select er.exam_id as exam_id,count(distinct er.uid) as uv,round(avg(score),1) as avg_score from user_info as uf right join exam_record as er on uf.uid=er.uid left join examination_info as ei on er.exam_id=ei.exam_id where ei.tag='SQL' and level>'5' and date_format(submit_time,'yyyy-mm-dd')=date_f...