#每个用户,8月份,联系的总题目,和回答正确题目数 select u.device_id, u.university, sum(if(q.result is not null,1,0)) question_cnt, sum(if(q.result = "right",1,0)) right_question_cnt from user_profile u left join question_practice_detail q on u.device_id = q.device_id and q.date between "202...