title: Doctrine Query Builder query some columns in table
body: <p>I am using Doctrine 2, and I have a request to the database, in the first table(t1) I selected needed columns, and how to select some columns from a table(t2 and t3). 
  I tried to do so, but I get an error. any idea?</p>
  
  <pre><code>addselect('partial t2.{id, name, description}')
  addselect('partial t3.{id, name, description}') 
  </code></pre>
  
  <p>my request</p>
  
  <pre><code>    $query = $this-&gt;getDoctrine()-&gt;getManager()
        -&gt;getRepository('YourBundle:Entity')
        -&gt;createQueryBuilder('t1')
        -&gt;leftJoin('t1.table2', 't2')
        -&gt;leftJoin('t1.table3', 't3')
        -&gt;select('partial t1.{id, name, description}')
        **-&gt;addselect('t2, t3')**
        -&gt;where('t1.name LIKE :q OR t1.description LIKE :q')
        -&gt;setParameter('q', $test.'%')
        -&gt;setMaxResults(16)
        -&gt;getQuery()
        -&gt;getArrayResult();
  </code></pre>