SQL分组排序去重复的小实例

复制代码 代码如下:

select

    *

from

    (

        select

            userid,

            classid,

            remark,

            row_number () over (

                partition by userid,

                classid

            order by

                addtime desc

            ) as row_bank

        from

            eng24vipcourseintention

    ) as ta

where

    row_bank = 1

==========================

 partitionbyuserid,classid 这里是按什么分组， 注意一下。