Update doctrine.rst

Uploading code of directly access in controller of the custom dbal connections.

Author: hectorprats

reference/configuration/doctrine.rst

@@ -155,7 +155,12 @@ which is the first one defined or the one configured via the
 ``default_connection`` parameter.
 
 Each connection is also accessible via the ``doctrine.dbal.[name]_connection``
-service where ``[name]`` is the name of the connection.
+service where ``[name]`` is the name of the connection. Or directly in the controller with 
+getConnection method and the name of the connection.
+
+.. code-block:: php
+    $conex = $this->getDoctrine()->getConnection('customer');
+    $res = $conex->fetchAll('select * from table');
 
 Doctrine ORM Configuration
 --------------------------