MySQL - 프로그래머스 코딩테스트 [GROUP BY - 식품분류별 가장 비싼 식품의 정보 조회하기]

SELECT A.CATEGORY, B.MAX_PRICE, A.PRODUCT_NAME
  FROM FOOD_PRODUCT A INNER JOIN (
    SELECT MAX(PRICE) AS MAX_PRICE, CATEGORY
      FROM FOOD_PRODUCT
     WHERE CATEGORY IN ('과자', '국', '김치', '식용유')
     GROUP BY CATEGORY
  ) B ON A.CATEGORY = B.CATEGORY AND B.MAX_PRICE = A.PRICE
 ORDER BY 2 DESC;