[프로그래머스 SQL 고득점 Kit] GROUP BY: 카테고리 별 도서 판매량 집계하기

🤔 문제

✅ 정답

SELECT A.CATEGORY, SUM(B.SALES) AS TOTAL_SALES
FROM BOOK AS A JOIN BOOK_SALES AS B ON A.BOOK_ID = B.BOOK_ID
WHERE B.SALES_DATE LIKE '%2022-01%'
GROUP BY A.CATEGORY
ORDER BY A.CATEGORY