title: how to make left join between two tables without relation in doctrine 1.2
body: <p>I have two tables.</p>
  
  <pre><code>Table invitations
  Columns:
       id         email         created_at
  
  Table orders
  Columns:
       id         amount         email         created_at
  </code></pre>
  
  <p>i need to create a DQL to select all the fields from invitations table and left join with count of all the record in orders table with on email </p>
  
  <p>NOTE I need to view the results so I need to paginate the results and there is no relation between the two tables </p>