[SQL] 리트코드 182. Duplicate Emails

문제

Table: Person

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

id is the primary key (column with unique values) for this table.
Each row of this table contains an email. The emails will not contain uppercase letters.
Write a solution to report all the duplicate emails. Note that it's guaranteed that the email field is not NULL.
Return the result table in any order.

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

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예시

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.

문제 풀이

SELECT email
FROM person
GROUP BY email
HAVING COUNT(email) > 1;

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SQL을 독학하시는 분들에게 도움이 되길 바라며,

혹 더 좋은 방법이 있거나 오류가 있다면 편하게 말씀 부탁드립니다.