How do I add some inserts in rails migration?

Question

After creating a table (by migration), I want to insert some entries directly. How must I write a migration for this?

thanks

Answer 1

Don't. If you're looking for seed data, you should use db/seeds.rb and rake db:seed instead. More info in this Railscast.

Side note: Always make sure that the code in db/seeds.rb is idempotent. i.e. It should always be safe to re-run your seeds.

But, if you must insert or modify data inside a migration (there are legitimate use-cases for this), it's best to use SQL statements instead. Your model class isn't guaranteed to still be around in the same form in a future version of your application, and running the migrations from scratch in the future might yield errors if you reference the model class directly.

execute "insert into system_settings (name, label, value) values ('notice', 'Use notice?', 1)" 

Answer 2

Update: This is the right answer: https://stackoverflow.com/a/2667747/7852

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Here's an example from ruby on rails api:

 class AddSystemSettings < ActiveRecord::Migration     # create the table     def self.up       create_table :system_settings do |t|         t.string  :name         t.string  :label         t.text  :value         t.string  :type         t.integer  :position       end        # populate the table       SystemSetting.create :name => "notice", :label => "Use notice?", :value => 1     end      def self.down       drop_table :system_settings     end   end