title: Select and Delete with a single query
body: <p>I have 2 tables:</p>
  
  <ul>
  <li>users (user_id, user_connected)</li>
  <li>rooms (room_id, room_initiating_user_id, room_target_user_id)</li>
  </ul>
  
  <p>I would like to delete all the "rooms" having both the initiating user and the target_user set to "user_connected=0"</p>
  
  <p>I have two problems here:</p>
  
  <ol>
  <li><p>How to target these users?
  Obviously this query won't work:</p>
  
  <pre><code>SELECT room_id
  FROM rooms,users
  WHERE
  ( 
   (room_target_user_id=user_id) AND (user_connected=0)
  )                   
  AND
  (                
   (room_initiating_user_id=user_id) AND (user_connected=0)
  )
  </code></pre></li>
  <li><p>I would like, with the same query if possible, to delete these rooms (no problem if I use a second query but it means that this query would be triggered for each result, which is a lot. Isn't it possible to delete these rooms at once?</p></li>
  </ol>