题解 | #牛客的课程订单分析(七)#

select IFNULL(client.name,'GroupBuy') source, count(order_info.id)
from order_info left join client on order_info.client_id=client.id
where order_info.date>'2025-10-15' and 
      order_info.product_name in ('C++','Python','Java') and 
      order_info.status='completed' and
      order_info.user_id in (select user_id 
                             from order_info 
                             where date>'2025-10-15' and 
                             product_name in ('C++','Python','Java') and
                             status='completed'
                             group by user_id having count(user_id)>=2)
group by client.name
order by source