LeetCode 182. Duplicate Emails

SQL Schema
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.

好久没写sql，很多写法都记不起来，本题解法如下：

select distinct p1.Email from Person p1, Person p2 where p1.Email = p2.Email and (p1.Id > p2.Id or p1.Id < p2.Id)

此写法速度超过92.86%，存储用量低于100%的解法