题解 | #统计复旦用户8月练题情况#

select 
b.device_id,
max(b.university) university,
sum(if(month(date)=8,1,0)) question_cnt,
sum( if((result="right" ) and (month(date)=8),1,0)) right_question_cnt
from question_practice_detail a
right join user_profile b using(device_id)
where university = "复旦大学"
group by b.device_id,university