题解 | 统计作答次数
统计作答次数
https://www.nowcoder.com/practice/45a87639110841b6950ef6a12d20175f
select
count(uid) as total_pv,
sum(is_commit) as complete_pv,
count(distinct ex_id_ok) as complete_exam_cnt
from
(
select
*,
if(submit_time is not null,1,0) as is_commit,
if(submit_time is not null,null,exam_id) as ex_id_ok
from exam_record
) as mid_t
