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Mysql(1) 题解(25)

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题解 | #获得积分最多的人(三)#

好像不算困难，比较简单 select id,name,grade_sum from ( select user_id ,dense_rank() over(order by grade_sum desc)t_rank ,grade_sum from (select user_...

Mysql

2021-09-22

0 210

题解 | #获得积分最多的人(二)#

select id,name,grade_num from (select user_id, dense_rank() over(order by grade_num desc) t_rank,grade_num from (select user_id,sum(grade_num)grade_...

Mysql

2021-09-21

0 225

题解 | #最差是第几名(二)#

逻辑游戏 select grade from (select grade,sum(number)over() as t,sum(number) over(order by grade) as p,number from class_grade)r1 where IF(t%2=1,p>=(t+1...

Mysql

2021-09-21

0 224

题解 | #实习广场投递简历分析(三)#

主要是时间转换函数，转过来转过去弄的我脑壳大。。。。找工作 select r2.*,r4.second_year_mon,r4.second_year_cnt from ( select job,first_year_mon,sum(num)first_year_cnt fro...

Mysql

2021-09-21

0 282

题解 | #牛客的课程订单分析(七)#

select case when name is null then 'GroupBuy' else name end as source, count(1) as cnt from (select id ,is_group_buy,client_id,count(1) over(partit...

Mysql

2021-09-21

0 191

题解 | #牛客的课程订单分析(五)#

select user_id, min(date) as first_buy_date, max(date) as second_buy_date, cnt from (select user_id,date,count(1) over w as cnt,row_number() over (w o...

Mysql

2021-09-20

0 302

题解 | #考试分数(五)#

select id,job,score,t_rank from (select id,job,score,row_number() over(s order by score desc) as t_rank, case when (count(1) over s)%2=1 then conver...

Mysql

2021-09-20

0 228

题解 | #牛客每个人最近的登录日期(六)#

select name,date,sum(number) over(partition by user_id order by date) from passing_number left join user u on u.id=user_id order by date,name 使用窗口函...

Mysql

2021-09-17

0 198

题解 | #牛客每个人最近的登录日期(五)#

select date,ifnull(round(count(next_date)/count(if(last_date is null ,1, null)) ,3 ),0.000) as p from (select t1.*,t2.last_date from (select l1.user_...

Mysql

2021-09-17

0 296

题解 | #牛客每个人最近的登录日期(四)#

select date,count(last_date is null or null) new from ( select t1.user_id,t1.date,t2.date last_date from login t1 left join login t2 ...

Mysql

2021-09-17

0 215