[프로그래머스/오라클] 저자 별 카테고리 별 매출액 집계 - Oracle

https://school.programmers.co.kr/learn/courses/30/lessons/144856

프로그래머스

 

 

SELECT A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY, sum(s.sales*b.price) as 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
where to_char(s.sales_date,'yyyy-mm') in '2022-01'
group by A.AUTHOR_ID, A.AUTHOR_NAME, B.CATEGORY
ORDER BY 1, 3 Desc;