SQL/SQL 문제
[LeetCode] Market Analysis I
Lim Seung Hyun
2023. 3. 18. 20:00
Source
Market Analysis I - LeetCode
Can you solve this real interview question? Market Analysis I - Table: Users +----------------+---------+ | Column Name | Type | +----------------+---------+ | user_id | int | | join_date | date | | favorite_brand | varchar | +----------------+---------+ u
leetcode.com
문제
- 2019년도에 주문 이력이 있는 user_id와 join_date 그리고 주문 총합을 구하는 쿼리 작성
Solution (MySQL)
SELECT user_id AS buyer_id, join_date, COUNT(order_id) AS orders_in_2019
FROM Users AS u
LEFT OUTER JOIN
(
SELECT order_id, buyer_id
FROM Orders
WHERE DATE_FORMAT(order_date, "%Y") = "2019"
) AS o
ON user_id = buyer_id
GROUP BY user_id;728x90