--SQL SERVER with tb as ( select uid ,MIN(CONVERT(nvarchar(10),in_time,120)) as fistTime ,max(CONVERT(nvarchar(10),out_time,120)) as lastTime ,(select max(CONVERT(nvarchar(10),out_time,120)) from tb_user_log) as today from tb_user_log group by uid ) select t1.user_grade,round(COUNT(t1.ui...