mysql - 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，并且我想再次将我的查询重新排序为 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 failed to execute the SQL statement: SQLSTATE[42000]: Syntax error or access violation: 1248 Every derived table must have its own alias. The SQL statement executed was: 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

我不明白如何将 mysql 别名按定义放在这里 here

我怎样才能让我的查询只获取我的 select 语句的最后 3 行，并使结果按 ASC 顺序排列？

Answer 1

错误只是告诉您需要调用您的子选择。您将别名放在子选择之后的右括号之后。这应该有效:

 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