저자 별 카테고리 별 매출액 집계하기

문제

코드

SELECT BOOK.AUTHOR_ID, AUTHOR.AUTHOR_NAME, BOOK.CATEGORY , SUM(BOOK_SALES.SALES * BOOK.PRICE) AS TOTAL_SALES
FROM BOOK JOIN AUTHOR ON BOOK.AUTHOR_ID = AUTHOR.AUTHOR_ID
            JOIN BOOK_SALES ON BOOK.BOOK_ID = BOOK_SALES.BOOK_ID
WHERE DATE_FORMAT(BOOK_SALES.SALES_DATE, '%Y-%m') = '2022-01'
GROUP BY BOOK.AUTHOR_ID, BOOK.CATEGORY
ORDER BY BOOK.AUTHOR_ID, BOOK.CATEGORY DESC

 

출처: 프로그래머스 코딩 테스트 연습, https://school.programmers.co.kr/learn/courses/30/lessons/144856