不想上网课的高级磨洋工练习时长两年半

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题解 | 找出每个学校GPA最低的同学

select device_id,university,gpa from (select device_id,university,gpa,(row_number() over (partition by university order by university,gpa)) as 'rank'...

2025-09-29

0 18

题解 | 提取博客URL中的用户名

select device_id, substring_index(blog_url,'/',-1) as user_name from user_submit

2025-09-29

0 24

题解 | 分析客户逾期情况

select B.pay_ability,concat(round(count(CASE WHEN A.overdue_days IS NULL then NULL else 1 end)/count(A.customer_id)*100,1),"%") as overdue_...

2025-09-28

0 23

题解 | 计算用户8月每天的练题数量

select DAY(date) as day,count(question_id) as question_cnt from question_practice_detail where MONTH(date) = 08 group by day

2025-09-25

0 21

题解 | 查看不同年龄段的用户明细

select device_id,gender, IF (age < 20,"20岁以下", IF(age <= 24,"20-24岁", IF(age >= 25,"25岁及以上","其他&qu...

2025-09-25

0 21

题解 | 计算25岁以上和以下的用户数量

select IF(age >= 25 ,'25岁及以上','25岁以下') as age_cut, count(device_id) from user_profile group by age_cut

2025-09-25

0 22

题解 | 查找山东大学或者性别为男生的信息

select device_id,gender,age,gpa from user_profile where university = "山东大学" UNION ALL select device_id,gender,age,gpa from user_profile w...

2025-09-25

0 27

题解 | 统计每个用户的平均刷题数

select B.university,C.difficult_level, count(B.answer_cnt)/count(distinct A.device_id) from question_practice_detail A Inner join user_profile B on ...

2025-09-25

0 22

题解 | 统计每个学校各难度的用户平均刷题数

SELECT B.university, C.difficult_level, COUNT(A.question_id) /COUNT(DISTINCT A.device_id) as avg_answer_cnt FROM question_practice_det...

2025-09-25

0 20

题解 | 统计每个学校的答过题的用户的平均答题数

select B.university, count(A.question_id)/count(distinct B.device_id) as avg_answer_cnt from question_practice_detail A left join user_profile B on...

2025-09-25

0 16