从count（）中选择max（）

Question

  

可能重复：
  every derived table must have its own alias

我需要找到每个用户最多的操作

表格列：action_id，action_status，user

要求：

SELECT MAX(`counted`) FROM
(
SELECT COUNT(*) AS `counted`
FROM `table_actions`
WHERE `status` = "good"
GROUP BY `user`
)

错误消息：“每个派生表必须有自己的别名”

出了什么问题？..

Answer 1

这只是意味着MySQL坚持要为内部SELECT提供一个名称，例如：

SELECT MAX(counted) FROM
(
    SELECT COUNT(*) AS counted
    FROM table_actions
    WHERE status = "good"
    GROUP BY user
) AS counts;