题解 | 统计有未完成状态的试卷的未完成数和未完成率
统计有未完成状态的试卷的未完成数和未完成率
https://www.nowcoder.com/practice/69fc2b1df4144c0991e4b8280d8aba27
select
exam_id,
count(
case
when score is null then 1
else null
end
) as incomplete_cnt,
round((count(start_time)-count(submit_time))/count(start_time),3) as incomplete_rate
from
exam_record
group by
exam_id
having
incomplete_cnt>0
