in(), where_not_in(), or_where_not_in()
+	 * @used-by	where_in()
+	 * @used-by	or_where_in()
+	 * @used-by	where_not_in()
+	 * @used-by	or_where_not_in()
 	 *
-	 * @param	string	$key = NULL	The field to search
-	 * @param	array	$values = NULL	The values searched on
-	 * @param	bool	$not = FALSE	If the statement would be IN or NOT IN
-	 * @param	string	$type = 'AND '
-	 * @param	bool	$escape = NULL
+	 * @param	string	$key	The field to search
+	 * @param	array	$values	The values searched on
+	 * @param	bool	$not	If the statement would be IN or NOT IN
+	 * @param	string	$type
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ', $escape = NULL)
@@ -628,15 +805,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Like
+	 * LIKE
 	 *
-	 * Generates a %LIKE% portion of the query. Separates
-	 * multiple calls with AND
+	 * Generates a %LIKE% portion of the query.
+	 * Separates multiple calls with 'AND'.
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$field
+	 * @param	string	$match
+	 * @param	string	$side
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function like($field, $match = '', $side = 'both', $escape = NULL)
@@ -647,15 +824,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Not Like
+	 * NOT LIKE
 	 *
-	 * Generates a NOT LIKE portion of the query. Separates
-	 * multiple calls with AND
+	 * Generates a NOT LIKE portion of the query.
+	 * Separates multiple calls with 'AND'.
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$field
+	 * @param	string	$match
+	 * @param	string	$side
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function not_like($field, $match = '', $side = 'both', $escape = NULL)
@@ -666,15 +843,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * OR Like
+	 * OR LIKE
 	 *
-	 * Generates a %LIKE% portion of the query. Separates
-	 * multiple calls with OR
+	 * Generates a %LIKE% portion of the query.
+	 * Separates multiple calls with 'OR'.
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$field
+	 * @param	string	$match
+	 * @param	string	$side
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function or_like($field, $match = '', $side = 'both', $escape = NULL)
@@ -685,15 +862,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * OR Not Like
+	 * OR NOT LIKE
 	 *
-	 * Generates a NOT LIKE portion of the query. Separates
-	 * multiple calls with OR
+	 * Generates a NOT LIKE portion of the query.
+	 * Separates multiple calls with 'OR'.
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$field
+	 * @param	string	$match
+	 * @param	string	$side
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function or_not_like($field, $match = '', $side = 'both', $escape = NULL)
@@ -704,16 +881,19 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Like
+	 * Internal LIKE
 	 *
-	 * Called by like(), or_like(), not_like, or_not_like()
+	 * @used-by	like()
+	 * @used-by	or_like()
+	 * @used-by	not_like()
+	 * @used-by	or_not_like()
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$field
+	 * @param	string	$match
+	 * @param	string	$type
+	 * @param	string	$side
+	 * @param	string	$not
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '', $escape = NULL)
@@ -770,8 +950,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Starts a query group.
 	 *
-	 * @param	string (Internal use only)
-	 * @param	string (Internal use only)
+	 * @param	string	$not	(Internal use only)
+	 * @param	string	$type	(Internal use only)
 	 * @return	object
 	 */
 	public function group_start($not = '', $type = 'AND ')
@@ -859,9 +1039,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Group_get_type
 	 *
-	 * Called by group_start(), _like(), _where() and _where_in()
+	 * @used-by	group_start()
+	 * @used-by	_like()
+	 * @used-by	_wh()
+	 * @used-by	_where_in()
 	 *
-	 * @param	string
+	 * @param	string	$type
 	 * @return	string
 	 */
 	protected function _group_get_type($type)
@@ -880,8 +1063,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * GROUP BY
 	 *
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$by
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function group_by($by, $escape = NULL)
@@ -918,13 +1101,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Sets the HAVING value
+	 * HAVING
 	 *
-	 * Separates multiple calls with AND
+	 * Separates multiple calls with 'AND'.
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$key
+	 * @param	string	$value
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function having($key, $value = NULL, $escape = NULL)
@@ -935,13 +1118,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Sets the OR HAVING value
+	 * OR HAVING
 	 *
-	 * Separates multiple calls with OR
+	 * Separates multiple calls with 'OR'.
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$key
+	 * @param	string	$value
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function or_having($key, $value = NULL, $escape = NULL)
@@ -952,11 +1135,11 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Sets the ORDER BY value
+	 * ORDER BY
 	 *
-	 * @param	string
-	 * @param	string	direction: ASC or DESC
-	 * @param	bool	enable field name escaping
+	 * @param	string	$orderby
+	 * @param	string	$direction	ASC or DESC
+	 * @param	bool	$escape
 	 * @return	object
 	 */
 	public function order_by($orderby, $direction = '', $escape = NULL)
@@ -1008,10 +1191,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Sets the LIMIT value
+	 * LIMIT
 	 *
-	 * @param	int	the limit value
-	 * @param	int	the offset value
+	 * @param	int	$value	LIMIT value
+	 * @param	int	$offset	OFFSET value
 	 * @return	object
 	 */
 	public function limit($value, $offset = FALSE)
@@ -1027,7 +1210,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Sets the OFFSET value
 	 *
-	 * @param	int	the offset value
+	 * @param	int	$offset	OFFSET value
 	 * @return	object
 	 */
 	public function offset($offset)
@@ -1039,11 +1222,11 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT string
 	 *
-	 * Generates a platform-specific LIMIT clause
+	 * Generates a platform-specific LIMIT clause.
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
@@ -1183,10 +1366,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Allows the where clause, limit and offset to be added directly
 	 *
-	 * @param	string	$table = ''
-	 * @param	string	$where = NULL
-	 * @param	int	$limit = NULL
-	 * @param	int	$offset = NULL
+	 * @param	string	$table
+	 * @param	string	$where
+	 * @param	int	$limit
+	 * @param	int	$offset
 	 * @return	object
 	 */
 	public function get_where($table = '', $where = NULL, $limit = NULL, $offset = NULL)
@@ -1218,15 +1401,16 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Compiles batch insert strings and runs the queries
 	 *
-	 * @param	string	$table = ''	table to insert into
-	 * @param	array	$set 		an associative array of insert values
-	 * @return	int	number of rows inserted or FALSE on failure
+	 * @param	string	$table	Table to insert into
+	 * @param	array	$set 	An associative array of insert values
+	 * @param	bool	$escape	Whether to escape values and identifiers
+	 * @return	int	Number of rows inserted or FALSE on failure
 	 */
-	public function insert_batch($table = '', $set = NULL)
+	public function insert_batch($table = '', $set = NULL, $escape = NULL)
 	{
 		if ( ! is_null($set))
 		{
-			$this->set_insert_batch($set);
+			$this->set_insert_batch($set, '', $escape);
 		}
 
 		if (count($this->qb_set) === 0)
@@ -1249,7 +1433,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		$affected_rows = 0;
 		for ($i = 0, $total = count($this->qb_set); $i < $total; $i += 100)
 		{
-			$this->query($this->_insert_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), $this->qb_keys, array_slice($this->qb_set, $i, 100)));
+			$this->query($this->_insert_batch($this->protect_identifiers($table, TRUE, $escape, FALSE), $this->qb_keys, array_slice($this->qb_set, $i, 100)));
 			$affected_rows += $this->affected_rows();
 		}
 
@@ -1260,13 +1444,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert_batch statement
+	 * Insert batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data.
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
 	 * @return	string
 	 */
 	protected function _insert_batch($table, $keys, $values)
@@ -1375,13 +1559,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * @param	string	the table to insert data into
 	 * @param	array	an associative array of insert values
+	 * @param	bool	$escape	Whether to escape values and identifiers
 	 * @return	object
 	 */
-	public function insert($table = '', $set = NULL)
+	public function insert($table = '', $set = NULL, $escape = NULL)
 	{
 		if ( ! is_null($set))
 		{
-			$this->set($set);
+			$this->set($set, '', $escape);
 		}
 
 		if ($this->_validate_insert($table) === FALSE)
@@ -1391,7 +1576,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		$sql = $this->_insert(
 			$this->protect_identifiers(
-				$this->qb_from[0], TRUE, NULL, FALSE
+				$this->qb_from[0], TRUE, $escape, FALSE
 			),
 			array_keys($this->qb_set),
 			array_values($this->qb_set)
@@ -1539,14 +1724,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update
+	 * UPDATE
 	 *
-	 * Compiles an update string and runs the query
+	 * Compiles an update string and runs the query.
 	 *
-	 * @param	string	$table = ''
-	 * @param	array	$set = NULL	an associative array of update values
-	 * @param	mixed	$where = NULL
-	 * @param	int	$limit = NULL
+	 * @param	string	$table
+	 * @param	array	$set	An associative array of update values
+	 * @param	mixed	$where
+	 * @param	int	$limit
 	 * @return	object
 	 */
 	public function update($table = '', $set = NULL, $where = NULL, $limit = NULL)
@@ -1575,7 +1760,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		$sql = $this->_update($this->protect_identifiers($this->qb_from[0], TRUE, NULL, FALSE), $this->qb_set);
-
 		$this->_reset_write();
 		return $this->query($sql);
 	}
@@ -1980,7 +2164,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * Generates a query string based on which functions were used.
 	 * Should not be called directly.
 	 *
-	 * @param	bool	$select_override = FALSE
+	 * @param	bool	$select_override
 	 * @return	string
 	 */
 	protected function _compile_select($select_override = FALSE)
@@ -2053,7 +2237,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * where(), or_where(), having(), or_having are called prior to from(),
 	 * join() and dbprefix is added only if needed.
 	 *
-	 * @param	string	'qb_where' or 'qb_having'
+	 * @param	string	$qb_key	'qb_where' or 'qb_having'
 	 * @return	string	SQL statement
 	 */
 	protected function _compile_wh($qb_key)
@@ -2291,7 +2475,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			'qb_cache_from'			=> array(),
 			'qb_cache_join'			=> array(),
 			'qb_cache_where'		=> array(),
-			'qb_cache_like'			=> array(),
 			'qb_cache_groupby'		=> array(),
 			'qb_cache_having'		=> array(),
 			'qb_cache_orderby'		=> array(),
@@ -2398,10 +2581,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	{
 		foreach ($qb_reset_items as $item => $default_value)
 		{
-			if ( ! in_array($item, $this->qb_store_array))
-			{
-				$this->$item = $default_value;
-			}
+			$this->$item = $default_value;
 		}
 	}
 
diff --git a/system/database/DB_result.php b/system/database/DB_result.php
index 76093f918..9d19075ba 100644
--- a/system/database/DB_result.php
+++ b/system/database/DB_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Result Class
@@ -38,19 +39,68 @@
  */
 class CI_DB_result {
 
+	/**
+	 * Connection ID
+	 *
+	 * @var	resource|object
+	 */
 	public $conn_id;
+
+	/**
+	 * Result ID
+	 *
+	 * @var	resource|object
+	 */
 	public $result_id;
+
+	/**
+	 * Result Array
+	 *
+	 * @var	array[]
+	 */
 	public $result_array			= array();
+
+	/**
+	 * Result Object
+	 *
+	 * @var	object[]
+	 */
 	public $result_object			= array();
+
+	/**
+	 * Custom Result Object
+	 *
+	 * @var	object[]
+	 */
 	public $custom_result_object		= array();
+
+	/**
+	 * Current Row index
+	 *
+	 * @var	int
+	 */
 	public $current_row			= 0;
+
+	/**
+	 * Number of rows
+	 *
+	 * @var	int
+	 */
 	public $num_rows;
+
+	/**
+	 * Row data
+	 *
+	 * @var	array
+	 */
 	public $row_data;
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	object
+	 * @param	object	$driver_object
 	 * @return	void
 	 */
 	public function __construct(&$driver_object)
@@ -89,7 +139,7 @@ class CI_DB_result {
 	/**
 	 * Query result. Acts as a wrapper function for the following functions.
 	 *
-	 * @param	string	'object', 'array' or a custom class name
+	 * @param	string	$type	'object', 'array' or a custom class name
 	 * @return	array
 	 */
 	public function result($type = 'object')
@@ -113,8 +163,8 @@ class CI_DB_result {
 	/**
 	 * Custom query result.
 	 *
-	 * @param	string	A string that represents the type of object you want back
-	 * @return	array	of objects
+	 * @param	string	$class_name
+	 * @return	array
 	 */
 	public function custom_result_object($class_name)
 	{
@@ -249,10 +299,12 @@ class CI_DB_result {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Query result.  Acts as a wrapper function for the following functions.
+	 * Row
+	 *
+	 * A wrapper method.
 	 *
-	 * @param	mixed	$n = 0
-	 * @param	string	$type = 'object'	'object' or 'array'
+	 * @param	mixed	$n
+	 * @param	string	$type	'object' or 'array'
 	 * @return	mixed
 	 */
 	public function row($n = 0, $type = 'object')
@@ -339,7 +391,7 @@ class CI_DB_result {
 	/**
 	 * Returns a single result row - object version
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	object
 	 */
 	public function row_object($n = 0)
@@ -363,7 +415,7 @@ class CI_DB_result {
 	/**
 	 * Returns a single result row - array version
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	array
 	 */
 	public function row_array($n = 0)
@@ -387,7 +439,7 @@ class CI_DB_result {
 	/**
 	 * Returns the "first" row
 	 *
-	 * @param	string	$type = 'object'
+	 * @param	string	$type
 	 * @return	mixed
 	 */
 	public function first_row($type = 'object')
@@ -401,7 +453,7 @@ class CI_DB_result {
 	/**
 	 * Returns the "last" row
 	 *
-	 * @param	string	$type = 'object'
+	 * @param	string	$type
 	 * @return	mixed
 	 */
 	public function last_row($type = 'object')
@@ -415,7 +467,7 @@ class CI_DB_result {
 	/**
 	 * Returns the "next" row
 	 *
-	 * @param	string	$type = 'object'
+	 * @param	string	$type
 	 * @return	mixed
 	 */
 	public function next_row($type = 'object')
@@ -439,7 +491,7 @@ class CI_DB_result {
 	/**
 	 * Returns the "previous" row
 	 *
-	 * @param	string	$type = 'object'
+	 * @param	string	$type
 	 * @return	mixed
 	 */
 	public function previous_row($type = 'object')
@@ -462,7 +514,7 @@ class CI_DB_result {
 	/**
 	 * Returns an unbuffered row and move pointer to next row
 	 *
-	 * @param	string	$type = 'object'	'array', 'object' or a custom class name
+	 * @param	string	$type	'array', 'object' or a custom class name
 	 * @return	mixed
 	 */
 	public function unbuffered_row($type = 'object')
@@ -482,7 +534,7 @@ class CI_DB_result {
 	// --------------------------------------------------------------------
 
 	/**
-	 * The following functions are normally overloaded by the identically named
+	 * The following methods are normally overloaded by the identically named
 	 * methods in the platform-specific driver -- except when query caching
 	 * is used. When caching is enabled we do not load the other driver.
 	 * These functions are primarily here to prevent undefined function errors
@@ -490,13 +542,118 @@ class CI_DB_result {
 	 * operational due to the unavailability of the database resource IDs with
 	 * cached results.
 	 */
-	public function num_fields() { return 0; }
-	public function list_fields() { return array(); }
-	public function field_data() { return array(); }
-	public function free_result() { $this->result_id = FALSE; }
-	protected function _data_seek() { return FALSE; }
-	protected function _fetch_assoc() { return array(); }
-	protected function _fetch_object() { return array(); }
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Number of fields in the result set
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @return	int
+	 */
+	public function num_fields()
+	{
+		return 0;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch Field Names
+	 *
+	 * Generates an array of column names.
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @return	array
+	 */
+	public function list_fields()
+	{
+		return array();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field data
+	 *
+	 * Generates an array of objects containing field meta-data.
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @return	array
+	 */
+	public function field_data()
+	{
+		return array();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Free the result
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @return	void
+	 */
+	public function free_result()
+	{
+		$this->result_id = FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Data Seek
+	 *
+	 * Moves the internal pointer to the desired offset. We call
+	 * this internally before fetching results to make sure the
+	 * result set starts at zero.
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @param	int	$n
+	 * @return	bool
+	 */
+	protected function _data_seek($n = 0)
+	{
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Result - associative array
+	 *
+	 * Returns the result set as an array.
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @return	array
+	 */
+	protected function _fetch_assoc()
+	{
+		return array();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Result - object
+	 *
+	 * Returns the result set as an object.
+	 *
+	 * Overriden by driver result classes.
+	 *
+	 * @param	string	$class_name
+	 * @return	object
+	 */
+	protected function _fetch_object($class_name = 'stdClass')
+	{
+		return array();
+	}
 
 }
 
diff --git a/system/database/DB_utility.php b/system/database/DB_utility.php
index 8078e2bf6..488ebf3ac 100644
--- a/system/database/DB_utility.php
+++ b/system/database/DB_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Utility Class
@@ -32,25 +33,49 @@
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
-abstract class CI_DB_utility extends CI_DB_forge {
+abstract class CI_DB_utility {
 
-	public $db;
+	/**
+	 * Database object
+	 *
+	 * @var	object
+	 */
+	protected $db;
+
+	// --------------------------------------------------------------------
 
-	// Platform specific SQL strings
-	// Just setting those defaults to FALSE as they are mostly MySQL-specific
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
+	protected $_list_databases		= FALSE;
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= FALSE;
+
+	/**
+	 * REPAIR TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_repair_table	= FALSE;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
+	 * @param	object	&$db	Database object
 	 * @return	void
 	 */
-	public function __construct()
+	public function __construct(&$db)
 	{
-		// Assign the main database object to $this->db
-		$CI =& get_instance();
-		$this->db =& $CI->db;
+		$this->db =& $db;
 		log_message('debug', 'Database Utility Class Initialized');
 	}
 
@@ -70,7 +95,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 		}
 		elseif ($this->_list_databases === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 
 		$this->db->data_cache['db_names'] = array();
@@ -94,7 +119,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Determine if a particular database exists
 	 *
-	 * @param	string
+	 * @param	string	$database_name
 	 * @return	bool
 	 */
 	public function database_exists($database_name)
@@ -107,14 +132,14 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Optimize Table
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table_name
 	 * @return	mixed
 	 */
 	public function optimize_table($table_name)
 	{
 		if ($this->_optimize_table === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 
 		$query = $this->db->query(sprintf($this->_optimize_table, $this->db->escape_identifiers($table_name)));
@@ -138,7 +163,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	{
 		if ($this->_optimize_table === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 
 		$result = array();
@@ -168,14 +193,14 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Repair Table
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table_name
 	 * @return	mixed
 	 */
 	public function repair_table($table_name)
 	{
 		if ($this->_repair_table === FALSE)
 		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
 
 		$query = $this->db->query(sprintf($this->_repair_table, $this->db->escape_identifiers($table_name)));
@@ -193,10 +218,10 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Generate CSV from a query result object
 	 *
-	 * @param	object	The query result object
-	 * @param	string	The delimiter - comma by default
-	 * @param	string	The newline character - \n by default
-	 * @param	string	The enclosure - double quote by default
+	 * @param	object	$query		Query result object
+	 * @param	string	$delim		Delimiter (default: ,)
+	 * @param	string	$newline	Newline character (default: \n)
+	 * @param	string	$enclosure	Enclosure (default: ")
 	 * @return	string
 	 */
 	public function csv_from_result($query, $delim = ',', $newline = "\n", $enclosure = '"')
@@ -233,8 +258,8 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Generate XML data from a query result object
 	 *
-	 * @param	object	The query result object
-	 * @param	array	Any preferences
+	 * @param	object	$query	Query result object
+	 * @param	array	$params	Any preferences
 	 * @return	string
 	 */
 	public function xml_from_result($query, $params = array())
@@ -280,7 +305,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Database Backup
 	 *
-	 * @param	array	$params = array()
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function backup($params = array())
@@ -293,8 +318,6 @@ abstract class CI_DB_utility extends CI_DB_forge {
 			$params = array('tables' => $params);
 		}
 
-		// ------------------------------------------------------
-
 		// Set up our default preferences
 		$prefs = array(
 				'tables'		=> array(),
@@ -338,7 +361,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 		{
 			if ($this->db->db_debug)
 			{
-				return $this->db->display_error('db_unsuported_compression');
+				return $this->db->display_error('db_unsupported_compression');
 			}
 
 			$prefs['format'] = 'txt';
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 8e77d8396..c89a924d3 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CUBRID Database Adapter Class
@@ -40,18 +41,33 @@
  */
 class CI_DB_cubrid_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'cubrid';
 
-	// The character used for escaping - no need in CUBRID
-	protected $_escape_char = '`';
+	/**
+	 * Auto-commit flag
+	 *
+	 * @var	bool
+	 */
+	public $auto_commit = TRUE;
 
-	protected $_random_keyword = ' RAND()'; // database specific random keyword
+	// --------------------------------------------------------------------
 
-	// CUBRID-specific properties
-	public $auto_commit = TRUE;
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '`';
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * @param	array	$params
 	 * @return	void
@@ -113,7 +129,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 * Except for determining if a persistent connection should be used,
 	 * the rest of the logic is the same for db_connect() and db_pconnect().
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	resource
 	 */
 	protected function _cubrid_connect($persistent = FALSE)
@@ -163,9 +179,18 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 */
 	public function version()
 	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = cubrid_get_server_info($this->conn_id);
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		return ( ! $this->conn_id OR ($version = cubrid_get_server_info($this->conn_id)) === FALSE)
+			? FALSE
+			: $this->data_cache['version'] = $version;
 	}
 
 	// --------------------------------------------------------------------
@@ -173,7 +198,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -186,7 +211,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -265,8 +290,8 @@ class CI_DB_cubrid_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -332,7 +357,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -354,7 +379,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -369,7 +394,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -399,9 +424,9 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
diff --git a/system/database/drivers/cubrid/cubrid_forge.php b/system/database/drivers/cubrid/cubrid_forge.php
index d328aa241..05762ba5a 100644
--- a/system/database/drivers/cubrid/cubrid_forge.php
+++ b/system/database/drivers/cubrid/cubrid_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CUBRID Forge Class
@@ -34,181 +35,175 @@
  */
 class CI_DB_cubrid_forge extends CI_DB_forge {
 
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= FALSE;
+
+	/**
+	 * CREATE TABLE keys flag
+	 *
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
+	 */
+	protected $_create_table_keys	= TRUE;
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_drop_database	= FALSE;
 
 	/**
-	 * Process Fields
+	 * CREATE TABLE IF statement
 	 *
-	 * @param	mixed	the fields
-	 * @return	string
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SHORT'		=> 'INTEGER',
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT',
+		'BIGINT'	=> 'NUMERIC',
+		'FLOAT'		=> 'DOUBLE',
+		'REAL'		=> 'DOUBLE'
+	);
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _process_fields($fields)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$current_field_count = 0;
-		$sql = '';
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
 
-		foreach ($fields as $field => $attributes)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				$sql .= "\n\t".$attributes;
+				$sqls[] = $sql.' CHANGE '.$field[$i]['_literal'];
 			}
 			else
 			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field);
-
-				empty($attributes['NAME']) OR $sql .= ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
-
-				if ( ! empty($attributes['TYPE']))
-				{
-					$sql .= ' '.$attributes['TYPE'];
-
-					if ( ! empty($attributes['CONSTRAINT']))
-					{
-						switch (strtolower($attributes['TYPE']))
-						{
-							case 'decimal':
-							case 'float':
-							case 'numeric':
-								$sql .= '('.implode(',', $attributes['CONSTRAINT']).')';
-								break;
-							case 'enum':
-								// Will be supported in the future as part a part of
-								// MySQL compatibility features.
-								break;
-							case 'set':
-								$sql .= '("'.implode('","', $attributes['CONSTRAINT']).'")';
-								break;
-							default:
-								$sql .= '('.$attributes['CONSTRAINT'].')';
-						}
-					}
-				}
-
-			/* As of version 8.4.1 CUBRID does not support UNSIGNED INTEGER data type.
-			 * Will be supported in the next release as a part of MySQL Compatibility.
-			 *
-				if (isset($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-			 */
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
-
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
+				$sqls[] = $sql.' CHANGE '.$this->_process_column($field[$i]);
+				if ( ! empty($field[$i]['new_name']))
 				{
-					$sql .= ' AUTO_INCREMENT';
+					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
+						.' AS '.$this->db->escape_identifiers($field[$i]['name']);
 				}
-
-				if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
-				{
-					$sql .= ' UNIQUE';
-				}
-			}
-
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
 			}
 		}
 
-		return $sql;
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * Process column
 	 *
-	 * @param	string	the table name
-	 * @param	mixed	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	array	$field
+	 * @return	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _process_column($field)
 	{
-		$sql = 'CREATE TABLE ';
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
 
-		/* As of version 8.4.1 CUBRID does not support this SQL syntax.
-		if ($if_not_exists === TRUE)
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
 		{
-			$sql .= 'IF NOT EXISTS ';
+			$extra_clause = ' FIRST';
 		}
-		*/
 
-		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields);
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : $this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
 
-		// If there is a PK defined
-		if (count($primary_keys) > 0)
-		{
-			$key_name = $this->db->escape_identifiers('pk_'.$table.'_'.implode('_', $primary_keys));
-			$sql .= ",\n\tCONSTRAINT ".$key_name.' PRIMARY KEY('.implode(', ', $this->db->escape_identifiers($primary_keys)).')';
-		}
+	// --------------------------------------------------------------------
 
-		if (is_array($keys) && count($keys) > 0)
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
 		{
-			foreach ($keys as $key)
-			{
-				if (is_array($key))
-				{
-					$key_name = $this->db->escape_identifiers('idx_'.$table.implode('_', $key));
-					$key = $this->db->escape_identifiers($key);
-				}
-				else
-				{
-					$key_name = $this->db->escape_identifiers('idx_'.$table.$key);
-					$key = array($key_name);
-				}
-
-				$sql .= ",\n\tKEY ".$key_name.' ('.implode(', ', $key).')';
-			}
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			default: return;
 		}
-
-		return $sql."\n);";
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
-	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Process indexes
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	array	fields
-	 * @param	string	the field after which we should add the new field
+	 * @param	string	$table	(ignored)
 	 * @return	string
 	 */
-	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
+	protected function _process_indexes($table = NULL)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' ';
+		$sql = '';
 
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
 		{
-			return $sql.$this->db->escape_identifiers($fields);
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
 		}
 
-		return $sql.$this->_process_fields($fields)
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+		$this->keys = array();
+
+		return $sql;
 	}
 
 }
diff --git a/system/database/drivers/cubrid/cubrid_result.php b/system/database/drivers/cubrid/cubrid_result.php
index 360c50dc2..30aed38d9 100644
--- a/system/database/drivers/cubrid/cubrid_result.php
+++ b/system/database/drivers/cubrid/cubrid_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CUBRID Result Class
@@ -130,9 +131,9 @@ class CI_DB_cubrid_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -161,7 +162,7 @@ class CI_DB_cubrid_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/cubrid/cubrid_utility.php b/system/database/drivers/cubrid/cubrid_utility.php
index ea8feb4e2..d76eca432 100644
--- a/system/database/drivers/cubrid/cubrid_utility.php
+++ b/system/database/drivers/cubrid/cubrid_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CUBRID Utility Class
@@ -62,7 +63,7 @@ class CI_DB_cubrid_utility extends CI_DB_utility {
 		// No SQL based support in CUBRID as of version 8.4.0. Database or
 		// table backup can be performed using CUBRID Manager
 		// database administration tool.
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 }
 
diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index c3be519bf..fc1c28f31 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Firebird/Interbase Database Adapter Class
@@ -40,15 +41,30 @@
  */
 class CI_DB_ibase_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'ibase';
 
-	// The character used to escape with
-	protected $_escape_char = '"';
+	// --------------------------------------------------------------------
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
+	protected $_random_keyword = ' Random()';
 
-	protected $_random_keyword = ' Random()'; // database specific random keyword
+	/**
+	 * IBase Transaction status flag
+	 *
+	 * @var	resource
+	 */
+	protected $_ibase_trans;
 
-	// Keeps track of the resource for the current transaction
-	protected $trans;
+	// --------------------------------------------------------------------
 
 	/**
 	 * Non-persistent database connection
@@ -103,7 +119,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -116,7 +132,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -132,7 +148,7 @@ class CI_DB_ibase_driver extends CI_DB {
 		// even if the queries produce a successful result.
 		$this->_trans_failure = ($test_mode === TRUE);
 
-		$this->trans = @ibase_trans($this->conn_id);
+		$this->_ibase_trans = @ibase_trans($this->conn_id);
 
 		return TRUE;
 	}
@@ -152,7 +168,7 @@ class CI_DB_ibase_driver extends CI_DB {
 			return TRUE;
 		}
 
-		return @ibase_commit($this->trans);
+		return @ibase_commit($this->_ibase_trans);
 	}
 
 	// --------------------------------------------------------------------
@@ -170,7 +186,7 @@ class CI_DB_ibase_driver extends CI_DB {
 			return TRUE;
 		}
 
-		return @ibase_rollback($this->trans);
+		return @ibase_rollback($this->_ibase_trans);
 	}
 
 	// --------------------------------------------------------------------
@@ -178,8 +194,8 @@ class CI_DB_ibase_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -239,7 +255,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -262,7 +278,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -277,7 +293,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -310,8 +326,8 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
 	protected function _update($table, $values)
@@ -327,10 +343,10 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -345,7 +361,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -357,11 +373,11 @@ class CI_DB_ibase_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/ibase/ibase_forge.php b/system/database/drivers/ibase/ibase_forge.php
index da75eb9c3..a0c4e6563 100644
--- a/system/database/drivers/ibase/ibase_forge.php
+++ b/system/database/drivers/ibase/ibase_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Interbase/Firebird Forge Class
@@ -34,12 +35,51 @@
  */
 class CI_DB_ibase_forge extends CI_DB_forge {
 
-	protected $_drop_table	= 'DROP TABLE %s';
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
+	/**
+	 * RENAME TABLE statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= FALSE;
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= FALSE;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SMALLINT'	=> 'INTEGER',
+		'INTEGER'	=> 'INT64',
+		'FLOAT'		=> 'DOUBLE PRECISION'
+	);
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
 
 	/**
 	 * Create database
 	 *
-	 * @param	string	the database name
+	 * @param	string	$db_name
 	 * @return	string
 	 */
 	public function create_database($db_name)
@@ -57,8 +97,7 @@ class CI_DB_ibase_forge extends CI_DB_forge {
 	/**
 	 * Drop database
 	 *
-	 * @param	string	the database name
-	 *		- not used in this driver, the current db is dropped
+	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
 	public function drop_database($db_name = '')
@@ -82,110 +121,119 @@ class CI_DB_ibase_forge extends CI_DB_forge {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	string
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = 'CREATE TABLE ';
-
-		$sql .= $this->db->escape_identifiers($table).'(';
-		$current_field_count = 0;
+	protected function _alter_table($alter_type, $table, $field)
+ 	{
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
 
-		foreach ($fields as $field => $attributes)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field), $sql .= $alter_type.' '; $i < $c; $i++)
 		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				$sql .= "\n\t".$attributes;
+				return FALSE;
 			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				empty($attributes['CONSTRAINT']) OR $sql .= '('.$attributes['CONSTRAINT'].')';
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
 
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
-
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
+			if (isset($field[$i]['type']))
+			{
+				$sqls[] = $sql.' TYPE '.$field[$i]['type'].$field[$i]['length'];
 			}
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
+			if ( ! empty($field[$i]['default']))
 			{
-				$sql .= ',';
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' SET '.$field[$i]['default'];
 			}
-		}
 
-		if (count($primary_keys) > 0)
-		{
-			$primary_keys = $this->db->escape_identifiers($primary_keys);
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $primary_keys).')';
-		}
-
-		if (is_array($keys) && count($keys) > 0)
-		{
-			foreach ($keys as $key)
+			if (isset($field[$i]['null']))
 			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
+				$sqls[] = 'UPDATE "RDB$RELATION_FIELDS" SET "RDB$NULL_FLAG" = '
+					.($field[$i]['null'] === TRUE ? 'NULL' : '1')
+					.' WHERE "RDB$FIELD_NAME" = '.$this->db->escape($field[$i]['name'])
+					.' AND "RDB$RELATION_NAME" = '.$this->db->escape($table);
+			}
 
-				$sql .= ",\n\tUNIQUE (".implode(', ', $key).')';
+			if ( ! empty($field[$i]['new_name']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
 			}
 		}
 
-		return $sql."\n)";
+		return $sqls;
+ 	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type'].$field['length']
+			.$field['null']
+			.$field['unique']
+			.$field['default'];
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute TYPE
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Performs a data type mapping between different databases.
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'INTEGER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'INT64';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_auto_increment(&$attributes, &$field)
 	{
-		return 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name)
-			.' '.$column_definition
-			.($default_value !== '' ? ' DEFAULT "'.$default_value.'"' : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+		// Not supported
 	}
 
 }
diff --git a/system/database/drivers/ibase/ibase_result.php b/system/database/drivers/ibase/ibase_result.php
index 95e55710b..bbad9d895 100644
--- a/system/database/drivers/ibase/ibase_result.php
+++ b/system/database/drivers/ibase/ibase_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Interbase/Firebird Result Class
@@ -128,7 +129,7 @@ class CI_DB_ibase_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/ibase/ibase_utility.php b/system/database/drivers/ibase/ibase_utility.php
index d0e84a7b2..5eb209ae1 100644
--- a/system/database/drivers/ibase/ibase_utility.php
+++ b/system/database/drivers/ibase/ibase_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Interbase/Firebird Utility Class
@@ -34,10 +35,8 @@
  */
 class CI_DB_ibase_utility extends CI_DB_utility {
 
-	protected $_list_databases	= FALSE;
-
 	/**
-	 * Interbase/Firebird Export
+	 * Export
 	 *
 	 * @param	string	$filename
 	 * @return	mixed
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 2063dad90..a9d53fb57 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MS SQL Database Adapter Class
@@ -40,18 +41,36 @@
  */
 class CI_DB_mssql_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'mssql';
 
-	// The character used for escaping
-	protected $_escape_char = '"';
+	// --------------------------------------------------------------------
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' NEWID()';
 
-	// MSSQL-specific properties
+	/**
+	 * Quoted identifier flag
+	 *
+	 * Whether to use SQL-92 standard quoted identifier
+	 * (double quotes) or brackets for identifier escaping.
+	 *
+	 * @var	bool
+	 */
 	protected $_quoted_identifier = TRUE;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Appends the port number to the hostname, if needed.
 	 *
@@ -73,7 +92,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	resource
 	 */
 	public function db_connect($persistent = FALSE)
@@ -113,7 +132,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @param	string	database name
+	 * @param	string	$database
 	 * @return	bool
 	 */
 	public function db_select($database = '')
@@ -139,7 +158,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	mixed	resource if rows are returned, bool otherwise
 	 */
 	protected function _execute($sql)
@@ -152,7 +171,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -212,8 +231,8 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -295,7 +314,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -320,7 +339,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -335,7 +354,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -367,8 +386,8 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
 	protected function _update($table, $values)
@@ -385,10 +404,10 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -403,7 +422,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -419,11 +438,11 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
@@ -470,6 +489,29 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		// Multiple-value inserts are only supported as of SQL Server 2008
+		if (version_compare($this->version(), '10', '>='))
+		{
+			return parent::_insert_batch($table, $keys, $values);
+		}
+
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index 3a3528f7b..5eebedbf7 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MS SQL Forge Class
@@ -34,124 +35,99 @@
  */
 class CI_DB_mssql_forge extends CI_DB_forge {
 
-	protected $_drop_table	= 'DROP TABLE %s';
-
 	/**
-	 * Create Table
+	 * CREATE TABLE IF statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	string
+	 * @var	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = ($if_not_exists === TRUE)
-			? "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'".$table."') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\n"
-			: '';
-
-		$sql .= 'CREATE TABLE '.$this->db->escape_identifiers($table).' (';
-
-		$current_field_count = 0;
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				if (stripos($attributes['TYPE'], 'INT') === FALSE && ! empty($attributes['CONSTRAINT']))
-				{
-					$sql .= '('.$attributes['CONSTRAINT'].')';
-				}
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
+	protected $_create_table_if	= "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nCREATE TABLE";
 
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= "IF EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nDROP TABLE";
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT'	=> 'SMALLINT',
+		'SMALLINT'	=> 'INT',
+		'INT'		=> 'BIGINT',
+		'REAL'		=> 'FLOAT'
+	);
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	// --------------------------------------------------------------------
 
-		if (count($primary_keys) > 0)
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('ADD', 'DROP'), TRUE))
 		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			return parent::_alter_table($alter_type, $table, $field);
 		}
 
-		if (is_array($keys) && count($keys) > 0)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' ALTER COLUMN ';
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';
-			}
+			$sqls[] = $sql.$this->_process_column($field[$i]);
 		}
 
-		return $sql."\n)";
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute TYPE
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Performs a data type mapping between different databases.
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_type(&$attributes)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		switch (strtoupper($attributes['TYPE']))
 		{
-			return $sql;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INTEGER':
+				$attributes['TYPE'] = 'INT';
+				return;
+			default: return;
 		}
+	}
 
-		return $sql.' '.$column_definition
-			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field != '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['auto_increment'] = ' IDENTITY(1,1)';
+		}
 	}
 
 }
diff --git a/system/database/drivers/mssql/mssql_result.php b/system/database/drivers/mssql/mssql_result.php
index 84d2814f1..c74c70abf 100644
--- a/system/database/drivers/mssql/mssql_result.php
+++ b/system/database/drivers/mssql/mssql_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MSSQL Result Class
@@ -131,9 +132,9 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -162,7 +163,7 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/mssql/mssql_utility.php b/system/database/drivers/mssql/mssql_utility.php
index 69fcec5f6..76c7cb9c2 100644
--- a/system/database/drivers/mssql/mssql_utility.php
+++ b/system/database/drivers/mssql/mssql_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MS SQL Utility Class
@@ -34,19 +35,30 @@
  */
 class CI_DB_mssql_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'EXEC sp_helpdb'; // Can also be: EXEC sp_databases
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'ALTER INDEX all ON %s REORGANIZE';
 
 	/**
-	 * MSSQL Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	bool
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index f82e775e6..b1edc2925 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Database Adapter Class
@@ -40,25 +41,46 @@
  */
 class CI_DB_mysql_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'mysql';
-	public $compress = FALSE;
 
-	// The character used for escaping
-	protected $_escape_char = '`';
-
-	protected $_random_keyword = ' RAND()'; // database specific random keyword
+	/**
+	 * Compression flag
+	 *
+	 * @var	bool
+	 */
+	public $compress = FALSE;
 
 	/**
+	 * DELETE hack flag
+	 *
 	 * Whether to use the MySQL "delete hack" which allows the number
 	 * of affected rows to be shown. Uses a preg_replace when enabled,
 	 * adding a bit more processing to all queries.
+	 *
+	 * @var	bool
 	 */
 	public $delete_hack = TRUE;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Identifier escape character
 	 *
-	 * @param	array
+	 * @var	string
+	 */
+	protected $_escape_char = '`';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -76,7 +98,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	resource
 	 */
 	public function db_connect($persistent = FALSE)
@@ -128,7 +150,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @param	string	database name
+	 * @param	string	$database
 	 * @return	bool
 	 */
 	public function db_select($database = '')
@@ -152,7 +174,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Set client character set
 	 *
-	 * @param	string
+	 * @param	string	$charset
 	 * @return	bool
 	 */
 	protected function _db_set_charset($charset)
@@ -169,9 +191,21 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public function version()
 	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = @mysql_get_server_info($this->conn_id);
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		if ( ! $this->conn_id OR ($version = @mysql_get_server_info($this->conn_id)) === FALSE)
+		{
+			return FALSE;
+		}
+
+		return $this->data_cache['version'] = $version;
 	}
 
 	// --------------------------------------------------------------------
@@ -179,7 +213,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	mixed
 	 */
 	protected function _execute($sql)
@@ -194,7 +228,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	string
 	 */
 	protected function _prep_query($sql)
@@ -214,7 +248,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -280,8 +314,8 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -340,7 +374,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -362,7 +396,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -375,7 +409,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Returns an object with field data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	object
 	 */
 	public function field_data($table = '')
@@ -426,9 +460,9 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index 2ac75bad2..6c5dfc665 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Forge Class
@@ -34,165 +35,167 @@
  */
 class CI_DB_mysql_forge extends CI_DB_forge {
 
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= 'CREATE DATABASE %s CHARACTER SET %s COLLATE %s';
 
 	/**
-	 * Process Fields
+	 * CREATE TABLE keys flag
 	 *
-	 * @param	mixed	the fields
-	 * @return	string
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
 	 */
-	protected function _process_fields($fields)
-	{
-		$current_field_count = 0;
-		$sql = '';
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field);
-
-				empty($attributes['NAME']) OR $sql .= ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
-
-				if ( ! empty($attributes['TYPE']))
-				{
-					$sql .=  ' '.$attributes['TYPE'];
-
-					if ( ! empty($attributes['CONSTRAINT']))
-					{
-						switch (strtolower($attributes['TYPE']))
-						{
-							case 'decimal':
-							case 'float':
-							case 'numeric':
-								$sql .= '('.implode(',', $attributes['CONSTRAINT']).')';
-								break;
-							case 'enum':
-							case 'set':
-								$sql .= '("'.implode('","', $attributes['CONSTRAINT']).'")';
-								break;
-							default:
-								$sql .= '('.$attributes['CONSTRAINT'].')';
-						}
-					}
-				}
+	protected $_create_table_keys	= TRUE;
 
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT',
+		'SMALLINT',
+		'MEDIUMINT',
+		'INT',
+		'INTEGER',
+		'BIGINT',
+		'REAL',
+		'DOUBLE',
+		'DOUBLE PRECISION',
+		'FLOAT',
+		'DECIMAL',
+		'NUMERIC'
+	);
 
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	// --------------------------------------------------------------------
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
 
-		return $sql;
+		$this->_create_table .= ' DEFAULT CHARSET '.$this->db->char_set.' COLLATE '.$this->db->dbcollat;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	mixed	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$sql = 'CREATE TABLE ';
-
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields);
-
-		if (count($primary_keys) > 0)
+		if ($alter_type === 'DROP')
 		{
-			$key_name = $this->db->escape_identifiers(implode('_', $primary_keys));
-			$sql .= ",\n\tPRIMARY KEY ".$key_name.' ('.implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			return parent::_alter_table($alter_type, $table, $field);
 		}
 
-		if (is_array($keys) && count($keys) > 0)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			foreach ($keys as $key)
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				if (is_array($key))
+				$field[$i] = ($alter_type === 'ADD')
+						? "\n\tADD ".$field[$i]['_literal']
+						: "\n\tMODIFY ".$field[$i]['_literal'];
+			}
+			else
+			{
+				if ($alter_type === 'ADD')
 				{
-					$key_name = $this->db->escape_identifiers(implode('_', $key));
-					$key = $this->db->escape_identifiers($key);
+					$field[$i]['_literal'] = "\n\tADD ";
 				}
 				else
 				{
-					$key_name = $this->db->escape_identifiers($key);
-					$key = array($key_name);
+					$field[$i]['_literal'] = empty($field[$i]['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
 				}
 
-				$sql .= ",\n\tKEY ".$key_name.' ('.implode(', ', $key).')';
+				$field[$i] = $field[$i]['_literal'].$this->_process_column($field[$i]);
 			}
 		}
 
-		return $sql."\n) DEFAULT CHARACTER SET ".$this->db->char_set.' COLLATE '.$this->db->dbcollat.';';
+		return array($sql.implode(',', $field));
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Process column
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column() and column_alter()
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : $this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	array	fields
-	 * @param	string	the field after which we should add the new field
+	 * @param	string	$table	(ignored)
 	 * @return	string
 	 */
-	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
+	protected function _process_indexes($table = NULL)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' ';
+		$sql = '';
 
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
 		{
-			return $sql.$this->db->escape_identifiers($fields);
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
 		}
 
-		return $sql.$this->_process_fields($fields)
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+		$this->keys = array();
+
+		return $sql;
 	}
 
 }
diff --git a/system/database/drivers/mysql/mysql_result.php b/system/database/drivers/mysql/mysql_result.php
index b3f669e40..4bfa0ae35 100644
--- a/system/database/drivers/mysql/mysql_result.php
+++ b/system/database/drivers/mysql/mysql_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Result Class
@@ -38,9 +39,9 @@
 class CI_DB_mysql_result extends CI_DB_result {
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
-	 * @param	object
+	 * @param	object	&$driver_object
 	 * @return	void
 	 */
 	public function __construct(&$driver_object)
@@ -144,9 +145,9 @@ class CI_DB_mysql_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -177,7 +178,7 @@ class CI_DB_mysql_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/mysql/mysql_utility.php b/system/database/drivers/mysql/mysql_utility.php
index f0bbc665e..8aa051755 100644
--- a/system/database/drivers/mysql/mysql_utility.php
+++ b/system/database/drivers/mysql/mysql_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Utility Class
@@ -34,14 +35,33 @@
  */
 class CI_DB_mysql_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'SHOW DATABASES';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'OPTIMIZE TABLE %s';
+
+	/**
+	 * REPAIR TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_repair_table	= 'REPAIR TABLE %s';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * MySQL Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 6c4f87513..ae17703ac 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQLi Database Adapter Class
@@ -40,25 +41,46 @@
  */
 class CI_DB_mysqli_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'mysqli';
-	public $compress = FALSE;
 
-	// The character used for escaping
-	protected $_escape_char = '`';
-
-	protected $_random_keyword = ' RAND()'; // database specific random keyword
+	/**
+	 * Compression flag
+	 *
+	 * @var	bool
+	 */
+	public $compress = FALSE;
 
 	/**
+	 * DELETE hack flag
+	 *
 	 * Whether to use the MySQL "delete hack" which allows the number
 	 * of affected rows to be shown. Uses a preg_replace when enabled,
 	 * adding a bit more processing to all queries.
+	 *
+	 * @var	bool
 	 */
 	public $delete_hack = TRUE;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Non-persistent database connection
+	 * Identifier escape character
 	 *
-	 * @param	bool
+	 * @var	string
+	 */
+	protected $_escape_char = '`';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Database connection
+	 *
+	 * @param	bool	$persistent
 	 * @return	object
 	 * @todo	SSL support
 	 */
@@ -110,7 +132,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @param	string	database name
+	 * @param	string	$database
 	 * @return	bool
 	 */
 	public function db_select($database = '')
@@ -134,7 +156,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Set client character set
 	 *
-	 * @param	string
+	 * @param	string	$charset
 	 * @return	bool
 	 */
 	protected function _db_set_charset($charset)
@@ -151,9 +173,16 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function version()
 	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = $this->conn_id->server_info;
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		return $this->data_cache['version'] = $this->conn_id->server_info;
 	}
 
 	// --------------------------------------------------------------------
@@ -161,7 +190,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	mixed
 	 */
 	protected function _execute($sql)
@@ -176,7 +205,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	string
 	 */
 	protected function _prep_query($sql)
@@ -196,7 +225,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -262,8 +291,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -322,7 +351,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -344,7 +373,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -357,7 +386,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Returns an object with field data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	object
 	 */
 	public function field_data($table = '')
@@ -416,9 +445,9 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
diff --git a/system/database/drivers/mysqli/mysqli_forge.php b/system/database/drivers/mysqli/mysqli_forge.php
index b74c775b2..a70eef88f 100644
--- a/system/database/drivers/mysqli/mysqli_forge.php
+++ b/system/database/drivers/mysqli/mysqli_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQLi Forge Class
@@ -34,165 +35,167 @@
  */
 class CI_DB_mysqli_forge extends CI_DB_forge {
 
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= 'CREATE DATABASE %s CHARACTER SET %s COLLATE %s';
 
 	/**
-	 * Process Fields
+	 * CREATE TABLE keys flag
 	 *
-	 * @param	mixed	the fields
-	 * @return	string
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
 	 */
-	protected function _process_fields($fields)
-	{
-		$current_field_count = 0;
-		$sql = '';
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field);
-
-				empty($attributes['NAME']) OR $sql .= ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
-
-				if ( ! empty($attributes['TYPE']))
-				{
-					$sql .= ' '.$attributes['TYPE'];
-
-					if ( ! empty($attributes['CONSTRAINT']))
-					{
-						switch (strtolower($attributes['TYPE']))
-						{
-							case 'decimal':
-							case 'float':
-							case 'numeric':
-								$sql .= '('.implode(',', $attributes['CONSTRAINT']).')';
-								break;
-							case 'enum':
-							case 'set':
-								$sql .= '("'.implode('","', $attributes['CONSTRAINT']).'")';
-								break;
-							default:
-								$sql .= '('.$attributes['CONSTRAINT'].')';
-						}
-					}
-				}
+	protected $_create_table_keys	= TRUE;
 
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT',
+		'SMALLINT',
+		'MEDIUMINT',
+		'INT',
+		'INTEGER',
+		'BIGINT',
+		'REAL',
+		'DOUBLE',
+		'DOUBLE PRECISION',
+		'FLOAT',
+		'DECIMAL',
+		'NUMERIC'
+	);
 
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	// --------------------------------------------------------------------
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
 
-		return $sql;
+		$this->_create_table .= ' DEFAULT CHARSET '.$this->db->char_set.' COLLATE '.$this->db->dbcollat;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	mixed	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$sql = 'CREATE TABLE ';
-
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields);
-
-		if (count($primary_keys) > 0)
+		if ($alter_type === 'DROP')
 		{
-			$key_name = $this->db->escape_identifiers(implode('_', $primary_keys));
-			$sql .= ",\n\tPRIMARY KEY ".$key_name.' ('.implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			return parent::_alter_table($alter_type, $table, $field);
 		}
 
-		if (is_array($keys) && count($keys) > 0)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			foreach ($keys as $key)
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				if (is_array($key))
+				$field[$i] = ($alter_type === 'ADD')
+						? "\n\tADD ".$field[$i]['_literal']
+						: "\n\tMODIFY ".$field[$i]['_literal'];
+			}
+			else
+			{
+				if ($alter_type === 'ADD')
 				{
-					$key_name = $this->db->escape_identifiers(implode('_', $key));
-					$key = $this->db->escape_identifiers($key);
+					$field[$i]['_literal'] = "\n\tADD ";
 				}
 				else
 				{
-					$key_name = $this->db->escape_identifiers($key);
-					$key = array($key_name);
+					$field[$i]['_literal'] = empty($field[$i]['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
 				}
 
-				$sql .= ",\n\tKEY ".$key_name.' ('.implode(', ', $key).')';
+				$field[$i] = $field[$i]['_literal'].$this->_process_column($field[$i]);
 			}
 		}
 
-		return $sql."\n) DEFAULT CHARACTER SET ".$this->db->char_set.' COLLATE '.$this->db->dbcollat.';';
+		return array($sql.implode(',', $field));
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Process column
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : $this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	array	fields
-	 * @param	string	the field after which we should add the new field
+	 * @param	string	$table	(ignored)
 	 * @return	string
 	 */
-	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
+	protected function _process_indexes($table = NULL)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' ';
+		$sql = '';
 
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
 		{
-			return $sql.$this->db->escape_identifiers($fields);
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
 		}
 
-		return $sql.$this->_process_fields($fields)
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+		$this->keys = array();
+
+		return $sql;
 	}
 
 }
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index f036302bb..15e15cd5f 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQLi Result Class
@@ -130,9 +131,9 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -161,7 +162,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/mysqli/mysqli_utility.php b/system/database/drivers/mysqli/mysqli_utility.php
index 5d2bdbce0..345691e84 100644
--- a/system/database/drivers/mysqli/mysqli_utility.php
+++ b/system/database/drivers/mysqli/mysqli_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQLi Utility Class
@@ -34,14 +35,33 @@
  */
 class CI_DB_mysqli_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'SHOW DATABASES';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'OPTIMIZE TABLE %s';
+
+	/**
+	 * REPAIR TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_repair_table	= 'REPAIR TABLE %s';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * MySQLi Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 81d73d073..eb01dd17e 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * oci8 Database Adapter Class
@@ -49,34 +50,76 @@
  */
 class CI_DB_oci8_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'oci8';
 
-	// The character used for excaping
-	protected $_escape_char = '"';
+	/**
+	 * Statement ID
+	 *
+	 * @var	resource
+	 */
+	public $stmt_id;
 
 	/**
-	 * 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.
+	 * Cursor ID
+	 *
+	 * @var	resource
 	 */
-	protected $_count_string = 'SELECT COUNT(1) AS ';
-	protected $_random_keyword = ' ASC'; // not currently supported
+	public $curs_id;
+
+	/**
+	 * Commit mode flag
+	 *
+	 * @var	int
+	 */
+	public $commit_mode = OCI_COMMIT_ON_SUCCESS;
 
+	/**
+	 * Limit used flag
+	 *
+	 * If we use LIMIT, we'll add a field that will
+	 * throw off num_fields later.
+	 *
+	 * @var	bool
+	 */
+	public $limit_used;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * List of reserved identifiers
+	 *
+	 * Identifiers that must NOT be escaped.
+	 *
+	 * @var	string[]
+	 */
 	protected $_reserved_identifiers = array('*', 'rownum');
 
-	// Set "auto commit" by default
-	public $commit_mode = OCI_COMMIT_ON_SUCCESS;
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
+	protected $_random_keyword = ' ASC'; // not currently supported
 
-	// need to track statement id and cursor id
-	public $stmt_id;
-	public $curs_id;
+	/**
+	 * COUNT string
+	 *
+	 * @used-by	CI_DB_driver::count_all()
+	 * @used-by	CI_DB_query_builder::count_all_results()
+	 *
+	 * @var	string
+	 */
+	protected $_count_string = 'SELECT COUNT(1) AS ';
 
-	// if we use a limit, we will add a field that will
-	// throw off num_fields later
-	public $limit_used;
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * @param	array	$params
 	 * @return	void
@@ -197,9 +240,21 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	public function version()
 	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = oci_server_version($this->conn_id);
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		if ( ! $this->conn_id OR ($version = oci_server_version($this->conn_id)) === FALSE)
+		{
+			return FALSE;
+		}
+
+		return $this->data_cache['version'] = $version;
 	}
 
 	// --------------------------------------------------------------------
@@ -207,7 +262,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -226,7 +281,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Generate a statement ID
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	void
 	 */
 	protected function _set_stmt_id($sql)
@@ -306,7 +361,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Bind parameters
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	protected function _bind_params($params)
@@ -335,7 +390,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -408,8 +463,8 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -469,7 +524,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -492,7 +547,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -507,7 +562,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -549,13 +604,13 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert_batch statement
+	 * Insert batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param 	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param 	array	$values	INSERT values
 	 * @return	string
 	 */
 	protected function _insert_batch($table, $keys, $values)
@@ -578,10 +633,10 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -596,7 +651,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -613,11 +668,11 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/oci8/oci8_forge.php b/system/database/drivers/oci8/oci8_forge.php
index 92e8c02ed..bd9d2df3c 100644
--- a/system/database/drivers/oci8/oci8_forge.php
+++ b/system/database/drivers/oci8/oci8_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Oracle Forge Class
@@ -34,122 +35,96 @@
  */
 class CI_DB_oci8_forge extends CI_DB_forge {
 
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= FALSE;
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_drop_database	= FALSE;
-	protected $_drop_table		= 'DROP TABLE %s';
 
 	/**
-	 * Create Table
+	 * DROP TABLE IF statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	string
+	 * @var	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = 'CREATE TABLE ';
+	protected $_drop_table_if	= FALSE;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
 
-		if ($if_not_exists === TRUE)
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'DROP')
 		{
-			$sql .= 'IF NOT EXISTS ';
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+		elseif ($alter_type === 'CHANGE')
+		{
+			$alter_type = 'MODIFY';
 		}
 
-		$sql .= $this->db->escape_identifiers($table).' (';
-		$current_field_count = 0;
-
-		foreach ($fields as $field => $attributes)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				$sql .= "\n\t".$attributes;
+				$field[$i] = "\n\t".$field[$i]['_literal'];
 			}
 			else
 			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				if (isset($attributes['UNSINGED']) && $attributes['UNSIGNED'] === TRUE)
+				$field[$i]['_literal'] = "\n\t".$this->_process_column($field[$i]);
+				if ($alter_type === 'MODIFY' && ! empty($field[$i]['new_name']))
 				{
-					$sql .= ' UNSIGNED';
+					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
+						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
 				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= (isset($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? '' : ' NOT NULL';
-
-				empty($attributes['CONSTRAINT']) OR ' CONSTRAINT '.$attributes['CONSTRAINT'];
-			}
-
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
 			}
 		}
 
-		if (count($primary_keys) > 0)
-		{
-			$sql .= ",\n\tCONSTRAINT ".$table.' PRIMARY KEY ('.implode(', ', $this->db->escape_identifiers($primary_keys)).')';
-		}
+		$sql .= ' '.$alter_type.' ';
+		$sql .= (count($field) === 1)
+				? $fields[0]
+				: '('.implode(',', $field).')';
 
-		if (is_array($keys) && count($keys) > 0)
-		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tUNIQUE COLUMNS (".implode(', ', $key).')';
-			}
-		}
-
-		return $sql."\n)";
+		// RENAME COLUMN must be executed after MODIFY
+		array_unshift($sqls, $sql);
+		return $sql;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
-	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Field attribute AUTO_INCREMENT
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_auto_increment(&$attributes, &$field)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
-		{
-			return $sql;
-		}
-
-		return $sql.' '.$column_definition
-			.($default_value !== '' ? ' DEFAULT "'.$default_value.'"' : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
-
+		// Not supported - sequences and triggers must be used instead
 	}
 
 }
diff --git a/system/database/drivers/oci8/oci8_result.php b/system/database/drivers/oci8/oci8_result.php
index ade186be7..7d5bf5172 100644
--- a/system/database/drivers/oci8/oci8_result.php
+++ b/system/database/drivers/oci8/oci8_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * oci8 Result Class
@@ -37,15 +38,40 @@
  */
 class CI_DB_oci8_result extends CI_DB_result {
 
+	/**
+	 * Statement ID
+	 *
+	 * @var	resource
+	 */
 	public $stmt_id;
+
+	/**
+	 * Cursor ID
+	 *
+	 * @var	resource
+	 */
 	public $curs_id;
+
+	/**
+	 * Limit used flag
+	 *
+	 * @var	bool
+	 */
 	public $limit_used;
+
+	/**
+	 * Commit mode flag
+	 *
+	 * @var	int
+	 */
 	public $commit_mode;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
-	 * @param	object
+	 * @param	object	&$driver_object
 	 * @return	void
 	 */
 	public function __construct(&$driver_object)
@@ -167,7 +193,7 @@ class CI_DB_oci8_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
@@ -211,9 +237,10 @@ class CI_DB_oci8_result extends CI_DB_result {
 	 * some point in the future, but it will only work for resetting the
 	 * pointer to zero.
 	 *
+	 * @param	int	$n	(ignored)
 	 * @return	bool
 	 */
-	protected function _data_seek()
+	protected function _data_seek($n = 0)
 	{
 		/* The PHP manual says that if OCI_NO_AUTO_COMMIT mode
 		 * is used, and oci_rollback() and/or oci_commit() are
diff --git a/system/database/drivers/oci8/oci8_utility.php b/system/database/drivers/oci8/oci8_utility.php
index 0183eda26..d15537fdf 100644
--- a/system/database/drivers/oci8/oci8_utility.php
+++ b/system/database/drivers/oci8/oci8_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Oracle Utility Class
@@ -34,18 +35,23 @@
  */
 class CI_DB_oci8_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'SELECT username FROM dba_users'; // Schemas are actual usernames
 
 	/**
-	 * Oracle Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index f6ea412ad..1710aafae 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * ODBC Database Adapter Class
@@ -40,24 +41,42 @@
  */
 class CI_DB_odbc_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'odbc';
 
-	// the character used to excape - not necessary for ODBC
-	protected $_escape_char = '';
+	/**
+	 * Database schema
+	 *
+	 * @var	string
+	 */
+	public $schema = 'public';
 
-	protected $_like_escape_str = " {escape '%s'} ";
+	// --------------------------------------------------------------------
 
-	protected $_random_keyword;
+	/**
+	 * Identifier escape character
+	 *
+	 * Must be empty for ODBC.
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '';
 
 	/**
-	 * Database schema
+	 * ESCAPE statement string
 	 *
 	 * @var	string
 	 */
-	public $schema = 'public';
+	protected $_like_escape_str = " {escape '%s'} ";
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * @param	array	$params
 	 * @return	void
@@ -104,7 +123,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -117,7 +136,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -181,8 +200,8 @@ class CI_DB_odbc_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -231,7 +250,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -241,7 +260,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool	$prefix_limit = FALSE
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -264,7 +283,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -279,7 +298,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -309,8 +328,8 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -327,10 +346,10 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -345,7 +364,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
diff --git a/system/database/drivers/odbc/odbc_forge.php b/system/database/drivers/odbc/odbc_forge.php
index d17b046ee..fb16ca5cf 100644
--- a/system/database/drivers/odbc/odbc_forge.php
+++ b/system/database/drivers/odbc/odbc_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * ODBC Forge Class
@@ -34,124 +35,39 @@
  */
 class CI_DB_odbc_forge extends CI_DB_forge {
 
-	protected $_drop_table		= 'DROP TABLE %s';
-
 	/**
-	 * Create Table
+	 * CREATE TABLE IF statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @var	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = 'CREATE TABLE ';
-
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' (';
-		$current_field_count = 0;
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				empty($attributes['CONSTRAINT']) OR $sql .= '('.$attributes['CONSTRAINT'].')';
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
-
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
-
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	protected $_create_table_if	= FALSE;
 
-		if (count($primary_keys) > 0)
-		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->escape_identifiers($primary_keys)).')';
-		}
-
-		if (is_array($keys) && count($keys) > 0)
-		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';
-			}
-		}
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= FALSE;
 
-		return $sql."\n)";
-	}
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute AUTO_INCREMENT
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
-	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_auto_increment(&$attributes, &$field)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
-		{
-			return $sql;
-		}
-
-		return $sql.' '.$column_definition
-			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field != '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+		// Not supported (in most databases at least)
 	}
 
 }
diff --git a/system/database/drivers/odbc/odbc_result.php b/system/database/drivers/odbc/odbc_result.php
index 48dc48dd9..2c50c255b 100644
--- a/system/database/drivers/odbc/odbc_result.php
+++ b/system/database/drivers/odbc/odbc_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * ODBC Result Class
@@ -165,7 +166,7 @@ class CI_DB_odbc_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
@@ -198,11 +199,11 @@ if ( ! function_exists('odbc_fetch_array'))
 	 * Emulates the native odbc_fetch_array() function when
 	 * it is not available (odbc_fetch_array() requires unixODBC)
 	 *
-	 * @param	resource
-	 * @param	int
+	 * @param	resource	&$result
+	 * @param	int		$rownumber
 	 * @return	array
 	 */
-	function odbc_fetch_array(& $result, $rownumber = 1)
+	function odbc_fetch_array(&$result, $rownumber = 1)
 	{
 		$rs = array();
 		if ( ! odbc_fetch_into($result, $rs, $rownumber))
@@ -231,11 +232,11 @@ if ( ! function_exists('odbc_fetch_object'))
 	 * Emulates the native odbc_fetch_object() function when
 	 * it is not available.
 	 *
-	 * @param	resource
-	 * @param	int
+	 * @param	resource	&$result
+	 * @param	int		$rownumber
 	 * @return	object
 	 */
-	function odbc_fetch_object(& $result, $rownumber = 1)
+	function odbc_fetch_object(&$result, $rownumber = 1)
 	{
 		$rs = array();
 		if ( ! odbc_fetch_into($result, $rs, $rownumber))
diff --git a/system/database/drivers/odbc/odbc_utility.php b/system/database/drivers/odbc/odbc_utility.php
index 224d48d2b..908674a9d 100644
--- a/system/database/drivers/odbc/odbc_utility.php
+++ b/system/database/drivers/odbc/odbc_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * ODBC Utility Class
@@ -34,18 +35,16 @@
  */
 class CI_DB_odbc_utility extends CI_DB_utility {
 
-	protected $_list_databases	= FALSE;
-
 	/**
-	 * ODBC Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 32a9e7509..923f0e125 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Database Adapter Class
@@ -40,22 +41,33 @@
  */
 class CI_DB_pdo_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'pdo';
 
-	// The character used to escaping
-	protected $_escape_char = '"';
-
-	protected $_random_keyword;
-
+	/**
+	 * Transaction enabled flag
+	 *
+	 * @var	bool
+	 */
 	public $trans_enabled = FALSE;
 
-	// need to track the PDO options
+	/**
+	 * PDO Options
+	 *
+	 * @var	array
+	 */
 	public $options = array();
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
-	 * Validates the DSN string and/or detects the subdriver
+	 * Validates the DSN string and/or detects the subdriver.
 	 *
 	 * @param	array	$params
 	 * @return	void
@@ -103,9 +115,9 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Non-persistent database connection
+	 * Database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	object
 	 */
 	public function db_connect($persistent = FALSE)
@@ -153,6 +165,10 @@ class CI_DB_pdo_driver extends CI_DB {
 		{
 			return $this->data_cache['version'];
 		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
 
 		// Not all subdrivers support the getAttribute() method
 		try
@@ -170,7 +186,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	SQL query
 	 * @return	mixed
 	 */
 	protected function _execute($sql)
@@ -183,7 +199,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -243,8 +259,8 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -296,7 +312,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Insert ID
 	 *
-	 * @param	string
+	 * @param	string	$name
 	 * @return	int
 	 */
 	public function insert_id($name = NULL)
@@ -311,7 +327,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -355,9 +371,9 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
@@ -401,10 +417,10 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -415,4 +431,4 @@ class CI_DB_pdo_driver extends CI_DB {
 }
 
 /* End of file pdo_driver.php */
-/* Location: ./system/database/drivers/pdo/pdo_driver.php */
+/* Location: ./system/database/drivers/pdo/pdo_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/pdo_forge.php b/system/database/drivers/pdo/pdo_forge.php
index 34a6ee44e..130d3667e 100644
--- a/system/database/drivers/pdo/pdo_forge.php
+++ b/system/database/drivers/pdo/pdo_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Forge Class
@@ -34,133 +35,19 @@
  */
 class CI_DB_pdo_forge extends CI_DB_forge {
 
-	protected $_drop_table		= 'DROP TABLE %s';
-
 	/**
-	 * Create Table
+	 * CREATE TABLE IF statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @var	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = 'CREATE TABLE ';
-
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' (';
-		$current_field_count = 0;
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-				$numeric = array('SERIAL', 'INTEGER');
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				if ( ! empty($attributes['CONSTRAINT']))
-				{
-					// Exception for Postgre numeric which not too happy with constraint within those type
-					if ( ! ($this->db->subdriver === 'pgsql' && in_array($attributes['TYPE'], $numeric)))
-					{
-						$sql .= '('.$attributes['CONSTRAINT'].')';
-					}
-				}
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
-
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
-
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
-
-		if (count($primary_keys) > 0)
-		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
-		}
-
-		if (is_array($keys) && count($keys) > 0)
-		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';
-			}
-		}
-
-		return $sql."\n)";
-	}
-
-	// --------------------------------------------------------------------
+	protected $_create_table_if	= FALSE;
 
 	/**
-	 * Alter table query
-	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * DROP TABLE IF statement
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @var	string
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
-	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
-		{
-			return $sql;
-		}
-
-		return $sql .' '.$column_definition
-			.($default_value !== '' ? " DEFAULT '".$default_value."'" : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
-	}
+	protected $_drop_table_if	= FALSE;
 
 }
 
diff --git a/system/database/drivers/pdo/pdo_result.php b/system/database/drivers/pdo/pdo_result.php
index 444406986..32ab1c280 100644
--- a/system/database/drivers/pdo/pdo_result.php
+++ b/system/database/drivers/pdo/pdo_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Result Class
@@ -162,7 +163,7 @@ class CI_DB_pdo_result extends CI_DB_result {
 		{
 			if ($this->db->db_debug)
 			{
-				return $this->db->display_error('db_unsuported_feature');
+				return $this->db->display_error('db_unsupported_feature');
 			}
 
 			return FALSE;
@@ -205,7 +206,7 @@ class CI_DB_pdo_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/pdo/pdo_utility.php b/system/database/drivers/pdo/pdo_utility.php
index 930842118..86f2b120a 100644
--- a/system/database/drivers/pdo/pdo_utility.php
+++ b/system/database/drivers/pdo/pdo_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Utility Class
@@ -34,18 +35,16 @@
  */
 class CI_DB_pdo_utility extends CI_DB_utility {
 
-	protected $_list_databases = FALSE;
-
 	/**
-	 * PDO Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
index 438d312a1..6ebd92a9b 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO 4D Database Adapter Class
@@ -40,19 +41,28 @@
  */
 class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = '4d';
 
-	// The character used for escaping
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string[]
+	 */
 	protected $_escape_char = array('[', ']');
 
-	protected $_random_keyword = ' RAND()';
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -80,7 +90,7 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -103,7 +113,7 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -119,7 +129,7 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -134,8 +144,8 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -152,7 +162,7 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -164,11 +174,11 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php b/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
new file mode 100644
index 000000000..231ad53a4
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
@@ -0,0 +1,209 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO 4D Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_4d_forge extends CI_DB_4d_forge {
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_database	= 'CREATE SCHEMA %s';
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_database	= 'DROP SCHEMA %s';
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+
+	/**
+	 * RENAME TABLE statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= FALSE;
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'INT16'		=> 'INT',
+		'SMALLINT'	=> 'INT',
+		'INT'		=> 'INT64',
+		'INT32'		=> 'INT64'
+	);
+
+	/**
+	 * DEFAULT value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_default		= FALSE;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('ADD', 'DROP'), TRUE))
+		{
+			return parent::_alter_table($alter_table, $table, $field);
+		}
+
+		// No method of modifying columns is supported
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type'].$field['length']
+			.$field['null']
+			.$field['unique']
+			.$field['auto_increment'];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INTEGER':
+				$attributes['TYPE'] = 'INT';
+				return;
+			case 'BIGINT':
+				$attribites['TYPE'] = 'INT64';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute UNIQUE
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_unique(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
+		{
+			$field['unique'] = ' UNIQUE';
+
+			// UNIQUE must be used with NOT NULL
+			$field['null'] = ' NOT NULL';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
+		{
+			if (stripos($field['type'], 'int') !== FALSE)
+			{
+				$field['auto_increment'] = ' AUTO_INCREMENT';
+			}
+			elseif (strcasecmp($field['type'], 'UUID') === 0)
+			{
+				$field['auto_increment'] = ' AUTO_GENERATE';
+			}
+		}
+	}
+
+}
+
+/* End of file pdo_4d_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_4d_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index d2a484d9e..4f762b91c 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO CUBRID Database Adapter Class
@@ -40,18 +41,28 @@
  */
 class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'cubrid';
 
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
 	protected $_escape_char = '`';
 
-	protected $_random_keyword = ' RAND()';
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -75,7 +86,7 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -97,7 +108,7 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -112,7 +123,7 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -127,9 +138,9 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
@@ -168,10 +179,10 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
new file mode 100644
index 000000000..e8421ec41
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
@@ -0,0 +1,212 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO CUBRID Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_cubrid_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_database	= FALSE;
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_database	= FALSE;
+
+	/**
+	 * CREATE TABLE keys flag
+	 *
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
+	 */
+	protected $_create_table_keys	= TRUE;
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SHORT'		=> 'INTEGER',
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT',
+		'BIGINT'	=> 'NUMERIC',
+		'FLOAT'		=> 'DOUBLE',
+		'REAL'		=> 'DOUBLE'
+	);
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				$sqls[] = $sql.' CHANGE '.$field[$i]['_literal'];
+			}
+			else
+			{
+				$sqls[] = $sql.' CHANGE '.$this->_process_column($field[$i]);
+				if ( ! empty($field[$i]['new_name']))
+				{
+					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
+						.' AS '.$this->db->escape_identifiers($field[$i]['name']);
+				}
+			}
+		}
+
+		return $sqls;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : $this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
+	 *
+	 * @param	string	$table	(ignored)
+	 * @return	string
+	 */
+	protected function _process_indexes($table = NULL)
+	{
+		$sql = '';
+
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
+		{
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
+		}
+
+		$this->keys = array();
+
+		return $sql;
+	}
+
+}
+
+/* End of file pdo_cubrid_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 785b2795c..7121819ec 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO DBLIB Database Adapter Class
@@ -40,18 +41,40 @@
  */
 class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'dblib';
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' NEWID()';
 
+	/**
+	 * Quoted identifier flag
+	 *
+	 * Whether to use SQL-92 standard quoted identifier
+	 * (double quotes) or brackets for identifier escaping.
+	 *
+	 * @var	bool
+	 */
 	protected $_quoted_identifier;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -85,9 +108,9 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Non-persistent database connection
+	 * Database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	object
 	 */
 	public function db_connect($persistent = FALSE)
@@ -115,7 +138,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -140,7 +163,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -157,8 +180,8 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -175,7 +198,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -191,11 +214,11 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
@@ -239,6 +262,29 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		// Multiple-value inserts are only supported as of SQL Server 2008
+		if (version_compare($this->version(), '10', '>='))
+		{
+			return parent::_insert_batch($table, $keys, $values);
+		}
+
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
+
 }
 
 /* End of file pdo_dblib_driver.php */
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
new file mode 100644
index 000000000..236e1cce2
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
@@ -0,0 +1,136 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO DBLIB Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_dblib_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nCREATE TABLE";
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= "IF EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nDROP TABLE";
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT'	=> 'SMALLINT',
+		'SMALLINT'	=> 'INT',
+		'INT'		=> 'BIGINT',
+		'REAL'		=> 'FLOAT'
+	);
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('ADD', 'DROP'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' ALTER COLUMN ';
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
+		{
+			$sqls[] = $sql.$this->_process_column($field[$i]);
+		}
+
+		return $sqls;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INTEGER':
+				$attributes['TYPE'] = 'INT';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['auto_increment'] = ' IDENTITY(1,1)';
+		}
+	}
+
+}
+
+/* End of file pdo_dblib_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index 32d1f219a..83b9648c1 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Firebird Database Adapter Class
@@ -40,21 +41,30 @@
  */
 class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'firebird';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * 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.
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
 	 */
-	protected $_random_keyword = ' RANDOM()'; // Currently not supported
+	protected $_random_keyword = ' RANDOM()';
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -90,7 +100,7 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -113,7 +123,7 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -128,7 +138,7 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -143,8 +153,8 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
 	protected function _update($table, $values)
@@ -160,10 +170,10 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
          */
 	protected function _truncate($table)
@@ -178,7 +188,7 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -190,11 +200,11 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
new file mode 100644
index 000000000..474188f4e
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
@@ -0,0 +1,228 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO Firebird Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_firebird_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * RENAME TABLE statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= FALSE;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SMALLINT'	=> 'INTEGER',
+		'INTEGER'	=> 'INT64',
+		'FLOAT'		=> 'DOUBLE PRECISION'
+	);
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Create database
+	 *
+	 * @param	string	$db_name
+	 * @return	string
+	 */
+	public function create_database($db_name)
+	{
+		// Firebird databases are flat files, so a path is required
+
+		// Hostname is needed for remote access
+		empty($this->db->hostname) OR $db_name = $this->hostname.':'.$db_name;
+
+		return parent::create_database('"'.$db_name.'"');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Drop database
+	 *
+	 * @param	string	$db_name	(ignored)
+	 * @return	bool
+	 */
+	public function drop_database($db_name = '')
+	{
+		if ( ! ibase_drop_db($this->conn_id))
+		{
+			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
+		}
+		elseif ( ! empty($this->db->data_cache['db_names']))
+		{
+			$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
+			if ($key !== FALSE)
+			{
+				unset($this->db->data_cache['db_names'][$key]);
+			}
+		}
+
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+ 	{
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field), $sql .= $alter_type.' '; $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				return FALSE;
+			}
+
+			if (isset($field[$i]['type']))
+			{
+				$sqls[] = $sql.' TYPE '.$field[$i]['type'].$field[$i]['length'];
+			}
+
+			if ( ! empty($field[$i]['default']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' SET '.$field[$i]['default'];
+			}
+
+			if (isset($field[$i]['null']))
+			{
+				$sqls[] = 'UPDATE "RDB$RELATION_FIELDS" SET "RDB$NULL_FLAG" = '
+					.($field[$i]['null'] === TRUE ? 'NULL' : '1')
+					.' WHERE "RDB$FIELD_NAME" = '.$this->db->escape($field[$i]['name'])
+					.' AND "RDB$RELATION_NAME" = '.$this->db->escape($table);
+			}
+
+			if ( ! empty($field[$i]['new_name']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
+			}
+		}
+
+		return $sqls;
+ 	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type'].$field['length']
+			.$field['null']
+			.$field['unique']
+			.$field['default'];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'INTEGER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'INT64';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		// Not supported
+	}
+
+}
+
+/* End of file pdo_firebird_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
index 22a5f928c..d8dbc50c0 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO IBM DB2 Database Adapter Class
@@ -40,16 +41,21 @@
  */
 class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'ibm';
 
-	protected $_random_keyword = ' RAND()';
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -115,7 +121,7 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -138,7 +144,7 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -154,7 +160,7 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -169,8 +175,8 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -187,7 +193,7 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -199,21 +205,19 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		$sql .= ' FETCH FIRST '.($limit + $offset).' ROWS ONLY';
+		$sql .= ' FETCH FIRST '.($this->qb_limit + $this->qb_offset).' ROWS ONLY';
 
-		return ($offset)
-			? 'SELECT * FROM ('.$sql.') WHERE rownum > '.$offset
+		return ($this->qb_offset)
+			? 'SELECT * FROM ('.$sql.') WHERE rownum > '.$this->qb_offset
 			: $sql;
 	}
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
new file mode 100644
index 000000000..f095c717a
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
@@ -0,0 +1,146 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO IBM DB2 Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_ibm_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * RENAME TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= 'RENAME TABLE %s TO %s';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT'
+	);
+
+	/**
+	 * DEFAULT value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_default		= FALSE;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'CHANGE')
+		{
+			$alter_type = 'MODIFY';
+		}
+
+		return parent::_alter_table($alter_type, $table, $field);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute UNIQUE
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_unique(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
+		{
+			$field['unique'] = ' UNIQUE';
+
+			// UNIQUE must be used with NOT NULL
+			$field['null'] = ' NOT NULL';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		// Not supported
+	}
+
+}
+
+/* End of file pdo_ibm_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index 8dd430184..8998670e1 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Informix Database Adapter Class
@@ -40,16 +41,21 @@
  */
 class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'informix';
 
-	protected $_random_keyword = ' RAND()';
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -108,7 +114,7 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -131,7 +137,7 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -148,7 +154,7 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -163,8 +169,8 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -181,10 +187,10 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -199,7 +205,7 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -211,11 +217,11 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	$SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php b/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
new file mode 100644
index 000000000..8722dd200
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
@@ -0,0 +1,155 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO Informix Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_informix_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * RENAME TABLE statement
+	 *
+	 * @var	string
+	 */
+	protected $_rename_table	= 'RENAME TABLE %s TO %s';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT',
+		'REAL'		=> 'DOUBLE PRECISION',
+		'SMALLFLOAT'	=> 'DOUBLE PRECISION'
+	);
+
+	/**
+	 * DEFAULT value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_default		= ', ';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'CHANGE')
+		{
+			$alter_type = 'MODIFY';
+		}
+
+		return parent::_alter_table($alter_type, $table, $field);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'BYTE':
+			case 'TEXT':
+			case 'BLOB':
+			case 'CLOB':
+				$attributes['UNIQUE'] = FALSE;
+				if (isset($attributes['DEFAULT']))
+				{
+					unset($attributes['DEFAULT']);
+				}
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute UNIQUE
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_unique(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
+		{
+			$field['unique'] = ' UNIQUE CONSTRAINT '.$this->db->escape_identifiers($field['name']);
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		// Not supported
+	}
+
+}
+
+/* End of file pdo_informix_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_informix_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index 0fb5d8f12..2d076f314 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO MySQL Database Adapter Class
@@ -40,19 +41,37 @@
  */
 class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'mysql';
+
+	/**
+	 * Compression flag
+	 *
+	 * @var	bool
+	 */
 	public $compress = FALSE;
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
 	protected $_escape_char = '`';
 
-	protected $_random_keyword = ' RAND()';
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -76,9 +95,9 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Non-persistent database connection
+	 * Database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	object
 	 * @todo	SSL support
 	 */
@@ -110,7 +129,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -132,7 +151,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -147,7 +166,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -162,9 +181,9 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	UPDATE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
@@ -203,10 +222,10 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
new file mode 100644
index 000000000..866b6fb21
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
@@ -0,0 +1,218 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO MySQL Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_mysql_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_database	= 'CREATE DATABASE %s CHARACTER SET %s COLLATE %s';
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+
+	/**
+	 * CREATE TABLE keys flag
+	 *
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
+	 */
+	protected $_create_table_keys	= TRUE;
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT',
+		'SMALLINT',
+		'MEDIUMINT',
+		'INT',
+		'INTEGER',
+		'BIGINT',
+		'REAL',
+		'DOUBLE',
+		'DOUBLE PRECISION',
+		'FLOAT',
+		'DECIMAL',
+		'NUMERIC'
+	);
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
+
+		$this->_create_table .= ' DEFAULT CHARSET '.$this->db->char_set.' COLLATE '.$this->db->dbcollat;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'DROP')
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		for ($i = 0, $c = count($field); $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				$field[$i] = ($alter_type === 'ADD')
+						? "\n\tADD ".$field[$i]['_literal']
+						: "\n\tMODIFY ".$field[$i]['_literal'];
+			}
+			else
+			{
+				if ($alter_type === 'ADD')
+				{
+					$field[$i]['_literal'] = "\n\tADD ";
+				}
+				else
+				{
+					$field[$i]['_literal'] = empty($field[$i]['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
+				}
+
+				$field[$i] = $field[$i]['_literal'].$this->_process_column($field[$i]);
+			}
+		}
+
+		return array($sql.implode(',', $field));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : $this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
+	 *
+	 * @param	string	$table	(ignored)
+	 * @return	string
+	 */
+	protected function _process_indexes($table = NULL)
+	{
+		$sql = '';
+
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
+		{
+			if ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
+		}
+
+		$this->keys = array();
+
+		return $sql;
+	}
+
+}
+
+/* End of file pdo_mysql_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index b03218fad..e1beb3683 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Oracle Database Adapter Class
@@ -40,24 +41,49 @@
  */
 class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'oci';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * 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.
+	 * List of reserved identifiers
+	 *
+	 * Identifiers that must NOT be escaped.
+	 *
+	 * @var	string[]
+	 */
+	protected $_reserved_identifiers = array('*', 'rownum');
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
 	 */
-	protected $_count_string = 'SELECT COUNT(1) AS ';
 	protected $_random_keyword = ' ASC'; // Currently not supported
 
-	protected $_reserved_identifiers = array('*', 'rownum');
+	/**
+	 * COUNT string
+	 *
+	 * @used-by	CI_DB_driver::count_all()
+	 * @used-by	CI_DB_query_builder::count_all_results()
+	 *
+	 * @var	string
+	 */
+	protected $_count_string = 'SELECT COUNT(1) AS ';
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -97,7 +123,7 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -120,7 +146,7 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -135,7 +161,7 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -146,11 +172,11 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert_batch statement
+	 * Insert batch statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
 	 * @return 	string
 	 */
 	protected function _insert_batch($table, $keys, $values)
@@ -173,7 +199,7 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -190,11 +216,11 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
new file mode 100644
index 000000000..8052d218f
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
@@ -0,0 +1,133 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO Oracle Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_database	= FALSE;
+
+	/**
+	 * DROP DATABASE statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_database	= FALSE;
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'DROP')
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+		elseif ($alter_type === 'CHANGE')
+		{
+			$alter_type = 'MODIFY';
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				$field[$i] = "\n\t".$field[$i]['_literal'];
+			}
+			else
+			{
+				$field[$i]['_literal'] = "\n\t".$this->_process_column($field[$i]);
+				if ($alter_type === 'MODIFY' && ! empty($field[$i]['new_name']))
+				{
+					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
+						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
+				}
+			}
+		}
+
+		$sql .= ' '.$alter_type.' ';
+		$sql .= (count($field) === 1)
+				? $fields[0]
+				: '('.implode(',', $field).')';
+
+		// RENAME COLUMN must be executed after MODIFY
+		array_unshift($sqls, $sql);
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		// Not supported - sequences and triggers must be used instead
+	}
+
+}
+
+/* End of file pdo_oci_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_oci_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index d64e9fb36..f6e0e215a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO ODBC Database Adapter Class
@@ -40,29 +41,46 @@
  */
 class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'odbc';
 
-	// The character used for escaping - not used in ODBC
-	protected $_escape_char = '';
+	/**
+	 * Database schema
+	 *
+	 * @var	string
+	 */
+	public $schema = 'public';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " {escape '%s'} ";
+	// --------------------------------------------------------------------
 
-	protected $_random_keyword = ' RAND()';
+	/**
+	 * Identifier escape character
+	 *
+	 * Must be empty for ODBC.
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '';
 
 	/**
-	 * Database schema
+	 * ESCAPE statement string
 	 *
 	 * @var	string
 	 */
-	public $schema = 'public';
+	protected $_like_escape_str = " {escape '%s'} ";
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -129,7 +147,7 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool	$prefix_limit = FALSE
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -152,7 +170,7 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -167,8 +185,8 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -185,10 +203,10 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -215,11 +233,11 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
new file mode 100644
index 000000000..ab4d2bf84
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO ODBC Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/database/
+ */
+class CI_DB_pdo_odbc_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		// Not supported (in most databases at least)
+	}
+
+}
+
+/* End of file pdo_odbc_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index 93674b576..c3f5b7603 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO PostgreSQL Database Adapter Class
@@ -40,10 +41,13 @@
  */
 class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'pgsql';
 
-	protected $_random_keyword = ' RANDOM()';
-
 	/**
 	 * Database schema
 	 *
@@ -51,12 +55,23 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 */
 	public $schema = 'public';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
+	protected $_random_keyword = ' RANDOM()';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -77,7 +92,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	/**
 	 * Insert ID
 	 *
-	 * @param	string
+	 * @param	string	$name
 	 * @return	int
 	 */
 	public function insert_id($name = NULL)
@@ -99,7 +114,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool	$prefix_limit = FALSE
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -123,7 +138,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -138,7 +153,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -153,8 +168,8 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -171,9 +186,9 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
@@ -212,7 +227,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -224,11 +239,11 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
new file mode 100644
index 000000000..484c1603d
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
@@ -0,0 +1,194 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO PostgreSQL Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'INT2'		=> 'INTEGER',
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INT4'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT',
+		'INT8'		=> 'NUMERIC',
+		'BIGINT'	=> 'NUMERIC',
+		'REAL'		=> 'DOUBLE PRECISION',
+		'FLOAT'		=> 'DOUBLE PRECISION'
+	);
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
+
+		if (version_compare($this->db->version(), '9.0', '>'))
+		{
+			$this->create_table_if = 'CREATE TABLE IF NOT EXISTS';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+ 	{
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field), $sql .= $alter_type.' '; $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				return FALSE;
+			}
+
+			if (version_compare($this->db->version(), '8', '>=') && isset($field[$i]['type']))
+			{
+				$sqls[] = $sql.' TYPE '.$field[$i]['type'].$field[$i]['length'];
+			}
+
+			if ( ! empty($field[$i]['default']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' SET '.$field[$i]['default'];
+			}
+
+			if (isset($field[$i]['null']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.($field[$i]['null'] === TRUE ? ' DROP NOT NULL' : ' SET NOT NULL');
+			}
+
+			if ( ! empty($field[$i]['new_name']))
+			{
+				$sqls[] = $sql.' RENAME '.$this->db->escape_identifiers($field[$i]['name'])
+					.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
+			}
+		}
+
+		return $sqls;
+ 	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		// Reset field lenghts for data types that don't support it
+		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
+		{
+			$attributes['CONSTRAINT'] = NULL;
+		}
+
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
+		{
+			$field['type'] = ($field['type'] === 'NUMERIC')
+						? 'BIGSERIAL'
+						: 'SERIAL';
+		}
+	}
+
+}
+
+/* End of file pdo_pgsql_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index bf0363f63..b24b13e76 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO SQLite Database Adapter Class
@@ -40,21 +41,30 @@
  */
 class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'sqlite';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * 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.
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
 	 */
-	protected $_random_keyword = ' RANDOM()'; // Currently not supported
+	protected $_random_keyword = ' RANDOM()';
+
+	// --------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -81,7 +91,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -104,7 +114,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -120,7 +130,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -133,9 +143,9 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	/**
 	 * Replace statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
 	 * @return 	string
 	 */
 	protected function _replace($table, $keys, $values)
@@ -150,10 +160,10 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
          */
 	protected function _truncate($table)
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
new file mode 100644
index 000000000..da098df31
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
@@ -0,0 +1,229 @@
+<?php
+/**
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO SQLite Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= 'DROP TABLE IF EXISTS';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
+
+		if (version_compare($this->db->version(), '3.3', '<'))
+		{
+			$this->_create_table_if = FALSE;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Create database
+	 *
+	 * @param	string	$db_name	(ignored)
+	 * @return	bool
+	 */
+	public function create_database($db_name = '')
+	{
+		// In SQLite, a database is created when you connect to the database.
+		// We'll return TRUE so that an error isn't generated
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Drop database
+	 *
+	 * @param	string	$db_name	(ignored)
+	 * @return	bool
+	 */
+	public function drop_database($db_name = '')
+	{
+		// In SQLite, a database is dropped when we delete a file
+		if (@file_exists($this->db->database))
+		{
+			// We need to close the pseudo-connection first
+			$this->db->close();
+			if ( ! @unlink($this->db->database))
+			{
+				return $this->db->db_debug ? $this->db->display_error('db_unable_to_drop') : FALSE;
+			}
+			elseif ( ! empty($this->db->data_cache['db_names']))
+			{
+				$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
+				if ($key !== FALSE)
+				{
+					unset($this->db->data_cache['db_names'][$key]);
+				}
+			}
+
+			return TRUE;
+		}
+
+		return $this->db->db_debug ? $this->db->display_error('db_unable_to_drop') : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
+		{
+			// drop_column():
+			//	BEGIN TRANSACTION;
+			//	CREATE TEMPORARY TABLE t1_backup(a,b);
+			//	INSERT INTO t1_backup SELECT a,b FROM t1;
+			//	DROP TABLE t1;
+			//	CREATE TABLE t1(a,b);
+			//	INSERT INTO t1 SELECT a,b FROM t1_backup;
+			//	DROP TABLE t1_backup;
+			//	COMMIT;
+
+			return FALSE;
+		}
+
+		return parent::_alter_table($alter_type, $table, $field);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type']
+			.$field['auto_increment']
+			.$field['null']
+			.$field['unique']
+			.$field['default'];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'ENUM':
+			case 'SET':
+				$attributes['TYPE'] = 'TEXT';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['type'] = 'INTEGER PRIMARY KEY';
+			$field['default'] = '';
+			$field['null'] = '';
+			$field['unique'] = '';
+			$field['auto_increment'] = ' AUTOINCREMENT';
+
+			$this->primary_keys = array();
+		}
+	}
+
+}
+
+/* End of file pdo_sqlite_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index 33bd7bea5..7bb7f8806 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO SQLSRV Database Adapter Class
@@ -40,18 +41,40 @@
  */
 class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 
+	/**
+	 * Sub-driver
+	 *
+	 * @var	string
+	 */
 	public $subdriver = 'sqlsrv';
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' NEWID()';
 
+	/**
+	 * Quoted identifier flag
+	 *
+	 * Whether to use SQL-92 standard quoted identifier
+	 * (double quotes) or brackets for identifier escaping.
+	 *
+	 * @var	bool
+	 */
 	protected $_quoted_identifier;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -109,9 +132,9 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Non-persistent database connection
+	 * Database connection
 	 *
-	 * @param	bool
+	 * @param	bool	$persistent
 	 * @return	object
 	 */
 	public function db_connect($persistent = FALSE)
@@ -144,7 +167,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -169,7 +192,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -186,8 +209,8 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
          */
 	protected function _update($table, $values)
@@ -204,7 +227,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -220,11 +243,11 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
@@ -273,6 +296,29 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		// Multiple-value inserts are only supported as of SQL Server 2008
+		if (version_compare($this->version(), '10', '>='))
+		{
+			return parent::_insert_batch($table, $keys, $values);
+		}
+
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
+
 }
 
 /* End of file pdo_sqlsrv_driver.php */
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
new file mode 100644
index 000000000..e4b669f6e
--- /dev/null
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
@@ -0,0 +1,136 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * 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:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PDO SQLSRV Forge Class
+ *
+ * @category	Database
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_sqlsrv_forge extends CI_DB_pdo_forge {
+
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nCREATE TABLE";
+
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= "IF EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nDROP TABLE";
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT'	=> 'SMALLINT',
+		'SMALLINT'	=> 'INT',
+		'INT'		=> 'BIGINT',
+		'REAL'		=> 'FLOAT'
+	);
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('ADD', 'DROP'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' ALTER COLUMN ';
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
+		{
+			$sqls[] = $sql.$this->_process_column($field[$i]);
+		}
+
+		return $sqls;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INTEGER':
+				$attributes['TYPE'] = 'INT';
+				return;
+			default: return;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['auto_increment'] = ' IDENTITY(1,1)';
+		}
+	}
+
+}
+
+/* End of file pdo_sqlsrv_forge.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php */
\ No newline at end of file
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index ca231f6f7..40f21b1e8 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Postgre Database Adapter Class
@@ -40,12 +41,13 @@
  */
 class CI_DB_postgre_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'postgre';
 
-	protected $_escape_char = '"';
-
-	protected $_random_keyword = ' RANDOM()'; // database specific random keyword
-
 	/**
 	 * Database schema
 	 *
@@ -53,8 +55,19 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public $schema = 'public';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
+	protected $_random_keyword = ' RANDOM()'; // database specific random keyword
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
 	 *
 	 * Creates a DSN string to be used for db_connect() and db_pconnect()
 	 *
@@ -170,7 +183,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Set client character set
 	 *
-	 * @param	string
+	 * @param	string	$charset
 	 * @return	bool
 	 */
 	protected function _db_set_charset($charset)
@@ -191,8 +204,12 @@ class CI_DB_postgre_driver extends CI_DB {
 		{
 			return $this->data_cache['version'];
 		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
 
-		if (($pg_version = pg_version($this->conn_id)) === FALSE)
+		if ( ! $this->conn_id OR ($pg_version = pg_version($this->conn_id)) === FALSE)
 		{
 			return FALSE;
 		}
@@ -212,7 +229,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -225,7 +242,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -285,8 +302,8 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -322,7 +339,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Escapes data based on type
 	 * Sets boolean and null types
 	 *
-	 * @param	string
+	 * @param	string	$str
 	 * @return	mixed
 	 */
 	public function escape($str)
@@ -400,7 +417,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool	$prefix_limit = FALSE
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -424,7 +441,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -439,7 +456,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -469,8 +486,8 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
 	protected function _update($table, $values)
@@ -487,9 +504,9 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	string	the where key
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index)
@@ -528,7 +545,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -540,11 +557,11 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index 1164d9bb3..425622fac 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Postgre Forge Class
@@ -34,182 +35,151 @@
  */
 class CI_DB_postgre_forge extends CI_DB_forge {
 
-	protected $_drop_table	= 'DROP TABLE IF EXISTS %s CASCADE';
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'INT2'		=> 'INTEGER',
+		'SMALLINT'	=> 'INTEGER',
+		'INT'		=> 'BIGINT',
+		'INT4'		=> 'BIGINT',
+		'INTEGER'	=> 'BIGINT',
+		'INT8'		=> 'NUMERIC',
+		'BIGINT'	=> 'NUMERIC',
+		'REAL'		=> 'DOUBLE PRECISION',
+		'FLOAT'		=> 'DOUBLE PRECISION'
+	);
 
 	/**
-	 * Process Fields
+	 * NULL value representation in CREATE/ALTER TABLE statements
 	 *
-	 * @param	mixed	$fields
-	 * @param	array	$primary_keys = array()
-	 * @return	string
+	 * @var	string
 	 */
-	protected function _process_fields($fields, $primary_keys = array())
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
 	{
-		$sql = '';
-		$current_field_count = 0;
+		parent::__construct($db);
 
-		foreach ($fields as $field => $attributes)
+		if (version_compare($this->db->version(), '9.0', '>'))
 		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
+			$this->create_table_if = 'CREATE TABLE IF NOT EXISTS';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+ 	{
+		if (in_array($alter_type, array('DROP', 'ADD'), TRUE))
+		{
+			return parent::_alter_table($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		$sqls = array();
+		for ($i = 0, $c = count($field), $sql .= $alter_type.' '; $i < $c; $i++)
+		{
+			if ($field[$i]['_literal'] !== FALSE)
+			{
+				return FALSE;
+			}
+
+			if (version_compare($this->db->version(), '8', '>=') && isset($field[$i]['type']))
 			{
-				$sql .= "\n\t".$attributes;
+				$sqls[] = $sql.' TYPE '.$field[$i]['type'].$field[$i]['length'];
 			}
-			else
+
+			if ( ! empty($field[$i]['default']))
+			{
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.' SET '.$field[$i]['default'];
+			}
+
+			if (isset($field[$i]['null']))
 			{
-				$sql .= "\n\t".$this->db->escape_identifiers($field);
-
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-				$is_unsigned = ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE);
-
-				// Convert datatypes to be PostgreSQL-compatible
-				switch (strtoupper($attributes['TYPE']))
-				{
-					case 'TINYINT':
-						$attributes['TYPE'] = 'SMALLINT';
-						break;
-					case 'SMALLINT':
-						$attributes['TYPE'] = ($is_unsigned) ? 'INTEGER' : 'SMALLINT';
-						break;
-					case 'MEDIUMINT':
-						$attributes['TYPE'] = 'INTEGER';
-						break;
-					case 'INT':
-						$attributes['TYPE'] = ($is_unsigned) ? 'BIGINT' : 'INTEGER';
-						break;
-					case 'BIGINT':
-						$attributes['TYPE'] = ($is_unsigned) ? 'NUMERIC' : 'BIGINT';
-						break;
-					case 'DOUBLE':
-						$attributes['TYPE'] = 'DOUBLE PRECISION';
-						break;
-					case 'DATETIME':
-						$attributes['TYPE'] = 'TIMESTAMP';
-						break;
-					case 'LONGTEXT':
-						$attributes['TYPE'] = 'TEXT';
-						break;
-					case 'BLOB':
-						$attributes['TYPE'] = 'BYTEA';
-						break;
-					default:
-						break;
-				}
-
-				// If this is an auto-incrementing primary key, use the serial data type instead
-				$sql .= (in_array($field, $primary_keys) && ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-					? ' SERIAL' : ' '.$attributes['TYPE'];
-
-				// Modified to prevent constraints with integer data types
-				if ( ! empty($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') === FALSE)
-				{
-					$sql .= '('.$attributes['CONSTRAINT'].')';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
-
-				// Added new attribute to create unique fields. Also works with MySQL
-				if ( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE)
-				{
-					$sql .= ' UNIQUE';
-				}
+				$sqls[] = $sql.' ALTER '.$this->db->escape_identifiers($field[$i]['name'])
+					.($field[$i]['null'] === TRUE ? ' DROP NOT NULL' : ' SET NOT NULL');
 			}
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
+			if ( ! empty($field[$i]['new_name']))
 			{
-				$sql .= ',';
+				$sqls[] = $sql.' RENAME '.$this->db->escape_identifiers($field[$i]['name'])
+					.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
 			}
 		}
 
-		return $sql;
-	}
+		return $sqls;
+ 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	array	&$attributes
+	 * @return	void
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _attr_type(&$attributes)
 	{
-		$sql = 'CREATE TABLE ';
-
-		// PostgreSQL doesn't support IF NOT EXISTS syntax so we check if table exists manually
-		if ($if_not_exists === TRUE && $this->db->table_exists($table))
+		// Reset field lenghts for data types that don't support it
+		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
-			return TRUE;
+			$attributes['CONSTRAINT'] = NULL;
 		}
 
-		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields, $primary_keys);
-
-		if (count($primary_keys) > 0)
+		switch (strtoupper($attributes['TYPE']))
 		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			case 'TINYINT':
+				$attributes['TYPE'] = 'SMALLINT';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			default: return;
 		}
-
-		$sql .= "\n);";
-
-		if (is_array($keys) && count($keys) > 0)
-		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				foreach ($key as $field)
-				{
-					$sql .= "\nCREATE INDEX ".$this->db->escape_identifiers($table.'_'.str_replace(array('"', "'"), '', $field).'_index')
-						.' ON '.$this->db->escape_identifiers($table).' ('.$this->db->escape_identifiers($field).');';
-				}
-			}
-		}
-
-		return $sql;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute AUTO_INCREMENT
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
-	 *
-	 * @param	string	$alter_type	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	$table		the table name
-	 * @param	string	$fields		the column definition
-	 * @param	string	$after_field = ''
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
- 	{
- 		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' ';
-
- 		// DROP has everything it needs now.
- 		if ($alter_type === 'DROP')
- 		{
- 			return $sql.$this->db->escape_identifiers($fields);
- 		}
-
- 		return $sql.$this->_process_fields($fields)
-			.($after_field !== '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
- 	}
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
+		{
+			$field['type'] = ($field['type'] === 'NUMERIC')
+						? 'BIGSERIAL'
+						: 'SERIAL';
+		}
+	}
 
 }
 
diff --git a/system/database/drivers/postgre/postgre_result.php b/system/database/drivers/postgre/postgre_result.php
index 458ae869c..3f73f84c7 100644
--- a/system/database/drivers/postgre/postgre_result.php
+++ b/system/database/drivers/postgre/postgre_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Postgres Result Class
@@ -129,9 +130,9 @@ class CI_DB_postgre_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -160,7 +161,7 @@ class CI_DB_postgre_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/postgre/postgre_utility.php b/system/database/drivers/postgre/postgre_utility.php
index c95e6df0c..d3b2b9cdc 100644
--- a/system/database/drivers/postgre/postgre_utility.php
+++ b/system/database/drivers/postgre/postgre_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Postgre Utility Class
@@ -34,19 +35,32 @@
  */
 class CI_DB_postgre_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'SELECT datname FROM pg_database';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'REINDEX TABLE %s';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Postgre Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 }
 
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 2fd39346f..85411735c 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite Database Adapter Class
@@ -40,13 +41,24 @@
  */
 class CI_DB_sqlite_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'sqlite';
 
-	// The character used to escape with - not needed for SQLite
-	protected $_escape_char = '"';
+	// --------------------------------------------------------------------
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' Random()'; // database specific random keyword
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -112,7 +124,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -127,7 +139,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -190,8 +202,8 @@ class CI_DB_sqlite_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -250,7 +262,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -272,7 +284,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	bool
 	 */
 	protected function _list_columns($table = '')
@@ -288,7 +300,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -320,9 +332,9 @@ class CI_DB_sqlite_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific replace string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
 	 * @return	string
 	 */
 	protected function _replace($table, $keys, $values)
@@ -337,10 +349,10 @@ class CI_DB_sqlite_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this function maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
diff --git a/system/database/drivers/sqlite/sqlite_forge.php b/system/database/drivers/sqlite/sqlite_forge.php
index e02e327f3..6ad583560 100644
--- a/system/database/drivers/sqlite/sqlite_forge.php
+++ b/system/database/drivers/sqlite/sqlite_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite Forge Class
@@ -35,9 +36,32 @@
 class CI_DB_sqlite_forge extends CI_DB_forge {
 
 	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Create database
 	 *
-	 * @param	string	the database name
+	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
 	public function create_database($db_name = '')
@@ -52,7 +76,7 @@ class CI_DB_sqlite_forge extends CI_DB_forge {
 	/**
 	 * Drop database
 	 *
-	 * @param	string	the database name (ignored)
+	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
 	public function drop_database($db_name = '')
@@ -76,126 +100,95 @@ class CI_DB_sqlite_forge extends CI_DB_forge {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @todo	implement drop_column(), modify_column()
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$sql = 'CREATE TABLE ';
-
-		// IF NOT EXISTS added to SQLite in 3.3.0
-		if ($if_not_exists === TRUE && version_compare($this->db->version(), '3.3.0', '>=') === TRUE)
+		if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
 		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' (';
-		$current_field_count = 0;
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				empty($attributes['CONSTRAINT']) OR $sql .= '('.$attributes['CONSTRAINT'].')';
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
+			// drop_column():
+			//	BEGIN TRANSACTION;
+			//	CREATE TEMPORARY TABLE t1_backup(a,b);
+			//	INSERT INTO t1_backup SELECT a,b FROM t1;
+			//	DROP TABLE t1;
+			//	CREATE TABLE t1(a,b);
+			//	INSERT INTO t1 SELECT a,b FROM t1_backup;
+			//	DROP TABLE t1_backup;
+			//	COMMIT;
 
+			return FALSE;
+		}
 
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+		return parent::_alter_table($alter_type, $table, $field);
+	}
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	// --------------------------------------------------------------------
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type']
+			.$field['auto_increment']
+			.$field['null']
+			.$field['unique']
+			.$field['default'];
+	}
 
-		if (count($primary_keys) > 0)
-		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
-		}
+	// --------------------------------------------------------------------
 
-		if (is_array($keys) && count($keys) > 0)
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
 		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tUNIQUE (".implode(', ', $key).')';
-			}
+			case 'ENUM':
+			case 'SET':
+				$attributes['TYPE'] = 'TEXT';
+				return;
+			default: return;
 		}
-
-		return $sql."\n)";
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute AUTO_INCREMENT
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
-	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_auto_increment(&$attributes, &$field)
 	{
-		/* SQLite only supports adding new columns and it does
-		 * NOT support the AFTER statement. Each new column will
-		 * be added as the last one in the table.
-		 */
-		if ($alter_type !== 'ADD COLUMN')
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
 		{
-			// Not supported
-			return FALSE;
-		}
+			$field['type'] = 'INTEGER PRIMARY KEY';
+			$field['default'] = '';
+			$field['null'] = '';
+			$field['unique'] = '';
+			$field['auto_increment'] = ' AUTOINCREMENT';
 
-		return 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name)
-			.' '.$column_definition
-			.($default_value != '' ? " DEFAULT '".$default_value."'" : '')
-			// If NOT NULL is specified, the field must have a DEFAULT value other than NULL
-			.(($null !== NULL && $default_value !== 'NULL') ? ' NOT NULL' : ' NULL');
+			$this->primary_keys = array();
+		}
 	}
 
 }
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
index 214841412..0e6335f73 100644
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ b/system/database/drivers/sqlite/sqlite_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite Result Class
@@ -113,9 +114,9 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	int	$n = 0
+	 * @param	int	$n
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
@@ -144,7 +145,7 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/sqlite/sqlite_utility.php b/system/database/drivers/sqlite/sqlite_utility.php
index 1bcb42d9f..222d02712 100644
--- a/system/database/drivers/sqlite/sqlite_utility.php
+++ b/system/database/drivers/sqlite/sqlite_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite Utility Class
@@ -34,18 +35,16 @@
  */
 class CI_DB_sqlite_utility extends CI_DB_utility {
 
-	protected $_list_databases	= FALSE;
-
 	/**
-	 * SQLite Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index 22c72b9b8..9a2c1eefc 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite3 Database Adapter Class
@@ -41,13 +42,24 @@
  */
 class CI_DB_sqlite3_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'sqlite3';
 
-	// The character used for escaping
-	protected $_escape_char = '"';
+	// --------------------------------------------------------------------
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' RANDOM()';
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -119,7 +131,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -179,8 +191,8 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -239,7 +251,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
@@ -257,7 +269,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -273,7 +285,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -303,9 +315,9 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific replace string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
 	 * @return	string
 	 */
 	protected function _replace($table, $keys, $values)
@@ -320,10 +332,10 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command, then,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
diff --git a/system/database/drivers/sqlite3/sqlite3_forge.php b/system/database/drivers/sqlite3/sqlite3_forge.php
index f9ae5bcce..e9b91e972 100644
--- a/system/database/drivers/sqlite3/sqlite3_forge.php
+++ b/system/database/drivers/sqlite3/sqlite3_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite3 Forge Class
@@ -35,9 +36,43 @@
 class CI_DB_sqlite3_forge extends CI_DB_forge {
 
 	/**
+	 * UNSIGNED support
+	 *
+	 * @var	bool|array
+	 */
+	protected $_unsigned		= FALSE;
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
+
+		if (version_compare($this->db->version(), '3.3', '<'))
+		{
+			$this->create_table_if = FALSE;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Create database
 	 *
-	 * @param	string	the database name
+	 * @param	string	$db_name
 	 * @return	bool
 	 */
 	public function create_database($db_name = '')
@@ -52,7 +87,7 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	/**
 	 * Drop database
 	 *
-	 * @param	string	the database name (ignored)
+	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
 	public function drop_database($db_name = '')
@@ -84,125 +119,95 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @todo	implement drop_column(), modify_column()
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$sql = 'CREATE TABLE ';
-
-		// IF NOT EXISTS added to SQLite in 3.3.0
-		if ($if_not_exists === TRUE && version_compare($this->db->version(), '3.3.0', '>=') === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->escape_identifiers($table).' (';
-		$current_field_count = 0;
-
-		foreach ($fields as $field => $attributes)
+		if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
 		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				empty($attributes['CONSTRAINT']) OR $sql .= '('.$attributes['CONSTRAINT'].')';
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
+			// drop_column():
+			//	BEGIN TRANSACTION;
+			//	CREATE TEMPORARY TABLE t1_backup(a,b);
+			//	INSERT INTO t1_backup SELECT a,b FROM t1;
+			//	DROP TABLE t1;
+			//	CREATE TABLE t1(a,b);
+			//	INSERT INTO t1 SELECT a,b FROM t1_backup;
+			//	DROP TABLE t1_backup;
+			//	COMMIT;
 
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
+			return FALSE;
+		}
 
-				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+		return parent::_alter_table($alter_type, $table, $field);
+	}
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	// --------------------------------------------------------------------
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	/**
+	 * Process column
+	 *
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		return $this->db->escape_identifiers($field['name'])
+			.' '.$field['type']
+			.$field['auto_increment']
+			.$field['null']
+			.$field['unique']
+			.$field['default'];
+	}
 
-		if (count($primary_keys) > 0)
-		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
-		}
+	// --------------------------------------------------------------------
 
-		if (is_array($keys) && count($keys) > 0)
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
 		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->db->escape_identifiers($key));
-
-				$sql .= ",\n\tUNIQUE (".implode(', ', $key).')';
-			}
+			case 'ENUM':
+			case 'SET':
+				$attributes['TYPE'] = 'TEXT';
+				return;
+			default: return;
 		}
-
-		return $sql."\n)";
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
-	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Field attribute AUTO_INCREMENT
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_auto_increment(&$attributes, &$field)
 	{
-		/* SQLite only supports adding new columns and it does
-		 * NOT support the AFTER statement. Each new column will
-		 * be added as the last one in the table.
-		 */
-		if ($alter_type !== 'ADD COLUMN')
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
 		{
-			// Not supported
-			return FALSE;
-		}
+			$field['type'] = 'INTEGER PRIMARY KEY';
+			$field['default'] = '';
+			$field['null'] = '';
+			$field['unique'] = '';
+			$field['auto_increment'] = ' AUTOINCREMENT';
 
-		return 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name)
-			.' '.$column_definition
-			.($default_value !== '' ? ' DEFAULT '.$default_value : '')
-			// If NOT NULL is specified, the field must have a DEFAULT value other than NULL
-			.(($null !== NULL && $default_value !== 'NULL') ? ' NOT NULL' : ' NULL');
+			$this->primary_keys = array();
+		}
 	}
 
 }
diff --git a/system/database/drivers/sqlite3/sqlite3_result.php b/system/database/drivers/sqlite3/sqlite3_result.php
index 35aecda36..153e3480a 100644
--- a/system/database/drivers/sqlite3/sqlite3_result.php
+++ b/system/database/drivers/sqlite3/sqlite3_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite3 Result Class
@@ -37,9 +38,6 @@
  */
 class CI_DB_sqlite3_result extends CI_DB_result {
 
-	// num_fields() might be called multiple times, so we'll use this one to cache it's result
-	protected $_num_fields;
-
 	/**
 	 * Number of fields in the result set
 	 *
@@ -47,9 +45,7 @@ class CI_DB_sqlite3_result extends CI_DB_result {
 	 */
 	public function num_fields()
 	{
-		return ( ! is_int($this->_num_fields))
-			? $this->_num_fields = $this->result_id->numColumns()
-			: $this->_num_fields;
+		return $this->result_id->numColumns();
 	}
 
 	// --------------------------------------------------------------------
@@ -134,7 +130,7 @@ class CI_DB_sqlite3_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
@@ -165,9 +161,9 @@ class CI_DB_sqlite3_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @param	$n = 0	(ignored)
+	 * @param	int	$n	(ignored)
 	 * @return	array
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/sqlite3/sqlite3_utility.php b/system/database/drivers/sqlite3/sqlite3_utility.php
index f58c3d168..c7736cc6d 100644
--- a/system/database/drivers/sqlite3/sqlite3_utility.php
+++ b/system/database/drivers/sqlite3/sqlite3_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLite3 Utility Class
@@ -34,18 +35,16 @@
  */
 class CI_DB_sqlite3_utility extends CI_DB_utility {
 
-	protected $_list_databases	= FALSE;
-
 	/**
-	 * SQLite Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
 	{
 		// Not supported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 32f1a59d6..09ccc0200 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.0.3
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLSRV Database Adapter Class
@@ -40,20 +41,38 @@
  */
 class CI_DB_sqlsrv_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'sqlsrv';
 
-	// The character used for escaping
-	protected $_escape_char = '"';
+	// --------------------------------------------------------------------
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	string
+	 */
 	protected $_random_keyword = ' NEWID()';
 
-	// SQLSRV-specific properties
+	/**
+	 * Quoted identifier flag
+	 *
+	 * Whether to use SQL-92 standard quoted identifier
+	 * (double quotes) or brackets for identifier escaping.
+	 *
+	 * @var	bool
+	 */
 	protected $_quoted_identifier = TRUE;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Non-persistent database connection
+	 * Database connection
 	 *
-	 * @param	bool	$pooling = FALSE
+	 * @param	bool	$pooling
 	 * @return	resource
 	 */
 	public function db_connect($pooling = FALSE)
@@ -106,7 +125,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @param	string	database name
+	 * @param	string	$database
 	 * @return	bool
 	 */
 	public function db_select($database = '')
@@ -130,7 +149,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
@@ -145,7 +164,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode = FALSE
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -205,8 +224,8 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -256,8 +275,12 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		{
 			return $this->data_cache['version'];
 		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
 
-		if (($info = sqlsrv_server_info($this->conn_id)) === FALSE)
+		if ( ! $this->conn_id OR ($info = sqlsrv_server_info($this->conn_id)) === FALSE)
 		{
 			return FALSE;
 		}
@@ -273,7 +296,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
 	 * @param	bool
-	 * @return	string
+	 * @return	string	$prefix_limit
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
@@ -297,7 +320,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
@@ -312,7 +335,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _field_data($table)
@@ -365,8 +388,8 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
 	protected function _update($table, $values)
@@ -383,10 +406,10 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
-	 * If the database does not support the truncate() command,
+	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
@@ -401,7 +424,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
@@ -417,11 +440,11 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @param	string	the sql query string
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
@@ -473,6 +496,29 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		// Multiple-value inserts are only supported as of SQL Server 2008
+		if (version_compare($this->version(), '10', '>='))
+		{
+			return parent::_insert_batch($table, $keys, $values);
+		}
+
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/sqlsrv/sqlsrv_forge.php b/system/database/drivers/sqlsrv/sqlsrv_forge.php
index ccdb36929..da8f68c56 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_forge.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.0.3
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLSRV Forge Class
@@ -34,124 +35,99 @@
  */
 class CI_DB_sqlsrv_forge extends CI_DB_forge {
 
-	protected $_drop_table	= 'DROP TABLE %s';
-
 	/**
-	 * Create Table
+	 * CREATE TABLE IF statement
 	 *
-	 * @param	string	the table name
-	 * @param	array	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	string
+	 * @var	string
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
-	{
-		$sql = ($if_not_exists === TRUE)
-			? "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'".$table."') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\n"
-			: '';
-
-		$sql .= 'CREATE TABLE '.$this->db->escape_identifiers($table).' (';
-
-		$current_field_count = 0;
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
-
-				if (stripos($attributes['TYPE'], 'INT') === FALSE && ! empty($attributes['CONSTRAINT']))
-				{
-					$sql .= '('.$attributes['CONSTRAINT'].')';
-				}
-
-				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
+	protected $_create_table_if	= "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nCREATE TABLE";
 
-				if (isset($attributes['DEFAULT']))
-				{
-					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
-				}
-
-				$sql .= ( ! empty($attributes['NULL']) && $attribues['NULL'] === TRUE)
-					? ' NULL' : ' NOT NULL';
+	/**
+	 * DROP TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_drop_table_if	= "IF EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nDROP TABLE";
 
-				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-			}
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT'	=> 'SMALLINT',
+		'SMALLINT'	=> 'INT',
+		'INT'		=> 'BIGINT',
+		'REAL'		=> 'FLOAT'
+	);
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	// --------------------------------------------------------------------
 
-		if (count($primary_keys) > 0)
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
+	 */
+	protected function _alter_table($alter_type, $table, $field)
+	{
+		if (in_array($alter_type, array('ADD', 'DROP'), TRUE))
 		{
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			return parent::_alter_table($alter_type, $table, $field);
 		}
 
-		if (is_array($keys) && count($keys) > 0)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' ALTER COLUMN ';
+		$sqls = array();
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			foreach ($keys as $key)
-			{
-				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
-					: array($this->escape_identifiers($key));
-
-				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';
-			}
+			$sqls[] = $sql.$this->_process_column($field[$i]);
 		}
 
-		return $sql."\n)";
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Field attribute TYPE
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column(), and column_alter(),
+	 * Performs a data type mapping between different databases.
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
-	 * @return	string
+	 * @param	array	&$attributes
+	 * @return	void
 	 */
-	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _attr_type(&$attributes)
 	{
-		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		switch (strtoupper($attributes['TYPE']))
 		{
-			return $sql;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'INTEGER';
+				$attributes['UNSIGNED'] = FALSE;
+				return;
+			case 'INTEGER':
+				$attributes['TYPE'] = 'INT';
+				return;
+			default: return;
 		}
+	}
 
-		return $sql.' '.$column_definition
-			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
-			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field != '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param	array	&$attributes
+	 * @param	array	&$field
+	 * @return	void
+	 */
+	protected function _attr_auto_increment(&$attributes, &$field)
+	{
+		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
+		{
+			$field['auto_increment'] = ' IDENTITY(1,1)';
+		}
 	}
 
 }
diff --git a/system/database/drivers/sqlsrv/sqlsrv_result.php b/system/database/drivers/sqlsrv/sqlsrv_result.php
index fb7a68647..6d24cc995 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_result.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLSRV Result Class
@@ -145,7 +146,7 @@ class CI_DB_sqlsrv_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @param	string
+	 * @param	string	$class_name
 	 * @return	object
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
diff --git a/system/database/drivers/sqlsrv/sqlsrv_utility.php b/system/database/drivers/sqlsrv/sqlsrv_utility.php
index d518cc15a..2bc7f9e03 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_utility.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 2.0.3
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * SQLSRV Utility Class
@@ -34,19 +35,32 @@
  */
 class CI_DB_sqlsrv_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'EXEC sp_helpdb'; // Can also be: EXEC sp_databases
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'ALTER INDEX all ON %s REORGANIZE';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * SQLSRV Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	bool
 	 */
 	protected function _backup($params = array())
 	{
 		// Currently unsupported
-		return $this->db->display_error('db_unsuported_feature');
+		return $this->db->display_error('db_unsupported_feature');
 	}
 
 }
diff --git a/system/helpers/array_helper.php b/system/helpers/array_helper.php
index ed2fe3c4a..0e66e4b77 100644
--- a/system/helpers/array_helper.php
+++ b/system/helpers/array_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Array Helpers
diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index 3aac14db8..e9b167fa9 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter CAPTCHA Helper
diff --git a/system/helpers/cookie_helper.php b/system/helpers/cookie_helper.php
index f396c76b0..02841409d 100644
--- a/system/helpers/cookie_helper.php
+++ b/system/helpers/cookie_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Cookie Helpers
diff --git a/system/helpers/date_helper.php b/system/helpers/date_helper.php
index 5d9251526..0fa400d7e 100644
--- a/system/helpers/date_helper.php
+++ b/system/helpers/date_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Date Helpers
@@ -449,20 +450,13 @@ if ( ! function_exists('human_to_unix'))
 			return FALSE;
 		}
 
-		$split = explode(' ', $datestr);
+		sscanf($datestr, '%d-%d-%d %s %s', $year, $month, $day, $time, $ampm);
+		sscanf($time, '%d:%d:%d', $hour, $min, $sec);
+		isset($sec) OR $sec = 0;
 
-		list($year, $month, $day) = explode('-', $split[0]);
-
-		$ex = explode(':', $split['1']);
-
-		$hour	= (int) $ex[0];
-		$min	= (int) $ex[1];
-		$sec	= ( ! empty($ex[2]) && preg_match('/[0-9]{1,2}/', $ex[2]))
-				? (int) $ex[2] : 0;
-
-		if (isset($split[2]))
+		if (isset($ampm))
 		{
-			$ampm = strtolower($split[2]);
+			$ampm = strtolower($ampm);
 
 			if ($ampm[0] === 'p' && $hour < 12)
 			{
diff --git a/system/helpers/directory_helper.php b/system/helpers/directory_helper.php
index 7d6b6770e..49dcfc8a9 100644
--- a/system/helpers/directory_helper.php
+++ b/system/helpers/directory_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Directory Helpers
@@ -46,9 +47,10 @@ if ( ! function_exists('directory_map'))
 	 * representation of it. Sub-folders contained with the
 	 * directory will be mapped as well.
 	 *
-	 * @param	string	path to source
-	 * @param	int	depth of directories to traverse (0 = fully recursive, 1 = current dir, etc)
-	 * @param	bool	whether to show hidden files
+	 * @param	string	$source_dir		Path to source
+	 * @param	int	$directory_depth	Depth of directories to traverse
+	 *						(0 = fully recursive, 1 = current dir, etc)
+	 * @param	bool	$hidden			Whether to show hidden files
 	 * @return	array
 	 */
 	function directory_map($source_dir, $directory_depth = 0, $hidden = FALSE)
@@ -67,9 +69,11 @@ if ( ! function_exists('directory_map'))
 					continue;
 				}
 
+				@is_dir($source_dir.$file) AND $file .= DIRECTORY_SEPARATOR;
+
 				if (($directory_depth < 1 OR $new_depth > 0) && @is_dir($source_dir.$file))
 				{
-					$filedata[$file] = directory_map($source_dir.$file.DIRECTORY_SEPARATOR, $new_depth, $hidden);
+					$filedata[$file] = directory_map($source_dir.$file, $new_depth, $hidden);
 				}
 				else
 				{
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index 2c26a36d5..8fe66e222 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Download Helpers
diff --git a/system/helpers/email_helper.php b/system/helpers/email_helper.php
index 2a63b36c9..dfb166a5a 100644
--- a/system/helpers/email_helper.php
+++ b/system/helpers/email_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Email Helpers
@@ -42,7 +43,8 @@ if ( ! function_exists('valid_email'))
 	/**
 	 * Validate email address
 	 *
-	 * @param	string
+	 * @deprecated	3.0.0	Use PHP's filter_var() instead
+	 * @param	string	$email
 	 * @return	bool
 	 */
 	function valid_email($email)
@@ -58,12 +60,13 @@ if ( ! function_exists('send_email'))
 	/**
 	 * Send an email
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	string
+	 * @deprecated	3.0.0	Use PHP's mail() instead
+	 * @param	string	$recipient
+	 * @param	string	$subject
+	 * @param	string	$message
 	 * @return	bool
 	 */
-	function send_email($recipient, $subject = 'Test email', $message = 'Hello World')
+	function send_email($recipient, $subject, $message)
 	{
 		return mail($recipient, $subject, $message);
 	}
diff --git a/system/helpers/file_helper.php b/system/helpers/file_helper.php
index 8f23a3d54..aebb6e47a 100644
--- a/system/helpers/file_helper.php
+++ b/system/helpers/file_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter File Helpers
@@ -65,12 +66,12 @@ if ( ! function_exists('write_file'))
 	 * Writes data to the file specified in the path.
 	 * Creates a new file if non-existent.
 	 *
-	 * @param	string	path to file
-	 * @param	string	file data
-	 * @param	int
+	 * @param	string	$path	File path
+	 * @param	string	$data	Data to write
+	 * @param	string	$mode	fopen() mode (default: 'wb')
 	 * @return	bool
 	 */
-	function write_file($path, $data, $mode = FOPEN_WRITE_CREATE_DESTRUCTIVE)
+	function write_file($path, $data, $mode = 'wb')
 	{
 		if ( ! $fp = @fopen($path, $mode))
 		{
@@ -98,13 +99,13 @@ if ( ! function_exists('delete_files'))
 	 * If the second parameter is set to TRUE, any directories contained
 	 * within the supplied base directory will be nuked as well.
 	 *
-	 * @param	string	path to file
-	 * @param	bool	whether to delete any directories found in the path
-	 * @param	int
-	 * @param	bool	whether to skip deleting .htaccess and index page files
+	 * @param	string	$path		File path
+	 * @param	bool	$del_dir	Whether to delete any directories found in the path
+	 * @param	bool	$htdocs		Whether to skip deleting .htaccess and index page files
+	 * @param	int	$_level		Current directory depth level (default: 0; internal use only)
 	 * @return	bool
 	 */
-	function delete_files($path, $del_dir = FALSE, $level = 0, $htdocs = FALSE)
+	function delete_files($path, $del_dir = FALSE, $htdocs = FALSE, $_level = 0)
 	{
 		// Trim the trailing slash
 		$path = rtrim($path, '/\\');
@@ -120,7 +121,7 @@ if ( ! function_exists('delete_files'))
 			{
 				if (is_dir($path.DIRECTORY_SEPARATOR.$filename) && $filename[0] !== '.')
 				{
-					delete_files($path.DIRECTORY_SEPARATOR.$filename, $del_dir, $level + 1, $htdocs);
+					delete_files($path.DIRECTORY_SEPARATOR.$filename, $del_dir, $htdocs, $_level + 1);
 				}
 				elseif ($htdocs !== TRUE OR ! preg_match('/^(\.htaccess|index\.(html|htm|php)|web\.config)$/i', $filename))
 				{
@@ -130,7 +131,7 @@ if ( ! function_exists('delete_files'))
 		}
 		@closedir($current_dir);
 
-		if ($del_dir === TRUE && $level > 0)
+		if ($del_dir === TRUE && $_level > 0)
 		{
 			return @rmdir($path);
 		}
@@ -318,12 +319,12 @@ if ( ! function_exists('get_mime_by_extension'))
 	 * Note: this is NOT an accurate way of determining file mime types, and is here strictly as a convenience
 	 * It should NOT be trusted, and should certainly NOT be used for security
 	 *
-	 * @param	string	path to file
-	 * @return	mixed
+	 * @param	string	$filename	File name
+	 * @return	string
 	 */
-	function get_mime_by_extension($file)
+	function get_mime_by_extension($filename)
 	{
-		$extension = strtolower(substr(strrchr($file, '.'), 1));
+		$extension = strtolower(substr(strrchr($filename, '.'), 1));
 
 		static $mimes;
 
@@ -358,7 +359,7 @@ if ( ! function_exists('symbolic_permissions'))
 	 * Takes a numeric value representing a file's permissions and returns
 	 * standard symbolic notation representing that value
 	 *
-	 * @param	int
+	 * @param	int	$perms	Permissions
 	 * @return	string
 	 */
 	function symbolic_permissions($perms)
@@ -425,7 +426,7 @@ if ( ! function_exists('octal_permissions'))
 	 * Takes a numeric value representing a file's permissions and returns
 	 * a three character string representing the file's octal permissions
 	 *
-	 * @param	int
+	 * @param	int	$perms	Permissions
 	 * @return	string
 	 */
 	function octal_permissions($perms)
diff --git a/system/helpers/form_helper.php b/system/helpers/form_helper.php
index 622622c0e..e7bea92cc 100644
--- a/system/helpers/form_helper.php
+++ b/system/helpers/form_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -22,7 +22,9 @@
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 1.0
+ * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Form Helpers
@@ -124,9 +126,9 @@ if ( ! function_exists('form_hidden'))
 	 * Generates hidden fields. You can pass a simple key/value string or
 	 * an associative array with multiple values.
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	bool
+	 * @param	mixed	$name		Field name
+	 * @param	string	$value		Field value
+	 * @param	bool	$recursing
 	 * @return	string
 	 */
 	function form_hidden($name, $value = '', $recursing = FALSE)
@@ -149,7 +151,7 @@ if ( ! function_exists('form_hidden'))
 
 		if ( ! is_array($value))
 		{
-			$form .= '<input type="hidden" name="'.$name.'" value="'.html_escape($value)."\" />\n";
+			$form .= '<input type="hidden" name="'.$name.'" value="'.form_prep($value)."\" />\n";
 		}
 		else
 		{
@@ -243,9 +245,9 @@ if ( ! function_exists('form_textarea'))
 	/**
 	 * Textarea field
 	 *
-	 * @param	mixed
-	 * @param	string
-	 * @param	string
+	 * @param	mixed	$data
+	 * @param	string	$value
+	 * @param	string	$extra
 	 * @return	string
 	 */
 	function form_textarea($data = '', $value = '', $extra = '')
@@ -263,7 +265,7 @@ if ( ! function_exists('form_textarea'))
 		}
 
 		$name = is_array($data) ? $data['name'] : $data;
-		return '<textarea '._parse_form_attributes($data, $defaults).$extra.'>'.html_escape($val)."</textarea>\n";
+		return '<textarea '._parse_form_attributes($data, $defaults).$extra.'>'.form_prep($val, TRUE)."</textarea>\n";
 	}
 }
 
@@ -298,10 +300,10 @@ if ( ! function_exists('form_dropdown'))
 	/**
 	 * Drop-down Menu
 	 *
-	 * @param	mixed	$name = ''
-	 * @param	mixed	$options = array()
-	 * @param	mixed	$selected = array()
-	 * @param	mixed	$extra = array()
+	 * @param	mixed	$name
+	 * @param	mixed	$options
+	 * @param	mixed	$selected
+	 * @param	mixed	$extra
 	 * @return	string
 	 */
 	function form_dropdown($name = '', $options = array(), $selected = array(), $extra = '')
@@ -349,7 +351,7 @@ if ( ! function_exists('form_dropdown'))
 				foreach ($val as $optgroup_key => $optgroup_val)
 				{
 					$sel = in_array($optgroup_key, $selected) ? ' selected="selected"' : '';
-					$form .= '<option value="'.html_escape($optgroup_key).'"'.$sel.'>'
+					$form .= '<option value="'.form_prep($optgroup_key).'"'.$sel.'>'
 						.(string) $optgroup_val."</option>\n";
 				}
 
@@ -357,7 +359,7 @@ if ( ! function_exists('form_dropdown'))
 			}
 			else
 			{
-				$form .= '<option value="'.html_escape($key).'"'
+				$form .= '<option value="'.form_prep($key).'"'
 					.(in_array($key, $selected) ? ' selected="selected"' : '').'>'
 					.(string) $val."</option>\n";
 			}
@@ -600,17 +602,28 @@ if ( ! function_exists('form_prep'))
 	 *
 	 * Formats text so that it can be safely placed in a form field in the event it has HTML tags.
 	 *
-	 * @todo	Remove in version 3.1+.
-	 * @deprecated	3.0.0	This function has been broken for a long time
-	 *			and is now just an alias for html_escape(). It's
-	 *			second argument is ignored.
-	 * @param	string	$str = ''
-	 * @param	string	$field_name = ''
-	 * @return	string
+	 * @param	string|string[]	$str		Value to escape
+	 * @param	bool		$is_textarea	Whether we're escaping for a textarea element
+	 * @return	string|string[]	Escaped values
 	 */
-	function form_prep($str = '', $field_name = '')
+	function form_prep($str = '', $is_textarea = FALSE)
 	{
-		return html_escape($str);
+		if (is_array($str))
+		{
+			foreach (array_keys($str) as $key)
+			{
+				$str[$key] = form_prep($str[$key], $is_textarea);
+			}
+
+			return $str;
+		}
+
+		if ($is_textarea === TRUE)
+		{
+			return str_replace(array('<', '>'), array('&lt;', '&gt;'), stripslashes($str));
+		}
+
+		return str_replace(array("'", '"'), array('&#39;', '&quot;'), stripslashes($str));
 	}
 }
 
@@ -625,23 +638,21 @@ if ( ! function_exists('set_value'))
 	 * re-populate an input field or textarea. If Form Validation
 	 * is active it retrieves the info from the validation class
 	 *
-	 * @param	string
-	 * @param	string
-	 * @return	mixed
+	 * @param	string	$field		Field name
+	 * @param	string	$default	Default value
+	 * @param	bool	$is_textarea	Whether the field is a textarea element
+	 * @return	string
 	 */
-	function set_value($field = '', $default = '')
+	function set_value($field = '', $default = '', $is_textarea = FALSE)
 	{
 		if (FALSE === ($OBJ =& _get_validation_object()))
 		{
-			if ( ! isset($_POST[$field]))
-			{
-				return html_escape($default);
-			}
-
-			return html_escape($_POST[$field]);
+			return isset($_POST[$field])
+				? form_prep($_POST[$field], $is_textarea)
+				: form_prep($default, $is_textarea);
 		}
 
-		return html_escape($OBJ->set_value($field, $default));
+		return form_prep($OBJ->set_value($field, $default), $is_textarea);
 	}
 }
 
@@ -862,8 +873,8 @@ if ( ! function_exists('_parse_form_attributes'))
 	 *
 	 * Helper function used by some of the form helpers
 	 *
-	 * @param	array
-	 * @param	array
+	 * @param	array	$attributes	List of attributes
+	 * @param	array	$default	Default values
 	 * @return	string
 	 */
 	function _parse_form_attributes($attributes, $default)
@@ -891,7 +902,7 @@ if ( ! function_exists('_parse_form_attributes'))
 		{
 			if ($key === 'value')
 			{
-				$val = html_escape($val);
+				$val = form_prep($val);
 			}
 			elseif ($key === 'name' && ! strlen($default['name']))
 			{
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index 2372e8174..fa49f7d75 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter HTML Helpers
@@ -156,12 +157,12 @@ if ( ! function_exists('br'))
 	/**
 	 * Generates HTML BR tags based on number supplied
 	 *
-	 * @param	int
+	 * @param	int	$count	Number of times to repeat the tag
 	 * @return	string
 	 */
-	function br($num = 1)
+	function br($count = 1)
 	{
-		return str_repeat('<br />', $num);
+		return str_repeat('<br />', $count);
 	}
 }
 
diff --git a/system/helpers/inflector_helper.php b/system/helpers/inflector_helper.php
index 647d840e4..59cb296b2 100644
--- a/system/helpers/inflector_helper.php
+++ b/system/helpers/inflector_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Inflector Helpers
@@ -44,7 +45,7 @@ if ( ! function_exists('singular'))
 	 *
 	 * Takes a plural word and makes it singular
 	 *
-	 * @param	string
+	 * @param	string	$str	Input string
 	 * @return	string
 	 */
 	function singular($str)
@@ -108,11 +109,10 @@ if ( ! function_exists('plural'))
 	 *
 	 * Takes a singular word and makes it plural
 	 *
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$str	Input string
 	 * @return	string
 	 */
-	function plural($str, $force = FALSE)
+	function plural($str)
 	{
 		$result = strval($str);
 
@@ -165,7 +165,7 @@ if ( ! function_exists('camelize'))
 	 *
 	 * Takes multiple words separated by spaces or underscores and camelizes them
 	 *
-	 * @param	string
+	 * @param	string	$str	Input string
 	 * @return	string
 	 */
 	function camelize($str)
@@ -183,7 +183,7 @@ if ( ! function_exists('underscore'))
 	 *
 	 * Takes multiple words separated by spaces and underscores them
 	 *
-	 * @param	string
+	 * @param	string	$str	Input string
 	 * @return	string
 	 */
 	function underscore($str)
@@ -201,8 +201,8 @@ if ( ! function_exists('humanize'))
 	 *
 	 * Takes multiple words separated by the separator and changes them to spaces
 	 *
-	 * @param	string	$str
-	 * @param 	string	$separator
+	 * @param	string	$str		Input string
+	 * @param 	string	$separator	Input separator
 	 * @return	string
 	 */
 	function humanize($str, $separator = '_')
@@ -218,12 +218,12 @@ if ( ! function_exists('is_countable'))
 	/**
 	 * Checks if the given word has a plural version.
 	 *
-	 * @param	string	the word to check
-	 * @return	bool	if the word is countable
+	 * @param	string	$word	Word to check
+	 * @return	bool
 	 */
 	function is_countable($word)
 	{
-		return ! in_array(strtolower(strval($word)),
+		return ! in_array(strtolower($word),
 					array(
 						'equipment', 'information', 'rice', 'money',
 						'species', 'series', 'fish', 'meta'
diff --git a/system/helpers/language_helper.php b/system/helpers/language_helper.php
index bd567ed79..658be6de7 100644
--- a/system/helpers/language_helper.php
+++ b/system/helpers/language_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Language Helpers
diff --git a/system/helpers/number_helper.php b/system/helpers/number_helper.php
index e49f2f7a0..b93096543 100644
--- a/system/helpers/number_helper.php
+++ b/system/helpers/number_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Number Helpers
diff --git a/system/helpers/path_helper.php b/system/helpers/path_helper.php
index 166fef065..5a798b118 100644
--- a/system/helpers/path_helper.php
+++ b/system/helpers/path_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Path Helpers
diff --git a/system/helpers/security_helper.php b/system/helpers/security_helper.php
index 8bbd06684..898a49c80 100644
--- a/system/helpers/security_helper.php
+++ b/system/helpers/security_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Security Helpers
diff --git a/system/helpers/smiley_helper.php b/system/helpers/smiley_helper.php
index b6b2afcf4..4b491758e 100644
--- a/system/helpers/smiley_helper.php
+++ b/system/helpers/smiley_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Smiley Helpers
@@ -130,10 +131,9 @@ if ( ! function_exists('get_clickable_smileys'))
 	 *
 	 * @param	string	the URL to the folder containing the smiley images
 	 * @param	array
-	 * @param	array
 	 * @return	array
 	 */
-	function get_clickable_smileys($image_url, $alias = '', $smileys = NULL)
+	function get_clickable_smileys($image_url, $alias = '')
 	{
 		// For backward compatibility with js_insert_smiley
 		if (is_array($alias))
@@ -142,7 +142,7 @@ if ( ! function_exists('get_clickable_smileys'))
 		}
 		elseif (FALSE === ($smileys = _get_smiley_array()))
 		{
-			return $smileys;
+			return FALSE;
 		}
 
 		// Add a trailing slash to the file path if needed
diff --git a/system/helpers/string_helper.php b/system/helpers/string_helper.php
index c5c493452..9fc24559a 100644
--- a/system/helpers/string_helper.php
+++ b/system/helpers/string_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter String Helpers
@@ -50,6 +51,9 @@ if ( ! function_exists('trim_slashes'))
 	 *
 	 * this/that/theother
 	 *
+	 * @todo	Remove in version 3.1+.
+	 * @deprecated	3.0.0	This is just an alias for PHP's native trim()
+	 *
 	 * @param	string
 	 * @return	string
 	 */
@@ -214,10 +218,10 @@ if ( ! function_exists('random_string'))
 						break;
 				}
 				return substr(str_shuffle(str_repeat($pool, ceil($len / strlen($pool)))), 0, $len);
-			case 'unique':
+			case 'unique': // todo: remove in 3.1+
 			case 'md5':
 				return md5(uniqid(mt_rand()));
-			case 'encrypt':
+			case 'encrypt': // todo: remove in 3.1+
 			case 'sha1':
 				return sha1(uniqid(mt_rand(), TRUE));
 		}
diff --git a/system/helpers/text_helper.php b/system/helpers/text_helper.php
index 89602fc28..cce659231 100644
--- a/system/helpers/text_helper.php
+++ b/system/helpers/text_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Text Helpers
diff --git a/system/helpers/typography_helper.php b/system/helpers/typography_helper.php
index 96bedd026..48f1f1147 100644
--- a/system/helpers/typography_helper.php
+++ b/system/helpers/typography_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Typography Helpers
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index dc77246dc..0aa358a0b 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter URL Helpers
@@ -473,9 +474,11 @@ if ( ! function_exists('url_title'))
 	 * human-friendly URL string with a "separator" string
 	 * as the word separator.
 	 *
-	 * @param	string	the string
-	 * @param	string	the separator
-	 * @param	bool
+	 * @todo	Remove old 'dash' and 'underscore' usage in 3.1+.
+	 * @param	string	$str		Input string
+	 * @param	string	$separator	Word separator
+	 *			(usually '-' or '_')
+	 * @param	bool	$lowercase	Wether to transform the output string to lowercase
 	 * @return	string
 	 */
 	function url_title($str, $separator = '-', $lowercase = FALSE)
@@ -524,10 +527,11 @@ if ( ! function_exists('redirect'))
 	 * For very fine grained control over headers, you could use the Output
 	 * Library's set_header() function.
 	 *
-	 * @param	string	the URL
-	 * @param	string	the method: location or refresh
-	 * @param	int
-	 * @return	string
+	 * @param	string	$uri	URL
+	 * @param	string	$method	Redirect method
+	 *			'auto', 'location' or 'refresh'
+	 * @param	int	$code	HTTP Response status code
+	 * @return	void
 	 */
 	function redirect($uri = '', $method = 'auto', $code = NULL)
 	{
diff --git a/system/helpers/xml_helper.php b/system/helpers/xml_helper.php
index 1431777d2..c3dfdcddb 100644
--- a/system/helpers/xml_helper.php
+++ b/system/helpers/xml_helper.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter XML Helpers
diff --git a/system/language/english/calendar_lang.php b/system/language/english/calendar_lang.php
index a70a564e8..288eb91d8 100644
--- a/system/language/english/calendar_lang.php
+++ b/system/language/english/calendar_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['cal_su']			= 'Su';
 $lang['cal_mo']			= 'Mo';
diff --git a/system/language/english/date_lang.php b/system/language/english/date_lang.php
index 6683e4c69..db1e9e0ff 100644
--- a/system/language/english/date_lang.php
+++ b/system/language/english/date_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['date_year'] = 'Year';
 $lang['date_years'] = 'Years';
diff --git a/system/language/english/db_lang.php b/system/language/english/db_lang.php
index 479cbb167..50ce6bbd6 100644
--- a/system/language/english/db_lang.php
+++ b/system/language/english/db_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['db_invalid_connection_str'] = 'Unable to determine the database settings based on the connection string you submitted.';
 $lang['db_unable_to_connect'] = 'Unable to connect to your database server using the provided settings.';
@@ -40,8 +41,8 @@ $lang['db_field_param_missing'] = 'To fetch fields requires the name of the tabl
 $lang['db_unsupported_function'] = 'This feature is not available for the database you are using.';
 $lang['db_transaction_failure'] = 'Transaction failure: Rollback performed.';
 $lang['db_unable_to_drop'] = 'Unable to drop the specified database.';
-$lang['db_unsuported_feature'] = 'Unsupported feature of the database platform you are using.';
-$lang['db_unsuported_compression'] = 'The file compression format you chose is not supported by your server.';
+$lang['db_unsupported_feature'] = 'Unsupported feature of the database platform you are using.';
+$lang['db_unsupported_compression'] = 'The file compression format you chose is not supported by your server.';
 $lang['db_filepath_error'] = 'Unable to write data to the file path you have submitted.';
 $lang['db_invalid_cache_path'] = 'The cache path you submitted is not valid or writable.';
 $lang['db_table_name_required'] = 'A table name is required for that operation.';
diff --git a/system/language/english/email_lang.php b/system/language/english/email_lang.php
index 0de9aa27e..646a49647 100644
--- a/system/language/english/email_lang.php
+++ b/system/language/english/email_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['email_must_be_array'] = 'The email validation method must be passed an array.';
 $lang['email_invalid_address'] = 'Invalid email address: %s';
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index 6ff0cc2f4..52ca21f92 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['required']				= 'The %s field is required.';
 $lang['isset']					= 'The %s field must have a value.';
diff --git a/system/language/english/ftp_lang.php b/system/language/english/ftp_lang.php
index 24923c8d8..090a88c28 100644
--- a/system/language/english/ftp_lang.php
+++ b/system/language/english/ftp_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['ftp_no_connection']			= 'Unable to locate a valid connection ID. Please make sure you are connected before peforming any file routines.';
 $lang['ftp_unable_to_connect']		= 'Unable to connect to your FTP server using the supplied hostname.';
diff --git a/system/language/english/imglib_lang.php b/system/language/english/imglib_lang.php
index d755437f2..296c4af68 100644
--- a/system/language/english/imglib_lang.php
+++ b/system/language/english/imglib_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['imglib_source_image_required'] = 'You must specify a source image in your preferences.';
 $lang['imglib_gd_required'] = 'The GD image library is required for this feature.';
diff --git a/system/language/english/migration_lang.php b/system/language/english/migration_lang.php
index a262d3018..689a72952 100644
--- a/system/language/english/migration_lang.php
+++ b/system/language/english/migration_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['migration_none_found']			= 'No migrations were found.';
 $lang['migration_not_found']			= 'No migration could be found with the version number: %d.';
@@ -34,6 +35,5 @@ $lang['migration_missing_up_method']	= 'The migration class "%s" is missing an "
 $lang['migration_missing_down_method']	= 'The migration class "%s" is missing a "down" method.';
 $lang['migration_invalid_filename']		= 'Migration "%s" has an invalid filename.';
 
-
 /* End of file migration_lang.php */
 /* Location: ./system/language/english/migration_lang.php */
\ No newline at end of file
diff --git a/system/language/english/number_lang.php b/system/language/english/number_lang.php
index 429c64738..019013a49 100644
--- a/system/language/english/number_lang.php
+++ b/system/language/english/number_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['terabyte_abbr'] = 'TB';
 $lang['gigabyte_abbr'] = 'GB';
diff --git a/system/language/english/profiler_lang.php b/system/language/english/profiler_lang.php
index 112527faa..6ffcd9349 100644
--- a/system/language/english/profiler_lang.php
+++ b/system/language/english/profiler_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['profiler_database']		= 'DATABASE';
 $lang['profiler_controller_info'] = 'CLASS/METHOD';
diff --git a/system/language/english/unit_test_lang.php b/system/language/english/unit_test_lang.php
index 146ec25b4..ed452615f 100644
--- a/system/language/english/unit_test_lang.php
+++ b/system/language/english/unit_test_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['ut_test_name']		= 'Test Name';
 $lang['ut_test_datatype']	= 'Test Datatype';
diff --git a/system/language/english/upload_lang.php b/system/language/english/upload_lang.php
index d70e7f20f..88f9ac372 100644
--- a/system/language/english/upload_lang.php
+++ b/system/language/english/upload_lang.php
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 $lang['upload_userfile_not_set'] = 'Unable to find a post variable called userfile.';
 $lang['upload_file_exceeds_limit'] = 'The uploaded file exceeds the maximum allowed size in your PHP configuration file.';
diff --git a/system/libraries/Cache/Cache.php b/system/libraries/Cache/Cache.php
index 7ec2380a5..e76fdc557 100644
--- a/system/libraries/Cache/Cache.php
+++ b/system/libraries/Cache/Cache.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_apc.php b/system/libraries/Cache/drivers/Cache_apc.php
index c85034f95..46e633463 100644
--- a/system/libraries/Cache/drivers/Cache_apc.php
+++ b/system/libraries/Cache/drivers/Cache_apc.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter APC Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_dummy.php b/system/libraries/Cache/drivers/Cache_dummy.php
index 3f2b4b956..a3bdc3c80 100644
--- a/system/libraries/Cache/drivers/Cache_dummy.php
+++ b/system/libraries/Cache/drivers/Cache_dummy.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Dummy Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_file.php b/system/libraries/Cache/drivers/Cache_file.php
index 37d77c268..5d370380e 100644
--- a/system/libraries/Cache/drivers/Cache_file.php
+++ b/system/libraries/Cache/drivers/Cache_file.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter File Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_memcached.php b/system/libraries/Cache/drivers/Cache_memcached.php
index bf90f6197..fae002347 100644
--- a/system/libraries/Cache/drivers/Cache_memcached.php
+++ b/system/libraries/Cache/drivers/Cache_memcached.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Memcached Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index e4a26b5f0..60033344b 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Redis Caching Class
diff --git a/system/libraries/Cache/drivers/Cache_wincache.php b/system/libraries/Cache/drivers/Cache_wincache.php
index 89e9f77c8..383b3afdd 100644
--- a/system/libraries/Cache/drivers/Cache_wincache.php
+++ b/system/libraries/Cache/drivers/Cache_wincache.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Wincache Caching Class
diff --git a/system/libraries/Calendar.php b/system/libraries/Calendar.php
index 95f537e42..caa496a5e 100644
--- a/system/libraries/Calendar.php
+++ b/system/libraries/Calendar.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Calendar Class
diff --git a/system/libraries/Cart.php b/system/libraries/Cart.php
index d4b17fa36..035a6a42b 100644
--- a/system/libraries/Cart.php
+++ b/system/libraries/Cart.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Shopping Cart Class
@@ -193,7 +194,7 @@ class CI_Cart {
 		$items['qty'] = (float) $items['qty'];
 
 		// If the quantity is zero or blank there's nothing for us to do
-		if ( ! is_numeric($items['qty']) OR $items['qty'] == 0)
+		if ($items['qty'] == 0)
 		{
 			return FALSE;
 		}
@@ -224,15 +225,6 @@ class CI_Cart {
 		// Prep the price. Remove leading zeros and anything that isn't a number or decimal point.
 		$items['price'] = (float) $items['price'];
 
-		// Is the price a valid number?
-		if ( ! is_numeric($items['price']))
-		{
-			log_message('error', 'An invalid price was submitted for product ID: '.$items['id']);
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
 		// We now need to create a unique identifier for the item being inserted into the cart.
 		// Every time something is added to the cart it is stored in the master cart array.
 		// Each row in the cart array, however, must have a unique index that identifies not only
@@ -350,12 +342,6 @@ class CI_Cart {
 		// Prep the quantity
 		$items['qty'] = (float) $items['qty'];
 
-		// Is the quantity a number?
-		if ( ! is_numeric($items['qty']))
-		{
-			return FALSE;
-		}
-
 		// Is the quantity zero?  If so we will remove the item from the cart.
 		// If the quantity is greater than zero we are updating
 		if ($items['qty'] == 0)
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
index 5d642b982..621d22631 100644
--- a/system/libraries/Driver.php
+++ b/system/libraries/Driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Driver Library Class
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 7280466a5..d23be1af1 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Email Class
@@ -38,55 +39,340 @@
  */
 class CI_Email {
 
+	/**
+	 * Used as the User-Agent and X-Mailer headers' value.
+	 *
+	 * @var	string
+	 */
 	public $useragent	= 'CodeIgniter';
+
+	/**
+	 * Path to the Sendmail binary.
+	 *
+	 * @var	string
+	 */
 	public $mailpath	= '/usr/sbin/sendmail';	// Sendmail path
+
+	/**
+	 * Which method to use for sending e-mails.
+	 *
+	 * @var	string	'mail', 'sendmail' or 'smtp'
+	 */
 	public $protocol	= 'mail';		// mail/sendmail/smtp
-	public $smtp_host	= '';			// SMTP Server. Example: mail.earthlink.net
-	public $smtp_user	= '';			// SMTP Username
-	public $smtp_pass	= '';			// SMTP Password
-	public $smtp_port	= 25;			// SMTP Port
-	public $smtp_timeout	= 5;			// SMTP Timeout in seconds
-	public $smtp_crypto	= '';			// SMTP Encryption. Can be null, tls or ssl.
-	public $wordwrap	= TRUE;			// TRUE/FALSE - Turns word-wrap on/off
-	public $wrapchars	= 76;			// Number of characters to wrap at.
-	public $mailtype	= 'text';		// text/html - Defines email formatting
-	public $charset		= 'utf-8';		// Default char set: iso-8859-1 or us-ascii
+
+	/**
+	 * STMP Server host
+	 *
+	 * @var	string
+	 */
+	public $smtp_host	= '';
+
+	/**
+	 * SMTP Username
+	 *
+	 * @var	string
+	 */
+	public $smtp_user	= '';
+
+	/**
+	 * SMTP Password
+	 *
+	 * @var	string
+	 */
+	public $smtp_pass	= '';
+
+	/**
+	 * SMTP Server port
+	 *
+	 * @var	int
+	 */
+	public $smtp_port	= 25;
+
+	/**
+	 * SMTP connection timeout in seconds
+	 *
+	 * @var	int
+	 */
+	public $smtp_timeout	= 5;
+
+	/**
+	 * SMTP Encryption
+	 *
+	 * @var	string	NULL, 'tls' or 'ssl'
+	 */
+	public $smtp_crypto	= NULL;
+
+	/**
+	 * Whether to apply word-wrapping to the message body.
+	 *
+	 * @var	bool
+	 */
+	public $wordwrap	= TRUE;
+
+	/**
+	 * Number of characters to wrap at.
+	 *
+	 * @see	CI_Email::$wordwrap
+	 * @var	int
+	 */
+	public $wrapchars	= 76;
+
+	/**
+	 * Message format.
+	 *
+	 * @var	string	'text' or 'html'
+	 */
+	public $mailtype	= 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var	string
+	 */
+	public $charset		= 'utf-8';
+
+	/**
+	 * Multipart message
+	 *
+	 * @var	string	'mixed' (in the body) or 'related' (separate)
+	 */
 	public $multipart	= 'mixed';		// "mixed" (in the body) or "related" (separate)
-	public $alt_message	= '';			// Alternative message for HTML emails
-	public $validate	= FALSE;		// TRUE/FALSE - Enables email validation
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var	string
+	 */
+	public $alt_message	= '';
+
+	/**
+	 * Whether to validate e-mail addresses.
+	 *
+	 * @var	bool
+	 */
+	public $validate	= FALSE;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var	int	1-5
+	 */
 	public $priority	= 3;			// Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link	http://www.ietf.org/rfc/rfc822.txt
+	 * @var	string	"\r\n" or "\n"
+	 */
 	public $newline		= "\n";			// Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-	public $crlf		= "\n";			// The RFC 2045 compliant CRLF for quoted-printable is "\r\n". Apparently some servers,
-									// even on the receiving end think they need to muck with CRLFs, so using "\n", while
-									// distasteful, is the only thing that seems to work for all environments.
-	public $dsn		= FALSE;		// Delivery Status Notification
-	public $send_multipart	= TRUE;		// TRUE/FALSE - Yahoo does not like multipart alternative, so this is an override. Set to FALSE for Yahoo.
-	public $bcc_batch_mode	= FALSE;	// TRUE/FALSE - Turns on/off Bcc batch feature
-	public $bcc_batch_size	= 200;		// If bcc_batch_mode = TRUE, sets max number of Bccs in each batch
 
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link	http://www.ietf.org/rfc/rfc822.txt
+	 * @var	string
+	 */
+	public $crlf		= "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var	bool
+	 */
+	public $dsn		= FALSE;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var	bool
+	 */
+	public $send_multipart	= TRUE;
+
+	/**
+	 * Whether to send messages to BCC recipients in batches.
+	 *
+	 * @var	bool
+	 */
+	public $bcc_batch_mode	= FALSE;
+
+	/**
+	 * BCC Batch max number size.
+	 *
+	 * @see	CI_Email::$bcc_batch_mode
+	 * @var	int
+	 */
+	public $bcc_batch_size	= 200;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Whether PHP is running in safe mode. Initialized by the class constructor.
+	 *
+	 * @var	bool
+	 */
 	protected $_safe_mode		= FALSE;
+
+	/**
+	 * Subject header
+	 *
+	 * @var	string
+	 */
 	protected $_subject		= '';
+
+	/**
+	 * Message body
+	 *
+	 * @var	string
+	 */
 	protected $_body		= '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var	string
+	 */
 	protected $_finalbody		= '';
+
+	/**
+	 * multipart/alternative boundary
+	 *
+	 * @var	string
+	 */
 	protected $_alt_boundary	= '';
+
+	/**
+	 * Attachment boundary
+	 *
+	 * @var	string
+	 */
 	protected $_atc_boundary	= '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var	string
+	 */
 	protected $_header_str		= '';
+
+	/**
+	 * SMTP Connection socket placeholder
+	 *
+	 * @var	resource
+	 */
 	protected $_smtp_connect	= '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var	string	'8bit' or '7bit'
+	 */
 	protected $_encoding		= '8bit';
-	protected $_IP			= FALSE;
+
+	/**
+	 * Whether to perform SMTP authentication
+	 *
+	 * @var	bool
+	 */
 	protected $_smtp_auth		= FALSE;
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var	bool
+	 */
 	protected $_replyto_flag	= FALSE;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see	CI_Email::print_debugger()
+	 * @var	string
+	 */
 	protected $_debug_msg		= array();
+
+	/**
+	 * Recipients
+	 *
+	 * @var	string[]
+	 */
 	protected $_recipients		= array();
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var	string[]
+	 */
 	protected $_cc_array		= array();
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var	string[]
+	 */
 	protected $_bcc_array		= array();
+
+	/**
+	 * Message headers
+	 *
+	 * @var	string[]
+	 */
 	protected $_headers		= array();
+
+	/**
+	 * Attachment data
+	 *
+	 * @var	array
+	 */
 	protected $_attachments		= array();
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see	CI_Email::$protocol
+	 * @var	string[]
+	 */
 	protected $_protocols		= array('mail', 'sendmail', 'smtp');
-	protected $_base_charsets	= array('us-ascii', 'iso-2022-');	// 7-bit charsets (excluding language suffix)
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var	string[]
+	 */
+	protected $_base_charsets	= array('us-ascii', 'iso-2022-');
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see	CI_Email::$_encoding
+	 * @var	string[]
+	 */
 	protected $_bit_depths		= array('7bit', '8bit');
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var	string[]
+	 */
 	protected $_priorities		= array('1 (Highest)', '2 (High)', '3 (Normal)', '4 (Low)', '5 (Lowest)');
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor - Sets Email Preferences
 	 *
@@ -771,7 +1057,7 @@ class CI_Email {
 		}
 
 		// Reduce multiple spaces
-		$str = preg_replace('| +|', ' ', $str);
+		$body = preg_replace('| +|', ' ', $body);
 
 		return ($this->wordwrap)
 			? $this->word_wrap($body, 76)
@@ -1446,11 +1732,14 @@ class CI_Email {
 	 */
 	protected function _send_with_sendmail()
 	{
-		$fp = @popen($this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From']).' -t'.' -r '.$this->clean_email($this->_headers['Return-Path']), 'w');
-
-		if ($fp === FALSE OR $fp === NULL)
+		// is popen() enabled?
+		if ( ! function_usable('popen')
+			OR FALSE === ($fp = @popen(
+						$this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From'])
+							.' -t -r '.$this->clean_email($this->_headers['Return-Path'])
+						, 'w'))
+		) // server probably has popen disabled, so nothing we can do to get a verbose error.
 		{
-			// server probably has popen disabled, so nothing we can do to get a verbose error.
 			return FALSE;
 		}
 
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index 73ab8ca7d..cdb0a6452 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Encryption Class
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index c1bf51935..e50eee4f2 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Form Validation Class
@@ -439,11 +440,10 @@ class CI_Form_validation {
 		// Load the language file containing error messages
 		$this->CI->lang->load('form_validation');
 
-		// Cycle through the rules for each field, match the
-		// corresponding $_POST item and test for errors
+		// Cycle through the rules for each field and match the corresponding $validation_data item
 		foreach ($this->_field_data as $field => $row)
 		{
-			// Fetch the data from the corresponding $_POST or validation array and cache it in the _field_data array.
+			// Fetch the data from the validation_data array item and cache it in the _field_data array.
 			// Depending on whether the field name is an array or a string will determine where we get it from.
 			if ($row['is_array'] === TRUE)
 			{
@@ -453,7 +453,13 @@ class CI_Form_validation {
 			{
 				$this->_field_data[$field]['postdata'] = $validation_array[$field];
 			}
+		}
 
+		// Execute validation rules
+		// Note: A second foreach (for now) is required in order to avoid false-positives
+		//	 for rules like 'matches', which correlate to other validation fields.
+		foreach ($this->_field_data as $field => $row)
+		{
 			// Don't try to validate if we have no rules set
 			if (empty($row['rules']))
 			{
@@ -1323,6 +1329,11 @@ class CI_Form_validation {
 	 */
 	public function prep_for_form($data = '')
 	{
+		if ($this->_safe_form_data === FALSE OR empty($data))
+		{
+			return $data;
+		}
+
 		if (is_array($data))
 		{
 			foreach ($data as $key => $val)
@@ -1333,11 +1344,6 @@ class CI_Form_validation {
 			return $data;
 		}
 
-		if ($this->_safe_form_data === FALSE OR $data === '')
-		{
-			return $data;
-		}
-
 		return str_replace(array("'", '"', '<', '>'), array('&#39;', '&quot;', '&lt;', '&gt;'), stripslashes($data));
 	}
 
diff --git a/system/libraries/Ftp.php b/system/libraries/Ftp.php
index ae85fdf37..60c03b5ad 100644
--- a/system/libraries/Ftp.php
+++ b/system/libraries/Ftp.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * FTP Class
@@ -36,18 +37,63 @@
  */
 class CI_FTP {
 
+	/**
+	 * FTP Server hostname
+	 *
+	 * @var	string
+	 */
 	public $hostname	= '';
+
+	/**
+	 * FTP Username
+	 *
+	 * @var	string
+	 */
 	public $username	= '';
+
+	/**
+	 * FTP Password
+	 *
+	 * @var	string
+	 */
 	public $password	= '';
+
+	/**
+	 * FTP Server port
+	 *
+	 * @var	int
+	 */
 	public $port		= 21;
+
+	/**
+	 * Passive mode flag
+	 *
+	 * @var	bool
+	 */
 	public $passive		= TRUE;
+
+	/**
+	 * Debug flag
+	 *
+	 * Specifies whether to display error messages.
+	 *
+	 * @var	bool
+	 */
 	public $debug		= FALSE;
+
+	/**
+	 * Connection
+	 *
+	 * @var	resource
+	 */
 	public $conn_id		= FALSE;
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	array	$config = array()
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function __construct($config = array())
@@ -65,7 +111,7 @@ class CI_FTP {
 	/**
 	 * Initialize preferences
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function initialize($config = array())
@@ -87,7 +133,7 @@ class CI_FTP {
 	/**
 	 * FTP Connect
 	 *
-	 * @param	array	 the connection values
+	 * @param	array	 $config	Connection values
 	 * @return	bool
 	 */
 	public function connect($config = array())
@@ -167,8 +213,8 @@ class CI_FTP {
 	 * so we do it by trying to change to a particular directory.
 	 * Internally, this parameter is only used by the "mirror" function below.
 	 *
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$path
+	 * @param	bool	$supress_debug
 	 * @return	bool
 	 */
 	public function changedir($path = '', $supress_debug = FALSE)
@@ -197,8 +243,8 @@ class CI_FTP {
 	/**
 	 * Create a directory
 	 *
-	 * @param	string
-	 * @param	int
+	 * @param	string	$path
+	 * @param	int	$permissions
 	 * @return	bool
 	 */
 	public function mkdir($path = '', $permissions = NULL)
@@ -233,10 +279,10 @@ class CI_FTP {
 	/**
 	 * Upload a file to the server
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	string
-	 * @param	int
+	 * @param	string	$locpath
+	 * @param	string	$rempath
+	 * @param	string	$mode
+	 * @param	int	$permissions
 	 * @return	bool
 	 */
 	public function upload($locpath, $rempath, $mode = 'auto', $permissions = NULL)
@@ -287,9 +333,9 @@ class CI_FTP {
 	/**
 	 * Download a file from a remote server to the local server
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	string
+	 * @param	string	$rempath
+	 * @param	string	$locpath
+	 * @param	string	$mode
 	 * @return	bool
 	 */
 	public function download($rempath, $locpath, $mode = 'auto')
@@ -328,9 +374,9 @@ class CI_FTP {
 	/**
 	 * Rename (or move) a file
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	bool
+	 * @param	string	$old_file
+	 * @param	string	$new_file
+	 * @param	bool	$move
 	 * @return	bool
 	 */
 	public function rename($old_file, $new_file, $move = FALSE)
@@ -359,8 +405,8 @@ class CI_FTP {
 	/**
 	 * Move a file
 	 *
-	 * @param	string
-	 * @param	string
+	 * @param	string	$old_file
+	 * @param	string	$new_file
 	 * @return	bool
 	 */
 	public function move($old_file, $new_file)
@@ -373,7 +419,7 @@ class CI_FTP {
 	/**
 	 * Rename (or move) a file
 	 *
-	 * @param	string
+	 * @param	string	$filepath
 	 * @return	bool
 	 */
 	public function delete_file($filepath)
@@ -403,7 +449,7 @@ class CI_FTP {
 	 * Delete a folder and recursively delete everything (including sub-folders)
 	 * containted within it.
 	 *
-	 * @param	string
+	 * @param	string	$filepath
 	 * @return	bool
 	 */
 	public function delete_dir($filepath)
@@ -450,8 +496,8 @@ class CI_FTP {
 	/**
 	 * Set file permissions
 	 *
-	 * @param	string	the file path
-	 * @param	int	the permissions
+	 * @param	string	$path	File path
+	 * @param	int	$perm	Permissions
 	 * @return	bool
 	 */
 	public function chmod($path, $perm)
@@ -480,7 +526,7 @@ class CI_FTP {
 	/**
 	 * FTP List files in the specified directory
 	 *
-	 * @param	string	$path = '.'
+	 * @param	string	$path
 	 * @return	array
 	 */
 	public function list_files($path = '.')
@@ -503,8 +549,8 @@ class CI_FTP {
 	 * Whatever the directory structure of the original file path will be
 	 * recreated on the server.
 	 *
-	 * @param	string	path to source with trailing slash
-	 * @param	string	path to destination - include the base folder with trailing slash
+	 * @param	string	$locpath	Path to source with trailing slash
+	 * @param	string	$rempath	Path to destination - include the base folder with trailing slash
 	 * @return	bool
 	 */
 	public function mirror($locpath, $rempath)
@@ -550,7 +596,7 @@ class CI_FTP {
 	/**
 	 * Extract the file extension
 	 *
-	 * @param	string
+	 * @param	string	$filename
 	 * @return	string
 	 */
 	protected function _getext($filename)
@@ -569,7 +615,7 @@ class CI_FTP {
 	/**
 	 * Set the upload type
 	 *
-	 * @param	string
+	 * @param	string	$ext	Filename extension
 	 * @return	string
 	 */
 	protected function _settype($ext)
@@ -616,7 +662,7 @@ class CI_FTP {
 	/**
 	 * Display error message
 	 *
-	 * @param	string
+	 * @param	string	$line
 	 * @return	void
 	 */
 	protected function _error($line)
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index ef4187847..9379e3ec8 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Image Manipulation class
@@ -866,7 +867,11 @@ class CI_Image_lib {
 		}
 
 		$retval = 1;
-		@exec($cmd, $output, $retval);
+		// exec() might be disabled
+		if (function_usable('exec'))
+		{
+			@exec($cmd, $output, $retval);
+		}
 
 		// Did it work?
 		if ($retval > 0)
@@ -946,7 +951,11 @@ class CI_Image_lib {
 		$cmd = $this->library_path.$cmd_in.' '.$this->full_src_path.' | '.$cmd_inner.' | '.$cmd_out.' > '.$this->dest_folder.'netpbm.tmp';
 
 		$retval = 1;
-		@exec($cmd, $output, $retval);
+		// exec() might be disabled
+		if (function_usable('exec'))
+		{
+			@exec($cmd, $output, $retval);
+		}
 
 		// Did it work?
 		if ($retval > 0)
@@ -958,7 +967,7 @@ class CI_Image_lib {
 		// With NetPBM we have to create a temporary image.
 		// If you try manipulating the original it fails so
 		// we have to rename the temp file.
-		copy ($this->dest_folder.'netpbm.tmp', $this->full_dst_path);
+		copy($this->dest_folder.'netpbm.tmp', $this->full_dst_path);
 		unlink($this->dest_folder.'netpbm.tmp');
 		@chmod($this->full_dst_path, FILE_WRITE_MODE);
 
diff --git a/system/libraries/Javascript.php b/system/libraries/Javascript.php
index 60309cd83..9a15cddaa 100644
--- a/system/libraries/Javascript.php
+++ b/system/libraries/Javascript.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Javascript Class
@@ -36,12 +37,19 @@
  */
 class CI_Javascript {
 
+	/**
+	 * JavaScript location
+	 *
+	 * @var	string
+	 */
 	protected $_javascript_location = 'js';
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	array	$params = array()
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params = array())
@@ -586,8 +594,8 @@ class CI_Javascript {
 	 *
 	 * gather together all script needing to be output
 	 *
-	 * @param	string	$view_var = 'script_foot'
-	 * @param	bool	$script_tags = TRUE
+	 * @param	string	$view_var
+	 * @param	bool	$script_tags
 	 * @return	string
 	 */
 	public function compile($view_var = 'script_foot', $script_tags = TRUE)
@@ -616,8 +624,8 @@ class CI_Javascript {
 	 *
 	 * Outputs a <script> tag with the source as an external js file
 	 *
-	 * @param	string	$external_file = ''
-	 * @param	bool	$relative = FALSE
+	 * @param	string	$external_file
+	 * @param	bool	$relative
 	 * @return	string
 	 */
 	public function external($external_file = '', $relative = FALSE)
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index f67725c18..275aeb048 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 3.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Migration Class
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index 36b57b332..ae8dba072 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Pagination Class
@@ -36,46 +37,269 @@
  */
 class CI_Pagination {
 
-	protected $base_url				= ''; // The page we are linking to
-	protected $prefix				= ''; // A custom prefix added to the path.
-	protected $suffix				= ''; // A custom suffix added to the path.
-	protected $total_rows			= 0; // Total number of items (database results)
-	protected $per_page				= 10; // Max number of items you want shown per page
-	protected $num_links			= 2; // Number of "digit" links to show before/after the currently viewed page
-	protected $cur_page				= 0; // The current page being viewed
-	protected $use_page_numbers		= FALSE; // Use page number for segment instead of offset
-	protected $first_link			= '&lsaquo; First';
-	protected $next_link			= '&gt;';
-	protected $prev_link			= '&lt;';
-	protected $last_link			= 'Last &rsaquo;';
-	protected $uri_segment			= 3;
-	protected $full_tag_open		= '';
-	protected $full_tag_close		= '';
-	protected $first_tag_open		= '';
-	protected $first_tag_close		= '';
-	protected $last_tag_open		= '';
-	protected $last_tag_close		= '';
-	protected $first_url			= ''; // Alternative URL for the First Page.
-	protected $cur_tag_open			= '<strong>';
-	protected $cur_tag_close		= '</strong>';
-	protected $next_tag_open		= '';
-	protected $next_tag_close		= '';
-	protected $prev_tag_open		= '';
-	protected $prev_tag_close		= '';
-	protected $num_tag_open			= '';
-	protected $num_tag_close		= '';
+	/**
+	 * Base URL
+	 *
+	 * The page that we're linking to
+	 *
+	 * @var	string
+	 */
+	protected $base_url		= '';
+
+	/**
+	 * Prefix
+	 *
+	 * @var	string
+	 */
+	protected $prefix		= '';
+
+	/**
+	 * Suffix
+	 *
+	 * @var	string
+	 */
+	protected $suffix		= '';
+
+	/**
+	 * Total number of items
+	 *
+	 * @var	int
+	 */
+	protected $total_rows		= 0;
+
+	/**
+	 * Items per page
+	 *
+	 * @var	int
+	 */
+	protected $per_page		= 10;
+
+	/**
+	 * Number of links to show
+	 *
+	 * Relates to "digit" type links shown before/after
+	 * the currently viewed page.
+	 *
+	 * @var	int
+	 */
+	protected $num_links		= 2;
+
+	/**
+	 * Current page
+	 *
+	 * @var	int
+	 */
+	protected $cur_page		= 0;
+
+	/**
+	 * Use page numbers flag
+	 *
+	 * Whether to use actual page numbers instead of an offset
+	 *
+	 * @var	bool
+	 */
+	protected $use_page_numbers	= FALSE;
+
+	/**
+	 * First link
+	 *
+	 * @var	string
+	 */
+	protected $first_link		= '&lsaquo; First';
+
+	/**
+	 * Next link
+	 *
+	 * @var	string
+	 */
+	protected $next_link		= '&gt;';
+
+	/**
+	 * Previous link
+	 *
+	 * @var	string
+	 */
+	protected $prev_link		= '&lt;';
+
+	/**
+	 * Last link
+	 *
+	 * @var	string
+	 */
+	protected $last_link		= 'Last &rsaquo;';
+
+	/**
+	 * URI Segment
+	 *
+	 * @var	int
+	 */
+	protected $uri_segment		= 3;
+
+	/**
+	 * Full tag open
+	 *
+	 * @var	string
+	 */
+	protected $full_tag_open	= '';
+
+	/**
+	 * Full tag close
+	 *
+	 * @var	string
+	 */
+	protected $full_tag_close	= '';
+
+	/**
+	 * First tag open
+	 *
+	 * @var	string
+	 */
+	protected $first_tag_open	= '';
+
+	/**
+	 * First tag close
+	 *
+	 * @var	string
+	 */
+	protected $first_tag_close	= '';
+
+	/**
+	 * Last tag open
+	 *
+	 * @var	string
+	 */
+	protected $last_tag_open	= '';
+
+	/**
+	 * Last tag close
+	 *
+	 * @var	string
+	 */
+	protected $last_tag_close	= '';
+
+	/**
+	 * First URL
+	 *
+	 * An alternative URL for the first page
+	 *
+	 * @var	string
+	 */
+	protected $first_url		= '';
+
+	/**
+	 * Current tag open
+	 *
+	 * @var	string
+	 */
+	protected $cur_tag_open		= '<strong>';
+
+	/**
+	 * Current tag close
+	 *
+	 * @var	string
+	 */
+	protected $cur_tag_close	= '</strong>';
+
+	/**
+	 * Next tag open
+	 *
+	 * @var	string
+	 */
+	protected $next_tag_open	= '';
+
+	/**
+	 * Next tag close
+	 *
+	 * @var	string
+	 */
+	protected $next_tag_close	= '';
+
+	/**
+	 * Previous tag open
+	 *
+	 * @var	string
+	 */
+	protected $prev_tag_open	= '';
+
+	/**
+	 * Previous tag close
+	 *
+	 * @var	string
+	 */
+	protected $prev_tag_close	= '';
+
+	/**
+	 * Number tag open
+	 *
+	 * @var	string
+	 */
+	protected $num_tag_open		= '';
+
+	/**
+	 * Number tag close
+	 *
+	 * @var	string
+	 */
+	protected $num_tag_close	= '';
+
+	/**
+	 * Page query string flag
+	 *
+	 * @var	bool
+	 */
 	protected $page_query_string	= FALSE;
+
+	/**
+	 * Query string segment
+	 *
+	 * @var	string
+	 */
 	protected $query_string_segment = 'per_page';
-	protected $display_pages		= TRUE;
-	protected $_attributes			= '';
-	protected $_link_types			= array();
+
+	/**
+	 * Display pages flag
+	 *
+	 * @var	bool
+	 */
+	protected $display_pages	= TRUE;
+
+	/**
+	 * Attributes
+	 *
+	 * @var	string
+	 */
+	protected $_attributes		= '';
+
+	/**
+	 * Link types
+	 *
+	 * "rel" attribute
+	 *
+	 * @see	CI_Pagination::_attr_rel()
+	 * @var	array
+	 */
+	protected $_link_types		= array();
+
+	/**
+	 * Reuse query string flag
+	 *
+	 * @var	bool
+	 */
 	protected $reuse_query_string   = FALSE;
-	protected $data_page_attr		= 'data-ci-pagination-page';
+
+	/**
+	 * Data page attribute
+	 *
+	 * @var	string
+	 */
+	protected $data_page_attr	= 'data-ci-pagination-page';
+
+	// --------------------------------------------------------------------
 
 	/**
 	 * Constructor
 	 *
-	 * @param	array	initialization parameters
+	 * @param	array	$params	Initialization parameters
 	 * @return	void
 	 */
 	public function __construct($params = array())
@@ -89,7 +313,7 @@ class CI_Pagination {
 	/**
 	 * Initialize Preferences
 	 *
-	 * @param	array	initialization parameters
+	 * @param	array	$params	Initialization parameters
 	 * @return	void
 	 */
 	public function initialize($params = array())
@@ -352,7 +576,7 @@ class CI_Pagination {
 	/**
 	 * Parse attributes
 	 *
-	 * @param	array
+	 * @param	array	$attributes
 	 * @return	void
 	 */
 	protected function _parse_attributes($attributes)
@@ -376,7 +600,7 @@ class CI_Pagination {
 	 * Add "rel" attribute
 	 *
 	 * @link	http://www.w3.org/TR/html5/links.html#linkTypes
-	 * @param	string
+	 * @param	string	$type
 	 * @return	string
 	 */
 	protected function _attr_rel($type)
diff --git a/system/libraries/Parser.php b/system/libraries/Parser.php
index b64c78254..d29eede02 100644
--- a/system/libraries/Parser.php
+++ b/system/libraries/Parser.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Parser Class
diff --git a/system/libraries/Profiler.php b/system/libraries/Profiler.php
index 1e961f6df..1c97e3481 100644
--- a/system/libraries/Profiler.php
+++ b/system/libraries/Profiler.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Profiler Class
@@ -74,12 +75,14 @@ class CI_Profiler {
 	 */
 	protected $CI;
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Initialize Profiler
 	 *
-	 * @param array $config
+	 * @param	array	$config	Parameters
 	 */
 	public function __construct($config = array())
 	{
@@ -111,7 +114,7 @@ class CI_Profiler {
 	 *
 	 * Sets the private _compile_* properties to enable/disable Profiler sections
 	 *
-	 * @param	mixed
+	 * @param	mixed	$config
 	 * @return	void
 	 */
 	public function set_sections($config)
@@ -190,11 +193,24 @@ class CI_Profiler {
 		$dbs = array();
 
 		// Let's determine which databases are currently connected to
-		foreach (get_object_vars($this->CI) as $CI_object)
+		foreach (get_object_vars($this->CI) as $name => $cobject)
 		{
-			if (is_object($CI_object) && is_subclass_of(get_class($CI_object), 'CI_DB'))
+			if (is_object($cobject))
 			{
-				$dbs[] = $CI_object;
+				if ($cobject instanceof CI_DB)
+				{
+					$dbs[get_class($this->CI).':$'.$name] = $cobject;
+				}
+				elseif ($cobject instanceof CI_Model)
+				{
+					foreach (get_object_vars($cobject) as $mname => $mobject)
+					{
+						if ($mobject instanceof CI_DB)
+						{
+							$dbs[get_class($cobject).':$'.$mname] = $mobject;
+						}
+					}
+				}
 			}
 		}
 
@@ -219,7 +235,7 @@ class CI_Profiler {
 		$output  = "\n\n";
 		$count = 0;
 
-		foreach ($dbs as $db)
+		foreach ($dbs as $name => $db)
 		{
 			$hide_queries = (count($db->queries) > $this->_query_toggle_count) ? ' display:none' : '';
 
@@ -233,7 +249,7 @@ class CI_Profiler {
 			$output .= '<fieldset style="border:1px solid #0000FF;padding:6px 10px 10px 10px;margin:20px 0 20px 0;background-color:#eee;">'
 				."\n"
 				.'<legend style="color:#0000FF;">&nbsp;&nbsp;'.$this->CI->lang->line('profiler_database')
-				.':&nbsp; '.$db->database.'&nbsp;&nbsp;&nbsp;'.$this->CI->lang->line('profiler_queries')
+				.':&nbsp; '.$db->database.' ('.$name.')&nbsp;&nbsp;&nbsp;'.$this->CI->lang->line('profiler_queries')
 				.': '.count($db->queries).'&nbsp;&nbsp;'.$show_hide_js."</legend>\n\n\n"
 				.'<table style="width:100%;'.$hide_queries.'" id="ci_profiler_queries_db_'.$count."\">\n";
 
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index fec9b5b31..96e65f154 100755
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -18,12 +18,13 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 2.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * CodeIgniter Session Class
@@ -51,10 +52,29 @@
  */
 class CI_Session extends CI_Driver_Library {
 
+	/**
+	 * Initialization parameters
+	 *
+	 * @var	array
+	 */
 	public $params = array();
+
+	/**
+	 * Current driver in use
+	 *
+	 * @var	string
+	 */
 	protected $current = NULL;
+
+	/**
+	 * User data
+	 *
+	 * @var	array
+	 */
 	protected $userdata = array();
 
+	// ------------------------------------------------------------------------
+
 	const FLASHDATA_KEY = 'flash';
 	const FLASHDATA_NEW = ':new:';
 	const FLASHDATA_OLD = ':old:';
@@ -62,6 +82,8 @@ class CI_Session extends CI_Driver_Library {
 	const EXPIRATION_KEY = '__expirations';
 	const TEMP_EXP_DEF = 300;
 
+	// ------------------------------------------------------------------------
+
 	/**
 	 * CI_Session constructor
 	 *
@@ -506,7 +528,7 @@ class CI_Session extends CI_Driver_Library {
 		foreach ($this->all_userdata() as $name => $value)
 		{
 			$parts = explode(self::FLASHDATA_NEW, $name);
-			if (is_array($parts) && count($parts) === 2)
+			if (count($parts) === 2)
 			{
 				$new_name = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1];
 				$this->set_userdata($new_name, $value);
@@ -595,8 +617,16 @@ class CI_Session extends CI_Driver_Library {
  */
 abstract class CI_Session_driver extends CI_Driver {
 
+	/**
+	 * CI Singleton
+	 *
+	 * @see	get_instance()
+	 * @var	object
+	 */
 	protected $CI;
 
+	// ------------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
diff --git a/system/libraries/Session/drivers/Session_cookie.php b/system/libraries/Session/drivers/Session_cookie.php
index 2f1bf3531..3c4848265 100755
--- a/system/libraries/Session/drivers/Session_cookie.php
+++ b/system/libraries/Session/drivers/Session_cookie.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -9,7 +9,7 @@
  * 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
+ * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
  * http://opensource.org/licenses/OSL-3.0
  * If you did not receive a copy of the license and are unable to obtain it
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Cookie-based session management driver
@@ -540,11 +541,25 @@ class CI_Session_cookie extends CI_Session_driver {
 		// Check for database
 		if ($this->sess_use_database === TRUE)
 		{
+			$this->CI->db->where('session_id', $old_sessid);
+
+			if ($this->sess_match_ip === TRUE)
+			{
+				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
+			}
+
+			if ($this->sess_match_useragent === TRUE)
+			{
+				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
+			}
+
 			// Update the session ID and last_activity field in the DB
-			$this->CI->db->update($this->sess_table_name, array(
-					 'last_activity' => $this->now,
-					 'session_id' => $this->userdata['session_id']
-			), array('session_id' => $old_sessid));
+			$this->CI->db->update($this->sess_table_name,
+				array(
+					'last_activity' => $this->now,
+					'session_id' => $this->userdata['session_id']
+				)
+			);
 		}
 
 		// Write the cookie
@@ -590,7 +605,19 @@ class CI_Session_cookie extends CI_Session_driver {
 			// Run the update query
 			// Any time we change the session id, it gets updated immediately,
 			// so our where clause below is always safe
-			$this->CI->db->update($this->sess_table_name, $set, array('session_id' => $this->userdata['session_id']));
+			$this->CI->db->where('session_id', $this->userdata['session_id']);
+
+			if ($this->sess_match_ip === TRUE)
+			{
+				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
+			}
+
+			if ($this->sess_match_useragent === TRUE)
+			{
+				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
+			}
+
+			$this->CI->db->update($this->sess_table_name, $set);
 
 			// Clear dirty flag to prevent double updates
 			$this->data_dirty = FALSE;
diff --git a/system/libraries/Session/drivers/Session_native.php b/system/libraries/Session/drivers/Session_native.php
index a837b89f6..3e700ad5d 100755
--- a/system/libraries/Session/drivers/Session_native.php
+++ b/system/libraries/Session/drivers/Session_native.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -9,7 +9,7 @@
  * 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
+ * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
  * http://opensource.org/licenses/OSL-3.0
  * If you did not receive a copy of the license and are unable to obtain it
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Native PHP session management driver
diff --git a/system/libraries/Table.php b/system/libraries/Table.php
index 0f8404d85..886fb6581 100644
--- a/system/libraries/Table.php
+++ b/system/libraries/Table.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.3.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * HTML Table Generating Class
diff --git a/system/libraries/Trackback.php b/system/libraries/Trackback.php
index 7bd7cba04..c923a6220 100644
--- a/system/libraries/Trackback.php
+++ b/system/libraries/Trackback.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Trackback Class
@@ -38,12 +39,45 @@
  */
 class CI_Trackback {
 
-	public $time_format	= 'local';
+	/**
+	 * Character set
+	 *
+	 * @var	string
+	 */
 	public $charset		= 'UTF-8';
-	public $data			= array('url' => '', 'title' => '', 'excerpt' => '', 'blog_name' => '', 'charset' => '');
+
+	/**
+	 * Trackback data
+	 *
+	 * @var	array
+	 */
+	public $data		= array('url' => '', 'title' => '', 'excerpt' => '', 'blog_name' => '', 'charset' => '');
+
+	/**
+	 * Convert ASCII flag
+	 *
+	 * Whether to convert high-ASCII and MS Word
+	 * characters to HTML entities.
+	 *
+	 * @var	bool
+	 */
 	public $convert_ascii	= TRUE;
-	public $response		= '';
-	public $error_msg		= array();
+
+	/**
+	 * Response
+	 *
+	 * @var	string
+	 */
+	public $response	= '';
+
+	/**
+	 * Error messages list
+	 *
+	 * @var	string[]
+	 */
+	public $error_msg	= array();
+
+	// --------------------------------------------------------------------
 
 	/**
 	 * Constructor
diff --git a/system/libraries/Typography.php b/system/libraries/Typography.php
index a50934f2c..d83bf519b 100644
--- a/system/libraries/Typography.php
+++ b/system/libraries/Typography.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Typography Class
diff --git a/system/libraries/Unit_test.php b/system/libraries/Unit_test.php
index 7b99dee0d..842b4aebd 100644
--- a/system/libraries/Unit_test.php
+++ b/system/libraries/Unit_test.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.3.1
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Unit Testing Class
@@ -38,13 +39,52 @@
  */
 class CI_Unit_test {
 
+	/**
+	 * Active flag
+	 *
+	 * @var	bool
+	 */
 	public $active			= TRUE;
+
+	/**
+	 * Test results
+	 *
+	 * @var	array
+	 */
 	public $results			= array();
+
+	/**
+	 * Strict comparison flag
+	 *
+	 * Whether to use === or == when comparing
+	 *
+	 * @var	bool
+	 */
 	public $strict			= FALSE;
+
+	/**
+	 * Template
+	 *
+	 * @var	string
+	 */
 	protected $_template		= NULL;
+
+	/**
+	 * Template rows
+	 *
+	 * @var	string
+	 */
 	protected $_template_rows	= NULL;
+
+	/**
+	 * List of visible test items
+	 *
+	 * @var	array
+	 */
 	protected $_test_items_visible	= array();
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
@@ -92,9 +132,9 @@ class CI_Unit_test {
 	 * Runs the supplied tests
 	 *
 	 * @param	mixed	$test
-	 * @param	mixed	$expected = TRUE
-	 * @param	string	$test_name = 'undefined'
-	 * @param	string	$notes = ''
+	 * @param	mixed	$expected
+	 * @param	string	$test_name
+	 * @param	string	$notes
 	 * @return	string
 	 */
 	public function run($test, $expected = TRUE, $test_name = 'undefined', $notes = '')
@@ -112,13 +152,13 @@ class CI_Unit_test {
 		}
 		else
 		{
-			$result = ($this->strict === TRUE) ? ($test === $expected) : ($test === $expected);
+			$result = ($this->strict === TRUE) ? ($test === $expected) : ($test == $expected);
 			$extype = gettype($expected);
 		}
 
 		$back = $this->_backtrace();
 
-		$report[] = array (
+		$report = array (
 							'test_name'			=> $test_name,
 							'test_datatype'		=> gettype($test),
 							'res_datatype'		=> $extype,
@@ -130,7 +170,7 @@ class CI_Unit_test {
 
 		$this->results[] = $report;
 
-		return $this->report($this->result($report));
+		return $this->report($this->result(array($report)));
 	}
 
 	// --------------------------------------------------------------------
@@ -140,7 +180,7 @@ class CI_Unit_test {
 	 *
 	 * Displays a table with the test data
 	 *
-	 * @param	array	 $result = array()
+	 * @param	array	 $result
 	 * @return	string
 	 */
 	public function report($result = array())
@@ -220,7 +260,7 @@ class CI_Unit_test {
 	 *
 	 * Returns the raw result data
 	 *
-	 * @param	array	$results = array()
+	 * @param	array	$results
 	 * @return	array
 	 */
 	public function result($results = array())
@@ -244,30 +284,11 @@ class CI_Unit_test {
 					continue;
 				}
 
-				if (is_array($val))
-				{
-					foreach ($val as $k => $v)
-					{
-						if ( ! in_array($k, $this->_test_items_visible))
-						{
-							continue;
-						}
-
-						if (FALSE !== ($line = $CI->lang->line(strtolower('ut_'.$v))))
-						{
-							$v = $line;
-						}
-						$temp[$CI->lang->line('ut_'.$k)] = $v;
-					}
-				}
-				else
+				if (FALSE !== ($line = $CI->lang->line(strtolower('ut_'.$val))))
 				{
-					if (FALSE !== ($line = $CI->lang->line(strtolower('ut_'.$val))))
-					{
-						$val = $line;
-					}
-					$temp[$CI->lang->line('ut_'.$key)] = $val;
+					$val = $line;
 				}
+				$temp[$CI->lang->line('ut_'.$key)] = $val;
 			}
 
 			$retval[] = $temp;
@@ -375,4 +396,4 @@ function is_false($test)
 }
 
 /* End of file Unit_test.php */
-/* Location: ./system/libraries/Unit_test.php */
\ No newline at end of file
+/* Location: ./system/libraries/Unit_test.php */
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 76bbc244e..b3e9f7515 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * File Uploading Class
@@ -36,40 +37,210 @@
  */
 class CI_Upload {
 
+	/**
+	 * Maximum file size
+	 *
+	 * @var	int
+	 */
 	public $max_size		= 0;
+
+	/**
+	 * Maximum image width
+	 *
+	 * @var	int
+	 */
 	public $max_width		= 0;
+
+	/**
+	 * Maximum image height
+	 *
+	 * @var	int
+	 */
 	public $max_height		= 0;
+
+	/**
+	 * Maximum filename length
+	 *
+	 * @var	int
+	 */
 	public $max_filename		= 0;
+
+	/**
+	 * Maximum duplicate filename increment ID
+	 *
+	 * @var	int
+	 */
 	public $max_filename_increment 	= 100;
+
+	/**
+	 * Allowed file types
+	 *
+	 * @var	string
+	 */
 	public $allowed_types		= '';
+
+	/**
+	 * Temporary filename
+	 *
+	 * @var	string
+	 */
 	public $file_temp		= '';
+
+	/**
+	 * Filename
+	 *
+	 * @var	string
+	 */
 	public $file_name		= '';
+
+	/**
+	 * Original filename
+	 *
+	 * @var	string
+	 */
 	public $orig_name		= '';
+
+	/**
+	 * File type
+	 *
+	 * @var	string
+	 */
 	public $file_type		= '';
-	public $file_size		= '';
+
+	/**
+	 * File size
+	 *
+	 * @var	int
+	 */
+	public $file_size		= NULL;
+
+	/**
+	 * Filename extension
+	 *
+	 * @var	string
+	 */
 	public $file_ext		= '';
+
+	/**
+	 * Upload path
+	 *
+	 * @var	string
+	 */
 	public $upload_path		= '';
+
+	/**
+	 * Overwrite flag
+	 *
+	 * @var	bool
+	 */
 	public $overwrite		= FALSE;
+
+	/**
+	 * Obfuscate filename flag
+	 *
+	 * @var	bool
+	 */
 	public $encrypt_name		= FALSE;
+
+	/**
+	 * Is image flag
+	 *
+	 * @var	bool
+	 */
 	public $is_image		= FALSE;
-	public $image_width		= '';
-	public $image_height		= '';
+
+	/**
+	 * Image width
+	 *
+	 * @var	int
+	 */
+	public $image_width		= NULL;
+
+	/**
+	 * Image height
+	 *
+	 * @var	int
+	 */
+	public $image_height		= NULL;
+
+	/**
+	 * Image type
+	 *
+	 * @var	string
+	 */
 	public $image_type		= '';
+
+	/**
+	 * Image size string
+	 *
+	 * @var	string
+	 */
 	public $image_size_str		= '';
+
+	/**
+	 * Error messages list
+	 *
+	 * @var	array
+	 */
 	public $error_msg		= array();
+
+	/**
+	 * MIME types list
+	 *
+	 * @var	array
+	 */
 	public $mimes			= array();
+
+	/**
+	 * Remove spaces flag
+	 *
+	 * @var	bool
+	 */
 	public $remove_spaces		= TRUE;
+
+	/**
+	 * MIME detection flag
+	 *
+	 * @var	bool
+	 */
 	public $detect_mime		= TRUE;
+
+	/**
+	 * XSS filter flag
+	 *
+	 * @var	bool
+	 */
 	public $xss_clean		= FALSE;
+
+	/**
+	 * Temporary filename prefix
+	 *
+	 * @var	string
+	 */
 	public $temp_prefix		= 'temp_file_';
+
+	/**
+	 * Filename sent by the client
+	 *
+	 * @var	bool
+	 */
 	public $client_name		= '';
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Filename override
+	 *
+	 * @var	string
+	 */
 	protected $_file_name_override	= '';
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	array
+	 * @param	array	$props
 	 * @return	void
 	 */
 	public function __construct($props = array())
@@ -89,7 +260,7 @@ class CI_Upload {
 	/**
 	 * Initialize preferences
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function initialize($config = array())
@@ -105,14 +276,14 @@ class CI_Upload {
 					'file_name'			=> '',
 					'orig_name'			=> '',
 					'file_type'			=> '',
-					'file_size'			=> '',
+					'file_size'			=> NULL,
 					'file_ext'			=> '',
 					'upload_path'			=> '',
 					'overwrite'			=> FALSE,
 					'encrypt_name'			=> FALSE,
 					'is_image'			=> FALSE,
-					'image_width'			=> '',
-					'image_height'			=> '',
+					'image_width'			=> NULL,
+					'image_height'			=> NULL,
 					'image_type'			=> '',
 					'image_size_str'		=> '',
 					'error_msg'			=> array(),
@@ -154,7 +325,7 @@ class CI_Upload {
 	/**
 	 * Perform the file upload
 	 *
-	 * @param	string	$field = 'userfile'
+	 * @param	string	$field
 	 * @return	bool
 	 */
 	public function do_upload($field = 'userfile')
@@ -356,7 +527,7 @@ class CI_Upload {
 	 * Returns an associative array containing all of the information
 	 * related to the upload, allowing the developer easy access in one array.
 	 *
-	 * @param	string
+	 * @param	string	$index
 	 * @return	mixed
 	 */
 	public function data($index = NULL)
@@ -391,7 +562,7 @@ class CI_Upload {
 	/**
 	 * Set Upload Path
 	 *
-	 * @param	string
+	 * @param	string	$path
 	 * @return	void
 	 */
 	public function set_upload_path($path)
@@ -409,8 +580,8 @@ class CI_Upload {
 	 * existence of a file with the same name. If found, it will append a
 	 * number to the end of the filename to avoid overwriting a pre-existing file.
 	 *
-	 * @param	string
-	 * @param	string
+	 * @param	string	$path
+	 * @param	string	$filename
 	 * @return	string
 	 */
 	public function set_filename($path, $filename)
@@ -454,7 +625,7 @@ class CI_Upload {
 	/**
 	 * Set Maximum File Size
 	 *
-	 * @param	int
+	 * @param	int	$n
 	 * @return	void
 	 */
 	public function set_max_filesize($n)
@@ -467,7 +638,7 @@ class CI_Upload {
 	/**
 	 * Set Maximum File Name Length
 	 *
-	 * @param	int
+	 * @param	int	$n
 	 * @return	void
 	 */
 	public function set_max_filename($n)
@@ -480,7 +651,7 @@ class CI_Upload {
 	/**
 	 * Set Maximum Image Width
 	 *
-	 * @param	int
+	 * @param	int	$n
 	 * @return	void
 	 */
 	public function set_max_width($n)
@@ -493,7 +664,7 @@ class CI_Upload {
 	/**
 	 * Set Maximum Image Height
 	 *
-	 * @param	int
+	 * @param	int	$n
 	 * @return	void
 	 */
 	public function set_max_height($n)
@@ -506,7 +677,7 @@ class CI_Upload {
 	/**
 	 * Set Allowed File Types
 	 *
-	 * @param	string
+	 * @param	string	$types
 	 * @return	void
 	 */
 	public function set_allowed_types($types)
@@ -526,7 +697,7 @@ class CI_Upload {
 	 *
 	 * Uses GD to determine the width/height/type of image
 	 *
-	 * @param	string
+	 * @param	string	$path
 	 * @return	void
 	 */
 	public function set_image_properties($path = '')
@@ -558,7 +729,7 @@ class CI_Upload {
 	 * Enables the XSS flag so that the file that was uploaded
 	 * will be run through the XSS filter.
 	 *
-	 * @param	bool
+	 * @param	bool	$flag
 	 * @return	void
 	 */
 	public function set_xss_clean($flag = FALSE)
@@ -600,7 +771,7 @@ class CI_Upload {
 	/**
 	 * Verify that the filetype is allowed
 	 *
-	 * @param	bool
+	 * @param	bool	$ignore_mime
 	 * @return	bool
 	 */
 	public function is_allowed_filetype($ignore_mime = FALSE)
@@ -737,7 +908,7 @@ class CI_Upload {
 	/**
 	 * Extract the file extension
 	 *
-	 * @param	string
+	 * @param	string	$filename
 	 * @return	string
 	 */
 	public function get_extension($filename)
@@ -751,7 +922,7 @@ class CI_Upload {
 	/**
 	 * Clean the file name for security
 	 *
-	 * @param	string
+	 * @param	string	$filename
 	 * @return	string
 	 */
 	public function clean_file_name($filename)
@@ -885,7 +1056,7 @@ class CI_Upload {
 	/**
 	 * Set an error message
 	 *
-	 * @param	string
+	 * @param	string	$msg
 	 * @return	void
 	 */
 	public function set_error($msg)
@@ -915,8 +1086,8 @@ class CI_Upload {
 	/**
 	 * Display the error message
 	 *
-	 * @param	string
-	 * @param	string
+	 * @param	string	$open
+	 * @param	string	$close
 	 * @return	string
 	 */
 	public function display_errors($open = '<p>', $close = '</p>')
@@ -932,7 +1103,7 @@ class CI_Upload {
 	 * This is a list of mime types. We use it to validate
 	 * the "allowed types" set by the developer
 	 *
-	 * @param	string
+	 * @param	string	$mime
 	 * @return	string
 	 */
 	public function mimes_types($mime)
@@ -945,10 +1116,12 @@ class CI_Upload {
 	/**
 	 * Prep Filename
 	 *
-	 * Prevents possible script execution from Apache's handling of files multiple extensions
-	 * http://httpd.apache.org/docs/1.3/mod/mod_mime.html#multipleext
+	 * Prevents possible script execution from Apache's handling
+	 * of files' multiple extensions.
+	 *
+	 * @link	http://httpd.apache.org/docs/1.3/mod/mod_mime.html#multipleext
 	 *
-	 * @param	string
+	 * @param	string	$filename
 	 * @return	string
 	 */
 	protected function _prep_filename($filename)
@@ -985,7 +1158,7 @@ class CI_Upload {
 	 * Detects the (actual) MIME type of the uploaded file, if possible.
 	 * The input array is expected to be $_FILES[$field]
 	 *
-	 * @param	array
+	 * @param	array	$file
 	 * @return	void
 	 */
 	protected function _file_mime_type($file)
@@ -1035,7 +1208,7 @@ class CI_Upload {
 				? 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1'
 				: 'file --brief --mime '.$file['tmp_name'].' 2>&1';
 
-			if (function_exists('exec'))
+			if (function_usable('exec'))
 			{
 				/* This might look confusing, as $mime is being populated with all of the output when set in the second parameter.
 				 * However, we only neeed the last line, which is the actual return value of exec(), and as such - it overwrites
@@ -1050,7 +1223,7 @@ class CI_Upload {
 				}
 			}
 
-			if ( (bool) @ini_get('safe_mode') === FALSE && function_exists('shell_exec'))
+			if ( (bool) @ini_get('safe_mode') === FALSE && function_usable('shell_exec'))
 			{
 				$mime = @shell_exec($cmd);
 				if (strlen($mime) > 0)
@@ -1064,7 +1237,7 @@ class CI_Upload {
 				}
 			}
 
-			if (function_exists('popen'))
+			if (function_usable('popen'))
 			{
 				$proc = @popen($cmd, 'r');
 				if (is_resource($proc))
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index 3387d4aa6..e920578d9 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * User Agent Class
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index 3ed050a2e..3ef823e29 100755
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,14 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+if ( ! function_exists('xml_parser_create'))
+{
+	show_error('Your PHP installation does not support XML');
+}
+
+// ------------------------------------------------------------------------
 
 /**
  * XML-RPC request handler class
@@ -34,56 +42,212 @@
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
-
-if ( ! function_exists('xml_parser_create'))
-{
-	show_error('Your PHP installation does not support XML');
-}
-
-// ------------------------------------------------------------------------
-
 class CI_Xmlrpc {
 
-	public $debug		= FALSE;	// Debugging on or off
+	/**
+	 * Debug flag
+	 *
+	 * @var	bool
+	 */
+	public $debug		= FALSE;
+
+	/**
+	 * I4 data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcI4	= 'i4';
+
+	/**
+	 * Integer data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcInt	= 'int';
+
+	/**
+	 * Boolean data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcBoolean	= 'boolean';
+
+	/**
+	 * Double data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcDouble	= 'double';
+
+	/**
+	 * String data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcString	= 'string';
+
+	/**
+	 * DateTime format
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcDateTime	= 'dateTime.iso8601';
+
+	/**
+	 * Base64 data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcBase64	= 'base64';
+
+	/**
+	 * Array data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcArray	= 'array';
+
+	/**
+	 * Struct data type
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcStruct	= 'struct';
 
+	/**
+	 * Data types list
+	 *
+	 * @var	array
+	 */
 	public $xmlrpcTypes	= array();
+
+	/**
+	 * Valid parents list
+	 *
+	 * @var	array
+	 */
 	public $valid_parents	= array();
-	public $xmlrpcerr		= array(); // Response numbers
-	public $xmlrpcstr		= array(); // Response strings
 
+	/**
+	 * Response error numbers list
+	 *
+	 * @var	array
+	 */
+	public $xmlrpcerr		= array();
+
+	/**
+	 * Response error messages list
+	 *
+	 * @var	string[]
+	 */
+	public $xmlrpcstr		= array();
+
+	/**
+	 * Encoding charset
+	 *
+	 * @var	string
+	 */
 	public $xmlrpc_defencoding	= 'UTF-8';
+
+	/**
+	 * XML-RPC client name
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcName		= 'XML-RPC for CodeIgniter';
+
+	/**
+	 * XML-RPC version
+	 *
+	 * @var	string
+	 */
 	public $xmlrpcVersion		= '1.1';
-	public $xmlrpcerruser		= 800; // Start of user errors
-	public $xmlrpcerrxml		= 100; // Start of XML Parse errors
-	public $xmlrpc_backslash	= ''; // formulate backslashes for escaping regexp
 
+	/**
+	 * Start of user errors
+	 *
+	 * @var	int
+	 */
+	public $xmlrpcerruser		= 800;
+
+	/**
+	 * Start of XML parse errors
+	 *
+	 * @var	int
+	 */
+	public $xmlrpcerrxml		= 100;
+
+	/**
+	 * Backslash replacement value
+	 *
+	 * @var	string
+	 */
+	public $xmlrpc_backslash	= '';
+
+	/**
+	 * XML-RPC Client object
+	 *
+	 * @var	object
+	 */
 	public $client;
+
+	/**
+	 * XML-RPC Method name
+	 *
+	 * @var	string
+	 */
 	public $method;
+
+	/**
+	 * XML-RPC Data
+	 *
+	 * @var	array
+	 */
 	public $data;
+
+	/**
+	 * XML-RPC Message
+	 *
+	 * @var	string
+	 */
 	public $message			= '';
-	public $error			= '';	// Error string for request
+
+	/**
+	 * Request error message
+	 *
+	 * @var	string
+	 */
+	public $error			= '';
+
+	/**
+	 * XML-RPC result object
+	 *
+	 * @var	object
+	 */
 	public $result;
+
+	/**
+	 * XML-RPC Reponse
+	 *
+	 * @var	array
+	 */
 	public $response		= array();  // Response from remote server
 
+	/**
+	 * XSS Filter flag
+	 *
+	 * @var	bool
+	 */
 	public $xss_clean		= TRUE;
 
+	// --------------------------------------------------------------------
 
 	/**
 	 * Constructor
 	 *
 	 * Initializes property default values
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function __construct($config = array())
@@ -148,7 +312,7 @@ class CI_Xmlrpc {
 	/**
 	 * Initialize
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function initialize($config = array())
@@ -171,9 +335,9 @@ class CI_Xmlrpc {
 	 * Parse server URL
 	 *
 	 * @param	string	$url
-	 * @param	int	$port = 80
-	 * @param	string	$proxy = FALSE
-	 * @param	int	$proxy_port = 8080
+	 * @param	int	$port
+	 * @param	string	$proxy
+	 * @param	int	$proxy_port
 	 * @return	void
 	 */
 	public function server($url, $port = 80, $proxy = FALSE, $proxy_port = 8080)
@@ -200,7 +364,7 @@ class CI_Xmlrpc {
 	/**
 	 * Set Timeout
 	 *
-	 * @param	int	seconds
+	 * @param	int	$seconds
 	 * @return	void
 	 */
 	public function timeout($seconds = 5)
@@ -216,7 +380,7 @@ class CI_Xmlrpc {
 	/**
 	 * Set Methods
 	 *
-	 * @param	string	method name
+	 * @param	string	$function	Method name
 	 * @return	void
 	 */
 	public function method($function)
@@ -229,7 +393,7 @@ class CI_Xmlrpc {
 	/**
 	 * Take Array of Data and Create Objects
 	 *
-	 * @param	array
+	 * @param	array	$incoming
 	 * @return	void
 	 */
 	public function request($incoming)
@@ -253,7 +417,7 @@ class CI_Xmlrpc {
 	/**
 	 * Set Debug
 	 *
-	 * @param	bool
+	 * @param	bool	$flag
 	 * @return	void
 	 */
 	public function set_debug($flag = TRUE)
@@ -266,7 +430,7 @@ class CI_Xmlrpc {
 	/**
 	 * Values Parsing
 	 *
-	 * @param	mixed
+	 * @param	mixed	$value
 	 * @return	object
 	 */
 	public function values_parsing($value)
@@ -349,8 +513,8 @@ class CI_Xmlrpc {
 	/**
 	 * Sends an Error Message for Server Request
 	 *
-	 * @param	int
-	 * @param	string
+	 * @param	int	$number
+	 * @param	string	$message
 	 * @return	object
 	 */
 	public function send_error_message($number, $message)
@@ -363,7 +527,7 @@ class CI_Xmlrpc {
 	/**
 	 * Send Response for Server Request
 	 *
-	 * @param	array
+	 * @param	array	$response
 	 * @return	object
 	 */
 	public function send_response($response)
@@ -384,24 +548,79 @@ class CI_Xmlrpc {
  */
 class XML_RPC_Client extends CI_Xmlrpc
 {
+	/**
+	 * Path
+	 *
+	 * @var	string
+	 */
 	public $path			= '';
+
+	/**
+	 * Server hostname
+	 *
+	 * @var	string
+	 */
 	public $server			= '';
+
+	/**
+	 * Server port
+	 *
+	 * @var	int
+	 */
 	public $port			= 80;
+
+	/**
+	 * Proxy hostname
+	 *
+	 * @var	string
+	 */
 	public $proxy			= FALSE;
+
+	/**
+	 * Proxy port
+	 *
+	 * @var	int
+	 */
 	public $proxy_port		= 8080;
+
+	/**
+	 * Error number
+	 *
+	 * @var	string
+	 */
 	public $errno			= '';
+
+	/**
+	 * Error message
+	 *
+	 * @var	string
+	 */
 	public $errstring		= '';
+
+	/**
+	 * Timeout in seconds
+	 *
+	 * @var	int
+	 */
 	public $timeout		= 5;
+
+	/**
+	 * No Multicall flag
+	 *
+	 * @var	bool
+	 */
 	public $no_multicall	= FALSE;
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
 	 * @param	string	$path
 	 * @param	object	$server
-	 * @param	int	$port = 80
-	 * @param	string	$proxy = FALSE
-	 * @param	int	$proxy_port = 8080
+	 * @param	int	$port
+	 * @param	string	$proxy
+	 * @param	int	$proxy_port
 	 * @return	void
 	 */
 	public function __construct($path, $server, $port = 80, $proxy = FALSE, $proxy_port = 8080)
@@ -420,7 +639,7 @@ class XML_RPC_Client extends CI_Xmlrpc
 	/**
 	 * Send message
 	 *
-	 * @param	mixed
+	 * @param	mixed	$msg
 	 * @return	object
 	 */
 	public function send($msg)
@@ -439,7 +658,7 @@ class XML_RPC_Client extends CI_Xmlrpc
 	/**
 	 * Send payload
 	 *
-	 * @param	object
+	 * @param	object	$msg
 	 * @return	object
 	 */
 	public function sendPayload($msg)
@@ -499,18 +718,50 @@ class XML_RPC_Client extends CI_Xmlrpc
  */
 class XML_RPC_Response
 {
+
+	/**
+	 * Value
+	 *
+	 * @var	mixed
+	 */
 	public $val		= 0;
+
+	/**
+	 * Error number
+	 *
+	 * @var	int
+	 */
 	public $errno		= 0;
+
+	/**
+	 * Error message
+	 *
+	 * @var	string
+	 */
 	public $errstr		= '';
+
+	/**
+	 * Headers list
+	 *
+	 * @var	array
+	 */
 	public $headers		= array();
+
+	/**
+	 * XSS Filter flag
+	 *
+	 * @var	bool
+	 */
 	public $xss_clean	= TRUE;
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	mixed
-	 * @param	int
-	 * @param	string
+	 * @param	mixed	$val
+	 * @param	int	$code
+	 * @param	string	$fstr
 	 * @return	void
 	 */
 	public function __construct($val, $code = 0, $fstr = '')
@@ -716,16 +967,42 @@ class XML_RPC_Response
  */
 class XML_RPC_Message extends CI_Xmlrpc
 {
+
+	/**
+	 * Payload
+	 *
+	 * @var	string
+	 */
 	public $payload;
+
+	/**
+	 * Method name
+	 *
+	 * @var	string
+	 */
 	public $method_name;
+
+	/**
+	 * Parameter list
+	 *
+	 * @var	array
+	 */
 	public $params		= array();
+
+	/**
+	 * XH?
+	 *
+	 * @var	array
+	 */
 	public $xh		= array();
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	string	method name
-	 * @param	array
+	 * @param	string	$method
+	 * @param	array	$pars
 	 * @return	void
 	 */
 	public function __construct($method, $pars = FALSE)
@@ -1303,14 +1580,27 @@ class XML_RPC_Message extends CI_Xmlrpc
  */
 class XML_RPC_Values extends CI_Xmlrpc
 {
+	/**
+	 * Value data
+	 *
+	 * @var	array
+	 */
 	public $me	= array();
+
+	/**
+	 * Value type
+	 *
+	 * @var	int
+	 */
 	public $mytype	= 0;
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
-	 * @param	mixed
-	 * @param	string
+	 * @param	mixed	$val
+	 * @param	string	$type
 	 * @return	void
 	 */
 	public function __construct($val = -1, $type = '')
diff --git a/system/libraries/Xmlrpcs.php b/system/libraries/Xmlrpcs.php
index 5d01d374d..3c3337bf2 100644
--- a/system/libraries/Xmlrpcs.php
+++ b/system/libraries/Xmlrpcs.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 if ( ! function_exists('xml_parser_create'))
 {
diff --git a/system/libraries/Zip.php b/system/libraries/Zip.php
index 5c4c257f8..9ecd0de9f 100644
--- a/system/libraries/Zip.php
+++ b/system/libraries/Zip.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Zip Compression Class
diff --git a/system/libraries/javascript/Jquery.php b/system/libraries/javascript/Jquery.php
index ed02fadb7..2bf47957f 100644
--- a/system/libraries/javascript/Jquery.php
+++ b/system/libraries/javascript/Jquery.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Jquery Class
@@ -36,14 +37,57 @@
  */
 class CI_Jquery extends CI_Javascript {
 
+	/**
+	 * JavaScript directory location
+	 *
+	 * @var	string
+	 */
 	protected $_javascript_folder = 'js';
+
+	/**
+	 * JQuery code for load
+	 *
+	 * @var	array
+	 */
 	public $jquery_code_for_load = array();
+
+	/**
+	 * JQuery code for compile
+	 *
+	 * @var	array
+	 */
 	public $jquery_code_for_compile = array();
+
+	/**
+	 * JQuery corner active flag
+	 *
+	 * @var	bool
+	 */
 	public $jquery_corner_active = FALSE;
+
+	/**
+	 * JQuery table sorter active flag
+	 *
+	 * @var	bool
+	 */
 	public $jquery_table_sorter_active = FALSE;
+
+	/**
+	 * JQuery table sorder pager active
+	 *
+	 * @var	bool
+	 */
 	public $jquery_table_sorter_pager_active = FALSE;
+
+	/**
+	 * JQuery AJAX image
+	 *
+	 * @var	string
+	 */
 	public $jquery_ajax_img = '';
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Constructor
 	 *
@@ -382,8 +426,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery addClass event
 	 *
-	 * @param	string	$element = 'this'
-	 * @param	string	$class = ''
+	 * @param	string	$element
+	 * @param	string	$class
 	 * @return	string
 	 */
 	protected function _addClass($element = 'this', $class = '')
@@ -399,10 +443,10 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery animate event
 	 *
-	 * @param	string	$element = 'this'
-	 * @param	array	$params = array()
-	 * @param	string	$speed = ''		'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	$extra = ''
+	 * @param	string	$element
+	 * @param	array	$params
+	 * @param	string	$speed	'slow', 'normal', 'fast', or time in milliseconds
+	 * @param	string	$extra
 	 * @return	string
 	 */
 	protected function _animate($element = 'this', $params = array(), $speed = '', $extra = '')
@@ -514,8 +558,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery remove class event
 	 *
-	 * @param	string	$element = 'this'
-	 * @param	string	$class = ''
+	 * @param	string	$element
+	 * @param	string	$class
 	 * @return	string
 	 */
 	protected function _removeClass($element = 'this', $class = '')
@@ -622,8 +666,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery toggle class event
 	 *
-	 * @param	string	$element = 'this'
-	 * @param	string	$class = ''
+	 * @param	string	$element
+	 * @param	string	$class
 	 * @return	string
 	 */
 	protected function _toggleClass($element = 'this', $class = '')
@@ -707,9 +751,9 @@ class CI_Jquery extends CI_Javascript {
 	/**
 	 * Zebra tables
 	 *
-	 * @param	string	$class = ''
-	 * @param	string	$odd = 'odd'
-	 * @param	string	$hover = ''
+	 * @param	string	$class
+	 * @param	string	$odd
+	 * @param	string	$hover
 	 * @return	string
 	 */
 	protected function _zebraTables($class = '', $odd = 'odd', $hover = '')
@@ -734,10 +778,9 @@ class CI_Jquery extends CI_Javascript {
 	/**
 	 * Corner Plugin
 	 *
-	 * http://www.malsup.com/jquery/corner/
-	 *
-	 * @param	string	$element = ''
-	 * @param	string	$corner_style = ''
+	 * @link	http://www.malsup.com/jquery/corner/
+	 * @param	string	$element
+	 * @param	string	$corner_style
 	 * @return	string
 	 */
 	public function corner($element = '', $corner_style = '')
@@ -761,7 +804,7 @@ class CI_Jquery extends CI_Javascript {
 	 * Load a thickbox modal window
 	 *
 	 * @param	string	$src
-	 * @param	bool	$relative = FALSE
+	 * @param	bool	$relative
 	 * @return	void
 	 */
 	public function modal($src, $relative = FALSE)
@@ -777,7 +820,7 @@ class CI_Jquery extends CI_Javascript {
 	 * Load an Effect library
 	 *
 	 * @param	string	$src
-	 * @param	bool	$relative = FALSE
+	 * @param	bool	$relative
 	 * @return	void
 	 */
 	public function effect($src, $relative = FALSE)
@@ -793,7 +836,7 @@ class CI_Jquery extends CI_Javascript {
 	 * Load a plugin library
 	 *
 	 * @param	string	$src
-	 * @param	bool	$relative = FALSE
+	 * @param	bool	$relative
 	 * @return	void
 	 */
 	public function plugin($src, $relative = FALSE)
@@ -809,7 +852,7 @@ class CI_Jquery extends CI_Javascript {
 	 * Load a user interface library
 	 *
 	 * @param	string	$src
-	 * @param	bool	$relative = FALSE
+	 * @param	bool	$relative
 	 * @return	void
 	 */
 	public function ui($src, $relative = FALSE)
@@ -825,7 +868,7 @@ class CI_Jquery extends CI_Javascript {
 	 * Creates a jQuery sortable
 	 *
 	 * @param	string	$element
-	 * @param	array	$options = array()
+	 * @param	array	$options
 	 * @return	string
 	 */
 	public function sortable($element, $options = array())
@@ -896,8 +939,8 @@ class CI_Jquery extends CI_Javascript {
 	 * As events are specified, they are stored in an array
 	 * This funciton compiles them all for output on a page
 	 *
-	 * @param	string	$view_var = 'script_foot'
-	 * @param	bool	$script_tags = TRUE
+	 * @param	string	$view_var
+	 * @param	bool	$script_tags
 	 * @return	void
 	 */
 	protected function _compile($view_var = 'script_foot', $script_tags = TRUE)
@@ -963,8 +1006,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs the script tag that loads the jquery.js file into an HTML document
 	 *
-	 * @param	string	$library_src = ''
-	 * @param	bool	$relative = FALSE
+	 * @param	string	$library_src
+	 * @param	bool	$relative
 	 * @return	string
 	 */
 	public function script($library_src = '', $relative = FALSE)