编写一个 SQL 查询，查找 Person 表中所有重复的电子邮箱。
示例：
+----+---------+ | Id | Email | +----+---------+ | 1 | [email protected] | | 2 | [email protected] | | 3 | [email protected] | +----+---------+
根据以上输入，你的查询应返回以下结果：
+---------+ | Email | +---------+ | [email protected] | +---------+
说明：所有电子邮箱都是小写字母。
题目标签：
题目链接：LeetCode / LeetCode中国
在用子查询时：
Every derived table must have its own alias
原因：要给子表取个别名。
| Language | Runtime | Memory |
|---|---|---|
| mysql | 401 ms | N/A |
SELECT Email FROM (SELECT Email, COUNT(Email) c FROM Person GROUP BY Email) t WHERE t.c>1;