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sql练习-面试前刷题

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题解 | 统计每个用户的平均刷题数

select university,difficult_level,count(answer_cnt)/count(distinct a.device_id) avg_answer_cnt from user_profile a inner join question_practice_detail...

2025-05-13

0 23

题解 | 统计每个学校各难度的用户平均刷题数

select university,difficult_level,count(difficult_level)/count(distinct a.device_id) avg_answer_cnt from user_profile a inner join ( select b.devi...

2025-05-09

0 29

题解 | 统计每个学校的答过题的用户的平均答题数

select university,count(question_id)/count(distinct a.device_id) avg_answer_cnt from user_profile a inner join question_practice_detail b on a.device_...

2025-05-09

0 28

题解 | 浙江大学用户题目回答情况

select a.device_id, question_id, result from user_profile a inner join question_practice_detail b on a.device_id = b.device_id whe...

2025-05-09

0 29

题解 | 分组排序练习题

select university,avg(question_cnt) avg_question_cnt from user_profile group by university order by avg_question_cnt

2025-05-09

0 25

题解 | 分组过滤练习题

# 使用子查询,运行时间35ms占用内存6664KB # select * # from # ( # select # university, # avg(question_cnt) avg_question_cnt, # ...

2025-05-09

0 32

题解 | 分组计算练习题

select gender,university,count(university) user_num,avg(active_days_within_30) avg_active_day,avg(question_cnt) avg_question_cnt from user_profile gro...

2025-05-09

0 31

题解 | 计算男生人数以及平均GPA

select count(*) male_num,avg(gpa) avg_gpa from user_profile where gender = 'male'

2025-05-09

0 29

题解 | 查找GPA最高值

select max(gpa) gpa from user_profile where university = '复旦大学';

2025-05-09

0 30

题解 | 查看学校名称中含北京的用户

select device_id,age,university from user_profile where university like '%北京%'

2025-05-09

0 24