Merge branch 'develop' of git://github.com/bcit-ci/CodeIgniter into develop

73 files changed, 1012 insertions, 1806 deletions

diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index f80b4db54..6e8aff7c6 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		Esen Sagynov
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_cubrid_driver extends CI_DB {
 
@@ -187,25 +187,17 @@ class CI_DB_cubrid_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if (($autocommit = cubrid_get_autocommit($this->conn_id)) === NULL)
 		{
-			return TRUE;
+			return FALSE;
 		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
-		if (cubrid_get_autocommit($this->conn_id))
+		elseif ($autocommit === TRUE)
 		{
-			cubrid_set_autocommit($this->conn_id, CUBRID_AUTOCOMMIT_FALSE);
+			return cubrid_set_autocommit($this->conn_id, CUBRID_AUTOCOMMIT_FALSE);
 		}
 
 		return TRUE;
@@ -218,19 +210,16 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if ( ! cubrid_commit($this->conn_id))
 		{
-			return TRUE;
+			return FALSE;
 		}
 
-		cubrid_commit($this->conn_id);
-
 		if ($this->auto_commit && ! cubrid_get_autocommit($this->conn_id))
 		{
-			cubrid_set_autocommit($this->conn_id, CUBRID_AUTOCOMMIT_TRUE);
+			return cubrid_set_autocommit($this->conn_id, CUBRID_AUTOCOMMIT_TRUE);
 		}
 
 		return TRUE;
@@ -243,16 +232,13 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if ( ! cubrid_rollback($this->conn_id))
 		{
-			return TRUE;
+			return FALSE;
 		}
 
-		cubrid_rollback($this->conn_id);
-
 		if ($this->auto_commit && ! cubrid_get_autocommit($this->conn_id))
 		{
 			cubrid_set_autocommit($this->conn_id, CUBRID_AUTOCOMMIT_TRUE);
@@ -264,7 +250,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -375,7 +361,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/cubrid/cubrid_forge.php b/system/database/drivers/cubrid/cubrid_forge.php
index 9484e94e1..27bfc1466 100644
--- a/system/database/drivers/cubrid/cubrid_forge.php
+++ b/system/database/drivers/cubrid/cubrid_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		Esen Sagynov
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_cubrid_forge extends CI_DB_forge {
 
@@ -178,6 +178,9 @@ class CI_DB_cubrid_forge extends CI_DB_forge {
 				$attributes['TYPE'] = 'INTEGER';
 				$attributes['UNSIGNED'] = FALSE;
 				return;
+			case 'LONGTEXT':
+				$attributes['TYPE'] = 'STRING';
+				return;
 			default: return;
 		}
 	}
diff --git a/system/database/drivers/cubrid/cubrid_result.php b/system/database/drivers/cubrid/cubrid_result.php
index e666bab56..251b70a63 100644
--- a/system/database/drivers/cubrid/cubrid_result.php
+++ b/system/database/drivers/cubrid/cubrid_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		Esen Sagynov
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_cubrid_result extends CI_DB_result {
 
diff --git a/system/database/drivers/cubrid/cubrid_utility.php b/system/database/drivers/cubrid/cubrid_utility.php
index de7d71568..555ae7a91 100644
--- a/system/database/drivers/cubrid/cubrid_utility.php
+++ b/system/database/drivers/cubrid/cubrid_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		Esen Sagynov
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_cubrid_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index 529c320cd..fea3bfe52 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_ibase_driver extends CI_DB {
 
@@ -126,7 +126,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 */
 	protected function _execute($sql)
 	{
-		return ibase_query($this->conn_id, $sql);
+		return ibase_query(isset($this->_ibase_trans) ? $this->_ibase_trans : $this->conn_id, $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -134,24 +134,16 @@ class CI_DB_ibase_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if (($trans_handle = ibase_trans($this->conn_id)) === FALSE)
 		{
-			return TRUE;
+			return FALSE;
 		}
 
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
-		$this->_ibase_trans = ibase_trans($this->conn_id);
-
+		$this->_ibase_trans = $trans_handle;
 		return TRUE;
 	}
 
@@ -162,15 +154,15 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans->depth > 0)
+		if (ibase_commit($this->_ibase_trans))
 		{
+			$this->_ibase_trans = NULL;
 			return TRUE;
 		}
 
-		return ibase_commit($this->_ibase_trans);
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -180,15 +172,15 @@ class CI_DB_ibase_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if (ibase_rollback($this->_ibase_trans))
 		{
+			$this->_ibase_trans = NULL;
 			return TRUE;
 		}
 
-		return ibase_rollback($this->_ibase_trans);
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -302,7 +294,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -392,6 +384,23 @@ class CI_DB_ibase_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, $values)
+	{
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/ibase/ibase_forge.php b/system/database/drivers/ibase/ibase_forge.php
index 0e748c710..44bb24e68 100644
--- a/system/database/drivers/ibase/ibase_forge.php
+++ b/system/database/drivers/ibase/ibase_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_ibase_forge extends CI_DB_forge {
 
@@ -111,7 +111,7 @@ class CI_DB_ibase_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		if ( ! ibase_drop_db($this->conn_id))
 		{
diff --git a/system/database/drivers/ibase/ibase_result.php b/system/database/drivers/ibase/ibase_result.php
index 991146f45..7d7dd79ac 100644
--- a/system/database/drivers/ibase/ibase_result.php
+++ b/system/database/drivers/ibase/ibase_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_ibase_result extends CI_DB_result {
 
diff --git a/system/database/drivers/ibase/ibase_utility.php b/system/database/drivers/ibase/ibase_utility.php
index 79d2788e5..3c152101a 100644
--- a/system/database/drivers/ibase/ibase_utility.php
+++ b/system/database/drivers/ibase/ibase_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_ibase_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 8f15d8d69..a490d206c 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_driver extends CI_DB {
 
@@ -108,6 +108,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
+		ini_set('mssql.charset', $this->char_set);
 		$this->conn_id = ($persistent)
 				? mssql_pconnect($this->hostname, $this->username, $this->password)
 				: mssql_connect($this->hostname, $this->username, $this->password);
@@ -158,6 +159,7 @@ class CI_DB_mssql_driver extends CI_DB {
 		if (mssql_select_db('['.$database.']', $this->conn_id))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -182,22 +184,10 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return $this->simple_query('BEGIN TRAN');
 	}
 
@@ -208,14 +198,8 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->simple_query('COMMIT TRAN');
 	}
 
@@ -226,14 +210,8 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->simple_query('ROLLBACK TRAN');
 	}
 
@@ -272,26 +250,13 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @param	string	$charset
-	 * @return	bool
-	 */
-	protected function _db_set_charset($charset)
-	{
-		return (ini_set('mssql.charset', $charset) !== FALSE);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @return	string
 	 */
 	protected function _version()
 	{
-		return 'SELECT @@VERSION AS ver';
+		return "SELECT SERVERPROPERTY('ProductVersion') AS ver";
 	}
 
 	// --------------------------------------------------------------------
@@ -375,15 +340,25 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
 	public function error()
 	{
-		$query = $this->query('SELECT @@ERROR AS code');
-		$query = $query->row();
-		return array('code' => $query->code, 'message' => mssql_get_last_message());
+		// We need this because the error info is discarded by the
+		// server the first time you request it, and query() already
+		// calls error() once for logging purposes when a query fails.
+		static $error = array('code' => 0, 'message' => NULL);
+
+		$message = mssql_get_last_message();
+		if ( ! empty($message))
+		{
+			$error['code']    = $this->query('SELECT @@ERROR AS code')->row()->code;
+			$error['message'] = $message;
+		}
+
+		return $error;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index 84406a016..6b6109868 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_forge extends CI_DB_forge {
 
@@ -113,6 +113,11 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/system/database/drivers/mssql/mssql_result.php b/system/database/drivers/mssql/mssql_result.php
index c1c42a486..38a0a0574 100644
--- a/system/database/drivers/mssql/mssql_result.php
+++ b/system/database/drivers/mssql/mssql_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_result extends CI_DB_result {
 
diff --git a/system/database/drivers/mssql/mssql_utility.php b/system/database/drivers/mssql/mssql_utility.php
index 1040b5e41..95ce88f13 100644
--- a/system/database/drivers/mssql/mssql_utility.php
+++ b/system/database/drivers/mssql/mssql_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index df0f24920..3a7fc9812 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysql_driver extends CI_DB {
 
@@ -84,7 +84,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * @var	bool
 	 */
-	public $stricton = FALSE;
+	public $stricton;
 
 	// --------------------------------------------------------------------
 
@@ -147,12 +147,41 @@ class CI_DB_mysql_driver extends CI_DB {
 				: FALSE;
 		}
 
-		if ($this->stricton && is_resource($this->conn_id))
+		if (is_resource($this->conn_id))
 		{
-			$this->simple_query('SET SESSION sql_mode="STRICT_ALL_TABLES"');
+			if ( ! mysql_set_charset($this->char_set, $this->conn_id))
+			{
+				log_message('error', "Database: Unable to set the configured connection charset ('{$this->char_set}').");
+				$this->close();
+				return ($this->db->debug) ? $this->display_error('db_unable_to_set_charset', $this->char_set) : FALSE;
+			}
+
+			if (isset($this->stricton))
+			{
+				if ($this->stricton)
+				{
+					$this->simple_query('SET SESSION sql_mode = CONCAT(@@sql_mode, ",", "STRICT_ALL_TABLES")');
+				}
+				else
+				{
+					$this->simple_query(
+						'SET SESSION sql_mode =
+						REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
+						@@sql_mode,
+						"STRICT_ALL_TABLES,", ""),
+						",STRICT_ALL_TABLES", ""),
+						"STRICT_ALL_TABLES", ""),
+						"STRICT_TRANS_TABLES,", ""),
+						",STRICT_TRANS_TABLES", ""),
+						"STRICT_TRANS_TABLES", "")'
+					);
+				}
+			}
+
+			return $this->conn_id;
 		}
 
-		return $this->conn_id;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -191,6 +220,7 @@ class CI_DB_mysql_driver extends CI_DB {
 		if (mysql_select_db($database, $this->conn_id))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -200,19 +230,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @param	string	$charset
-	 * @return	bool
-	 */
-	protected function _db_set_charset($charset)
-	{
-		return mysql_set_charset($charset, $this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
@@ -272,25 +289,12 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		$this->simple_query('SET AUTOCOMMIT=0');
-		$this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK
-		return TRUE;
+		return $this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK
 	}
 
 	// --------------------------------------------------------------------
@@ -300,17 +304,15 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if ($this->simple_query('COMMIT'))
 		{
+			$this->simple_query('SET AUTOCOMMIT=1');
 			return TRUE;
 		}
 
-		$this->simple_query('COMMIT');
-		$this->simple_query('SET AUTOCOMMIT=1');
-		return TRUE;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -320,23 +322,21 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if ($this->simple_query('ROLLBACK'))
 		{
+			$this->simple_query('SET AUTOCOMMIT=1');
 			return TRUE;
 		}
 
-		$this->simple_query('ROLLBACK');
-		$this->simple_query('SET AUTOCOMMIT=1');
-		return TRUE;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -447,7 +447,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index cb90065f2..7ed8f8d38 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysql_forge extends CI_DB_forge {
 
diff --git a/system/database/drivers/mysql/mysql_result.php b/system/database/drivers/mysql/mysql_result.php
index 26aaddd32..7aa265ebb 100644
--- a/system/database/drivers/mysql/mysql_result.php
+++ b/system/database/drivers/mysql/mysql_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysql_result extends CI_DB_result {
 
diff --git a/system/database/drivers/mysql/mysql_utility.php b/system/database/drivers/mysql/mysql_utility.php
index 55857ab08..bc01fc58d 100644
--- a/system/database/drivers/mysql/mysql_utility.php
+++ b/system/database/drivers/mysql/mysql_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysql_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index dd3cc77c6..290101153 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysqli_driver extends CI_DB {
 
@@ -84,7 +84,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * @var	bool
 	 */
-	public $stricton = FALSE;
+	public $stricton;
 
 	// --------------------------------------------------------------------
 
@@ -98,6 +98,17 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * MySQLi object
+	 *
+	 * Has to be preserved without being assigned to $conn_id.
+	 *
+	 * @var	MySQLi
+	 */
+	protected $_mysqli;
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Database connection
 	 *
 	 * @param	bool	$persistent
@@ -114,21 +125,37 @@ class CI_DB_mysqli_driver extends CI_DB {
 		}
 		else
 		{
-			// Persistent connection support was added in PHP 5.3.0
-			$hostname = ($persistent === TRUE && is_php('5.3'))
+			$hostname = ($persistent === TRUE)
 				? 'p:'.$this->hostname : $this->hostname;
 			$port = empty($this->port) ? NULL : $this->port;
 			$socket = NULL;
 		}
 
 		$client_flags = ($this->compress === TRUE) ? MYSQLI_CLIENT_COMPRESS : 0;
-		$mysqli = mysqli_init();
+		$this->_mysqli = mysqli_init();
 
-		$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 10);
+		$this->_mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 10);
 
-		if ($this->stricton)
+		if (isset($this->stricton))
 		{
-			$mysqli->options(MYSQLI_INIT_COMMAND, 'SET SESSION sql_mode="STRICT_ALL_TABLES"');
+			if ($this->stricton)
+			{
+				$this->_mysqli->options(MYSQLI_INIT_COMMAND, 'SET SESSION sql_mode = CONCAT(@@sql_mode, ",", "STRICT_ALL_TABLES")');
+			}
+			else
+			{
+				$this->_mysqli->options(MYSQLI_INIT_COMMAND,
+					'SET SESSION sql_mode =
+					REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
+					@@sql_mode,
+					"STRICT_ALL_TABLES,", ""),
+					",STRICT_ALL_TABLES", ""),
+					"STRICT_ALL_TABLES", ""),
+					"STRICT_TRANS_TABLES,", ""),
+					",STRICT_TRANS_TABLES", ""),
+					"STRICT_TRANS_TABLES", "")'
+				);
+			}
 		}
 
 		if (is_array($this->encrypt))
@@ -142,13 +169,26 @@ class CI_DB_mysqli_driver extends CI_DB {
 
 			if ( ! empty($ssl))
 			{
-				if ( ! empty($this->encrypt['ssl_verify']) && defined('MYSQLI_OPT_SSL_VERIFY_SERVER_CERT'))
+				if (isset($this->encrypt['ssl_verify']))
 				{
-					$mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, TRUE);
+					if ($this->encrypt['ssl_verify'])
+					{
+						defined('MYSQLI_OPT_SSL_VERIFY_SERVER_CERT') && $this->_mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, TRUE);
+					}
+					// Apparently (when it exists), setting MYSQLI_OPT_SSL_VERIFY_SERVER_CERT
+					// to FALSE didn't do anything, so PHP 5.6.16 introduced yet another
+					// constant ...
+					//
+					// https://secure.php.net/ChangeLog-5.php#5.6.16
+					// https://bugs.php.net/bug.php?id=68344
+					elseif (defined('MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT'))
+					{
+						$client_flags |= MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT;
+					}
 				}
 
 				$client_flags |= MYSQLI_CLIENT_SSL;
-				$mysqli->ssl_set(
+				$this->_mysqli->ssl_set(
 					isset($ssl['key'])    ? $ssl['key']    : NULL,
 					isset($ssl['cert'])   ? $ssl['cert']   : NULL,
 					isset($ssl['ca'])     ? $ssl['ca']     : NULL,
@@ -158,22 +198,29 @@ class CI_DB_mysqli_driver extends CI_DB {
 			}
 		}
 
-		if ($mysqli->real_connect($hostname, $this->username, $this->password, $this->database, $port, $socket, $client_flags))
+		if ($this->_mysqli->real_connect($hostname, $this->username, $this->password, $this->database, $port, $socket, $client_flags))
 		{
 			// Prior to version 5.7.3, MySQL silently downgrades to an unencrypted connection if SSL setup fails
 			if (
 				($client_flags & MYSQLI_CLIENT_SSL)
-				&& version_compare($mysqli->client_info, '5.7.3', '<=')
-				&& empty($mysqli->query("SHOW STATUS LIKE 'ssl_cipher'")->fetch_object()->Value)
+				&& version_compare($this->_mysqli->client_info, '5.7.3', '<=')
+				&& empty($this->_mysqli->query("SHOW STATUS LIKE 'ssl_cipher'")->fetch_object()->Value)
 			)
 			{
-				$mysqli->close();
+				$this->_mysqli->close();
 				$message = 'MySQLi was configured for an SSL connection, but got an unencrypted connection instead!';
 				log_message('error', $message);
 				return ($this->db->db_debug) ? $this->db->display_error($message, '', TRUE) : FALSE;
 			}
 
-			return $mysqli;
+			if ( ! $this->_mysqli->set_charset($this->char_set))
+			{
+				log_message('error', "Database: Unable to set the configured connection charset ('{$this->char_set}').");
+				$this->_mysqli->close();
+				return ($this->db->db_debug) ? $this->display_error('db_unable_to_set_charset', $this->char_set) : FALSE;
+			}
+
+			return $this->_mysqli;
 		}
 
 		return FALSE;
@@ -215,6 +262,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 		if ($this->conn_id->select_db($database))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -224,19 +272,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @param	string	$charset
-	 * @return	bool
-	 */
-	protected function _db_set_charset($charset)
-	{
-		return $this->conn_id->set_charset($charset);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
@@ -291,22 +326,10 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		$this->conn_id->autocommit(FALSE);
 		return is_php('5.5')
 			? $this->conn_id->begin_transaction()
@@ -320,14 +343,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		if ($this->conn_id->commit())
 		{
 			$this->conn_id->autocommit(TRUE);
@@ -344,14 +361,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		if ($this->conn_id->rollback())
 		{
 			$this->conn_id->autocommit(TRUE);
@@ -364,7 +375,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -481,11 +492,11 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function error()
 	{
-		if ( ! empty($this->conn_id->connect_errno))
+		if ( ! empty($this->_mysqli->connect_errno))
 		{
 			return array(
-				'code' => $this->conn_id->connect_errno,
-				'message' => is_php('5.2.9') ? $this->conn_id->connect_error : mysqli_connect_error()
+				'code'    => $this->_mysqli->connect_errno,
+				'message' => $this->_mysqli->connect_error
 			);
 		}
 
diff --git a/system/database/drivers/mysqli/mysqli_forge.php b/system/database/drivers/mysqli/mysqli_forge.php
index 196afa845..c5b23b6ca 100644
--- a/system/database/drivers/mysqli/mysqli_forge.php
+++ b/system/database/drivers/mysqli/mysqli_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysqli_forge extends CI_DB_forge {
 
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index d648828bd..929c2b455 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysqli_result extends CI_DB_result {
 
diff --git a/system/database/drivers/mysqli/mysqli_utility.php b/system/database/drivers/mysqli/mysqli_utility.php
index 04fcd1ded..4a3dad4d1 100644
--- a/system/database/drivers/mysqli/mysqli_utility.php
+++ b/system/database/drivers/mysqli/mysqli_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysqli_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index f2e40da9b..fb2f6b31b 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.4.1
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage  Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 
 /**
@@ -252,12 +252,16 @@ class CI_DB_oci8_driver extends CI_DB {
 			return $this->data_cache['version'];
 		}
 
-		if ( ! $this->conn_id OR ($version = oci_server_version($this->conn_id)) === FALSE)
+		if ( ! $this->conn_id OR ($version_string = oci_server_version($this->conn_id)) === FALSE)
 		{
 			return FALSE;
 		}
+		elseif (preg_match('#Release\s(\d+(?:\.\d+)+)#', $version_string, $match))
+		{
+			return $this->data_cache['version'] = $match[1];
+		}
 
-		return $this->data_cache['version'] = $version;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -378,28 +382,11 @@ class CI_DB_oci8_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
-		$this->commit_mode = is_php('5.3.2') ? OCI_NO_AUTO_COMMIT : OCI_DEFAULT;
+		$this->commit_mode = OCI_NO_AUTO_COMMIT;
 		return TRUE;
 	}
 
@@ -410,20 +397,10 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		$this->commit_mode = OCI_COMMIT_ON_SUCCESS;
+
 		return oci_commit($this->conn_id);
 	}
 
@@ -434,14 +411,8 @@ class CI_DB_oci8_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		$this->commit_mode = OCI_COMMIT_ON_SUCCESS;
 		return oci_rollback($this->conn_id);
 	}
@@ -582,29 +553,35 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
 	public function error()
 	{
-		/* oci_error() returns an array that already contains the
-		 * 'code' and 'message' keys, so we can just return it.
-		 */
+		// oci_error() returns an array that already contains
+		// 'code' and 'message' keys, but it can return false
+		// if there was no error ....
 		if (is_resource($this->curs_id))
 		{
-			return oci_error($this->curs_id);
+			$error = oci_error($this->curs_id);
 		}
 		elseif (is_resource($this->stmt_id))
 		{
-			return oci_error($this->stmt_id);
+			$error = oci_error($this->stmt_id);
 		}
 		elseif (is_resource($this->conn_id))
 		{
-			return oci_error($this->conn_id);
+			$error = oci_error($this->conn_id);
+		}
+		else
+		{
+			$error = oci_error();
 		}
 
-		return oci_error();
+		return is_array($error)
+			? $error
+			: array('code' => '', 'message' => '');
 	}
 
 	// --------------------------------------------------------------------
@@ -683,6 +660,14 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _limit($sql)
 	{
+		if (version_compare($this->version(), '12.1', '>='))
+		{
+			// OFFSET-FETCH can be used only with the ORDER BY clause
+			empty($this->qb_orderby) && $sql .= ' ORDER BY 1';
+
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
+		}
+
 		$this->limit_used = TRUE;
 		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
 			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1) : '');
diff --git a/system/database/drivers/oci8/oci8_forge.php b/system/database/drivers/oci8/oci8_forge.php
index 80100977a..867a94341 100644
--- a/system/database/drivers/oci8/oci8_forge.php
+++ b/system/database/drivers/oci8/oci8_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.4.1
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_oci8_forge extends CI_DB_forge {
 
@@ -54,6 +54,13 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 	protected $_create_database	= FALSE;
 
 	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
+	/**
 	 * DROP DATABASE statement
 	 *
 	 * @var	string
@@ -119,6 +126,8 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
 						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
 				}
+
+				$field[$i] = "\n\t".$field[$i]['_literal'];
 			}
 		}
 
@@ -129,7 +138,7 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 
 		// RENAME COLUMN must be executed after MODIFY
 		array_unshift($sqls, $sql);
-		return $sql;
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
@@ -146,4 +155,33 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 		// Not supported - sequences and triggers must be used instead
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * 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'] = 'NUMBER';
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			default: return;
+		}
+	}
 }
diff --git a/system/database/drivers/oci8/oci8_result.php b/system/database/drivers/oci8/oci8_result.php
index 9ec54cc5c..0c3543333 100644
--- a/system/database/drivers/oci8/oci8_result.php
+++ b/system/database/drivers/oci8/oci8_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.4.1
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_oci8_result extends CI_DB_result {
 
diff --git a/system/database/drivers/oci8/oci8_utility.php b/system/database/drivers/oci8/oci8_utility.php
index 90022a8c1..ce0dfc5f8 100644
--- a/system/database/drivers/oci8/oci8_utility.php
+++ b/system/database/drivers/oci8/oci8_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.4.1
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_oci8_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index f5d77a147..ed44412c1 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -48,9 +48,9 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
-class CI_DB_odbc_driver extends CI_DB {
+class CI_DB_odbc_driver extends CI_DB_driver {
 
 	/**
 	 * Database driver
@@ -94,6 +94,22 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * ODBC result ID resource returned from odbc_prepare()
+	 *
+	 * @var	resource
+	 */
+	private $odbc_result;
+
+	/**
+	 * Values to use with odbc_execute() for prepared statements
+	 *
+	 * @var	array
+	 */
+	private $binds = array();
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Class constructor
 	 *
 	 * @param	array	$params
@@ -128,6 +144,74 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Compile Bindings
+	 *
+	 * @param	string	$sql	SQL statement
+	 * @param	array	$binds	An array of values to bind
+	 * @return	string
+	 */
+	public function compile_binds($sql, $binds)
+	{
+		if (empty($binds) OR empty($this->bind_marker) OR strpos($sql, $this->bind_marker) === FALSE)
+		{
+			return $sql;
+		}
+		elseif ( ! is_array($binds))
+		{
+			$binds = array($binds);
+			$bind_count = 1;
+		}
+		else
+		{
+			// Make sure we're using numeric keys
+			$binds = array_values($binds);
+			$bind_count = count($binds);
+		}
+
+		// We'll need the marker length later
+		$ml = strlen($this->bind_marker);
+
+		// Make sure not to replace a chunk inside a string that happens to match the bind marker
+		if ($c = preg_match_all("/'[^']*'|\"[^\"]*\"/i", $sql, $matches))
+		{
+			$c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i',
+				str_replace($matches[0],
+					str_replace($this->bind_marker, str_repeat(' ', $ml), $matches[0]),
+					$sql, $c),
+				$matches, PREG_OFFSET_CAPTURE);
+
+			// Bind values' count must match the count of markers in the query
+			if ($bind_count !== $c)
+			{
+				return $sql;
+			}
+		}
+		elseif (($c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i', $sql, $matches, PREG_OFFSET_CAPTURE)) !== $bind_count)
+		{
+			return $sql;
+		}
+
+		if ($this->bind_marker !== '?')
+		{
+			do
+			{
+				$c--;
+				$sql = substr_replace($sql, '?', $matches[0][$c][1], $ml);
+			}
+			while ($c !== 0);
+		}
+
+		if (FALSE !== ($this->odbc_result = odbc_prepare($this->conn_id, $sql)))
+		{
+			$this->binds = array_values($binds);
+		}
+
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Execute the query
 	 *
 	 * @param	string	$sql	an SQL query
@@ -135,7 +219,25 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	protected function _execute($sql)
 	{
-		return odbc_exec($this->conn_id, $sql);
+		if ( ! isset($this->odbc_result))
+		{
+			return odbc_exec($this->conn_id, $sql);
+		}
+		elseif ($this->odbc_result === FALSE)
+		{
+			return FALSE;
+		}
+
+		if (TRUE === ($success = odbc_execute($this->odbc_result, $this->binds)))
+		{
+			// For queries that return result sets, return the result_id resource on success
+			$this->is_write_type($sql) OR $success = $this->odbc_result;
+		}
+
+		$this->odbc_result = NULL;
+		$this->binds       = array();
+
+		return $success;
 	}
 
 	// --------------------------------------------------------------------
@@ -143,22 +245,10 @@ class CI_DB_odbc_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return odbc_autocommit($this->conn_id, FALSE);
 	}
 
@@ -169,17 +259,15 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if (odbc_commit($this->conn_id))
 		{
+			odbc_autocommit($this->conn_id, TRUE);
 			return TRUE;
 		}
 
-		$ret = odbc_commit($this->conn_id);
-		odbc_autocommit($this->conn_id, TRUE);
-		return $ret;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -189,30 +277,46 @@ class CI_DB_odbc_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
+		if (odbc_rollback($this->conn_id))
 		{
+			odbc_autocommit($this->conn_id, TRUE);
 			return TRUE;
 		}
 
-		$ret = odbc_rollback($this->conn_id);
-		odbc_autocommit($this->conn_id, TRUE);
-		return $ret;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Determines if a query is a "write" type.
+	 *
+	 * @param	string	An SQL query string
+	 * @return	bool
+	 */
+	public function is_write_type($sql)
+	{
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
+		{
+			return FALSE;
+		}
+
+		return parent::is_write_type($sql);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		return remove_invisible_characters($str);
+		$this->db->display_error('db_unsupported_feature');
 	}
 
 	// --------------------------------------------------------------------
@@ -298,7 +402,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -310,58 +414,6 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @param	array	$values
-	 * @return	string
-	 */
-	protected function _update($table, $values)
-	{
-		$this->qb_limit = FALSE;
-		$this->qb_orderby = array();
-		return parent::_update($table, $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this method maps to 'DELETE FROM table'
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'DELETE FROM '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete statement
-	 *
-	 * Generates a platform-specific delete string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _delete($table)
-	{
-		$this->qb_limit = FALSE;
-		return parent::_delete($table);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
@@ -370,5 +422,4 @@ class CI_DB_odbc_driver extends CI_DB {
 	{
 		odbc_close($this->conn_id);
 	}
-
 }
diff --git a/system/database/drivers/odbc/odbc_forge.php b/system/database/drivers/odbc/odbc_forge.php
index 45c5dc108..77b2fdf62 100644
--- a/system/database/drivers/odbc/odbc_forge.php
+++ b/system/database/drivers/odbc/odbc_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/database/
+ * @link		https://codeigniter.com/database/
  */
 class CI_DB_odbc_forge extends CI_DB_forge {
 
diff --git a/system/database/drivers/odbc/odbc_result.php b/system/database/drivers/odbc/odbc_result.php
index 10b93d4fc..845aa9c79 100644
--- a/system/database/drivers/odbc/odbc_result.php
+++ b/system/database/drivers/odbc/odbc_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_odbc_result extends CI_DB_result {
 
diff --git a/system/database/drivers/odbc/odbc_utility.php b/system/database/drivers/odbc/odbc_utility.php
index 0e6c23328..643f6ec0c 100644
--- a/system/database/drivers/odbc/odbc_utility.php
+++ b/system/database/drivers/odbc/odbc_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/database/
+ * @link		https://codeigniter.com/database/
  */
 class CI_DB_odbc_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index cc77e9568..6afc999c2 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_driver extends CI_DB {
 
@@ -126,7 +126,10 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		$this->options[PDO::ATTR_PERSISTENT] = $persistent;
+		if ($persistent === TRUE)
+		{
+			$this->options[PDO::ATTR_PERSISTENT] = TRUE;
+		}
 
 		try
 		{
@@ -186,22 +189,10 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return $this->conn_id->beginTransaction();
 	}
 
@@ -212,14 +203,8 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->conn_id->commit();
 	}
 
@@ -230,21 +215,15 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->conn_id->rollBack();
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -306,7 +285,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -332,52 +311,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update_Batch statement
-	 *
-	 * Generates a platform-specific batch update string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$values	Update data
-	 * @param	string	$index	WHERE key
-	 * @return	string
-	 */
-	protected function _update_batch($table, $values, $index)
-	{
-		$ids = array();
-		foreach ($values as $key => $val)
-		{
-			$ids[] = $val[$index];
-
-			foreach (array_keys($val) as $field)
-			{
-				if ($field !== $index)
-				{
-					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
-				}
-			}
-		}
-
-		$cases = '';
-		foreach ($final as $k => $v)
-		{
-			$cases .= $k.' = CASE '."\n";
-
-			foreach ($v as $row)
-			{
-				$cases .= $row."\n";
-			}
-
-			$cases .= 'ELSE '.$k.' END, ';
-		}
-
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
-
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
diff --git a/system/database/drivers/pdo/pdo_forge.php b/system/database/drivers/pdo/pdo_forge.php
index eedd9722d..685b6776d 100644
--- a/system/database/drivers/pdo/pdo_forge.php
+++ b/system/database/drivers/pdo/pdo_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/database/
+ * @link		https://codeigniter.com/database/
  */
 class CI_DB_pdo_forge extends CI_DB_forge {
 
diff --git a/system/database/drivers/pdo/pdo_result.php b/system/database/drivers/pdo/pdo_result.php
index fe26fea6e..bbc2cdc5a 100644
--- a/system/database/drivers/pdo/pdo_result.php
+++ b/system/database/drivers/pdo/pdo_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_result extends CI_DB_result {
 
diff --git a/system/database/drivers/pdo/pdo_utility.php b/system/database/drivers/pdo/pdo_utility.php
index 72169c3ca..5029cac94 100644
--- a/system/database/drivers/pdo/pdo_utility.php
+++ b/system/database/drivers/pdo/pdo_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.1.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/database/
+ * @link		https://codeigniter.com/database/
  */
 class CI_DB_pdo_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
index 7a767ef40..7eaeaa1fd 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php b/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
index 6b420540c..3f636d3bd 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_4d_forge extends CI_DB_pdo_forge {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index 98ac89f3d..fc49e0dd0 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 
@@ -171,47 +171,6 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update_Batch statement
-	 *
-	 * Generates a platform-specific batch update string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$values	Update data
-	 * @param	string	$index	WHERE key
-	 * @return	string
-	 */
-	protected function _update_batch($table, $values, $index)
-	{
-		$ids = array();
-		foreach ($values as $key => $val)
-		{
-			$ids[] = $val[$index];
-
-			foreach (array_keys($val) as $field)
-			{
-				if ($field !== $index)
-				{
-					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
-				}
-			}
-		}
-
-		$cases = '';
-		foreach ($final as $k => $v)
-		{
-			$cases .= $k." = CASE \n"
-				.implode("\n", $v)."\n"
-				.'ELSE '.$k.' END), ';
-		}
-
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
-
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
index 15b100d9b..276cbb6bc 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_cubrid_forge extends CI_DB_pdo_forge {
 
@@ -178,6 +178,9 @@ class CI_DB_pdo_cubrid_forge extends CI_DB_pdo_forge {
 				$attributes['TYPE'] = 'INTEGER';
 				$attributes['UNSIGNED'] = FALSE;
 				return;
+			case 'LONGTEXT':
+				$attributes['TYPE'] = 'STRING';
+				return;
 			default: return;
 		}
 	}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index ae2b9983b..3249a1d7f 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 
@@ -126,7 +126,12 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		$this->conn_id = parent::db_connect($persistent);
+		if ($persistent === TRUE)
+		{
+			log_message('debug', "dblib driver doesn't support persistent connections");
+		}
+
+		$this->conn_id = parent::db_connect(FALSE);
 
 		if ( ! is_object($this->conn_id))
 		{
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
index d3dd9032e..d0cca38dd 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_dblib_forge extends CI_DB_pdo_forge {
 
@@ -111,6 +111,11 @@ class CI_DB_pdo_dblib_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index 0bafde861..aa5e7d6e7 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 
@@ -260,4 +260,20 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $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, $values)
+	{
+		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+	}
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
index ad28a6550..20c5a6897 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_firebird_forge extends CI_DB_pdo_forge {
 
@@ -97,7 +97,7 @@ class CI_DB_pdo_firebird_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		if ( ! ibase_drop_db($this->conn_id))
 		{
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
index 5dba26ec9..26b556a78 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
index d1b5f92c9..4238ca082 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_ibm_forge extends CI_DB_pdo_forge {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index 9f8c017a5..050171f64 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php b/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
index 22bdf6104..2ddc2a933 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_informix_forge extends CI_DB_pdo_forge {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index e9d25cebc..66c15dac6 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 
@@ -73,7 +73,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * @var	bool
 	 */
-	public $stricton = FALSE;
+	public $stricton;
 
 	// --------------------------------------------------------------------
 
@@ -106,7 +106,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 			empty($this->database) OR $this->dsn .= ';dbname='.$this->database;
 			empty($this->char_set) OR $this->dsn .= ';charset='.$this->char_set;
 		}
-		elseif ( ! empty($this->char_set) && strpos($this->dsn, 'charset=', 6) === FALSE && is_php('5.3.6'))
+		elseif ( ! empty($this->char_set) && strpos($this->dsn, 'charset=', 6) === FALSE)
 		{
 			$this->dsn .= ';charset='.$this->char_set;
 		}
@@ -122,26 +122,34 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		/* Prior to PHP 5.3.6, even if the charset was supplied in the DSN
-		 * on connect - it was ignored. This is a work-around for the issue.
-		 *
-		 * Reference: http://www.php.net/manual/en/ref.pdo-mysql.connection.php
-		 */
-		if ( ! is_php('5.3.6') && ! empty($this->char_set))
+		if (isset($this->stricton))
 		{
-			$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES '.$this->char_set
-				.(empty($this->dbcollat) ? '' : ' COLLATE '.$this->dbcollat);
-		}
-
-		if ($this->stricton)
-		{
-			if (empty($this->options[PDO::MYSQL_ATTR_INIT_COMMAND]))
+			if ($this->stricton)
 			{
-				$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET SESSION sql_mode="STRICT_ALL_TABLES"';
+				$sql = 'CONCAT(@@sql_mode, ",", "STRICT_ALL_TABLES")';
 			}
 			else
 			{
-				$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] .= ', @@session.sql_mode = "STRICT_ALL_TABLES"';
+				$sql = 'REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
+                                        @@sql_mode,
+                                        "STRICT_ALL_TABLES,", ""),
+                                        ",STRICT_ALL_TABLES", ""),
+                                        "STRICT_ALL_TABLES", ""),
+                                        "STRICT_TRANS_TABLES,", ""),
+                                        ",STRICT_TRANS_TABLES", ""),
+                                        "STRICT_TRANS_TABLES", "")';
+			}
+
+			if ( ! empty($sql))
+			{
+				if (empty($this->options[PDO::MYSQL_ATTR_INIT_COMMAND]))
+				{
+					$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET SESSION sql_mode = '.$sql;
+				}
+				else
+				{
+					$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] .= ', @@session.sql_mode = '.$sql;
+				}
 			}
 		}
 
@@ -150,8 +158,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 			$this->options[PDO::MYSQL_ATTR_COMPRESS] = TRUE;
 		}
 
-		// SSL support was added to PDO_MYSQL in PHP 5.3.7
-		if (is_array($this->encrypt) && is_php('5.3.7'))
+		if (is_array($this->encrypt))
 		{
 			$ssl = array();
 			empty($this->encrypt['ssl_key'])    OR $ssl[PDO::MYSQL_ATTR_SSL_KEY]    = $this->encrypt['ssl_key'];
@@ -199,6 +206,56 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 		if (FALSE !== $this->simple_query('USE '.$this->escape_identifiers($database)))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_begin()
+	{
+		$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, FALSE);
+		return $this->conn_id->beginTransaction();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_commit()
+	{
+		if ($this->conn_id->commit())
+		{
+			$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, TRUE);
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_rollback()
+	{
+		if ($this->conn_id->rollBack())
+		{
+			$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, TRUE);
 			return TRUE;
 		}
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
index e8e24c6b3..c7a92b826 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_mysql_forge extends CI_DB_pdo_forge {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index d17e311f7..abf9167d6 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 
@@ -130,6 +130,29 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Database version number
+	 *
+	 * @return	string
+	 */
+	public function version()
+	{
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+
+		$version_string = parent::version();
+		if (preg_match('#Release\s(?<version>\d+(?:\.\d+)+)#', $version_string, $match))
+		{
+			return $this->data_cache['version'] = $match[1];
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Show table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
@@ -288,6 +311,14 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 */
 	protected function _limit($sql)
 	{
+		if (version_compare($this->version(), '12.1', '>='))
+		{
+			// OFFSET-FETCH can be used only with the ORDER BY clause
+			empty($this->qb_orderby) && $sql .= ' ORDER BY 1';
+
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
+		}
+
 		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
 			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1): '');
 	}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
index e2078cf39..c8983ee56 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 
@@ -54,18 +54,18 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 	protected $_create_database	= FALSE;
 
 	/**
-	 * DROP DATABASE statement
+	 * CREATE TABLE IF statement
 	 *
 	 * @var	string
 	 */
-	protected $_drop_database	= FALSE;
+	protected $_create_table_if	= FALSE;
 
 	/**
-	 * CREATE TABLE IF statement
+	 * DROP DATABASE statement
 	 *
 	 * @var	string
 	 */
-	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
+	protected $_drop_database	= FALSE;
 
 	/**
 	 * UNSIGNED support
@@ -146,4 +146,31 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 		// Not supported - sequences and triggers must be used instead
 	}
 
+	/**
+	 * 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'] = 'NUMBER';
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			default: return;
+		}
+	}
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index 51c70b630..5a492d881 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 
@@ -161,106 +161,69 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Show table query
-	 *
-	 * Generates a platform-specific query string so that the table names can be fetched
+	 * Platform-dependent string escape
 	 *
-	 * @param	bool	$prefix_limit
+	 * @param	string
 	 * @return	string
 	 */
-	protected function _list_tables($prefix_limit = FALSE)
+	protected function _escape_str($str)
 	{
-		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = '".$this->schema."'";
-
-		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
-		{
-			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' "
-				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
-		}
-
-		return $sql;
+		$this->db->display_error('db_unsupported_feature');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Show column query
+	 * Determines if a query is a "write" type.
 	 *
-	 * Generates a platform-specific query string so that the column names can be fetched
-	 *
-	 * @param	string	$table
-	 * @return	string
+	 * @param	string	An SQL query string
+	 * @return	bool
 	 */
-	protected function _list_columns($table = '')
+	public function is_write_type($sql)
 	{
-		return 'SELECT column_name FROM information_schema.columns WHERE table_name = '.$this->escape($table);
-	}
-
-	// --------------------------------------------------------------------
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
+		{
+			return FALSE;
+		}
 
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @param	array	$values
-	 * @return	string
-	 */
-	protected function _update($table, $values)
-	{
-		$this->qb_limit = FALSE;
-		$this->qb_orderby = array();
-		return parent::_update($table, $values);
+		return parent::is_write_type($sql);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
+	 * Show table query
 	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this method maps to 'DELETE FROM table'
+	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	string	$table
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
-	protected function _truncate($table)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
-		return 'DELETE FROM '.$table;
-	}
+		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = '".$this->schema."'";
 
-	// --------------------------------------------------------------------
+		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
+		{
+			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
+		}
 
-	/**
-	 * Delete statement
-	 *
-	 * Generates a platform-specific delete string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _delete($table)
-	{
-		$this->qb_limit = FALSE;
-		return parent::_delete($table);
+		return $sql;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * LIMIT
+	 * Show column query
 	 *
-	 * Generates a platform-specific LIMIT clause
+	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	$sql	SQL Query
+	 * @param	string	$table
 	 * @return	string
 	 */
-	protected function _limit($sql)
+	protected function _list_columns($table = '')
 	{
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$this->qb_limit.' ', $sql);
+		return 'SELECT column_name FROM information_schema.columns WHERE table_name = '.$this->escape($table);
 	}
-
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
index 291352982..a2a3bada3 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/database/
+ * @link		https://codeigniter.com/database/
  */
 class CI_DB_pdo_odbc_forge extends CI_DB_pdo_forge {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index 2dd41ca87..9aed3a2fe 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 
@@ -154,7 +154,12 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		return (bool) preg_match('/^\s*"?(SET|INSERT(?![^\)]+\)\s+RETURNING)|UPDATE(?!.*\sRETURNING)|DELETE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i', str_replace(array("\r\n", "\r", "\n"), ' ', $sql));
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
+		{
+			return FALSE;
+		}
+
+		return parent::is_write_type($sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -321,13 +326,13 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 		$ids = array();
 		foreach ($values as $key => $val)
 		{
-			$ids[] = $val[$index];
+			$ids[] = $val[$index]['value'];
 
 			foreach (array_keys($val) as $field)
 			{
 				if ($field !== $index)
 				{
-					$final[$field][] = 'WHEN '.$val[$index].' THEN '.$val[$field];
+					$final[$val[$field]['field']][] = 'WHEN '.$val[$index]['value'].' THEN '.$val[$field]['value'];
 				}
 			}
 		}
@@ -335,12 +340,12 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 		$cases = '';
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = (CASE '.$index."\n"
+			$cases .= $k.' = (CASE '.$val[$index]['field']."\n"
 				.implode("\n", $v)."\n"
 				.'ELSE '.$k.' END), ';
 		}
 
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+		$this->where($val[$index]['field'].' IN('.implode(',', $ids).')', NULL, FALSE);
 
 		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
index b4a6160a8..b00af4ad0 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
 
@@ -168,7 +168,7 @@ class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index 409e6501b..9b70f3ea6 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 
@@ -66,7 +66,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * @var	array
 	 */
-	protected $_random_keyword = ' RANDOM()';
+	protected $_random_keyword = array('RANDOM()', 'RANDOM()');
 
 	// --------------------------------------------------------------------
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
index 15afbdef5..18c475b17 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
 
@@ -101,7 +101,7 @@ class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function create_database($db_name = '')
+	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
@@ -116,7 +116,7 @@ class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		// In SQLite, a database is dropped when we delete a file
 		if (file_exists($this->db->database))
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index f8ae5f6db..1cf6c614d 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
index 602a1d426..82a0d515d 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_sqlsrv_forge extends CI_DB_pdo_forge {
 
@@ -111,6 +111,11 @@ class CI_DB_pdo_sqlsrv_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 7be07c3bf..75b1d4c37 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_postgre_driver extends CI_DB {
 
@@ -163,6 +163,13 @@ class CI_DB_postgre_driver extends CI_DB {
 				return FALSE;
 			}
 
+			if (pg_set_client_encoding($this->conn_id, $this->char_set) !== 0)
+			{
+				log_message('error', "Database: Unable to set the configured connection charset ('{$this->char_set}').");
+				pg_close($this->conn_id);
+				return ($this->db->db_debug) ? $this->display_error('db_unable_to_set_charset', $this->char_set) : FALSE;
+			}
+
 			empty($this->schema) OR $this->simple_query('SET search_path TO '.$this->schema.',public');
 		}
 
@@ -190,19 +197,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @param	string	$charset
-	 * @return	bool
-	 */
-	protected function _db_set_charset($charset)
-	{
-		return (pg_set_client_encoding($this->conn_id, $charset) === 0);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
@@ -247,22 +241,10 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return (bool) pg_query($this->conn_id, 'BEGIN');
 	}
 
@@ -273,14 +255,8 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return (bool) pg_query($this->conn_id, 'COMMIT');
 	}
 
@@ -291,14 +267,8 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return (bool) pg_query($this->conn_id, 'ROLLBACK');
 	}
 
@@ -312,13 +282,18 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function is_write_type($sql)
 	{
-		return (bool) preg_match('/^\s*"?(SET|INSERT(?![^\)]+\)\s+RETURNING)|UPDATE(?!.*\sRETURNING)|DELETE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i', str_replace(array("\r\n", "\r", "\n"), ' ', $sql));
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
+		{
+			return FALSE;
+		}
+
+		return parent::is_write_type($sql);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -340,7 +315,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function escape($str)
 	{
-		if (is_php('5.4.4') && (is_string($str) OR (is_object($str) && method_exists($str, '__toString'))))
+		if (is_string($str) OR (is_object($str) && method_exists($str, '__toString')))
 		{
 			return pg_escape_literal($this->conn_id, $str);
 		}
@@ -490,7 +465,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -569,13 +544,13 @@ class CI_DB_postgre_driver extends CI_DB {
 		$ids = array();
 		foreach ($values as $key => $val)
 		{
-			$ids[] = $val[$index];
+			$ids[] = $val[$index]['value'];
 
 			foreach (array_keys($val) as $field)
 			{
 				if ($field !== $index)
 				{
-					$final[$field][] = 'WHEN '.$val[$index].' THEN '.$val[$field];
+					$final[$val[$field]['field']][] = 'WHEN '.$val[$index]['value'].' THEN '.$val[$field]['value'];
 				}
 			}
 		}
@@ -583,12 +558,12 @@ class CI_DB_postgre_driver extends CI_DB {
 		$cases = '';
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = (CASE '.$index."\n"
+			$cases .= $k.' = (CASE '.$val[$index]['field']."\n"
 				.implode("\n", $v)."\n"
 				.'ELSE '.$k.' END), ';
 		}
 
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+		$this->where($val[$index]['field'].' IN('.implode(',', $ids).')', NULL, FALSE);
 
 		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index d26e84cbc..cdbff4c4b 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_postgre_forge extends CI_DB_forge {
 
@@ -163,7 +163,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/system/database/drivers/postgre/postgre_result.php b/system/database/drivers/postgre/postgre_result.php
index a8ad24edf..57864a7f3 100644
--- a/system/database/drivers/postgre/postgre_result.php
+++ b/system/database/drivers/postgre/postgre_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_postgre_result extends CI_DB_result {
 
diff --git a/system/database/drivers/postgre/postgre_utility.php b/system/database/drivers/postgre/postgre_utility.php
index 7c6c02590..5ca358da5 100644
--- a/system/database/drivers/postgre/postgre_utility.php
+++ b/system/database/drivers/postgre/postgre_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_postgre_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/sqlite/index.html b/system/database/drivers/sqlite/index.html
deleted file mode 100644
index b702fbc39..000000000
--- a/system/database/drivers/sqlite/index.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-	<title>403 Forbidden</title>
-</head>
-<body>
-
-<p>Directory access is forbidden.</p>
-
-</body>
-</html>
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
deleted file mode 100644
index 9d9caa0b4..000000000
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ /dev/null
@@ -1,357 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Database Adapter Class
- *
- * Note: _DB is an extender class that the app controller
- * creates dynamically based on whether the query builder
- * class is being used or not.
- *
- * @package		CodeIgniter
- * @subpackage	Drivers
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_driver extends CI_DB {
-
-	/**
-	 * Database driver
-	 *
-	 * @var	string
-	 */
-	public $dbdriver = 'sqlite';
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * ORDER BY random keyword
-	 *
-	 * @var	array
-	 */
-	protected $_random_keyword = array('RANDOM()', 'RANDOM()');
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Non-persistent database connection
-	 *
-	 * @param	bool	$persistent
-	 * @return	resource
-	 */
-	public function db_connect($persistent = FALSE)
-	{
-		$error = NULL;
-		$conn_id = ($persistent === TRUE)
-			? sqlite_popen($this->database, 0666, $error)
-			: sqlite_open($this->database, 0666, $error);
-
-		isset($error) && log_message('error', $error);
-
-		return $conn_id;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Database version number
-	 *
-	 * @return	string
-	 */
-	public function version()
-	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = sqlite_libversion();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Execute the query
-	 *
-	 * @param	string	$sql	an SQL query
-	 * @return	resource
-	 */
-	protected function _execute($sql)
-	{
-		return $this->is_write_type($sql)
-			? sqlite_exec($this->conn_id, $sql)
-			: sqlite_query($this->conn_id, $sql);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Begin Transaction
-	 *
-	 * @param	bool	$test_mode
-	 * @return	bool
-	 */
-	public function trans_begin($test_mode = FALSE)
-	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
-		$this->simple_query('BEGIN TRANSACTION');
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Commit Transaction
-	 *
-	 * @return	bool
-	 */
-	public function trans_commit()
-	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		$this->simple_query('COMMIT');
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Rollback Transaction
-	 *
-	 * @return	bool
-	 */
-	public function trans_rollback()
-	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		$this->simple_query('ROLLBACK');
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Platform-dependant string escape
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _escape_str($str)
-	{
-		return sqlite_escape_string($str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Affected Rows
-	 *
-	 * @return	int
-	 */
-	public function affected_rows()
-	{
-		return sqlite_changes($this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert ID
-	 *
-	 * @return	int
-	 */
-	public function insert_id()
-	{
-		return sqlite_last_insert_rowid($this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * List table query
-	 *
-	 * Generates a platform-specific query string so that the table names can be fetched
-	 *
-	 * @param	bool	$prefix_limit
-	 * @return	string
-	 */
-	protected function _list_tables($prefix_limit = FALSE)
-	{
-		$sql = "SELECT name FROM sqlite_master WHERE type='table'";
-
-		if ($prefix_limit !== FALSE && $this->dbprefix != '')
-		{
-			return $sql." AND 'name' LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-		}
-
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Show column query
-	 *
-	 * Generates a platform-specific query string so that the column names can be fetched
-	 *
-	 * @param	string	$table
-	 * @return	bool
-	 */
-	protected function _list_columns($table = '')
-	{
-		// Not supported
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Returns an object with field data
-	 *
-	 * @param	string	$table
-	 * @return	array
-	 */
-	public function field_data($table)
-	{
-		if (($query = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
-		{
-			return FALSE;
-		}
-
-		$query = $query->result_array();
-		if (empty($query))
-		{
-			return FALSE;
-		}
-
-		$retval = array();
-		for ($i = 0, $c = count($query); $i < $c; $i++)
-		{
-			$retval[$i]			= new stdClass();
-			$retval[$i]->name		= $query[$i]['name'];
-			$retval[$i]->type		= $query[$i]['type'];
-			$retval[$i]->max_length		= NULL;
-			$retval[$i]->default		= $query[$i]['dflt_value'];
-			$retval[$i]->primary_key	= isset($query[$i]['pk']) ? (int) $query[$i]['pk'] : 0;
-		}
-
-		return $retval;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Error
-	 *
-	 * Returns an array containing code and message of the last
-	 * database error that has occured.
-	 *
-	 * @return	array
-	 */
-	public function error()
-	{
-		$error = array('code' => sqlite_last_error($this->conn_id));
-		$error['message'] = sqlite_error_string($error['code']);
-		return $error;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Replace statement
-	 *
-	 * Generates a platform-specific replace string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$keys	INSERT keys
-	 * @param	array	$values	INSERT values
-	 * @return	string
-	 */
-	protected function _replace($table, $keys, $values)
-	{
-		return 'INSERT OR '.parent::_replace($table, $keys, $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this function maps to 'DELETE FROM table'
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'DELETE FROM '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Close DB Connection
-	 *
-	 * @return	void
-	 */
-	protected function _close()
-	{
-		sqlite_close($this->conn_id);
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_forge.php b/system/database/drivers/sqlite/sqlite_forge.php
deleted file mode 100644
index 2bba330c0..000000000
--- a/system/database/drivers/sqlite/sqlite_forge.php
+++ /dev/null
@@ -1,205 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Forge Class
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
- */
-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	$db_name	(ignored)
-	 * @return	bool
-	 */
-	public function create_database($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 = '')
-	{
-		if ( ! file_exists($this->db->database) OR ! @unlink($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;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * ALTER TABLE
-	 *
-	 * @todo	implement drop_column(), modify_column()
-	 * @param	string	$alter_type	ALTER type
-	 * @param	string	$table		Table name
-	 * @param	mixed	$field		Column definition
-	 * @return	string|string[]
-	 */
-	protected function _alter_table($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();
-		}
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
deleted file mode 100644
index 487d00366..000000000
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ /dev/null
@@ -1,164 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Result Class
- *
- * This class extends the parent result class: CI_DB_result
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_result extends CI_DB_result {
-
-	/**
-	 * Number of rows in the result set
-	 *
-	 * @return	int
-	 */
-	public function num_rows()
-	{
-		return is_int($this->num_rows)
-			? $this->num_rows
-			: $this->num_rows = @sqlite_num_rows($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Number of fields in the result set
-	 *
-	 * @return	int
-	 */
-	public function num_fields()
-	{
-		return @sqlite_num_fields($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch Field Names
-	 *
-	 * Generates an array of column names
-	 *
-	 * @return	array
-	 */
-	public function list_fields()
-	{
-		$field_names = array();
-		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
-		{
-			$field_names[$i] = sqlite_field_name($this->result_id, $i);
-		}
-
-		return $field_names;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Field data
-	 *
-	 * Generates an array of objects containing field meta-data
-	 *
-	 * @return	array
-	 */
-	public function field_data()
-	{
-		$retval = array();
-		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
-		{
-			$retval[$i]			= new stdClass();
-			$retval[$i]->name		= sqlite_field_name($this->result_id, $i);
-			$retval[$i]->type		= NULL;
-			$retval[$i]->max_length		= NULL;
-		}
-
-		return $retval;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * 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.
-	 *
-	 * @param	int	$n
-	 * @return	bool
-	 */
-	public function data_seek($n = 0)
-	{
-		return sqlite_seek($this->result_id, $n);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Result - associative array
-	 *
-	 * Returns the result set as an array
-	 *
-	 * @return	array
-	 */
-	protected function _fetch_assoc()
-	{
-		return sqlite_fetch_array($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Result - object
-	 *
-	 * Returns the result set as an object
-	 *
-	 * @param	string	$class_name
-	 * @return	object
-	 */
-	protected function _fetch_object($class_name = 'stdClass')
-	{
-		return sqlite_fetch_object($this->result_id, $class_name);
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_utility.php b/system/database/drivers/sqlite/sqlite_utility.php
deleted file mode 100644
index 9cb454274..000000000
--- a/system/database/drivers/sqlite/sqlite_utility.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Utility Class
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_utility extends CI_DB_utility {
-
-	/**
-	 * Export
-	 *
-	 * @param	array	$params	Preferences
-	 * @return	mixed
-	 */
-	protected function _backup($params = array())
-	{
-		// Currently unsupported
-		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 31e37de91..d131baad7 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		Andrey Andreev
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlite3_driver extends CI_DB {
 
@@ -134,22 +134,10 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return $this->conn_id->exec('BEGIN TRANSACTION');
 	}
 
@@ -160,14 +148,8 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->conn_id->exec('END TRANSACTION');
 	}
 
@@ -178,21 +160,15 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return $this->conn_id->exec('ROLLBACK');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -315,7 +291,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/sqlite3/sqlite3_forge.php b/system/database/drivers/sqlite3/sqlite3_forge.php
index 24690ba20..5ee6daae3 100644
--- a/system/database/drivers/sqlite3/sqlite3_forge.php
+++ b/system/database/drivers/sqlite3/sqlite3_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/database/
+ * @link	https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlite3_forge extends CI_DB_forge {
 
@@ -87,7 +87,7 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	 * @param	string	$db_name
 	 * @return	bool
 	 */
-	public function create_database($db_name = '')
+	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
@@ -102,7 +102,7 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		// In SQLite, a database is dropped when we delete a file
 		if (file_exists($this->db->database))
diff --git a/system/database/drivers/sqlite3/sqlite3_result.php b/system/database/drivers/sqlite3/sqlite3_result.php
index 387481b7f..03751f0dc 100644
--- a/system/database/drivers/sqlite3/sqlite3_result.php
+++ b/system/database/drivers/sqlite3/sqlite3_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		Andrey Andreev
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlite3_result extends CI_DB_result {
 
diff --git a/system/database/drivers/sqlite3/sqlite3_utility.php b/system/database/drivers/sqlite3/sqlite3_utility.php
index 336f68754..20d562f96 100644
--- a/system/database/drivers/sqlite3/sqlite3_utility.php
+++ b/system/database/drivers/sqlite3/sqlite3_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/database/
+ * @link	https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlite3_utility extends CI_DB_utility {
 
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 16f77fab2..e4f403180 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.3
  * @filesource
  */
@@ -48,7 +48,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlsrv_driver extends CI_DB {
 
@@ -141,13 +141,14 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 			unset($connection['UID'], $connection['PWD']);
 		}
 
-		$this->conn_id = sqlsrv_connect($this->hostname, $connection);
-
-		// Determine how identifiers are escaped
-		$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
-		$query = $query->row_array();
-		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
-		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
+		if (FALSE !== ($this->conn_id = sqlsrv_connect($this->hostname, $connection)))
+		{
+			// Determine how identifiers are escaped
+			$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
+			$query = $query->row_array();
+			$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
+			$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
+		}
 
 		return $this->conn_id;
 	}
@@ -170,6 +171,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		if ($this->_execute('USE '.$this->escape_identifiers($database)))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -196,22 +198,10 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		return sqlsrv_begin_transaction($this->conn_id);
 	}
 
@@ -222,14 +212,8 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return sqlsrv_commit($this->conn_id);
 	}
 
@@ -240,14 +224,8 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		return sqlsrv_rollback($this->conn_id);
 	}
 
@@ -274,9 +252,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		$query = $this->query('SELECT @@IDENTITY AS insert_id');
-		$query = $query->row();
-		return $query->insert_id;
+		return $this->query('SELECT SCOPE_IDENTITY() AS insert_id')->row()->insert_id;
 	}
 
 	// --------------------------------------------------------------------
@@ -382,7 +358,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/sqlsrv/sqlsrv_forge.php b/system/database/drivers/sqlsrv/sqlsrv_forge.php
index b22b60a4a..aa8490ee4 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_forge.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.3
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlsrv_forge extends CI_DB_forge {
 
@@ -111,6 +111,11 @@ class CI_DB_sqlsrv_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/system/database/drivers/sqlsrv/sqlsrv_result.php b/system/database/drivers/sqlsrv/sqlsrv_result.php
index d2be926aa..f784ebea8 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_result.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.3
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlsrv_result extends CI_DB_result {
 
diff --git a/system/database/drivers/sqlsrv/sqlsrv_utility.php b/system/database/drivers/sqlsrv/sqlsrv_utility.php
index 77cf0aaf3..19c93d0c6 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_utility.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.3
  * @filesource
  */
@@ -42,7 +42,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *
  * @category	Database
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_sqlsrv_utility extends CI_DB_utility {