题解 | #牛客的课程订单分析(七)#

• 参考答案

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

• 答案解析
  本题解决关键是以下两段代码
  第一段代码帅选出了符合条件的user_id,
  第二段代码分组,从而得到我们想要的数据

and user_id in
    (select user_id from order_info o
    where date>'2025-10-15'
     and status='completed'
     and product_name in ('C++','Java','Python')
    group by user_id
    having count(o.id)>=2)

和

group by oi.client_id