题解 | #牛客的课程订单分析(六)#

select a.id,case when a.client_id =0 then 'Yes' else 'No' end as is_group_buy, case when a.client_id =0 then null else b.name end as client_name from (select id,client_id,row_number()over(partition by user_id order by date) as r_number, count(*)over(partition by user_id ) as ct from order_info where date>'2025-10-15' and status='completed' and product_name in('C++','Java','Python'))as a left join client as b on a.client_id=b.id where a.ct>=2 order by 1;

#利用窗口函数以及左连接配合case when 求出结果#