题解 | 牛客的课程订单分析(七)
牛客的课程订单分析(七)
https://www.nowcoder.com/practice/d6f4a37f966145da8900ba9edcc4c068
select
case when name is null then 'GroupBuy' else name end as source,
count(*) cnt
from(
select o.id,c.name,
count(*) over(partition by user_id) cn
from order_info o
left join client c on o.client_id = c.id
where status='completed'
and date > '2025-10-15'
and product_name in ('C++','Java','Python')
) a
where a.cn>1
group by name
order by source
