[Oracle] 즐겨찾기가 가장 많은 식당 정보 출력하기

https://school.programmers.co.kr/learn/courses/30/lessons/131123

프로그래머스

정답

SELECT FOOD_TYPE,REST_ID,REST_NAME,FAVORITES
FROM REST_INFO 
WHERE (FOOD_TYPE,FAVORITES) IN (SELECT FOOD_TYPE,MAX(FAVORITES)
                                  FROM REST_INFO 
                                  GROUP BY FOOD_TYPE)
ORDER BY FOOD_TYPE DESC;

풀이

Step1) 서브쿼리

SELECT FOOD_TYPE,MAX(FAVORITES)
FROM REST_INFO 
GROUP BY FOOD_TYPE

//메인쿼리
SELECT FOOD_TYPE,REST_ID,REST_NAME,FAVORITES
FROM REST_INFO

SELECT FOOD_TYPE,REST_ID,REST_NAME,FAVORITES
FROM REST_INFO 
WHERE (FOOD_TYPE,FAVORITES) IN (SELECT FOOD_TYPE,MAX(FAVORITES)
                                  FROM REST_INFO 
                                  GROUP BY FOOD_TYPE)

https://lavender1122.tistory.com/324

[Oracle] SQL 서브쿼리 SELECT,FROM,WHERE