[프로그래머스] (MySQL) 49. 저자 별 카테고리 별 매출액 집계하기

예시

코드

SELECT
    A.AUTHOR_ID,
    A.AUTHOR_NAME,
    B.CATEGORY,
    SUM(BS.SALES * B.PRICE) AS TOTAL_SALES
FROM
    BOOK AS B
INNER JOIN
    AUTHOR AS A
ON
    B.AUTHOR_ID = A.AUTHOR_ID
INNER JOIN
    BOOK_SALES AS BS
ON
    B.BOOK_ID = BS.BOOK_ID
WHERE
    BS.SALES_DATE LIKE '2022-01%'
GROUP BY
    A.AUTHOR_ID,
    B.CATEGORY
ORDER BY
    A.AUTHOR_ID,
    B.CATEGORY DESC;