[ORACLE_SQL]저자 별 카테고리 별 매출액 집계하기(ㅇ)

-- 코드를 입력하세요
SELECT A.AUTHOR_ID,  B.AUTHOR_NAME, A.CATEGORY, SUM(C.SALES*A.PRICE) AS TOTAL_SALES FROM BOOK A INNER JOIN AUTHOR B 
ON A.AUTHOR_ID = B.AUTHOR_ID
INNER JOIN BOOK_SALES C
ON A.BOOK_ID = C.BOOK_ID
WHERE EXTRACT (YEAR FROM C.SALES_DATE) = '2022' AND EXTRACT (MONTH FROM C.SALES_DATE) = '1'
GROUP BY A.AUTHOR_ID, B.AUTHOR_NAME, A.CATEGORY
ORDER BY A.AUTHOR_ID ASC, A.CATEGORY DESC

where 조건 보지못해서 틀렸지만, 넣으니까 맞출수 있었던 문제