title: How can I join a subquery using Zend_Db_Select
body: <p>How would I construct this query using <code>Zend_Db_Select?</code>:</p>
  
  <pre><code>SELECT users.user_id, email_address, t1.value as 'languages'    
  FROM users
  LEFT JOIN (
    SELECT
      user_id
      , field_id
      , GROUP_CONCAT(value SEPARATOR ',') AS value
    FROM user_multivalued
    WHERE field_id=25
    GROUP BY user_id, field_id) t1
  ON t1.user_id = users.users_id
  WHERE list_id = 45
  </code></pre>