[LeetCode]182. 查找重复的电子邮箱

查找重复的电子邮箱

Posted by JinFei on November 26, 2021

题目描述

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 | a@b.com | | 2 | c@d.com | | 3 | a@b.com | +—-+———+ 根据以上输入,你的查询应返回以下结果:

+———+ | Email | +———+ | a@b.com | +———+

Note:

解题思路

# Write your MySQL query statement below
select Email from
(
    select Email, count(Email) as num
    from Person
    group by Email
 ) as statistic  
where num > 1
;