Ruby-on-rails – the best way to seed a database in Rails


I have a rake task that populates some initial data in my rails app. For example, countries, states, mobile carriers, etc.

The way I have it set up now, is I have a bunch of create statements in files in /db/fixtures and a rake task that processes them. For example, one model I have is themes. I have a theme.rb file in /db/fixtures that looks like this:

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"

The idea here is that I want to install some stock themes for users to start with. I have a problem with this method.

Setting the ID does not work. This means that if I decide to add a theme, let's call it 'Red', then I would simply like to add the theme statement to this fixture file and call the rake task to reseed the database. If I do that, because themes belong to other objects and their id's change upon this re-initialization, all links are broken.

My question is first of all, is this a good way to handle seeding a database? In a previous post, this was recommended to me.

If so, how can I hard code the IDs, and are there any downsides to that?

If not, what is the best way to seed the database?

I will truly appreciate long and thought out answers that incorporate best practices.

Best Solution

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...

*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")