北岛以北

分类

/ 注册

全部文章（共38篇）

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 date like '%2021-08%';

2025-05-18

0 30

题解 | 查找后降序排列

select device_id,gpa,age from user_profile order by gpa desc, age desc;

2025-05-18

0 28

题解 | 查找后多列排序

select device_id,gpa,age from user_profile order by gpa,age;

2025-05-18

0 35

题解 | 查找后排序

select device_id,age from user_profile order by age;

2025-05-18

0 29

题解 | 查找除复旦大学的用户信息

select device_id, gender, age, university from user_profile where university != '复旦大学';

2025-05-18

0 36

题解 | 查找某个年龄段的用户信息

select device_id,gender,age from user_profile where age >=20 AND age <=23;

2025-05-18

0 18

题解 | 查询结果限制返回行数

select device_id from user_profile limit 0,2;

2025-05-18

0 25

题解 | 查询结果去重

select university from user_profile group by university;

2025-05-18

0 21

题解 | 处理文本

#!/bin/bash awk -F ":" '{a[$1]=a[$1]$2 "\n"}END{for(i in a){printf("[%s]\n%s",i,a[i])}}' nowcoder.txt

2024-12-21

0 43

题解 | 去掉不需要的单词

#!/bin/bash while read line do if [[ ! $line =~ [B,b] ]]; then echo $line fi done < nowcoder.txt

2024-12-21

0 53