MySQL: Bedingtes ORDER BY?

[DGL-luke]

Hallo,

ich verstümmle ja hier seit längerer Zeit ein phpbb-forum zur Datenbank.

Folgendes Statement:

SQL-Code:

$sql = "SELECT t.*, u.username, u.user_id, u2.username as user2, u2.user_id as id2, p.post_username, p2.post_username AS post_username2, p2.post_time 
   FROM " . TOPICS_TABLE . " t, " . USERS_TABLE . " u, " . POSTS_TABLE . " p, " . POSTS_TABLE . " p2, " . USERS_TABLE . " u2
   WHERE t.forum_id = $forum_id
      AND t.topic_poster = u.user_id
      AND p.post_id = t.topic_first_post_id
      AND p2.post_id = t.topic_last_post_id
      AND u2.user_id = p2.poster_id 
      AND t.topic_type <> " . POST_ANNOUNCE . " 
      AND t.topic_title LIKE '$start_letter%'
      $limit_topics_time
   ORDER BY t.topic_type DESC, t.topic_title ASC
   LIMIT $start, ".$board_config['topics_per_page'];

Beim ORDER BY (ORDER BY t.topic_type DESC, t.topic_title ASC) würd ich jetzt gerne falls (t.forum_id = 1 OR t.forum_id = 2) das erste Ordnungskriterium komplett rausschmeissen. Geht das?