title: MYSQL left join on multiple fields
body: <p>I have a friends table.  Is it possible to do a left join on two fields of the table.  In other words, I don't know which of the two fields may have the match I need.  If not is there another way to do this?</p>
  
  <pre><code>$sql = "SELECT * FROM `friends` f
  LEFT JOIN `users` u
  ON f.askee OR f.asker = u.ID
  where (asker='$userid' OR askee='$userid') AND status='3'";
  </code></pre>