Duplicate Emails

Question

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.

Thought

In order to check the count for duplicated emails, it is necessary to split the table by Email with GROUP BY. The approach of filtering records for GROUP BY is HAVING clause, which is very similar to WHERE except that HAVING only works for the groups generated by GROUP BY.

Code

-- Write your MySQL query statement below
SELECT Email
FROM Person
GROUP BY Email
HAVING COUNT(*) > 1;