# 182. 查找重复的电子邮箱
# https://leetcode-cn.com/problems/duplicate-emails/

# SQL架构
Create table If Not Exists Person (id int, email varchar(255));
Truncate table Person;
insert into Person (id, email) values ('1', 'a@b.com');
insert into Person (id, email) values ('2', 'c@d.com');
insert into Person (id, email) values ('3', 'a@b.com');

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

# clean-up
drop table Person;