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。
select Email from Person group by Email having count(Email) > 1