[leetcode] 196. Delete Duplicate Emails

DELETE 

 

1. 기본 구문

DELETE
FROM 테이블명 ;

2. 조건이 있을때 

DELETE
FROM 테이블명
WHERE 조건절 ;

 

리트코드 정답 쿼리

1. 서브쿼리 사용

DELETE
FROM person
WHERE id NOT IN
(SELECT sub.min_id
FROM (SELECT email, MIN(id) AS min_id
      FROM person
      GROUP BY email )sub )

 

2. 셀프 조인 사용

DELETE p1
FROM person AS p1
INNER JOIN person AS p2
    ON p1.email = p2.email
WHERE p1.id > p2.id