title: Symfony2 - Sonata datagrid without entity
body: <p>Is there a way to take advantage of the Sonata's Datagrid functionnality to display a resultset ?</p>
  
  <pre><code>class DefaultController extends Controller
  {
      public function nl_listAction()
      {
          $obj = array();
          $cnx = $this-&gt;get('doctrine.dbal.a_connection');
          $cnx-&gt;query('CALL(a_procedure)');
          $obj['cnx'] = $cnx;
          return $this-&gt;render('GlideConfigBundle:Default:nl_list.html.twig', $obj);
      }
  }
  </code></pre>
  
  <p>Here from a controller I'm calling a procedure and I'd like to display the resulting data using Datagrid.<br>
  Is it a good idea ?<br>
  How can I do it ?</p>