题解 | #牛客的课程订单分析(二)#
牛客的课程订单分析(二)
https://www.nowcoder.com/practice/4ca4137cb490420cad06d2147ae67456
select distinct user_id from order_info a where exists( select count(1) cnt from order_info b where product_name in ("C++","Java","Python") and status = "completed" and a.user_id = b.user_id and date>"2025-10-15" group by user_id having cnt>=2 ) order by user_id
exists方法