Problem

Table: Person

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+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| email       | varchar |
+-------------+---------+

id is the primary key column for this table.
Each row of this table contains an email. The emails will not contain uppercase letters.

Write an SQL query to report all the duplicate emails.

Return the result table in any order.

The query result format is in the following example.

Examples

Example 1:

Input: Person table:

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+----+---------+
| id | email   |
+----+---------+
| 1  | [email protected] |
| 2  | [email protected] |
| 3  | [email protected] |
+----+---------+

Output:

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+---------+
| Email   |
+---------+
| [email protected] |
+---------+

Explanation: [email protected] is repeated two times.

Solution

Method 1 - Using group by and having

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SELECT p.email AS Email
FROM Person p
GROUP BY p.email
HAVING COUNT(p.email) > 1;