题解 | #统计复旦用户8月练题情况#
统计复旦用户8月练题情况
https://www.nowcoder.com/practice/53235096538a456b9220fce120c062b3
select a.device_id,university ,sum(case when month(date)=8 then 1 else 0 end) as quesiton_cnt,
sum(case when b.result !="right" or b.result is null then 0 else 1 end) as right_question_cnt
from user_profile as a LEFT JOIN question_practice_detail as b
on a.device_id = b.device_id where a.university = "复旦大学" group by a.device_id ;
sum(case when b.result !="right" or b.result is null then 0 else 1 end) as right_question_cnt
from user_profile as a LEFT JOIN question_practice_detail as b
on a.device_id = b.device_id where a.university = "复旦大学" group by a.device_id ;
