在 Rails 中建立数据库的最佳方法是什么?

我有一个 rake 任务,填充一些初始数据在我的轨道应用程序。例如,国家、州、移动运营商等。

我现在设置它的方式是,在/db/fixture 中的文件中有一堆 create 语句,并且有一个 rake 任务来处理它们。例如,我有一个模型是主题。我在/db/fixture 中有一个 theme.rb 文件,如下所示:

Theme.delete_all
Theme.create(:id => 1, :name=>'Lite', :background_color=>'0xC7FFD5', :title_text_color=>'0x222222',
:component_theme_color=>'0x001277', :carrier_select_color=>'0x7683FF', :label_text_color=>'0x000000',
:join_upper_gradient=>'0x6FAEFF', :join_lower_gradient=>'0x000000', :join_text_color=>'0xFFFFFF',
:cancel_link_color=>'0x001277', :border_color=>'0x888888', :carrier_text_color=>'0x000000', :public => true)


Theme.create(:id => 2, :name=>'Metallic', :background_color=>'0x000000', :title_text_color=>'0x7299FF',
:component_theme_color=>'0xDBF2FF', :carrier_select_color=>'0x000000', :label_text_color=>'0xDBF2FF',
:join_upper_gradient=>'0x2B25FF', :join_lower_gradient=>'0xBEFFAC', :join_text_color=>'0x000000',
:cancel_link_color=>'0xFF7C12', :border_color=>'0x000000', :carrier_text_color=>'0x000000', :public => true)


Theme.create(:id => 3, :name=>'Blues', :background_color=>'0x0060EC', :title_text_color=>'0x000374',
:component_theme_color=>'0x000374', :carrier_select_color=>'0x4357FF', :label_text_color=>'0x000000',
:join_upper_gradient=>'0x4357FF', :join_lower_gradient=>'0xffffff', :join_text_color=>'0x000000',
:cancel_link_color=>'0xffffff', :border_color=>'0x666666', :carrier_text_color=>'0x000000', :public => true)
puts "Success: Theme data loaded"

这里的想法是,我想安装一些股票主题用户开始。我对这种方法有疑问。

设置 ID 无效。这意味着如果我决定添加一个主题,让我们称之为“ Red”,那么我只需要将主题语句添加到这个 fixture 文件中,并调用 rake 任务重新播种数据库。如果我这样做,因为主题属于其他对象,并且在重新初始化时它们的 id 发生了变化,所有链接都会中断。

我的问题首先是,这是处理数据库种子化的好方法吗?在之前的一篇文章中,有人建议我这样做。

如果是这样,我如何硬编码的 ID,并有任何缺点呢?

如果没有,那么在数据库中添加种子的最佳方法是什么?

我将真正欣赏长期和深思熟虑的答案,纳入最佳做法。

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The best way is to use fixtures.

Note: Keep in mind that fixtures do direct inserts and don't use your model so if you have callbacks that populate data you will need to find a workaround.

Add it in database migrations, that way everyone gets it as they update. Handle all of your logic in the ruby/rails code, so you never have to mess with explicit ID settings.

factory_bot sounds like it will do what you are trying to achieve. You can define all the common attributes in the default definition and then override them at creation time. You can also pass an id to the factory:

Factory.define :theme do |t|
t.background_color '0x000000'
t.title_text_color '0x000000',
t.component_theme_color '0x000000'
t.carrier_select_color '0x000000'
t.label_text_color '0x000000',
t.join_upper_gradient '0x000000'
t.join_lower_gradient '0x000000'
t.join_text_color '0x000000',
t.cancel_link_color '0x000000'
t.border_color '0x000000'
t.carrier_text_color '0x000000'
t.public true
end


Factory(:theme, :id => 1, :name => "Lite", :background_color => '0xC7FFD5')
Factory(:theme, :id => 2, :name => "Metallic", :background_color => '0xC7FFD5')
Factory(:theme, :id => 3, :name => "Blues", :background_color => '0x0060EC')

When used with faker it can populate a database really quickly with associations without having to mess about with Fixtures (yuck).

I have code like this in a rake task.

100.times do
Factory(:company, :address => Factory(:address), :employees => [Factory(:employee)])
end

Updating since these answers are slightly outdated (although some still apply).

Simple feature added in rails 2.3.4, db/seeds.rb

Provides a new rake task

rake db:seed

Good for populating common static records like states, countries, etc...

http://railscasts.com/episodes/179-seed-data

*Note that you can use fixtures if you had already created them to also populate with the db:seed task by putting the following in your seeds.rb file (from the railscast episode):

require 'active_record/fixtures'
Fixtures.create_fixtures("#{Rails.root}/test/fixtures", "operating_systems")

For Rails 3.x use 'ActiveRecord::Fixtures' instead of 'Fixtures' constant

require 'active_record/fixtures'
ActiveRecord::Fixtures.create_fixtures("#{Rails.root}/test/fixtures", "fixtures_file_name")

Usually there are 2 types of seed data required.

  • Basic data upon which the core of your application may rely. I call this the common seeds.
  • Environmental data, for example to develop the app it is useful to have a bunch of data in a known state that us can use for working on the app locally (the Factory Girl answer above covers this kind of data).

In my experience I was always coming across the need for these two types of data. So I put together a small gem that extends Rails' seeds and lets you add multiple common seed files under db/seeds/ and any environmental seed data under db/seeds/ENV for example db/seeds/development.

I have found this approach is enough to give my seed data some structure and gives me the power to setup my development or staging environment in a known state just by running:

rake db:setup

Fixtures are fragile and flakey to maintain, as are regular sql dumps.

Using seeds.rb file or FactoryBot is great, but these are respectively great for fixed data structures and testing.

The seedbank gem might give you more control and modularity to your seeds. It inserts rake tasks and you can also define dependencies between your seeds. Your rake task list will have these additions (e.g.):

rake db:seed                    # Load the seed data from db/seeds.rb, db/seeds/*.seeds.rb and db/seeds/ENVIRONMENT/*.seeds.rb. ENVIRONMENT is the current environment in Rails.env.
rake db:seed:bar                # Load the seed data from db/seeds/bar.seeds.rb
rake db:seed:common             # Load the seed data from db/seeds.rb and db/seeds/*.seeds.rb.
rake db:seed:development        # Load the seed data from db/seeds.rb, db/seeds/*.seeds.rb and db/seeds/development/*.seeds.rb.
rake db:seed:development:users  # Load the seed data from db/seeds/development/users.seeds.rb
rake db:seed:foo                # Load the seed data from db/seeds/foo.seeds.rb
rake db:seed:original           # Load the seed data from db/seeds.rb

Rails has a built in way to seed data as explained here.

Another way would be to use a gem for more advanced or easy seeding such as: seedbank.

The main advantage of this gem and the reason I use it is that it has advanced capabilities such as data loading dependencies and per environment seed data.

Adding an up to date answer as this answer was first on google.