[SQL문제풀기] 카테고리 별 도서 판매량 집계하기

문제

MYSQL

SELECT B.CATEGORY, SUM(A.SALES) TOTAL_SALES
FROM BOOK_SALES A
JOIN BOOK B ON A.BOOK_ID = B.BOOK_ID
WHERE A.SALES_DATE LIKE '2022-01%'
GROUP BY B.CATEGORY
ORDER BY B.CATEGORY ASC

ORACLE

SELECT B.CATEGORY, SUM(S.SALES) TOTAL_SALES
FROM BOOK B
JOIN BOOK_SALES S ON B.BOOK_ID = S.BOOK_ID
WHERE TO_CHAR(SALES_DATE,'YYMM') = '2201'
GROUP BY B.CATEGORY
ORDER BY B.CATEGORY ASC