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题解 | #牛客网用户数据集的大小#

import pandas as pd Nowcoder = pd.read_csv('Nowcoder.csv',sep=',',dtype=object) a = len(Nowcoder) b = len(Nowcoder.columns) print((a,b))

Python3

2022-07-24

0 170

题解 | #用pandas查看牛客网用户数据#

import pandas as pd Nowcoder = pd.read_csv('Nowcoder.csv',sep=',',dtype=object) print(Nowcoder.head(6))

Python3

2022-07-24

0 249

题解 | #每份试卷每月作答数和截止当月的作答总数。#

select exam_id, date_format(start_time, '%Y%m') as start_month, count(start_time) as month...

Mysql

2022-06-30

0 126

题解 | #平均活跃天数和月活人数#

select date_format(submit_time,'%Y%m') month ,round((count(distinct uid, date_format(submit_time, '%y%m%d'))/ count(distinct uid)),2) avg_...

Mysql

2022-06-24

0 146

题解 | #得分不小于平均分的最低分#

select min(e.score) min_score_over_avg from exam_record e join examination_info e1 on e.exam_id = e1.exam_id where e1.tag='SQL' and...

Mysql

2022-06-24

0 127

题解 | #统计作答次数#

select count(exam_id) total_pv , count(submit_time) complete_pv ,count(distinct if(submit_time,exam_id,null) ) complete_exam_cnt fro...

Mysql

2022-06-24

0 160

题解 | #SQL类别高难度试卷得分的截断平均值#

select tag,difficulty,round((sum(e.score)-max(e.score)-min(e.score))/ (count(e.score)-2),1) clip_avg_score from examination_info f join exam_rec...

Mysql

2022-06-24

0 140

题解 | #创建索引#

alter table examination_info add index idx_duration(duration); alter table examination_info add unique index uniq_idx_exam_id(exam_id); alter table ex...

Mysql

2022-06-24

0 155

题解 | #创建索引#

create index idx_duration on examination_info(duration); create unique index uniq_idx_exam_id on examination_info(exam_id); create fulltext inde...

Mysql

2022-06-24

0 176

题解 | #修改表#

alter table user_info add school varchar(15) after level; alter table user_info change job profession varchar(10); alter table user_info c...

Mysql

2022-06-24

0 205