expires_at migration

class AddExpiresAtToOffer < ActiveRecord::Migration
  def change
    add_column :offers, :expires_at, :date

    Offer.reset_column_information
    
    Offer.find_each do |offer|
    	puts '...running loop'
		offer.update_attribute(:expires_at, offer.created_at + 6.months)
		offer.save    	
    end
  end
end