最后一组添加了所有类别的内容（MySQL）

Question

我的查询：

  SELECT a.id, a.title, a.introtext, a.fulltext, a.created, a.image, a.catid, a.sectionid
  FROM jos_content AS a 
  LEFT JOIN jos_categories AS c 
  ON a.catid = c.id 
  WHERE a.state = 1
  AND c.published = 1
  AND ( publish_up = "0000-00-00 00:00:00" OR publish_up <= "2012-02-08 11:10:25" )
  AND ( publish_down = "0000-00-00 00:00:00" OR publish_down >= "2012-02-08 11:10:25" ) 
  AND a.access <= 0

  AND a.catid = 41

  ORDER BY a.created DESC, a.id DESC 
  LIMIT 0, 1

对于30个类别，我在MySQL中有30个请求（更改AND a.catid = 21，AND a.catid = 42及以上）。

如何对所有类别（21,41,42）进行分组，并从jos_content中选择最后添加的内容

Answer 1

类别是否分配到同一部分？ 如果是，只需选择sectionid而不是catid。