https://school.programmers.co.kr/learn/courses/30/lessons/77487
코드설명
INNER JOIN + SUBQUERY + GROUP BY + HAVING 를 활용합니다.
코드
# -- 코드를 입력하세요
SELECT P.ID, P.NAME, P.HOST_ID
FROM PLACES AS P
INNER JOIN ( select host_id from places group by host_id having count(*) >= 2) AS P2
ON P.HOST_ID = P2.HOST_ID
ORDER BY P.ID ASC
ORACLE
SELECT P.ID, P.NAME, P.HOST_ID
FROM PLACES P
INNER JOIN (SELECT P.HOST_ID FROM PLACES P GROUP BY P.HOST_ID HAVING COUNT(P.HOST_ID) >= 2 ) P2
ON P.HOST_ID = P2.HOST_ID
ORDER BY P.ID ASC