您好，我与您的思路大致相同，但是报错：“Unknown column 'incomplete_cnt' in 'field list'”，可以帮我看看问题出在哪里了吗： select uid,sum(if(submit_time is null,1,0)) as incomplete_cnt, sum(if(submit_time is not null,1,0)) as complete_cnt, group_concat(distinct concat(date_format(start_time,'%Y-%m-%d'),':',tag) order by incomplete_cnt desc separator ';') as detail from exam_record as er join examination_info as ei on er.exam_id=ei.exam_id where year(start_time)=2021 group by uid having complete_cnt>=1 and incomplete_cnt between 2 and 4