diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 9c9fdac..23df983 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -107,11 +107,9 @@
 	/**
 	 * Initialize Database Settings
 	 *
-	 * @access	private Called by the constructor
-	 * @param	mixed
-	 * @return	void
+	 * @return	bool
 	 */
-	function initialize()
+	public function initialize()
 	{
 		// If an existing connection resource is available
 		// there is no need to connect and select the database
@@ -125,7 +123,7 @@
 		// Connect to the database and set the connection ID
 		$this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect();
 
-		// No connection resource?  Check if there is a failover else throw an error
+		// No connection resource? Check if there is a failover else throw an error
 		if ( ! $this->conn_id)
 		{
 			// Check if there is a failover set
@@ -167,31 +165,19 @@
 		// ----------------------------------------------------------------
 
 		// Select the DB... assuming a database name is specified in the config file
-		if ($this->database != '')
+		if ($this->database !== '' && ! $this->db_select())
 		{
-			if ( ! $this->db_select())
-			{
-				log_message('error', 'Unable to select database: '.$this->database);
+			log_message('error', 'Unable to select database: '.$this->database);
 
-				if ($this->db_debug)
-				{
-					$this->display_error('db_unable_to_select', $this->database);
-				}
-				return FALSE;
-			}
-			else
+			if ($this->db_debug)
 			{
-				// We've selected the DB. Now we set the character set
-				if ( ! $this->db_set_charset($this->char_set, $this->dbcollat))
-				{
-					return FALSE;
-				}
-
-				return TRUE;
+				$this->display_error('db_unable_to_select', $this->database);
 			}
+			return FALSE;
 		}
 
-		return TRUE;
+		// Now we set the character set and that's all
+		return $this->db_set_charset($this->char_set, $this->dbcollat);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 2a10989..25a32f3 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -114,14 +114,25 @@
 	/**
 	 * Select the database
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @param	string	database name
+	 * @return	bool
 	 */
-	function db_select()
+	public function db_select($database = '')
 	{
+		if ($database === '')
+		{
+			$database = $this->database;
+		}
+
 		// Note: The brackets are required in the event that the DB name
 		// contains reserved characters
-		return @mssql_select_db('['.$this->database.']', $this->conn_id);
+		if (@mssql_select_db('['.$database.']', $this->conn_id))
+		{
+			$this->database = $database;
+			return TRUE;
+		}
+
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -676,4 +687,4 @@
 
 
 /* End of file mssql_driver.php */
-/* Location: ./system/database/drivers/mssql/mssql_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/mssql/mssql_driver.php */
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 067710f..c88a8a7 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -119,11 +119,23 @@
 	/**
 	 * Select the database
 	 *
+	 * @param	string	database name
 	 * @return	bool
 	 */
-	public function db_select()
+	public function db_select($database = '')
 	{
-		return @mysql_select_db($this->database, $this->conn_id);
+		if ($database === '')
+		{
+			$database = $this->database;
+		}
+
+		if (@mysql_select_db($database, $this->conn_id))
+		{
+			$this->database = $database;
+			return TRUE;
+		}
+
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index d310713..0f251b0 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -147,7 +147,7 @@
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table).' ('.$this->_process_fields($fields);
+		$sql .= $this->db->protect_identifiers($table).' ('.$this->_process_fields($fields);
 
 		if (count($primary_keys) > 0)
 		{
@@ -187,7 +187,7 @@
 	 */
 	public function _drop_table($table)
 	{
-		return 'DROP TABLE IF EXISTS '.$this->db->_escape_identifiers($table);
+		return 'DROP TABLE IF EXISTS '.$this->db->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_utility.php b/system/database/drivers/mysql/mysql_utility.php
index 0e7c18e..952f887 100644
--- a/system/database/drivers/mysql/mysql_utility.php
+++ b/system/database/drivers/mysql/mysql_utility.php
@@ -56,7 +56,7 @@
 	 */
 	public function _optimize_table($table)
 	{
-		return 'OPTIMIZE TABLE '.$this->db->_escape_identifiers($table);
+		return 'OPTIMIZE TABLE '.$this->db->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -71,7 +71,7 @@
 	 */
 	public function _repair_table($table)
 	{
-		return 'REPAIR TABLE '.$this->db->_escape_identifiers($table);
+		return 'REPAIR TABLE '.$this->db->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -102,7 +102,7 @@
 			}
 
 			// Get the table schema
-			$query = $this->db->query('SHOW CREATE TABLE `'.$this->db->database.'`.`'.$table.'`');
+			$query = $this->db->query('SHOW CREATE TABLE '.$this->db->protect_identifiers($this->db->database).'.'.$this->db->protect_identifiers($table));
 
 			// No result means the table name was invalid
 			if ($query === FALSE)
@@ -115,7 +115,7 @@
 
 			if ($add_drop == TRUE)
 			{
-				$output .= 'DROP TABLE IF EXISTS '.$table.';'.$newline.$newline;
+				$output .= 'DROP TABLE IF EXISTS '.$this->db->protect_identifiers($table).';'.$newline.$newline;
 			}
 
 			$i = 0;
@@ -135,7 +135,7 @@
 			}
 
 			// Grab all the data from the current table
-			$query = $this->db->query('SELECT * FROM '.$table);
+			$query = $this->db->query('SELECT * FROM '.$this->db->protect_identifiers($table));
 
 			if ($query->num_rows() == 0)
 			{
@@ -157,7 +157,7 @@
 							TRUE);
 
 				// Create a string of field names
-				$field_str .= '`'.$field->name.'`, ';
+				$field_str .= $this->db->protect_identifiers($field->name).', ';
 				$i++;
 			}
 
@@ -192,14 +192,15 @@
 				$val_str = preg_replace('/, $/' , '', $val_str);
 
 				// Build the INSERT string
-				$output .= 'INSERT INTO '.$table.' ('.$field_str.') VALUES ('.$val_str.');'.$newline;
+				$output .= 'INSERT INTO '.$this->db->protect_identifiers($table).' ('.$field_str.') VALUES ('.$val_str.');'.$newline;
 			}
 
-			return $output.$newline.$newline;
+			$output .= $newline.$newline;
 		}
 
 		return $output;
 	}
+
 }
 
 /* End of file mysql_utility.php */
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index a79b2a4..dbba12e 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -119,11 +119,23 @@
 	/**
 	 * Select the database
 	 *
+	 * @param	string	database name
 	 * @return	bool
 	 */
-	public function db_select()
+	public function db_select($database = '')
 	{
-		return @mysqli_select_db($this->conn_id, $this->database);
+		if ($database === '')
+		{
+			$database = $this->database;
+		}
+
+		if (@mysqli_select_db($this->conn_id, $database))
+		{
+			$this->database = $database;
+			return TRUE;
+		}
+
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index fc378da..de2b0ab 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -116,8 +116,15 @@
 			// hostname generally would have this prototype
 			// $db['hostname'] = 'pdodriver:host(/Server(/DSN))=hostname(/DSN);';
 			// We need to get the prefix (pdodriver used by PDO).
-			$this->dsn = $this->hostname;
-			$this->pdodriver = substr($this->hostname, 0, strpos($this->hostname, ':'));
+			$dsnarray = explode(':', $this->hostname);
+			$this->pdodriver = $dsnarray[0];
+
+			// End dsn with a semicolon for extra backward compability
+			// if database property was not empty.
+			if ( ! empty($this->database))
+			{
+				$this->dsn .= rtrim($this->hostname, ';').';';
+			}
 		}
 		else
 		{
@@ -132,7 +139,9 @@
 			$this->dsn = $this->pdodriver.':';
 
 			// Add hostname to the DSN for databases that need it
-			if ( ! empty($this->hostname) && in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'sybase', 'mssql', 'dblib', 'cubrid')))
+			if ( ! empty($this->hostname) 
+				&& strpos($this->hostname, ':') === FALSE
+				&& in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'sybase', 'mssql', 'dblib', 'cubrid')))
 			{
 			    $this->dsn .= 'host='.$this->hostname.';';
 			}
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 0c24ef3..9d61afc 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -118,11 +118,23 @@
 	/**
 	 * Select the database
 	 *
-	 * @return	resource
+	 * @param	string	database name
+	 * @return	bool
 	 */
-	public function db_select()
+	public function db_select($database = '')
 	{
-		return $this->_execute('USE ' . $this->database);
+		if ($database === '')
+		{
+			$database = $this->database;
+		}
+
+		if ($this->_execute('USE '.$database))
+		{
+			$this->database = $database;
+			return TRUE;
+		}
+
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -564,5 +576,12 @@
 
 }
 
+<<<<<<< HEAD
 /* End of file sqlsrv_driver.php */
 /* Location: ./system/database/drivers/sqlsrv/sqlsrv_driver.php */
+=======
+
+
+/* End of file mssql_driver.php */
+/* Location: ./system/database/drivers/mssql/mssql_driver.php */
+>>>>>>> upstream/develop