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题解 | #牛客直播各科目同时在线人数#

with tb1 as( select user_id, course_id, in_datetime dt, 1 as diff from attend_tb union all select user_id, course_id, out_datetime dt, -1 as diff from...

2023-04-05

0 205

题解 | #牛客直播各科目出勤率#

select tb1.course_id, course_name, round(count(tb2.user_id)/count(tb1.user_id)*100,2) from (select user_id, course_id from behavior_tb where if...

2023-04-04

0 211

题解 | #重载运算#

class Coordinate(object): def __init__(self,x,y): self.x = x self.y = y #描述信息 def __str__(self): return '({}, {}...

2023-04-03

0 198

题解 | #修改属性2#

#定义类和方法 class Employee(object): def __init__(self,name,salary): self.name = name self.salary = salary def printclass(self...

2023-04-03

0 181

题解 | #牛客直播各科目平均观看时长#

select course_name, round(avg(timestampdiff(second,in_datetime,out_datetime))/60,2) avg_Len from attend_tb left join course_tb using(course_id) group...

2023-04-03

0 160

题解 | #牛客直播开始时各直播间在线人数#

select course_id, course_name, count(in_datetime) from attend_tb left join course_tb using(course_id) where '190000' between date_format(in_datetime,'...

2023-04-02

0 178

题解 | #修改属性1#

class Employee(object): def __init__(self,name,salary): self.name = name self.salary = salary def printclass(self): t...

2023-04-02

0 166

题解 | #班级管理#

class Student(object): def __init__(self,name,id,score,grade): self.name = name self.id = id self.score = score s...

2023-04-02

0 217

题解 | #球的表面积#

import math def vv(r): return 4*(math.pi)*r*r a = [1, 2, 4, 9, 10, 13] for i in a: v = round(vv(i),2) print(v)

2023-04-01

0 155

题解 | #某宝店铺连续2天及以上购物的用户及其对应的天数#

with tb1 as( select distinct sales_date, user_id from sales_tb) select user_id, count(a) days_count from ( select *, date_sub(sales_date, interval (r...

2023-04-01

0 152