mysql - 从 count() 中选择 max()

Question

可能重复：
每个派生表都必须有自己的别名

我需要找到每个用户的最大操作

表列：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：“每个派生表都必须有自己的别名”

怎么了？..

Answer 1

这只是意味着 MySQL 坚持你给内部SELECT一个名字，比如：

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