根据表找出每个用户得分最高的视频，得分相同时按照视频id选择最大的表a：uid：用户id；d：视频id；score：得分

回答思路

select uid, d, score from (select uid, d, score, row_number() over(partition by uid order by score desc, d desc) as rk ' from a) t where rk = 1