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
*
from (select
exam_id,
sum(case
when submit_time is null then 1
else 0
end) as incomplete_cnt,
round(sum(case when submit_time is null then 1 else 0 end) / count(*), 3) as complete_rate
from exam_record
group by exam_id
) t
where t.incomplete_cnt <> 0
开发你这个也没有项目啊
