MySQL: Bedingtes ORDER BY?

[omata]

Hallo DGL-luke,

klar geht das...

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 CASE WHEN t.forum_id IN (1, 2) 
                   THEN NULL 
                   ELSE t.topic_type 
                 END DESC, t.topic_title ASC
   LIMIT $start, ".$board_config['topics_per_page'];

ich würde die Abfrage allerdings mit JOINs machen...

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
        INNER JOIN " . USERS_TABLE . " u
          ON t.topic_poster = u.user_id
        INNER JOIN " . POSTS_TABLE . " p
          ON t.topic_first_post_id = p.post_id
        INNER JOIN " . POSTS_TABLE . " p2
          ON t.topic_last_post_id = p2.post_id
        INNER JOIN " . USERS_TABLE . " u2
          ON p2.poster_id = u2.user_id 
   WHERE t.forum_id = $forum_id
     AND t.topic_type <> " . POST_ANNOUNCE . " 
     AND t.topic_title LIKE '$start_letter%'
     $limit_topics_time
   ORDER BY CASE WHEN t.forum_id IN (1, 2) 
                   THEN NULL 
                   ELSE t.topic_type 
                 END DESC, t.topic_title ASC
   LIMIT $start, ".$board_config['topics_per_page'];

Gruss
Thorsten