题解 | #牛客的课程订单分析(七)#

select ifnull(cc.name, 'GroupBuy') as source
     , count(1)                   as cnt
from order_info oo2
         left join client cc on oo2.client_id = cc.id
where user_id in (select user_id
                  from order_info oi
                           inner join client c on oi.client_id = c.id
                  where date >= '2025-10-15'
                    and status = 'completed'
                    and product_name in ('C++', 'Python', 'Java')
                  group by user_id
                  having count(1) >= 2
                  union
                  select user_id
                  from order_info
                  where client_id = 0)
  and date >= '2025-10-15'
  and status = 'completed'
  and product_name in ('C++', 'Python', 'Java')
group by cc.name
order by source;