https://school.programmers.co.kr/learn/courses/30/lessons/131533#qna
SELECT P.PRODUCT_CODE, P.PRICE * SUM(O.SALES_AMOUNT) AS SALES
FROM PRODUCT P
JOIN OFFLINE_SALE O
ON P.PRODUCT_ID = O.PRODUCT_ID
GROUP BY PRODUCT_CODE
ORDER BY 2 DESC, 1 ASC;
코테가 이 정도 수준으로만 나오면 얼마나 좋을까 ,,,,, ㅋ.ㅋ