LeetCode #182 Duplicate Emails 查找重复的电子邮箱

182 Duplicate Emails 查找重复的电子邮箱

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

+----+---------+
| Id | Email   |
+----+---------+
| 1  | [email protected] |
| 2  | [email protected] |
| 3  | [email protected] |
+----+---------+

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

+---------+
| Email   |
+---------+
| [email protected] |
+---------+

Note: All emails are in lowercase.

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  | [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。

思路:

GROUP BY
HAVING
COUNT

代码:
MySQL:

# Write your MySQL query statement below
SELECT Email FROM Person GROUP BY Person.Email HAVING(COUNT(*) > 1)