获取SELECT语句中的最后3行并使其成为ASC顺序

Question

我有这个mysql查询,我只想查询我的SELECT语句的最后3行,并且我想再次重新排序我的查询到ASC顺序,因为子查询在DESC中.

 SELECT * FROM( 
      SELECT * 
      FROM post_replies 
      WHERE post_replies.post_hash=:posthash 
      ORDER BY post_replies.reply_id DESC 
      LIMIT 3)
    ORDER BY reply_id ASC

这是出现的错误

CDbCommand无法执行SQL语句:SQLSTATE [42000]:语法错误或访问冲突:1248每个派生表必须具有自己的别名.执行的SQL语句是:SELECT*FROM(SELECT*FROM post_replies WHERE post_replies.post_hash =:posthash ORDER BY post_replies.reply_id DESC LIMIT 3)ORDER BY reply_id ASC

我不想我怎么可以把MySQL的别名这里所定义的理解在这里

如何使我的查询只获取我的select语句的最后3行并以ASC顺序生成结果？

Answer 1

错误只是告诉你需要调用你的subselect东西.您将子别名后的别名放在子选择之后.这应该工作:

 SELECT a.* FROM( 
      SELECT * 
      FROM post_replies 
      WHERE post_replies.post_hash=:posthash 
      ORDER BY post_replies.reply_id DESC 
      LIMIT 3) a
    ORDER BY a.reply_id ASC