这篇文章介绍了SQL分组排序去重复的实例代码，有需要的朋友可以参考一下
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。
