[프로그래머스 SQL] 카테고리 별 도서 판매량 집계하기

https://school.programmers.co.kr/learn/courses/30/lessons/144855

프로그래머스

SELECT
    A.CATEGORY AS 'CATEGORY',
    SUM(B.SALES) AS 'TOTAL_SALES'
FROM BOOK AS A 
LEFT JOIN BOOK_SALES AS B
ON A.BOOK_ID = B.BOOK_ID
WHERE YEAR(SALES_DATE)=2022 AND MONTH(SALES_DATE)=1
GROUP BY A.CATEGORY
ORDER BY A.CATEGORY ASC;