상품 별 오프라인 매출 구하기(Programmers)

답 쿼리입니다.

SELECT P.PRODUCT_CODE
     , SUM(P.PRICE * OS.SALES_AMOUNT) SALES
FROM PRODUCT P 
     JOIN OFFLINE_SALE OS ON P.PRODUCT_ID = OS.PRODUCT_ID
GROUP BY P.PRODUCT_CODE
ORDER BY SALES DESC, PRODUCT_CODE