牛牛菌不是男娘

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题解 | 直角三角形

{"html":"<!DOCTYPE html>\r\n<html lang=\"en\">\r\n <head>\r\n <meta charset=\"UTF-8\"...

2025-09-01

0 10

题解 | 列表内容排序再渲染

{"html":"<!DOCTYPE html>\n<html>\n\n<head>\n <meta charset=\"utf-8\" />\n <meta name=\"view...

2025-09-01

0 10

题解 | 浙大不同难度题目的正确率

select difficult_level, round(sum(if(qpd.result = 'right', 1, 0)) / count(qpd.result), 4) correct_rate from user_profile up inner join questi...

2025-08-31

0 13

题解 | 统计复旦用户8月练题情况

select device_id ,university ,count(is_month_08) question_cnt ,count(is_right) right_question_cnt from ( select up.device_id d...

2025-08-31

0 14

题解 | 统计每种性别的人数

select gender ,count(*) number from (select device_id ,case when INSTR(profile, 'female') then 'female' ...

2025-08-31

0 10

题解 | 计算用户的平均次日留存率

select avg(if(datediff(date2, date)=1, 1, 0)) as avg_ret from ( select distinct device_id, date, l...

2025-08-31

0 9

题解 | 计算用户8月每天的练题数量

select date_format(date, '%d') day ,count(*) question_cnt from question_practice_detail where date_format(date, '%y-%m') = '21-08' group by d...

2025-08-31

0 11

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 up.device_id), 4) avg_answer_cnt from user_profile up inner join quest...

2025-08-31

0 13

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(question_id)/count(distinct up.device_id), 4) avg_answer_cnt from user_profile up inner join question_practice_detail q...

2025-08-31

0 10