title: How to use a findBy method with comparative criteria
body: <p>I'd need to use a "magic finder" findBy method using comparative criteria (not only exact criteria). In other words, I need to do something like this:</p>
  
  <pre><code>$result = $purchases_repository-&gt;findBy(array("prize" =&gt; "&gt;200"));
  </code></pre>
  
  <p>so that I'd get all purchases where the prize is above 200.</p>