What is the best way to seed a database in Rails?

Question

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.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" 

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.

Answer 1

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") 

Answer 2

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.