题解 | 牛客的课程订单分析(五)

select distinct user_id,m2 as first_buy_date,date as second_buy_date,m1 as cnt 
from
(select user_id ,count(*) over(partition by user_id) as m1,  date,min(date) over(partition by user_id) as m2, dense_rank() over(partition by user_id order by date) as m3
from order_info 
where date > '2025-10-15' 
and (status='completed') 
And (product_name in ('Python','C++','Java'))  
)  as pp WHERE m1>=2 and m3=2 order by user_id;