delete from exam_record
where score is null or timestampdiff(minute,
start_time,
submit_time) < 5
order by start_time
limit 3
未完成作答意思就是score没有分数 也不能是0

delete from exam_record
where score is null or timestampdiff(minute,
start_time,
submit_time) < 5
order by start_time
limit 3
未完成作答意思就是score没有分数 也不能是0