[프로그래머스] [SQL] 년, 월, 성별 별 상품 구매 회원 수 구하기

문제 설명

문제 풀이

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

실행 결과