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题解 | #某宝店铺的实际销售额与客单价#

select sum(sales_price) sales_total, round(sum(sales_price)/count(distinct user_id),2) per_trans from sales_tb

Mysql

2021-11-30

0 441

题解 | #牛客直播各科目同时在线人数#

select a.course_id, b.course_name, a.max_num from (select course_id, max(num) max_num from (select course_id , ...

Mysql

2021-11-30

0 309

题解 | #牛客直播各科目出勤率#

我回到了外面的标题，才注意到，是得出席10分钟及以上，这个条件题干里面没写 select a.course_id, a.course_name, round((b.cnt/a.sign)*100,2) `attend_rate(%)` from (select a.co...

Mysql

2021-11-30

0 326

题解 | #牛客直播各科目平均观看时长#

select course_name, round(avg(len),2) avg_Len from (select b.course_name, TIMESTAMPDIFF(MINUTE,in_datetime,out_datetime) Len ...

Mysql

2021-11-30

0 317

题解 | #牛客直播开始时各直播间在线人数#

select a.course_id, b.course_name, count(distinct user_id) online_num from attend_tb a left join course_tb b on a.course_id = b.course_...

Mysql

2021-11-30

13 1644

题解 | #牛客直播转换率#

select a.course_id, b.course_name, round(sum(if_sign)/sum(if_vw)*100,2) `sign_rate(%)` from behavior_tb a left join course_tb b on a.co...

Mysql

2021-11-30

0 269

题解 | #某乎问答最大连续回答问题天数大于等于3天的用户及其对应等级#

select a.author_id, b.author_level, count(*) as day_cnt from (select * , row_number() over(partition by author_id order by answer_date) ...

Mysql

2021-11-30

1 784

题解 | #某乎问答回答过教育类问题的用户里有多少用户回答过职场类问题#

select count(distinct a.author_id) num from answer_tb a join answer_tb b on a.author_id = b.author_id where a.issue_id in (select issue_id ...

Mysql

2021-11-30

1 313

题解 | #某乎问答回答过教育类问题的用户里有多少用户回答过职场类问题#

select count(distinct author_id) from answer_tb where issue_id in (select issue_id from issue_tb where issue_...

Mysql

2021-11-30

5 800

题解 | #某乎问答单日回答问题数大于等于3个的所有用户#

select answer_date, author_id, count(issue_id) answer_cnt from answer_tb where month(answer_date) = 11 group by answer_date,author_id ha...

Mysql

2021-11-30

1 494