기존학습자료/leetcode, hackerrank

Leetcode 196 - Delete Duplicate Emails (1)

gooreumsea 2023. 6. 24. 19:05

https://leetcode.com/problems/Delete-Duplicate-Emails/

# email 가지고 group by를 한 뒤, 이 이메일이 가지고 있는 id값이 무엇이냐
# WHERE 절에 들어간 min ID들을 제외하고 삭제
# 서브쿼리가 동작하지 않음

DELETE >>> 지울 테이블 지정(조인을 활용 할 경우)
FROM Person >>> 삭제를 해주고 싶은 테이블 명
WHERE Id NOT IN
(

SELECT sub.min_id
FROM(

SELECT Email, MIN(id) AS min_id
FROM Person
GROUP BY Email
) sub 

)