题解 | #牛客的课程订单分析(四)#

/*
select 
            user_id
            ,min(date) first_buy_date
            ,count(user_id) cnt
from 
            order_info
where 
            date > '2025-10-15' and product_name in ('C++','Java','Python') and status = 'completed'
group by 
            user_id
having 
            count(user_id) > 1
order by 
            user_id
*/
select
*
from
(
select  distinct
            user_id
            ,min(date) over (partition by user_id) 
            ,count(*) over (partition by user_id) as 'cnt'
from
            order_info
where
            date > '2025-10-15' and product_name in ('C++','Java','Python') and status = 'completed' 
) t1
where   t1.cnt >1
order by t1.user_id