题解 | #牛客的课程订单分析(二)#

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