title: Exclude property from persistence in Doctrine 2
body: <p>I have an array for mapping properties in my PHP model:
  <code>
  /**
   * @var array
   */
   protected $mapping = array('q' =&gt; 'query', 's' =&gt; 'start');
  </code><br>
  I want to exclude this property from being persisted by Doctrine, but I found no proper annotation for it. How can I achieve this?</p>