프로그래머스 - 상품 별 오프라인 매출 구하기

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 P.PRODUCT_ID
ORDER BY (P.PRICE*SUM(O.SALES_AMOUNT)) DESC, P.PRODUCT_CODE ASC;