2019.12.8 LeetCode 从零单刷个人笔记整理(持续更新)
github:https://github.com/ChopinXBP/LeetCode-Babel
传送门:查找重复的电子邮箱
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。
SELECT a.Email
FROM (
SELECT Email, COUNT(Email) 'num'
FROM Person
GROUP BY Email
) a
WHERE a.num > 1;
select Email
from Person
group by Email
having count(Email) > 1;
#Coding一小时,Copying一秒钟。留个言点个赞呗,谢谢你#