title: Symfony2 + Doctrine : select query with conditional statment
body: <p>I would like to do something like : </p>
  
  <pre><code>return $qb
          -&gt;select("f, g")
          -&gt;addSelect(" (CASE WHEN (f.type = 'p') THEN 'panel' ELSE 'glass' END) as 'typeLable' ")
          -&gt;from("Win4uAdminBundle:Filling", "f")
          -&gt;join("f.gammes", "g")
          -&gt;andWhere("f.isActive = :active")
          -&gt;andWhere("g.id = :gamme")
          -&gt;setParameter("active", 1)
          -&gt;setParameter("gamme", $gammeId)
  </code></pre>
  
  <p>But doesn't work. error is :</p>
  
  <pre><code>[Syntax Error] line 0, col 74: Error: Expected Doctrine\ORM\Query\Lexer::T_FROM, got 'typeLable'
  </code></pre>
  
  <p>The goal is select the type and translate it in the query.</p>
  
  <p>Thanks! </p>