- Published on
Leetcode - 1158. Market Analysis I
- Authors
- Name
- Indo Yoon
Table of Contents
문제
정답
SELECT user_id AS buyer_id, join_date, IFNULL(COUNT(order_date), 0) AS orders_in_2019
FROM Users
LEFT JOIN Orders ON user_id = buyer_id AND YEAR(order_date) = '2019'
GROUP BY user_id