题解 | #牛客的课程订单分析(七)#

select
if(client_id="0",'GroupBuy',c.name)source, -- 3.if函数来实现订单拼团与否的区分
count(client_id) cnt
from
(select *,COUNT(DATE)OVER(PARTITION BY USER_ID) ct from order_info o where 
date>"2025-10-15"
and status="completed" 
and product_name in("C++","Python","Java")) t1 
left join
client c on t1.client_id=c.id
where t1.ct>=2                             -- 1.选出符合要求的订单信息
group by client_id                         -- 2.通过group by设备id来实现题目
order by source