题解 | #牛客的课程订单分析(七)#

select 
*
 from 
(select 
 case when a.is_group_buy='Yes' then 'GroupBuy' else a.name end as source,
count(*) as cnt from 
(select o.*, c.name, count(1)over(partition by user_id) as cnt
from order_info o
left join client c on o.client_id=c.id
where date>='2025-10-15'
and product_name in ('Java','python','C++')
and status='completed') a 
where a.cnt>=2
group by 1) b
order by source