题解 | #统计作答次数#
统计作答次数
https://www.nowcoder.com/practice/45a87639110841b6950ef6a12d20175f
select
count(*) total_pv,
sum(case
when submit_time is null
then 0
else 1
end) complete_pv,
count(distinct exam_id and score is not null) complete_exam_cnt
from
exam_record
