Merge upstream branch

19 files changed, 436 insertions, 465 deletions

diff --git a/system/database/DB.php b/system/database/DB.php
index 116116bf4..0d81e40d3 100755
--- a/system/database/DB.php
+++ b/system/database/DB.php
@@ -37,11 +37,11 @@
 function &DB($params = '', $active_record_override = NULL)
 {
 	// Load the DB config file if a DSN string wasn't passed
-	if (is_string($params) AND strpos($params, '://') === FALSE)
+	if (is_string($params) && strpos($params, '://') === FALSE)
 	{
 		// Is the config file in the environment folder?
 		if (( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/database.php'))
-			AND ! file_exists($file_path = APPPATH.'config/database.php'))
+			&& ! file_exists($file_path = APPPATH.'config/database.php'))
 		{
 			show_error('The configuration file database.php does not exist.');
 		}
@@ -74,34 +74,30 @@ function &DB($params = '', $active_record_override = NULL)
 		 *  parameter. DSNs must have this prototype:
 		 *  $dsn = 'driver://username:password@hostname/database';
 		 */
-		if (($dns = @parse_url($params)) === FALSE)
+		if (($dsn = @parse_url($params)) === FALSE)
 		{
 			show_error('Invalid DB Connection String');
 		}
 
 		$params = array(
-				'dbdriver'	=> $dns['scheme'],
-				'hostname'	=> (isset($dns['host'])) ? rawurldecode($dns['host']) : '',
-				'port'		=> (isset($dns['port'])) ? rawurldecode($dns['port']) : '',
-				'username'	=> (isset($dns['user'])) ? rawurldecode($dns['user']) : '',
-				'password'	=> (isset($dns['pass'])) ? rawurldecode($dns['pass']) : '',
-				'database'	=> (isset($dns['path'])) ? rawurldecode(substr($dns['path'], 1)) : ''
+				'dbdriver'	=> $dsn['scheme'],
+				'hostname'	=> isset($dsn['host']) ? rawurldecode($dsn['host']) : '',
+				'port'		=> isset($dsn['port']) ? rawurldecode($dsn['port']) : '',
+				'username'	=> isset($dsn['user']) ? rawurldecode($dsn['user']) : '',
+				'password'	=> isset($dsn['pass']) ? rawurldecode($dsn['pass']) : '',
+				'database'	=> isset($dsn['path']) ? rawurldecode(substr($dsn['path'], 1)) : ''
 			);
 
 		// were additional config items set?
-		if (isset($dns['query']))
+		if (isset($dsn['query']))
 		{
-			parse_str($dns['query'], $extra);
+			parse_str($dsn['query'], $extra);
+
 			foreach ($extra as $key => $val)
 			{
-				// booleans please
-				if (strtoupper($val) === 'TRUE')
-				{
-					$val = TRUE;
-				}
-				elseif (strtoupper($val) === 'FALSE')
+				if (is_string($val) && in_array(strtoupper($val), array('TRUE', 'FALSE', 'NULL')))
 				{
-					$val = FALSE;
+					$val = var_export($val);
 				}
 
 				$params[$key] = $val;
@@ -138,7 +134,12 @@ function &DB($params = '', $active_record_override = NULL)
 		class CI_DB extends CI_DB_driver { }
 	}
 
-	require_once(BASEPATH.'database/drivers/'.$params['dbdriver'].'/'.$params['dbdriver'].'_driver.php');
+	// Load the DB driver
+	$driver_file = BASEPATH.'database/drivers/'.$params['dbdriver'].'/'.$params['dbdriver'].'_driver.php';
+
+	if ( ! file_exists($driver_file)) show_error('Invalid DB driver');
+
+	require_once($driver_file);
 
 	// Instantiate the DB adapter
 	$driver = 'CI_DB_'.$params['dbdriver'].'_driver';
@@ -158,4 +159,4 @@ function &DB($params = '', $active_record_override = NULL)
 }
 
 /* End of file DB.php */
-/* Location: ./system/database/DB.php */
+/* Location: ./system/database/DB.php */
\ No newline at end of file
diff --git a/system/database/DB_active_rec.php b/system/database/DB_active_rec.php
index fe591dda1..b324226ab 100644
--- a/system/database/DB_active_rec.php
+++ b/system/database/DB_active_rec.php
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * Active Record Class
  *
@@ -422,7 +420,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->ar_where) === 0 AND count($this->ar_cache_where) === 0) ? '' : $type;
+			$prefix = (count($this->ar_where) === 0 && count($this->ar_cache_where) === 0) ? '' : $type;
 
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
@@ -537,7 +535,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * @param	string	The field to search
 	 * @param	array	The values searched on
-	 * @param	boolean	If the statement would be IN or NOT IN
+	 * @param	bool	If the statement would be IN or NOT IN
 	 * @param	string
 	 * @return	object
 	 */
@@ -719,7 +717,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	{
 		$type = $this->_group_get_type($type);
 		$this->ar_where_group_started = TRUE;
-		$prefix = (count($this->ar_where) === 0 AND count($this->ar_cache_where) === 0) ? '' : $type;
+		$prefix = (count($this->ar_where) === 0 && count($this->ar_cache_where) === 0) ? '' : $type;
 		$this->ar_where[] = $value = $prefix.$not.str_repeat(' ', ++$this->ar_where_group_count).' (';
 
 		if ($this->ar_caching)
@@ -984,8 +982,8 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	/**
 	 * Sets the LIMIT value
 	 *
-	 * @param	integer	the limit value
-	 * @param	integer	the offset value
+	 * @param	int	the limit value
+	 * @param	int	the offset value
 	 * @return	object
 	 */
 	public function limit($value, $offset = NULL)
@@ -1005,7 +1003,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	/**
 	 * Sets the OFFSET value
 	 *
-	 * @param	integer	the offset value
+	 * @param	int	the offset value
 	 * @return	object
 	 */
 	public function offset($offset)
@@ -1021,7 +1019,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * @param	mixed
 	 * @param	string
-	 * @param	boolean
+	 * @param	bool
 	 * @return	object
 	 */
 	public function set($key, $value = '', $escape = TRUE)
@@ -1055,9 +1053,8 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Compiles a SELECT query string and returns the sql.
 	 *
-	 * @access	public
 	 * @param	string	the table name to select from (optional)
-	 * @param	boolean	TRUE: resets AR values; FALSE: leave AR vaules alone
+	 * @param	bool	TRUE: resets AR values; FALSE: leave AR vaules alone
 	 * @return	string
 	 */
 	public function get_compiled_select($table = '', $reset = TRUE)
@@ -1226,7 +1223,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * @param	mixed
 	 * @param	string
-	 * @param	boolean
+	 * @param	bool
 	 * @return	object
 	 */
 	public function set_insert_batch($key, $value = '', $escape = TRUE)
@@ -1283,9 +1280,8 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Compiles an insert query and returns the sql
 	 *
-	 * @access	public
 	 * @param	string	the table to insert into
-	 * @param	boolean	TRUE: reset AR values; FALSE: leave AR values alone
+	 * @param	bool	TRUE: reset AR values; FALSE: leave AR values alone
 	 * @return	string
 	 */
 	public function get_compiled_insert($table = '', $reset = TRUE)
@@ -1316,7 +1312,6 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Compiles an insert string and runs the query
 	 *
-	 * @access	public
 	 * @param	string	the table to insert data into
 	 * @param	array	an associative array of insert values
 	 * @return	object
@@ -1352,7 +1347,6 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 * validate that the there data is actually being set and that table
 	 * has been chosen to be inserted into.
 	 *
-	 * @access	public
 	 * @param	string	the table to insert data into
 	 * @return	string
 	 */
@@ -1423,9 +1417,8 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Compiles an update query and returns the sql
 	 *
-	 * @access	public
 	 * @param	string	the table to update
-	 * @param	boolean	TRUE: reset AR values; FALSE: leave AR values alone
+	 * @param	bool	TRUE: reset AR values; FALSE: leave AR values alone
 	 * @return	string
 	 */
 	public function get_compiled_update($table = '', $reset = TRUE)
@@ -1499,7 +1492,6 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 * validate that data is actually being set and that a table has been
 	 * chosen to be update.
 	 *
-	 * @access	public
 	 * @param	string	the table to update data on
 	 * @return	bool
 	 */
@@ -1584,7 +1576,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * @param	array
 	 * @param	string
-	 * @param	boolean
+	 * @param	bool
 	 * @return	object
 	 */
 	public function set_update_batch($key, $index = '', $escape = TRUE)
@@ -1696,9 +1688,8 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Compiles a delete query string and returns the sql
 	 *
-	 * @access	public
 	 * @param	string	the table to delete from
-	 * @param	boolean	TRUE: reset AR values; FALSE: leave AR values alone
+	 * @param	bool	TRUE: reset AR values; FALSE: leave AR values alone
 	 * @return	string
 	 */
 	public function get_compiled_delete($table = '', $reset = TRUE)
@@ -1719,7 +1710,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 * @param	mixed	the table(s) to delete from. String or array
 	 * @param	mixed	the where clause
 	 * @param	mixed	the limit clause
-	 * @param	boolean
+	 * @param	bool
 	 * @return	object
 	 */
 	public function delete($table = '', $where = '', $limit = NULL, $reset_data = TRUE)
@@ -2062,7 +2053,6 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	 *
 	 * Empties the AR cache
 	 *
-	 * @access	public
 	 * @return	void
 	 */
 	public function flush_cache()
@@ -2114,7 +2104,7 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 
 		// If we are "protecting identifiers" we need to examine the "from"
 		// portion of the query to determine if there are any aliases
-		if ($this->_protect_identifiers === TRUE AND count($this->ar_cache_from) > 0)
+		if ($this->_protect_identifiers === TRUE && count($this->ar_cache_from) > 0)
 		{
 			$this->_track_aliases($this->ar_from);
 		}
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 9f1a0b895..45f17e8ec 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -99,9 +99,13 @@ abstract class CI_DB_driver {
 	 */
 	public function initialize()
 	{
-		// If an existing connection resource is available
-		// there is no need to connect and select the database
-		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		/* If an established connection is available, then there's
+		 * no need to connect and select the database.
+		 *
+		 * Depending on the database driver, conn_id can be either
+		 * boolean TRUE, a resource or an object.
+		 */
+		if ($this->conn_id)
 		{
 			return TRUE;
 		}
@@ -188,10 +192,24 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Select database
+	 *
+	 * This is just a dummy method to allow drivers without such
+	 * functionality to not declare it, while others will override it.
+	 *
+	 * @return      bool
+	 */
+	public function db_select()
+	{
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Set client character set
 	 *
 	 * @param	string
-	 * @param	string
 	 * @return	bool
 	 */
 	public function db_set_charset($charset)
@@ -283,17 +301,13 @@ abstract class CI_DB_driver {
 		{
 			log_message('error', 'Invalid query: '.$sql);
 
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_invalid_query');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
 		}
 
 		// Verify table prefix and replace if necessary
-		if ( ($this->dbprefix != '' AND $this->swap_pre != '') AND ($this->dbprefix != $this->swap_pre) )
+		if ($this->dbprefix != '' && $this->swap_pre != '' && $this->dbprefix != $this->swap_pre)
 		{
-			$sql = preg_replace("/(\W)".$this->swap_pre."(\S+?)/", "\\1".$this->dbprefix."\\2", $sql);
+			$sql = preg_replace('/(\W)'.$this->swap_pre.'(\S+?)/', '\\1'.$this->dbprefix.'\\2', $sql);
 		}
 
 		// Compile binds if needed
@@ -305,15 +319,12 @@ abstract class CI_DB_driver {
 		// Is query caching enabled? If the query is a "read type"
 		// we will load the caching class and return the previously
 		// cached query if it exists
-		if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))
+		if ($this->cache_on == TRUE && stripos($sql, 'SELECT') !== FALSE && $this->_cache_init())
 		{
-			if ($this->_cache_init())
+			$this->load_rdriver();
+			if (FALSE !== ($cache = $this->CACHE->read($sql)))
 			{
-				$this->load_rdriver();
-				if (FALSE !== ($cache = $this->CACHE->read($sql)))
-				{
-					return $cache;
-				}
+				return $cache;
 			}
 		}
 
@@ -352,13 +363,7 @@ abstract class CI_DB_driver {
 				$this->trans_complete();
 
 				// Display errors
-				return $this->display_error(
-								array(
-									'Error Number: '.$error['code'],
-									$error['message'],
-									$sql
-								)
-							);
+				return $this->display_error(array('Error Number: '.$error['code'], $error['message'], $sql));
 			}
 
 			return FALSE;
@@ -382,7 +387,7 @@ abstract class CI_DB_driver {
 		{
 			// If caching is enabled we'll auto-cleanup any
 			// existing files related to this particular URI
-			if ($this->cache_on == TRUE AND $this->cache_autodel == TRUE AND $this->_cache_init())
+			if ($this->cache_on == TRUE && $this->cache_autodel == TRUE && $this->_cache_init())
 			{
 				$this->CACHE->delete();
 			}
@@ -404,9 +409,9 @@ abstract class CI_DB_driver {
 
 		$RES->num_rows	= $RES->num_rows();
 
-		// Is query caching enabled?  If so, we'll serialize the
+		// Is query caching enabled? If so, we'll serialize the
 		// result object and save it to a cache file.
-		if ($this->cache_on == TRUE AND $this->_cache_init())
+		if ($this->cache_on == TRUE && $this->_cache_init())
 		{
 			// We'll create a new instance of the result object
 			// only without the platform specific driver since
@@ -415,9 +420,9 @@ abstract class CI_DB_driver {
 			// result object, so we'll have to compile the data
 			// and save it)
 			$CR = new CI_DB_result();
-			$CR->num_rows		= $RES->num_rows();
 			$CR->result_object	= $RES->result_object();
 			$CR->result_array	= $RES->result_array();
+			$CR->num_rows		= $RES->num_rows();
 
 			// Reset these since cached objects can not utilize resource IDs.
 			$CR->conn_id		= NULL;
@@ -608,7 +613,8 @@ abstract class CI_DB_driver {
 
 		// The count of bind should be 1 less then the count of segments
 		// If there are more bind arguments trim it down
-		if (count($binds) >= count($segments)) {
+		if (count($binds) >= count($segments))
+		{
 			$binds = array_slice($binds, 0, count($segments)-1);
 		}
 
@@ -617,8 +623,7 @@ abstract class CI_DB_driver {
 		$i = 0;
 		foreach ($binds as $bind)
 		{
-			$result .= $this->escape($bind);
-			$result .= $segments[++$i];
+			$result .= $this->escape($bind).$segments[++$i];
 		}
 
 		return $result;
@@ -689,15 +694,15 @@ abstract class CI_DB_driver {
 	{
 		if (is_string($str) OR method_exists($str, '__toString'))
 		{
-			$str = "'".$this->escape_str($str)."'";
+			return "'".$this->escape_str($str)."'";
 		}
 		elseif (is_bool($str))
 		{
-			$str = ($str === FALSE) ? 0 : 1;
+			return ($str === FALSE) ? 0 : 1;
 		}
 		elseif (is_null($str))
 		{
-			$str = 'NULL';
+			return 'NULL';
 		}
 
 		return $str;
@@ -733,13 +738,7 @@ abstract class CI_DB_driver {
 	public function primary($table = '')
 	{
 		$fields = $this->list_fields($table);
-
-		if ( ! is_array($fields))
-		{
-			return FALSE;
-		}
-
-		return current($fields);
+		return is_array($fields) ? current($fields) : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -759,35 +758,40 @@ abstract class CI_DB_driver {
 
 		if (FALSE === ($sql = $this->_list_tables($constrain_by_prefix)))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
-		$retval = array();
+		$this->data_cache['table_names'] = array();
 		$query = $this->query($sql);
 
-		if ($query->num_rows() > 0)
+		foreach ($query->result_array() as $row)
 		{
-			$table = FALSE;
-			$rows = $query->result_array();
-			$key = (($row = current($rows)) && in_array('table_name', array_map('strtolower', array_keys($row))));
-
-			if ($key)
+			// Do we know from which column to get the table name?
+			if ( ! isset($key))
 			{
-				$table = array_key_exists('TABLE_NAME', $row) ? 'TABLE_NAME' : 'table_name';
+				if (isset($row['table_name']))
+				{
+					$key = 'table_name';
+				}
+				elseif (isset($row['TABLE_NAME']))
+				{
+					$key = 'TABLE_NAME';
+				}
+				else
+				{
+					/* We have no other choice but to just get the first element's key.
+					 * Due to array_shift() accepting it's argument by reference, if
+					 * E_STRICT is on, this would trigger a warning. So we'll have to
+					 * assign it first.
+					 */
+					$key = array_keys($row);
+					$key = array_shift($key);
+				}
 			}
 
-			foreach ($rows as $row)
-			{
-				$retval[] = ( ! $table) ? current($row) : $row[$table];
-			}
+			$this->data_cache['table_names'][] = $row[$key];
 		}
 
-		$this->data_cache['table_names'] = $retval;
-
 		return $this->data_cache['table_names'];
 	}
 
@@ -821,38 +825,45 @@ abstract class CI_DB_driver {
 
 		if ($table == '')
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_field_param_missing');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
 		}
 
 		if (FALSE === ($sql = $this->_list_columns($table)))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
 		$query = $this->query($sql);
+		$this->data_cache['field_names'][$table] = array();
 
-		$retval = array();
 		foreach ($query->result_array() as $row)
 		{
-			if (isset($row['COLUMN_NAME']))
+			// Do we know from where to get the column's name?
+			if ( ! isset($key))
 			{
-				$retval[] = $row['COLUMN_NAME'];
-			}
-			else
-			{
-				$retval[] = current($row);
+				if (isset($row['column_name']))
+				{
+					$key = 'column_name';
+				}
+				elseif (isset($row['COLUMN_NAME']))
+				{
+					$key = 'COLUMN_NAME';
+				}
+				else
+				{
+					/* We have no other choice but to just get the first element's key.
+					 * Due to array_shift() accepting it's argument by reference, if
+					 * E_STRICT is on, this would trigger a warning. So we'll have to
+					 * assign it first.
+					 */
+					$key = array_keys($row);
+					$key = array_shift($key);
+				}
 			}
+
+			$this->data_cache['field_names'][$table][] = $row[$key];
 		}
 
-		$this->data_cache['field_names'][$table] = $retval;
 		return $this->data_cache['field_names'][$table];
 	}
 
@@ -867,7 +878,7 @@ abstract class CI_DB_driver {
 	 */
 	public function field_exists($field_name, $table_name)
 	{
-		return ( ! in_array($field_name, $this->list_fields($table_name))) ? FALSE : TRUE;
+		return in_array($field_name, $this->list_fields($table_name));
 	}
 
 	// --------------------------------------------------------------------
@@ -882,15 +893,10 @@ abstract class CI_DB_driver {
 	{
 		if ($table == '')
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_field_param_missing');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
 		}
 
 		$query = $this->query($this->_field_data($this->protect_identifiers($table, TRUE, NULL, FALSE)));
-
 		return $query->field_data();
 	}
 
@@ -905,8 +911,7 @@ abstract class CI_DB_driver {
 	 */
 	public function insert_string($table, $data)
 	{
-		$fields = array();
-		$values = array();
+		$fields = $values = array();
 
 		foreach ($data as $key => $val)
 		{
@@ -979,13 +984,7 @@ abstract class CI_DB_driver {
 	 */
 	protected function _has_operator($str)
 	{
-		$str = trim($str);
-		if ( ! preg_match("/(\s|<|>|!|=|is null|is not null)/i", $str))
-		{
-			return FALSE;
-		}
-
-		return TRUE;
+		return (bool) preg_match('/(\s|<|>|!|=|IS NULL|IS NOT NULL)/i', trim($str));
 	}
 
 	// --------------------------------------------------------------------
@@ -1008,25 +1007,12 @@ abstract class CI_DB_driver {
 
 		if ( ! function_exists($function))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
-		else
-		{
-			$args = (func_num_args() > 1) ? array_splice(func_get_args(), 1) : null;
 
-			if (is_null($args))
-			{
-				return call_user_func($function);
-			}
-			else
-			{
-				return call_user_func_array($function, $args);
-			}
-		}
+		return (func_num_args() > 1)
+			? call_user_func_array($function, array_splice(func_get_args(), 1))
+			: call_user_func($function);
 	}
 
 	// --------------------------------------------------------------------
@@ -1051,8 +1037,7 @@ abstract class CI_DB_driver {
 	 */
 	public function cache_on()
 	{
-		$this->cache_on = TRUE;
-		return TRUE;
+		return $this->cache_on = TRUE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1064,8 +1049,7 @@ abstract class CI_DB_driver {
 	 */
 	public function cache_off()
 	{
-		$this->cache_on = FALSE;
-		return FALSE;
+		return $this->cache_on = FALSE;
 	}
 
 
@@ -1078,11 +1062,9 @@ abstract class CI_DB_driver {
 	 */
 	public function cache_delete($segment_one = '', $segment_two = '')
 	{
-		if ( ! $this->_cache_init())
-		{
-			return FALSE;
-		}
-		return $this->CACHE->delete($segment_one, $segment_two);
+		return ($this->_cache_init())
+			? $this->CACHE->delete($segment_one, $segment_two)
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1094,12 +1076,9 @@ abstract class CI_DB_driver {
 	 */
 	public function cache_delete_all()
 	{
-		if ( ! $this->_cache_init())
-		{
-			return FALSE;
-		}
-
-		return $this->CACHE->delete_all();
+		return ($this->_cache_init())
+			? $this->CACHE->delete_all()
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1111,18 +1090,17 @@ abstract class CI_DB_driver {
 	 */
 	protected function _cache_init()
 	{
-		if (is_object($this->CACHE) AND class_exists('CI_DB_Cache'))
-		{
-			return TRUE;
-		}
-
-		if ( ! class_exists('CI_DB_Cache'))
+		if (class_exists('CI_DB_Cache'))
 		{
-			if ( ! @include(BASEPATH.'database/DB_cache.php'))
+			if (is_object($this->CACHE))
 			{
-				return $this->cache_off();
+				return TRUE;
 			}
 		}
+		elseif ( ! @include_once(BASEPATH.'database/DB_cache.php'))
+		{
+			return $this->cache_off();
+		}
 
 		$this->CACHE = new CI_DB_Cache($this); // pass db object to support multiple db connections and returned db objects
 		return TRUE;
@@ -1137,11 +1115,11 @@ abstract class CI_DB_driver {
 	 */
 	public function close()
 	{
-		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		if ($this->conn_id)
 		{
 			$this->_close($this->conn_id);
+			$this->conn_id = FALSE;
 		}
-		$this->conn_id = FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1173,9 +1151,7 @@ abstract class CI_DB_driver {
 		// Find the most likely culprit of the error by going through
 		// the backtrace until the source file is no longer in the
 		// database folder.
-
 		$trace = debug_backtrace();
-
 		foreach ($trace as $call)
 		{
 			if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
@@ -1183,7 +1159,6 @@ abstract class CI_DB_driver {
 				// Found it - use a relative path for safety
 				$message[] = 'Filename: '.str_replace(array(BASEPATH, APPPATH), '', $call['file']);
 				$message[] = 'Line Number: '.$call['line'];
-
 				break;
 			}
 		}
@@ -1201,7 +1176,7 @@ abstract class CI_DB_driver {
 	 * This function is used extensively by the Active Record class, and by
 	 * a couple functions in this class.
 	 * It takes a column or table name (optionally with an alias) and inserts
-	 * the table prefix onto it.  Some logic is necessary in order to deal with
+	 * the table prefix onto it. Some logic is necessary in order to deal with
 	 * column names that include the path. Consider a query like this:
 	 *
 	 * SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
@@ -1244,12 +1219,15 @@ abstract class CI_DB_driver {
 
 		// If the item has an alias declaration we remove it and set it aside.
 		// Basically we remove everything to the right of the first space
-		$alias = '';
 		if (strpos($item, ' ') !== FALSE)
 		{
-			$alias = strstr($item, " ");
+			$alias = strstr($item, ' ');
 			$item = substr($item, 0, - strlen($alias));
 		}
+		else
+		{
+			$alias = '';
+		}
 
 		// This is basically a bug fix for queries that use MAX, MIN, etc.
 		// If a parenthesis is found we know that we do not need to
@@ -1284,6 +1262,7 @@ abstract class CI_DB_driver {
 
 					$item = implode('.', $parts);
 				}
+
 				return $item.$alias;
 			}
 
@@ -1318,13 +1297,12 @@ abstract class CI_DB_driver {
 				}
 
 				// Verify table prefix and replace if necessary
-				if ($this->swap_pre != '' && strncmp($parts[$i], $this->swap_pre, strlen($this->swap_pre)) === 0)
+				if ($this->swap_pre != '' && strpos($parts[$i], $this->swap_pre) === 0)
 				{
-					$parts[$i] = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $parts[$i]);
+					$parts[$i] = preg_replace('/^'.$this->swap_pre.'(\S+?)/', $this->dbprefix.'\\1', $parts[$i]);
 				}
-
 				// We only add the table prefix if it does not already exist
-				if (substr($parts[$i], 0, strlen($this->dbprefix)) != $this->dbprefix)
+				elseif (strpos($parts[$i], $this->dbprefix) !== 0)
 				{
 					$parts[$i] = $this->dbprefix.$parts[$i];
 				}
@@ -1345,19 +1323,18 @@ abstract class CI_DB_driver {
 		if ($this->dbprefix != '')
 		{
 			// Verify table prefix and replace if necessary
-			if ($this->swap_pre != '' && strncmp($item, $this->swap_pre, strlen($this->swap_pre)) === 0)
+			if ($this->swap_pre != '' && strpos($item, $this->swap_pre) === 0)
 			{
-				$item = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $item);
+				$item = preg_replace('/^'.$this->swap_pre.'(\S+?)/', $this->dbprefix.'\\1', $item);
 			}
-
 			// Do we prefix an item with no segments?
-			if ($prefix_single == TRUE AND substr($item, 0, strlen($this->dbprefix)) != $this->dbprefix)
+			elseif ($prefix_single == TRUE && strpos($item, $this->dbprefix) !== 0)
 			{
 				$item = $this->dbprefix.$item;
 			}
 		}
 
-		if ($protect_identifiers === TRUE AND ! in_array($item, $this->_reserved_identifiers))
+		if ($protect_identifiers === TRUE && ! in_array($item, $this->_reserved_identifiers))
 		{
 			$item = $this->_escape_identifiers($item);
 		}
@@ -1374,7 +1351,9 @@ abstract class CI_DB_driver {
 	 *
 	 * @return	void
 	 */
-	abstract protected function _reset_select();
+	protected function _reset_select()
+	{
+	}
 
 }
 
diff --git a/system/database/DB_result.php b/system/database/DB_result.php
index 04f964fb1..bb09c014c 100644
--- a/system/database/DB_result.php
+++ b/system/database/DB_result.php
@@ -57,7 +57,7 @@ class CI_DB_result {
 	 * Query result.  Acts as a wrapper function for the following functions.
 	 *
 	 * @param	string	can be "object" or "array"
-	 * @return	mixed	either a result object or array
+	 * @return	object
 	 */
 	public function result($type = 'object')
 	{
@@ -108,9 +108,9 @@ class CI_DB_result {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Query result.  "object" version.
+	 * Query result. "object" version.
 	 *
-	 * @return	object
+	 * @return	array
 	 */
 	public function result_object()
 	{
@@ -224,7 +224,7 @@ class CI_DB_result {
 			return;
 		}
 
-		if ($key != '' AND ! is_null($value))
+		if ($key != '' && ! is_null($value))
 		{
 			$this->row_data[$key] = $value;
 		}
@@ -245,7 +245,7 @@ class CI_DB_result {
 			return $result;
 		}
 
-		if ($n != $this->current_row AND isset($result[$n]))
+		if ($n != $this->current_row && isset($result[$n]))
 		{
 			$this->current_row = $n;
 		}
@@ -266,7 +266,7 @@ class CI_DB_result {
 			return $result;
 		}
 
-		if ($n != $this->current_row AND isset($result[$n]))
+		if ($n != $this->current_row && isset($result[$n]))
 		{
 			$this->current_row = $n;
 		}
@@ -289,7 +289,7 @@ class CI_DB_result {
 			return $result;
 		}
 
-		if ($n != $this->current_row AND isset($result[$n]))
+		if ($n != $this->current_row && isset($result[$n]))
 		{
 			$this->current_row = $n;
 		}
@@ -297,7 +297,6 @@ class CI_DB_result {
 		return $result[$this->current_row];
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
@@ -374,9 +373,9 @@ class CI_DB_result {
 	/**
 	 * The following functions are normally overloaded by the identically named
 	 * methods in the platform-specific driver -- except when query caching
-	 * is used.  When caching is enabled we do not load the other driver.
+	 * is used. When caching is enabled we do not load the other driver.
 	 * These functions are primarily here to prevent undefined function errors
-	 * when a cached result object is in use.  They are not otherwise fully
+	 * when a cached result object is in use. They are not otherwise fully
 	 * operational due to the unavailability of the database resource IDs with
 	 * cached results.
 	 */
@@ -384,7 +383,7 @@ class CI_DB_result {
 	public function num_fields() { return 0; }
 	public function list_fields() { return array(); }
 	public function field_data() { return array(); }
-	public function free_result() { return TRUE; }
+	public function free_result() { $this->result_id = FALSE; }
 	protected function _data_seek() { return TRUE; }
 	protected function _fetch_assoc() { return array(); }
 	protected function _fetch_object() { return array(); }
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index f39c2ad76..0f9c427e6 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -57,38 +57,35 @@ class CI_DB_cubrid_driver extends CI_DB {
 	protected $_count_string = 'SELECT COUNT(*) AS ';
 	protected $_random_keyword = ' RAND()'; // database specific random keyword
 
-	/**
-	 * Non-persistent database connection
-	 *
-	 * @return	resource
-	 */
-	public function db_connect()
-	{
-		// If no port is defined by the user, use the default value
-		if ($this->port == '')
-		{
-			// Default CUBRID Broker port
-			$this->port = 33000;
-		}
+	// CUBRID-specific properties
+	public $auto_commit = TRUE;
 
-		$conn = cubrid_connect($this->hostname, $this->port, $this->database, $this->username, $this->password);
+	public function __construct($params)
+	{
+		parent::__construct($params);
 
-		if ($conn)
+		if (preg_match('/^CUBRID:[^:]+(:[0-9][1-9]{0,4})?:[^:]+:[^:]*:[^:]*:(\?.+)?$/', $this->dsn, $matches))
 		{
-			// Check if a user wants to run queries in dry, i.e. run the
-			// queries but not commit them.
-			if (isset($this->auto_commit) && ! $this->auto_commit)
-			{
-				cubrid_set_autocommit($conn, CUBRID_AUTOCOMMIT_FALSE);
-			}
-			else
+			if (stripos($matches[2], 'autocommit=off') !== FALSE)
 			{
-				cubrid_set_autocommit($conn, CUBRID_AUTOCOMMIT_TRUE);
-				$this->auto_commit = TRUE;
+				$this->auto_commit = FALSE;
 			}
 		}
+		else
+		{
+			// If no port is defined by the user, use the default value
+			$this->port == '' OR $this->port = 33000;
+		}
+	}
 
-		return $conn;
+	/**
+	 * Non-persistent database connection
+	 *
+	 * @return	resource
+	 */
+	public function db_connect()
+	{
+		return $this->_cubrid_connect();
 	}
 
 	// --------------------------------------------------------------------
@@ -100,49 +97,63 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 * engine which can be configured in the CUBRID Broker configuration
 	 * file by setting the CCI_PCONNECT parameter to ON. In that case, all
 	 * connections established between the client application and the
-	 * server will become persistent. This is calling the same
-	 * @cubrid_connect function will establish persisten connection
-	 * considering that the CCI_PCONNECT is ON.
+	 * server will become persistent.
 	 *
 	 * @return	resource
 	 */
 	public function db_pconnect()
 	{
-		return $this->db_connect();
+		return $this->_cubrid_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Reconnect
+	 * CUBRID connection
 	 *
-	 * Keep / reestablish the db connection if no queries have been
-	 * sent for a length of time exceeding the server's idle timeout
+	 * A CUBRID-specific method to create a connection to the database.
+	 * Except for determining if a persistent connection should be used,
+	 * the rest of the logic is the same for db_connect() and db_pconnect().
 	 *
-	 * @return	void
+	 * @param	bool
+	 * @return	resource
 	 */
-	public function reconnect()
+	protected function _cubrid_connect($persistent = FALSE)
 	{
-		if (cubrid_ping($this->conn_id) === FALSE)
+		if (preg_match('/^CUBRID:[^:]+(:[0-9][1-9]{0,4})?:[^:]+:([^:]*):([^:]*):(\?.+)?$/', $this->dsn, $matches))
 		{
-			$this->conn_id = FALSE;
+			$_temp = ($persistent !== TRUE) ? 'cubrid_connect_with_url' : 'cubrid_pconnect_with_url';
+			$conn_id = ($matches[2] === '' && $matches[3] === '' && $this->username !== '' && $this->password !== '')
+					? $_temp($this->dsn, $this->username, $this->password)
+					: $_temp($this->dsn);
+		}
+		else
+		{
+			$_temp = ($persistent !== TRUE) ? 'cubrid_connect' : 'cubrid_pconnect';
+			$conn_id = ($this->username !== '')
+					? $_temp($this->hostname, $this->port, $this->database, $this->username, $this->password)
+					: $_temp($this->hostname, $this->port, $this->database);
 		}
+
+		return $conn_id;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
+	 * Reconnect
 	 *
-	 * @return	resource
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout
+	 *
+	 * @return	void
 	 */
-	public function db_select()
+	public function reconnect()
 	{
-		// In CUBRID there is no need to select a database as the database
-		// is chosen at the connection time.
-		// So, to determine if the database is "selected", all we have to
-		// do is ping the server and return that value.
-		return cubrid_ping($this->conn_id);
+		if (cubrid_ping($this->conn_id) === FALSE)
+		{
+			$this->conn_id = FALSE;
+		}
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index d8b6ae571..6d3346292 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -85,19 +85,6 @@ class CI_DB_interbase_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
-	 *
-	 * @return	bool
-	 */
-	public function db_select()
-	{
-		// Connection selects the database
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index f2933fe43..81af6cd72 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -52,10 +52,10 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
-	 * used for the count_all() and count_all_results() functions.
+	 * used for the count_all() and count_all_results() methods.
 	 */
 	protected $_count_string = 'SELECT COUNT(*) AS ';
-	protected $_random_keyword = ' ASC'; // not currently supported
+	protected $_random_keyword = ' NEWID()';
 
 	/**
 	 * Non-persistent database connection
@@ -539,13 +539,12 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';
 
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 4c5d52127..47b0449d6 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -72,8 +72,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 	public function db_connect()
 	{
 		return ($this->port != '')
-			? @mysqli_connect($this->hostname, $this->username, $this->password, $this->database, $this->port)
-			: @mysqli_connect($this->hostname, $this->username, $this->password, $this->database);
+			? @new mysqli($this->hostname, $this->username, $this->password, $this->database, $this->port)
+			: @new mysqli($this->hostname, $this->username, $this->password, $this->database);
 	}
 
 	// --------------------------------------------------------------------
@@ -92,8 +92,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 		}
 
 		return ($this->port != '')
-			? @mysqli_connect('p:'.$this->hostname, $this->username, $this->password, $this->database, $this->port)
-			: @mysqli_connect('p:'.$this->hostname, $this->username, $this->password, $this->database);
+			? @new mysqli('p:'.$this->hostname, $this->username, $this->password, $this->database, $this->port)
+			: @new mysqli('p:'.$this->hostname, $this->username, $this->password, $this->database);
 	}
 
 	// --------------------------------------------------------------------
@@ -108,7 +108,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function reconnect()
 	{
-		if (mysqli_ping($this->conn_id) === FALSE)
+		if ($this->conn_id !== FALSE && $this->conn_id->ping() === FALSE)
 		{
 			$this->conn_id = FALSE;
 		}
@@ -129,7 +129,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 			$database = $this->database;
 		}
 
-		if (@mysqli_select_db($this->conn_id, $database))
+		if (@$this->conn_id->select_db($database))
 		{
 			$this->database = $database;
 			return TRUE;
@@ -148,7 +148,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	protected function _db_set_charset($charset)
 	{
-		return @mysqli_set_charset($this->conn_id, $charset);
+		return @$this->conn_id->set_charset($charset);
 	}
 
 	// --------------------------------------------------------------------
@@ -162,7 +162,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	{
 		return isset($this->data_cache['version'])
 			? $this->data_cache['version']
-			: $this->data_cache['version'] = @mysqli_get_server_info($this->conn_id);
+			: $this->data_cache['version'] = $this->conn_id->server_info;
 	}
 
 	// --------------------------------------------------------------------
@@ -175,7 +175,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	protected function _execute($sql)
 	{
-		return @mysqli_query($this->conn_id, $this->_prep_query($sql));
+		return @$this->conn_id->query($this->_prep_query($sql));
 	}
 
 	// --------------------------------------------------------------------
@@ -286,7 +286,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 			return $str;
 		}
 
-		$str = is_object($this->conn_id) ? mysqli_real_escape_string($this->conn_id, $str) : addslashes($str);
+		$str = is_object($this->conn_id) ? $this->conn_id->real_escape_string($str) : addslashes($str);
 
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
@@ -306,7 +306,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function affected_rows()
 	{
-		return @mysqli_affected_rows($this->conn_id);
+		return $this->conn_id->affected_rows;
 	}
 
 	// --------------------------------------------------------------------
@@ -318,7 +318,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		return @mysqli_insert_id($this->conn_id);
+		return $this->conn_id->insert_id;
 	}
 
 	// --------------------------------------------------------------------
@@ -357,7 +357,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
 	 * @param	bool
 	 * @return	string
 	 */
@@ -434,7 +433,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function error()
 	{
-		return array('code' => mysqli_errno($this->conn_id), 'message' => mysqli_error($this->conn_id));
+		return array('code' => $this->conn_id->errno, 'message' => $this->conn_id->error);
 	}
 
 	// --------------------------------------------------------------------
@@ -691,7 +690,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	protected function _close($conn_id)
 	{
-		@mysqli_close($conn_id);
+		$this->conn_id->close();
+		$this->conn_id = FALSE;
 	}
 
 }
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index 83d88aae3..cf0362217 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -43,7 +43,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 */
 	public function num_rows()
 	{
-		return @mysqli_num_rows($this->result_id);
+		return $this->result_id->num_rows;
 	}
 
 	// --------------------------------------------------------------------
@@ -55,7 +55,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 */
 	public function num_fields()
 	{
-		return @mysqli_num_fields($this->result_id);
+		return $this->result_id->field_count;
 	}
 
 	// --------------------------------------------------------------------
@@ -70,7 +70,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
-		while ($field = mysqli_fetch_field($this->result_id))
+		while ($field = $this->result_id->fetch_field())
 		{
 			$field_names[] = $field->name;
 		}
@@ -90,7 +90,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	public function field_data()
 	{
 		$retval = array();
-		$field_data = mysqli_fetch_fields($this->result_id);
+		$field_data = $this->result_id->fetch_fields();
 		for ($i = 0, $c = count($field_data); $i < $c; $i++)
 		{
 			$retval[$i]			= new stdClass();
@@ -115,7 +115,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	{
 		if (is_object($this->result_id))
 		{
-			mysqli_free_result($this->result_id);
+			$this->result_id->free();
 			$this->result_id = FALSE;
 		}
 	}
@@ -133,7 +133,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 */
 	protected function _data_seek($n = 0)
 	{
-		return mysqli_data_seek($this->result_id, $n);
+		return $this->result_id->data_seek($n);
 	}
 
 	// --------------------------------------------------------------------
@@ -147,7 +147,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 */
 	protected function _fetch_assoc()
 	{
-		return mysqli_fetch_assoc($this->result_id);
+		return $this->result_id->fetch_assoc();
 	}
 
 	// --------------------------------------------------------------------
@@ -161,7 +161,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 */
 	protected function _fetch_object()
 	{
-		return mysqli_fetch_object($this->result_id);
+		return $this->result_id->fetch_object();
 	}
 
 }
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index c9e791d63..45b0198eb 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -78,6 +78,85 @@ class CI_DB_oci8_driver extends CI_DB {
 	// throw off num_fields later
 	public $limit_used;
 
+	public function __construct($params)
+	{
+		parent::__construct($params);
+
+		$valid_dsns = array(
+					'tns'	=> '/^\(DESCRIPTION=(\(.+\)){2,}\)$/', // TNS
+					// Easy Connect string (Oracle 10g+)
+					'ec'	=> '/^(\/\/)?[a-z0-9.:_-]+(:[1-9][0-9]{0,4})?(\/[a-z0-9$_]+)?(:[^\/])?(\/[a-z0-9$_]+)?$/i',
+					'in'	=> '/^[a-z0-9$_]+$/i' // Instance name (defined in tnsnames.ora)
+				);
+
+		/* Space characters don't have any effect when actually
+		 * connecting, but can be a hassle while validating the DSN.
+		 */
+		$this->dsn = str_replace(array("\n", "\r", "\t", ' '), '', $this->dsn);
+
+		if ($this->dsn !== '')
+		{
+			foreach ($valid_dsns as $regexp)
+			{
+				if (preg_match($regexp, $this->dsn))
+				{
+					return;
+				}
+			}
+		}
+
+		// Legacy support for TNS in the hostname configuration field
+		$this->hostname = str_replace(array("\n", "\r", "\t", ' '), '', $this->hostname);
+		if (preg_match($valid_dsns['tns'], $this->hostname))
+		{
+			$this->dsn = $this->hostname;
+			return;
+		}
+		elseif ($this->hostname !== '' && strpos($this->hostname, '/') === FALSE && strpos($this->hostname, ':') === FALSE
+			&& (( ! empty($this->port) && ctype_digit($this->port)) OR $this->database !== ''))
+		{
+			/* If the hostname field isn't empty, doesn't contain
+			 * ':' and/or '/' and if port and/or database aren't
+			 * empty, then the hostname field is most likely indeed
+			 * just a hostname. Therefore we'll try and build an
+			 * Easy Connect string from these 3 settings, assuming
+			 * that the database field is a service name.
+			 */
+			$this->dsn = $this->hostname
+					.(( ! empty($this->port) && ctype_digit($this->port)) ? ':'.$this->port : '')
+					.($this->database !== '' ? '/'.ltrim($this->database, '/') : '');
+
+			if (preg_match($valid_dsns['ec'], $this->dsn))
+			{
+				return;
+			}
+		}
+
+		/* At this point, we can only try and validate the hostname and
+		 * database fields separately as DSNs.
+		 */
+		if (preg_match($valid_dsns['ec'], $this->hostname) OR preg_match($valid_dsns['in'], $this->hostname))
+		{
+			$this->dsn = $this->hostname;
+			return;
+		}
+
+		$this->database = str_replace(array("\n", "\r", "\t", ' '), '', $this->database);
+		foreach ($valid_dsns as $regexp)
+		{
+			if (preg_match($regexp, $this->database))
+			{
+				return;
+			}
+		}
+
+		/* Well - OK, an empty string should work as well.
+		 * PHP will try to use environment variables to
+		 * determine which Oracle instance to connect to.
+		 */
+		$this->dsn = '';
+	}
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -85,7 +164,9 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	public function db_connect()
 	{
-		return @oci_connect($this->username, $this->password, $this->hostname, $this->char_set);
+		return ( ! empty($this->char_set))
+			? @oci_connect($this->username, $this->password, $this->dsn, $this->char_set)
+			: @oci_connect($this->username, $this->password, $this->dsn);
 	}
 
 	// --------------------------------------------------------------------
@@ -97,20 +178,9 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @oci_pconnect($this->username, $this->password, $this->hostname, $this->char_set);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Select the database
-	 *
-	 * @return	resource
-	 */
-	public function db_select()
-	{
-		// Not in Oracle - schemas are actually usernames
-		return TRUE;
+		return ( ! empty($this->char_set))
+			? @oci_pconnect($this->username, $this->password, $this->dsn, $this->char_set)
+			: @oci_pconnect($this->username, $this->password, $this->dsn);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 901787ff3..ed901bd81 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -57,12 +57,17 @@ class CI_DB_odbc_driver extends CI_DB {
 	protected $_count_string = 'SELECT COUNT(*) AS ';
 	protected $_random_keyword;
 
-
 	public function __construct($params)
 	{
 		parent::__construct($params);
 
 		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
+
+		// Legacy support for DSN in the hostname field
+		if ($this->dsn == '')
+		{
+			$this->dsn = $this->hostname;
+		}
 	}
 
 	/**
@@ -72,7 +77,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	public function db_connect()
 	{
-		return @odbc_connect($this->hostname, $this->username, $this->password);
+		return @odbc_connect($this->dsn, $this->username, $this->password);
 	}
 
 	// --------------------------------------------------------------------
@@ -84,20 +89,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @odbc_pconnect($this->hostname, $this->username, $this->password);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Select the database
-	 *
-	 * @return	resource
-	 */
-	public function db_select()
-	{
-		// Not needed for ODBC
-		return TRUE;
+		return @odbc_pconnect($this->dsn, $this->username, $this->password);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 19338e30f..a9bed367e 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -247,19 +247,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
-	 *
-	 * @return	resource
-	 */
-	public function db_select()
-	{
-		// Not needed for PDO
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
@@ -484,7 +471,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	public function count_all($table = '')
 	{
 		if ($table == '')
 		{
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 3bfccad05..a033d74f3 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -57,29 +57,64 @@ class CI_DB_postgre_driver extends CI_DB {
 	protected $_random_keyword = ' RANDOM()'; // database specific random keyword
 
 	/**
-	 * Connection String
+	 * Constructor
 	 *
-	 * @return	string
+	 * Creates a DSN string to be used for db_connect() and db_pconnect()
+	 *
+	 * @return	void
 	 */
-	protected function _connect_string()
+	public function __construct($params)
 	{
-		$components = array(
-								'hostname'	=> 'host',
-								'port'		=> 'port',
-								'database'	=> 'dbname',
-								'username'	=> 'user',
-								'password'	=> 'password'
-							);
-
-		$connect_string = "";
-		foreach ($components as $key => $val)
+		parent::__construct($params);
+
+		if ( ! empty($this->dsn))
+		{
+			return;
+		}
+
+		$this->dsn === '' OR $this->dsn = '';
+
+		if (strpos($this->hostname, '/') !== FALSE)
 		{
-			if (isset($this->$key) && $this->$key != '')
+			// If UNIX sockets are used, we shouldn't set a port
+			$this->port = '';
+		}
+
+		$this->hostname === '' OR $this->dsn = 'host='.$this->hostname;
+
+		if ( ! empty($this->port) && ctype_digit($this->port))
+		{
+			$this->dsn .= 'host='.$this->port.' ';
+		}
+
+		if ($this->username !== '')
+		{
+			$this->dsn .= 'username='.$this->username.' ';
+
+			/* An empty password is valid!
+			 *
+			 * $db['password'] = NULL must be done in order to ignore it.
+			 */
+			$this->password === NULL OR $this->dsn .= "password='".$this->password."' ";
+		}
+
+		$this->database === '' OR $this->dsn .= 'dbname='.$this->database.' ';
+
+		/* We don't have these options as elements in our standard configuration
+		 * array, but they might be set by parse_url() if the configuration was
+		 * provided via string. Example:
+		 *
+		 * postgre://username:password@localhost:5432/database?connect_timeout=5&sslmode=1
+		 */
+		foreach (array('connect_timeout', 'options', 'sslmode', 'service') as $key)
+		{
+			if (isset($this->$key) && is_string($this->key) && $this->key !== '')
 			{
-				$connect_string .= " $val=".$this->$key;
+				$this->dsn .= $key."='".$this->key."' ";
 			}
 		}
-		return trim($connect_string);
+
+		$this->dsn = rtrim($this->dsn);
 	}
 
 	// --------------------------------------------------------------------
@@ -91,7 +126,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function db_connect()
 	{
-		return @pg_connect($this->_connect_string());
+		return @pg_connect($this->dsn);
 	}
 
 	// --------------------------------------------------------------------
@@ -103,7 +138,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @pg_pconnect($this->_connect_string());
+		return @pg_pconnect($this->dsn);
 	}
 
 	// --------------------------------------------------------------------
@@ -127,19 +162,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
-	 *
-	 * @return	resource
-	 */
-	public function db_select()
-	{
-		// Not needed for Postgre so we'll return TRUE
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Set client character set
 	 *
 	 * @param       string
diff --git a/system/database/drivers/postgre/postgre_result.php b/system/database/drivers/postgre/postgre_result.php
index 8b22564b3..394b8b6fd 100644
--- a/system/database/drivers/postgre/postgre_result.php
+++ b/system/database/drivers/postgre/postgre_result.php
@@ -70,7 +70,7 @@ class CI_DB_postgre_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
 			$field_names[] = pg_field_name($this->result_id, $i);
 		}
@@ -90,16 +90,14 @@ class CI_DB_postgre_result extends CI_DB_result {
 	public function field_data()
 	{
 		$retval = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
-			$F				= new stdClass();
-			$F->name		= pg_field_name($this->result_id, $i);
-			$F->type		= pg_field_type($this->result_id, $i);
-			$F->max_length	= pg_field_size($this->result_id, $i);
-			$F->primary_key = 0;
-			$F->default		= '';
-
-			$retval[] = $F;
+			$retval[$i]			= new stdClass();
+			$retval[$i]->name		= pg_field_name($this->result_id, $i);
+			$retval[$i]->type		= pg_field_type($this->result_id, $i);
+			$retval[$i]->max_length		= pg_field_size($this->result_id, $i);
+			$retval[$i]->primary_key	= 0;
+			$retval[$i]->default		= '';
 		}
 
 		return $retval;
diff --git a/system/database/drivers/postgre/postgre_utility.php b/system/database/drivers/postgre/postgre_utility.php
index c6b71b4d9..cf29201ff 100644
--- a/system/database/drivers/postgre/postgre_utility.php
+++ b/system/database/drivers/postgre/postgre_utility.php
@@ -78,7 +78,7 @@ class CI_DB_postgre_utility extends CI_DB_utility {
 	 * @param	array	Preferences
 	 * @return	mixed
 	 */
-	function _backup($params = array())
+	public function _backup($params = array())
 	{
 		// Currently unsupported
 		return $this->db->display_error('db_unsuported_feature');
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index fa7e4846a..ef543c9b5 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -106,18 +106,6 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
-	 *
-	 * @return	resource
-	 */
-	public function db_select()
-	{
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
@@ -245,9 +233,9 @@ class CI_DB_sqlite_driver extends CI_DB {
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(	array('%', '_', $this->_like_escape_chr),
-								array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
-								$str);
+			return str_replace(array($this->_like_escape_chr, '%', '_'),
+						array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
+						$str);
 		}
 
 		return $str;
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
index b002aeff1..4af80abf7 100644
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ b/system/database/drivers/sqlite/sqlite_result.php
@@ -70,9 +70,9 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
-			$field_names[] = sqlite_field_name($this->result_id, $i);
+			$field_names[$i] = sqlite_field_name($this->result_id, $i);
 		}
 
 		return $field_names;
@@ -90,16 +90,14 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	public function field_data()
 	{
 		$retval = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
-			$F				= new stdClass();
-			$F->name		= sqlite_field_name($this->result_id, $i);
-			$F->type		= 'varchar';
-			$F->max_length	= 0;
-			$F->primary_key = 0;
-			$F->default		= '';
-
-			$retval[] = $F;
+			$retval[$i]			= new stdClass();
+			$retval[$i]->name		= sqlite_field_name($this->result_id, $i);
+			$retval[$i]->type		= 'varchar';
+			$retval[$i]->max_length		= 0;
+			$retval[$i]->primary_key	= 0;
+			$retval[$i]->default		= '';
 		}
 
 		return $retval;
@@ -108,18 +106,6 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Free the result
-	 *
-	 * @return	void
-	 */
-	public function free_result()
-	{
-		// Not implemented in SQLite
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Data Seek
 	 *
 	 * Moves the internal pointer to the desired offset. We call
@@ -162,17 +148,9 @@ class CI_DB_sqlite_result extends CI_DB_result {
 		{
 			return sqlite_fetch_object($this->result_id);
 		}
-		else
-		{
-			$arr = sqlite_fetch_array($this->result_id, SQLITE_ASSOC);
-			if (is_array($arr))
-			{
-				$obj = (object) $arr;
-				return $obj;
-			} else {
-				return NULL;
-			}
-		}
+
+		$arr = sqlite_fetch_array($this->result_id, SQLITE_ASSOC);
+		return is_array($arr) ? (object) $arr : FALSE;
 	}
 
 }
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index 39d1e2141..de3705296 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -92,19 +92,6 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
-	 *
-	 * @return	bool
-	 */
-	public function db_select()
-	{
-		// Not needed, in SQLite every pseudo-connection is a database
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 9f2f88699..bb4f009bc 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -55,7 +55,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * used for the count_all() and count_all_results() functions.
 	 */
 	protected $_count_string = 'SELECT COUNT(*) AS ';
-	protected $_random_keyword = ' ASC'; // not currently supported
+	protected $_random_keyword = ' NEWID()'; // not currently supported
 
 	/**
 	 * Non-persistent database connection
@@ -68,12 +68,12 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		$character_set = (0 === strcasecmp('utf8', $this->char_set)) ? 'UTF-8' : $this->char_set;
 
 		$connection = array(
-			'UID'				=> empty($this->username) ? '' : $this->username,
-			'PWD'				=> empty($this->password) ? '' : $this->password,
-			'Database'			=> $this->database,
-			'ConnectionPooling' => $pooling ? 1 : 0,
+			'UID'			=> empty($this->username) ? '' : $this->username,
+			'PWD'			=> empty($this->password) ? '' : $this->password,
+			'Database'		=> $this->database,
+			'ConnectionPooling'	=> $pooling ? 1 : 0,
 			'CharacterSet'		=> $character_set,
-			'ReturnDatesAsStrings' => 1
+			'ReturnDatesAsStrings'	=> 1
 		);
 
 		// If the username and password are both empty, assume this is a
@@ -259,23 +259,6 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Parse major version
-	 *
-	 * Grabs the major version number from the
-	 * database server version string passed in.
-	 *
-	 * @param	string	$version
-	 * @return	int	major version number
-	 */
-	protected function _parse_major_version($version)
-	{
-		preg_match('/([0-9]+)\.([0-9]+)\.([0-9]+)/', $version, $ver_info);
-		return $ver_info[1]; // return the major version b/c that's all we're interested in.
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Database version number
 	 *
 	 * @return	string