182. Duplicate Emails (Easy)

https://leetcode.com/problems/duplicate-emails/

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

+----+---------+
| Id | Email   |
+----+---------+
| 1  | a@b.com |
| 2  | c@d.com |
| 3  | a@b.com |
+----+---------+

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

+---------+
| Email   |
+---------+
| a@b.com |
+---------+

Note: All emails are in lowercase.

Solutions

SELECT 
    DISTINCT a.Email
FROM 
    Person as a, Person as b
WHERE 
    a.Email = b.Email and a.Id <> b.Id;

Incorrect Solutions

References