题解 | #未完成试卷数大于1的有效用户#

select uid, sum(if(submit_time is null,1,0)) as incomplete_cnt, count(submit_time) as complete_cnt, group_concat(distinct CONCAT(DATE_FORMAT(start_time, '%Y-%m-%d'),':',tag) separator ';') as detail from exam_record left join examination_info using(exam_id) where year(start_time) =2021 and uid in ( select uid from exam_record where year(start_time) =2021 group by uid having sum(if(submit_time is null,1,0)) >=2 and sum(if(submit_time is null,1,0))<=4 ) group by uid having count(submit_time) >=1 order by uid desc