题解 | #牛客的课程订单分析(三)#

mysql套中套语句：
select s.* from order_info s,
(
select user_id,count(*) as gg from order_info
where product_name in ('C++','Java','Python')
and date>'2025-10-15'
and status = 'completed'
group by user_id) t
where s.user_id = t.user_id
and product_name in ('C++','Java','Python')
and date>'2025-10-15'
and status = 'completed' and t.gg>=2