merb_seed
merb_seed 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.
Support
merb_seed 0.1 currently only supports datamapper. ActiveRecord and Sequel support
Usage
rake db:seed
Setting up Seed Data
Seed data is taken from the schema/data 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 schema/data/ENVIRONMENT that will only be loaded if that is the current environment.
Let’s say we want to populate a few default users. In schema/data/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.
Callbacks
Seed data can also define callbacks that will run after the record is created
Category.seed do |s|
s.id = 2
s.name = "Bobbins"
s.parent_id = 1
# run code after creation (record is the newly created model)
s.after_seed do |record|
record.enable!
end
end
Source Code
Need a change? Help out by forking and doing a pull request. I’ll merge in any new features or bug fixes that you make. github.com/merbjedi/merb_seed
Seed Fu
merb_seed is a port of seed-fu to Merb