[SQL문제풀기] 저자 별 카테고리 별 매출액 집계하기

문제

MYSQL

내가 작성한 정답

SELECT A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY, SUM(S.SALES*B.PRICE) TOTAL_SALES
FROM BOOK B
JOIN AUTHOR A ON B.AUTHOR_ID = A.AUTHOR_ID
JOIN BOOK_SALES S ON B.BOOK_ID = S.BOOK_ID AND DATE_FORMAT(S.SALES_DATE,'%y%m') = '2201'
GROUP BY A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY
ORDER BY 1,3 DESC;

ORACLE

내가 작성한 정답

SELECT A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY, SUM(S.SALES*B.PRICE) TOTAL_SALES
FROM BOOK B
JOIN AUTHOR A ON B.AUTHOR_ID = A.AUTHOR_ID
JOIN BOOK_SALES S ON B.BOOK_ID = S.BOOK_ID AND TO_CHAR(S.SALES_DATE,'YYMM') = '2201'
GROUP BY A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY
ORDER BY 1,3 DESC;