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

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 taWHERE    row_bank = 1========================== PARTITIONBYuserid,classid 这里是按什么分组， 注意一下。