class M20060112C < ActiveRecord::Migration
  def self.up
  	change_column :contacts, :account_id, :int

  end

  def self.down
  	change_column :contacts, :account_id, :string
  end
end

rakrapha@proactivity:~/eLaborate$ rake migrate
(in /home/rapha/eLaborate)
rake aborted!
You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occured while evaluating nil.[]

rapha@proactivity:~/eLaborate$