版权声明： https://blog.csdn.net/qq_39539470/article/details/81839662
问题描述：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。
所用的表和数据
Create table If Not Exists Person (Id int,Email varchar(255));
Truncate table Person;
insert into Person (Id, Email) values ('1','[email protected]');
insert into Person (Id, Email) values ('2','[email protected]');
insert into Person (Id, Email) values ('3','[email protected]');
解决方法：
# Write your MySQL query statement below
select Email from person group by Email having count(Email)>1;