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题解 | #考试分数(五)#

with r1 as (select id,job,score,row_number()over(partition by job order by score desc) t_rank from grade ),r2 as ( select job,if(mod(count(id),2)...

2024-05-24

1 136

题解 | #考试分数(四)#

select job,if(mod(count(id),2)=0,count(id) div 2,(count(id) div 2)+1) start,if(mod(count(id),2)=0,(count(id) div 2)+1,(count(id) div 2)+1) end from gr...

2024-05-21

0 179

题解 | #牛客每个人最近的登录日期(六)#

select u.name,p.date,sum(p.number)over(partition by p.user_id order by date) from passing_number p join user u on p.user_id=u.id order by p.date,u.nam...

2024-05-21

1 138

题解 | #异常的邮件概率#

select date,round(count(if(type='no_completed',1,null))/count(type),3) from email where send_id in(select id from user where is_blacklist=0) and recei...

2024-05-11

0 128

题解 | #牛客每个人最近的登录日期(五)#

with new as ( select user_id,min(date) nu from login group by user_id--找出新用户 ), jg as ( select new.nu,lo.user_id,lo.client_id,lo.date da,d...

2024-05-10

0 145

题解 | #浙大不同难度题目的正确率#

select qde.difficult_level,count(if(qp.result='right',1,null))/count(qp.question_id) correct_rate from (select device_id from user_profile where unive...

2024-05-09

0 142

题解 | #统计复旦用户8月练题情况#

select user.device_id,university,count(id) question_cnt,count(if(result='right',1,null)) right_question_cnt from (select device_id,university from use...

2024-05-09

0 131

题解 | #牛客每个人最近的登录日期(四)#

比较简洁的写法 select date,sum(ne) new from (select *,if(first_value(date)over(partition by user_id order by date)=date,1,0) ne from login) l1 group by ...

2024-04-24

0 140

题解 | #牛客每个人最近的登录日期(三)#

个人感觉十分的简洁 select round(sum(p1)/count(distinct user_id),3) p from ( select *,if(date=date_add(d1,interval 1 day),1,0) p1 from (select *,first_value(dat...

2024-04-24

0 124

题解 | #异常的邮件概率#

select e.date,round(if(c2 is null,0,c2)/c1,3) p from (select date,count(type) c1 from email where send_id in(select id from user where is_blacklist=0)...

2024-04-23

0 159