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