SQL SUM来自内部查询的COUNT

Question

如何从这样的内部查询中总结一列？显然这不起作用，但它本质上是我想要做的。这里有很多类似的帖子，但这是独一无二的，因为我的帖子有HAVING。

SELECT SUM(cnt)
FROM
    (
        SELECT COUNT(*) as cnt
        FROM users
        GROUP BY email
        HAVING COUNT(*)>1
    )

Answer 1

如果你有查询的别名，你写的内容应该有用

SELECT SUM(cnt)
FROM
    (
        SELECT COUNT(*) as cnt
        FROM users
        GROUP BY email
        HAVING COUNT(*)>1
    ) as t

SQL Fiddle