title: Symfony2 Select one column in doctrine
body: <p>I'm trying to refine the query trying to select fewer possible values ​​..
  For example I have an entity "Anagrafic" that contains your name, address, city, etc.,
  and a form where I want to change only one of these fields, such as address.
  I have created this query:</p>
  
  <pre><code>//AnagraficRepository
  public function findAddress($Id)
  {
       $qb = $this-&gt;createQueryBuilder('r')
               -&gt;select('r.address')
               -&gt;where('r.id = :id')
               -&gt;setParameter('id', $Id)
               -&gt;getQuery();
  
       return $qb-&gt;getResult();
  }
  </code></pre>
  
  <p>there is something wrong with this query because I do not return any value, but if I do the query normally:</p>
  
  <pre><code>//Controller
  $entity = $em-&gt;getRepository('MyBusinessBundle:Anagrafic')-&gt;find($id);
  </code></pre>
  
  <p>Return the right value.
  How do I do a query selecting only one column?</p>