思路:这道题先用case when函数把减分的情况全部*-1,变成负数。再针对结果,用窗口函数的sum功能,累加,算出所有用户的最终累计分。针对最终累计分,max函数找出所有人里的最高分with t2 as(select user_id, sum(newscore) over (partition by user_id) as grade_numfrom(select user_id ,case when type='reduce' then grade_num*(-1) else grade_num end as newscorefrom grade_info)t1 )select dis...