只有抓住所有主题帖子的最后从PHPBB类别

Question

我只想攫取的所有主题的最后发表的帖子在从PHPBB数据库在一个单一的查询的类别（类别 - >论坛 - > Topic->发表）。目前，我已经熟了这一点，但它仅返回后的第一个，不是最后一次。

SELECT *, MAX(p.post_id)
FROM phpbb_forums f, phpbb_topics t, phpbb_posts p
WHERE f.parent_id IN (<categories>)
AND t.forum_id = f.forum_id
AND p.topic_id = t.topic_id
GROUP BY p.topic_id

有谁知道如何正确地做到这一点？

Answer 1

SELECT  *
FROM    phpbb_forums f
JOIN    phpbb_topics t
ON      t.forum_id = f.forum_id
JOIN    phpbb_posts p
ON      p.post_id = 
        (
        SELECT  pi.post_id
        FROM    phpbb_posts pi
        WHERE   pi.topic_id = t.topic_id
        ORDER BY
                pi.date DESC
        LIMIT 1
        )
WHERE   f.parent_id IN (…)