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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 gpa) rk from user_profile) a ...

2026-03-29

0 34

题解 | 计算用户的平均次日留存率

select count(distinct q2.device_id,q2.date)/count(distinct q1.device_id,q1.date) avg_ret from question_practice_detail q1 left join question_practice_...

2026-03-28

0 55

题解 | 统计每个学校各难度的用户平均刷题数

select university,difficult_level,round(count(qpd.question_id)/count(distinct(qpd.device_id)),4) avg_answer_cnt from user_profile u join question_pr...

2026-03-28

0 33

题解 | 统计每个学校的答过题的用户的平均答题数

select university,round(count(user_profile.device_id)/count(distinct (question_practice_detail.device_id)),4) avg_answer_cnt from user_profile,questio...

2026-03-28

0 40

题解 | 分组排序练习题

select university,round(avg(question_cnt),4) avg_question_cnt from user_profile group by university order by avg_question_cnt

2026-03-27

0 35

题解 | 分组过滤练习题

select university,round(avg(question_cnt),3) avg_question_cnt,round(avg(answer_cnt),3) avg_answer_cnt from user_profile group by university having avg...

2026-03-27

0 37

题解 | 分组计算练习题

select gender,university,count(gender) user_num,round(avg(active_days_within_30),1) avg_active_day,round(avg(question_cnt),1) avg_question_cnt from us...

2026-03-27

0 40

题解 | 计算男生人数以及平均GPA

select count(*) male_num,round(avg(gpa),1) avg_gpa from user_profile where gender='male'

2026-03-27

0 39