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题解 | #浙大不同难度题目的正确率#

老规矩打标签 sum统计这类需求通杀 select difficult_level, sum(if(result="right",1,0))/count(q.question_id) correct_rate from question_practice_detail q,u...

Mysql

2021-10-14

1 357

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_...

Mysql

2021-10-14

1 354