如何在 Ruby 中生成随机日期？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/4894198/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to generate a random date in Ruby?
提问by Misha Moroshko
I have a model in my Rails 3 application which has a datefield:
我的 Rails 3 应用程序中有一个模型，它有一个date字段：
class CreateJobs < ActiveRecord::Migration
def self.up
create_table :jobs do |t|
t.date "job_date", :null => false
...
t.timestamps
end
end
...
end
I would like to prepopulate my database with random date values.
我想用随机日期值预填充我的数据库。
What is the easiest way to generate a random date ?
生成随机日期的最简单方法是什么？
回答by Mladen Jablanovi?
Here's a slight expansion on Chris' answer, with optional fromand toparameters:
这是对 Chris 的回答的轻微扩展，带有可选from和to参数：
def time_rand from = 0.0, to = Time.now
Time.at(from + rand * (to.to_f - from.to_f))
end
> time_rand
=> 1977-11-02 04:42:02 0100
> time_rand Time.local(2010, 1, 1)
=> 2010-07-17 00:22:42 0200
> time_rand Time.local(2010, 1, 1), Time.local(2010, 7, 1)
=> 2010-06-28 06:44:27 0200
回答by Chris Heald
Try this:
尝试这个：
Time.at(rand * Time.now.to_i)
回答by iGallina
Keeping simple..
保持简单..
Date.today-rand(10000) #for previous dates
Date.today+rand(10000) #for future dates
PS. Increasing/Decreasing the '10000' parameter, changes the range of dates available.
附注。增加/减少“10000”参数会改变可用日期的范围。
回答by idrinkpabst
rand(Date.civil(1990, 1, 1)..Date.civil(2050, 12, 31))
my favorite method
我最喜欢的方法
def random_date_in_year(year)
return rand(Date.civil(year.min, 1, 1)..Date.civil(year.max, 12, 31)) if year.kind_of?(Range)
rand(Date.civil(year, 1, 1)..Date.civil(year, 12, 31))
end
then use like
然后使用像
random_date = random_date_in_year(2000..2020)
回答by Cyril Duchon-Doris
For recent versions of Ruby/Rails, You can use randon a Timerange ?? !!
对于最新版本的 Ruby/Rails，您可以rand在Time范围内使用?? !!
min_date = Time.now - 8.years
max_date = Time.now - 1.year
rand(min_date..max_date)
# => "2009-12-21T15:15:17.162+01:00" (Time)
Feel free to add to_date, to_datetime, etc. to convert to your favourite class
随意添加to_date,to_datetime等以转换为您喜欢的类
Tested on Rails 5.0.3 and Ruby 2.3.3, but apparently available from Ruby 1.9+ and Rails 3+
在 Rails 5.0.3 和 Ruby 2.3.3 上测试，但显然可从 Ruby 1.9+ 和 Rails 3+ 获得
回答by Merovex
The following returns a random date-time in the past 3 weeks in Ruby (sans Rails).
以下在 Ruby (sans Rails) 中返回过去 3 周的随机日期时间。
DateTime.now - (rand * 21)
DateTime.now - (rand * 21)
回答by Markus Andreas
The prettiest solution to me is:
对我来说最漂亮的解决方案是：
rand(1.year.ago..50.weeks.from_now).to_date
回答by loybert
Here's also a more (in my oppinion) improved version of Mladen's code-snippet. Luckily Ruby's rand()function can also handle Time-Objects. Regarding the Date-Object is defined when including Rails, the rand() method gets overwritten so it can handle also Date-Objects. e.g.:
这也是 Mladen 代码片段的更多（在我看来）改进版本。幸运的是 Ruby 的rand()函数也可以处理时间对象。关于在包含 Rails 时定义的日期对象，rand() 方法被覆盖，因此它也可以处理日期对象。例如：
# works even with basic ruby
def random_time from = Time.at(0.0), to = Time.now
rand(from..to)
end
# works only with rails. syntax is quite similar to time method above :)
def random_date from = Date.new(1970), to = Time.now.to_date
rand(from..to)
end
Edit: this code won't work before ruby v1.9.3
编辑：此代码在 ruby v1.9.3 之前不起作用
回答by Matt
Here's my one liner to generate a random date in the last 30 days (for example):
这是我在过去 30 天内生成随机日期的一个班轮（例如）：
Time.now - (0..30).to_a.sample.days - (0..24).to_a.sample.hours
Works great for my lorem ipsum. Obviously minutes and seconds would be fixed.
非常适合我的 lorem ipsum。显然分钟和秒是固定的。
回答by dhaliman
Mladen's answer is a little difficult to understand from just a single look. Here's my take on this.
单看一眼，姆拉登的回答有点难以理解。这是我对此的看法。
def time_rand from=0, to= Time.now
Time.at(rand(from.to_i..to.to_i))
end
