DuplicateEmails.sql

-- Source : https://leetcode.com/problems/duplicate-emails/
-- Author : Hamza Mogni
-- Date   : 2022-06-14

/***************************************************************************************************** 
 *
 * Table: Person
 * 
 * +-------------+---------+
 * | 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.
 * 
 * Example 1:
 * 
 * Input: 
 * Person table:
 * +----+---------+
 * | id | email   |
 * +----+---------+
 * | 1  | a@b.com |
 * | 2  | c@d.com |
 * | 3  | a@b.com |
 * +----+---------+
 * Output: 
 * +---------+
 * | Email   |
 * +---------+
 * | a@b.com |
 * +---------+
 * Explanation: a@b.com is repeated two times.
 ******************************************************************************************************/


SELECT 
    email AS "Email"
FROM
    Person
GROUP BY
    email
HAVING
    COUNT(email) > 1