[MySQL] 프로그래머스 131534. 상품을 구매한 회원 비율 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/131534

프로그래머스

정답 코드

SELECT YEAR(SALES_DATE) AS YEAR, MONTH(SALES_DATE) AS MONTH,
    COUNT(DISTINCT USER_ID) AS PUCHASED_USERS,
    ROUND(COUNT(DISTINCT USER_ID)/(SELECT COUNT(USER_ID) FROM USER_INFO WHERE YEAR(JOINED) = 2021), 1) AS PUCHASED_RATIO
FROM USER_INFO JOIN ONLINE_SALE USING (USER_ID)
WHERE JOINED LIKE "2021%"
GROUP BY YEAR, MONTH
ORDER BY YEAR, MONTH;

WITH USER_2021 AS(
    SELECT USER_ID
    FROM USER_INFO
    WHERE YEAR(JOINED) = 2021
)

SELECT YEAR(SALES_DATE) AS YEAR, MONTH(SALES_DATE) AS MONTH,
COUNT(DISTINCT USER_ID) AS PUCHASED_USERS,
ROUND(COUNT(DISTINCT USER_ID) / (SELECT COUNT(USER_ID) FROM USER_2021),1) AS PUCHASED_RATIO
FROM ONLINE_SALE
WHERE USER_ID IN (SELECT USER_ID FROM USER_2021)
GROUP BY YEAR, MONTH
ORDER BY YEAR, MONTH

• 문제 자체에 오타가 있어서 PURCHASED가 아니라 PUCHASED라고 해야한다.