胖橘不乖

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题解 | #查看不同年龄段的用户明细#

select device_id,gender, case when age < 20 then '20岁以下' when age >= 25 then '25岁及以上' when age >= 20 then '20-24岁' else '其他' end as age...

Mysql

2022-04-24

0 241

题解 | #统计每个用户的平均刷题数#

select university,difficult_level, round(count(q.question_id) / count(distinct u.device_id),4) from question_practice_detail q left join user_pr...

Mysql

2022-04-23

0 270

题解 | #统计每个学校的答过题的用户的平均答题数#

select u.university,convert(count(question_id) / count(distinct u.device_id),decimal(10,4)) from user_profile u inner join question_...

Mysql

2022-04-22

0 247

题解 | #浙江大学用户题目回答情况#

select u.device_id, q.question_id,q.result from user_profile u inner join question_practice_detail q on u.device_id = q.device_id where u.university =...

Mysql

2022-04-17

0 257

题解 | #操作符混合运用#

select device_id,question_id,result from question_practice_detail where device_id in (select device_id from user_profile where university = '浙江大学');

Mysql

2022-04-16

0 196

题解 | #操作符混合运用#

select device_id,gender,age,university,gpa from user_profile where gpa > 3.5 and university = '山东大学' OR gpa > 3.8 and university = '复旦大学';

Mysql

2022-04-16

0 209