blah.rb

class ConvertWorkAddressToManyToMany < ActiveRecord::Migration
  def self.up
    # note that some fields have no "work_" prefix in newfields
    oldfields = [:department, :title, :work_street, :work_city, :work_province, :work_postalcode, :work_country, :work_phone, :work_fax, :email]
    newfields = [:department, :title, :street, :city, :province, :postalcode, :country, :phone, :fax, :email]
    
    newfields.each do |field|
      add_column :contact_organizations, field, String
    end

    # Copy over all the attributes into the join model.
    # I sure as hell hope everyone has a join.
    Contact.find(:all).each do |contact|
      corg = contact.contact_organizations[0]
      # this is decidedly un-ruby-esque, but it'll work fine.
      newfields.size.times do |i|
        corg[newfields[i]] = contact[oldfields[i]]
      end
      corg.save!
    end
    
    oldfields.each do |field|
      remove_column :contacts, field
    end
      
  end

  def self.down
    raise ActiveRecord::IrreversibleMigration
  end
end