-- 方法一 /* with t1 as (select er.exam_id, ei.duration, ei.release_time, timestampdiff(second,er.start_time,er.submit_time) as time_diff, row_number() over(partition by er.exam_id order by timestampdiff(second,er.start_time,er.submit_time) desc) as rank_desc, row_number() over(partition by er.exam_id ...