题解 | #牛客的课程订单分析(四)#

select
	a.user_id,
    a.date,
    a.CN
from
(SELECT 
	user_id,
    date,
	row_number()over(partition by user_id order by date asc) as RN,
	count(id)over(partition by user_id ) as CN
FROM
	order_info
WHERE
	date>"2025-10-15"
	AND	status="completed"
	AND	product_name	IN("C++","Java","Python")
	AND	user_id		IN(SELECT 
					user_id
				   FROM
					order_info
				   WHERE
					date>"2025-10-10"
				   AND	status="completed"
				   AND	product_name	IN("C++","Java","Python")
					)
)a
where
	a.RN=1
    and a.cn>=2
order by user_id asc