LeetCode:182. Duplicate Emails

发表于 | 分类于

题目描述

Write a SQL query to find all duplicate emails in a table named Person.

1
2
3
4
5
6
7
+----+---------+
| Id | Email   |
+----+---------+
| 1  | a@b.com |
| 2  | c@d.com |
| 3  | a@b.com |
+----+---------+

For example, your query should return the following for the above table:

1
2
3
4
5
+---------+
| Email   |
+---------+
| a@b.com |
+---------+

这题考查having语句的用法

代码实现

1
2
3
4
select email 
from person 
group by email
having count(email) > 1;