tujin

分类

/ 注册

全部文章（共25篇）

题解 | #浙大不同难度题目的正确率#

select difficult_level,avg(if(result='right',1,0)) as correct_rate from (select up.device_id,university,answer_cnt,result,difficult_level from user_p...

2023-09-26

0 155

题解 | #统计复旦用户8月练题情况#

select a.device_id,university,sum(if(b.question_id is not null,1,0)),sum(if(result='right',1,0)) from ( select device_id,university from user_profile ...

2023-09-26

1 200

题解 | #找出每个学校GPA最低的同学#

select device_id,university,gpa from( select device_id,university,gpa, row_number() over(partition by university order by gpa) as gpa_rank from user_...

2023-09-26

0 204

题解 | #计算用户的平均次日留存率#

select avg(if(b.device_id is not null,1,0)) as avg_ret from (select distinct device_id,date from question_practice_detail )a left join ( select dist...

2023-09-25

0 216

题解 | #21年8月份练题总数#

select count(distinct device_id) as did_cnt,count(question_id) as question_cnt from question_practice_detail where Year(date) = '2021' and month(date)...

2023-09-25

0 181