题解 | #统计作答次数#
统计作答次数
http://www.nowcoder.com/practice/45a87639110841b6950ef6a12d20175f
select count(*) as total_pv,count(submit_time) as complete_pv
,count(distinct if(submit_time is not null ,exam_id,null)) as examcnt
from exam_record
统计作答次数
http://www.nowcoder.com/practice/45a87639110841b6950ef6a12d20175f
select count(*) as total_pv,count(submit_time) as complete_pv
,count(distinct if(submit_time is not null ,exam_id,null)) as examcnt
from exam_record
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