title: MySQL query error with CASE and INNER JOIN
body: <p>I have a table with user info called 'a' and a table with data from different API's (twitter,foursquare) which in the example, based on the value
  of the a.api_type should become b. What I want in the end is to be able to grab the right avatar from the active API (either api_foursquare or api_twitter).</p>
  
  <p>I have been trying to get this to work with this query for a while, but I keep getting this error. Sql is not my strongest point, so any tips on how to fix this would be great :)</p>
  
  <pre><code>  "[Err] 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near
  
    INNER JOIN b ON b.user_id = a.user_id  at line 11"
  
  SELECT a.user_id, 
         a.api_type, 
         b.avatar, 
         b.user_id
  (CASE
         WHEN a.api_type = 0 THEN api_foursquare
         WHEN a.api_type = 1 THEN api_twitter
  END) as b
  FROM a WHERE a.cookie_hash = :cookie_hash
  INNER JOIN b ON b.user_id = a.user_id
  </code></pre>
  
  <p>
  </p>