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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 NOT IN ("复旦大学") select device_id,gender,age,university from use...

2025-12-11

0 12

题解 | 电话号码格式校验

SELECT * FROM contacts WHERE phone_number REGEXP '^[1-9][0-9]{2}-?[0-9]{3}-?[0-9]{4}$';

2025-12-10

0 12

题解 | 21年8月份练题总数

SELECT COUNT(distinct device_id),COUNT(question_id) FROM question_practice_detail WHERE date_format(date, '%Y-%m')='2021-08' SELECT COUNT(distinct de...

2025-12-10

0 13

题解 | 查找后降序排列

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

2025-12-10

0 11

题解 | 查找后多列排序

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

2025-12-09

0 10

题解 | 查找后排序

select device_id,age from user_profile order by age

2025-12-09

0 15

题解 | 将查询后的列重新命名

select device_id as 'user_infos_example' from user_profile limit 2

2025-12-09

0 13

题解 | 查询结果限制返回行数

select device_id from user_profile limit 2

2025-12-09

0 15

题解 | 查询结果去重

SELECT DISTINCT university FROM user_profile

2025-12-09

0 11