File: README — Documentation for jcnetdev-seed-fu (1.11)

Seed Fu

Seed Fu is an attempt to once and for all solve the problem of inserting and maintaining seed data in a database. It uses a variety of techniques gathered from various places around the web and combines them to create what is hopefully the most robust seed data system around.

If you have suggestions or come across problems, please report them on the Lighthouse project for Seed Fu: mbleigh.lighthouseapp.com/projects/10223-seed-fu/overview

Usage

Seed data is taken from the db/fixtures directory. Simply make descriptive .rb files in that directory (they can be named anything, but users.rb for the User model seed data makes sense, etc.). These scripts will be run whenever the db:seed rake task is called. You can put arbitrary Ruby code in these files, but remember that it will be executed every time the rake task is called, so it needs to be runnable multiple times on the same database.

You can also have environment-specific seed data placed in db/fixtures/ENVIRONMENT that will only be loaded if that is the current environment.

Let’s say we want to populate a few default users. In db/fixtures/users.rb we write the following code:

User.seed(:login, :email) do |s|
  s.login = "bob"
  s.email = "[email protected]"
  s.first_name = "Bob"
  s.last_name = "Bobson"
end

User.seed(:login, :email) do |s|
  s.login = "bob"
  s.email = "[email protected]"
  s.first_name = "Bob"
  s.last_name = "Stevenson"
end

That’s all you have to do! You will now have two users created in the system and you can change their first and last names in the users.rb file and it will be updated as such.

The arguments passed to the <ActiveRecord>.seed method are the constraining attributes: these must remain unchanged between db:seed calls to avoid data duplication. By default, seed data will constrain to the id like so:

Category.seed do |s|
  s.id = 1
  s.name = "Buttons"
end

Category.seed do |s|
  s.id = 2
  s.name = "Bobbins"
  s.parent_id = 1
end

Note that any constraints that are passed in must be present in the subsequent seed data setting.