题解 | 每天登陆最早的用户的内容喜好

WITH first_login AS(
    SELECT 
        user_id,
        DATE(log_time) AS log_day,
        rank() over(partition by DATE(log_time) order by log_time ASC) as rk #ranking，选择每天第一名登陆的人员
    FROM login_tb
)
SELECT 
    first_login.log_day,
    first_login.user_id,
    user_action_tb.hobby
FROM first_login
LEFT JOIN user_action_tb
ON first_login.user_id=user_action_tb.user_id
WHERE first_login.rk=1;