SQL分组排序去重复的小实例

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

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