[프로그래머스] [MySQL] [Level 4] [GROUP BY] 년, 월, 성별 별 상품 구매 회원 수 구하기

문제 설명

 

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예시

 

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-- 코드를 입력하세요
SELECT YEAR(A.SALES_DATE) AS YEAR, MONTH(A.SALES_DATE) AS MONTH, 
B.GENDER, COUNT(DISTINCT B.USER_ID) AS USERS
FROM ONLINE_SALE A
JOIN USER_INFO B
ON A.USER_ID = B.USER_ID
WHERE GENDER IS NOT NULL
GROUP BY YEAR, MONTH, B.GENDER 
ORDER BY YEAR, MONTH, B.GENDER