select emp_id,emp_level,tag as exam_tag from (select t4.exam_id as exam_id,avg_time,avg_record,emp_id,tag,emp_level,time_count,score from (select exam_id,sum(timestampdiff(second,start_time,submit_time))/count(1)/60 as avg_time,sum(score)/count(1) as avg_record from exam_record group by exam_id) as ...