[SQL 문제 풀이] 식품분류별 가장 비싼 식품의 정보 조회하기

SELECT 
    CATEGORY AS 식품분류, 
    PRICE AS 가격, 
    PRODUCT_NAME AS 이름
FROM FOOD_PRODUCT
WHERE CATEGORY IN ('과자', '국', '김치', '식용유')
  AND (CATEGORY, PRICE) IN (
      SELECT CATEGORY, MAX(PRICE)
      FROM FOOD_PRODUCT
      WHERE CATEGORY IN ('과자', '국', '김치', '식용유')
      GROUP BY CATEGORY
  )
ORDER BY PRICE DESC;