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。