题解 | #牛客的课程订单分析(四)#

在（三）的基础上：
with t as
(select * from order_info where date>'2025-10-15' and status='completed' and product_name in ('C++','Python','Java'))
select user_id,min(date) first_buy_date,count()
from t
where user_id in (select user_id from t group by user_id having count()>=2)
group by user_id order by user_id;