LC-182

LC-182 - Duplicate Emails

Create table If Not Exists Person (Id int, Email varchar(255))
Truncate table Person
insert into Person (Id, Email) values ('1', '[email protected]')
insert into Person (Id, Email) values ('2', '[email protected]')
insert into Person (Id, Email) values ('3', '[email protected]')

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] |
+---------+

• Difficulty: EASY

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Notes

• All emails are in lowercase.

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Solutions

1. Using GROUP BY and a temporary table
2. Using GROUP BY and HAVING condition