title: Doctrine2 random query
body: <p>I want to fetch 2 rows from my database randomly with doctrine2, and I can't manage to do it. I figured out that there is no possibility to do it easily with RAND(), but then which is the best solution?</p>
  
  <p>And from the table I want to select rows which are for example for sale, I mark it with 1 in is_sale, so because of this I couldn't do it with simple offset.</p>
  
  <p>Thanks</p>