Question

I have an app on Heroku and need to clean up the database there, again run all (edited) migrations (in the migrations are added the default rows into the table) with the new default rows.

I ran

heroku run rake db:reset

this command cleared up the database, but didn’t add the new rows into the tables. I am trying to add the new lines this way:

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      ...columns definitions...

      t.timestamps
    end
  end

  def self.up
    Users.new(:name => 'my name', :password => 'super-secret-pass')
  end
end

But the new user is not added. What am I missing?

Answer 1

Migrations should have one of:

1. A change method.
2. up and down methods (preferably instance methods in 3+ but class methods are fine too).

You have a change method and a self.up method. The migration system looks for change first:

ActiveRecord::Base.connection_pool.with_connection do |conn|
  @connection = conn
  if respond_to?(:change)
    #...
  else
    time = Benchmark.measure { send(direction) }
  end
  @connection = nil
end

so your self.up will never get run.

Two solutions immediately present themselves:

1. Use separate up and down methods. You might want to review the guide’s Using Models in Your Migrations section.
2. Use two separate migrations: one to create the table and a separate one to create your user.

I’d probably go with 2.