题解 | #牛客的课程订单分析(三)#
牛客的课程订单分析(三)
http://www.nowcoder.com/practice/4ae8cff2505f4d7cb68fb0ec7cf80c57
select id,user_id,product_name,status,client_id,date
from(SELECT *,count(*) over(partition by user_id) as cnt
FROM order_info oi
WHERE date>'2025-10-15'
and status='completed'
and product_name in ('C++','Python','Java')) od
WHERE cnt>=2
ORDER BY id
窗口函数不改变行数，同时将结果附加到每一行
