问题描述
题目看链接：https://leetcode.com/problems/duplicate-emails/
解决思路
Inner join相当于取两个表的交集；Distinct是返回唯一不同的值。
代码
# Write your MySQL query statement below
SELECT DISTINCT tb1.Email
FROM Person as tb1
INNER JOIN Person as tb2
WHERE tb1.Email = tb2.Email AND tb1.Id != tb2.Id;
