class RemoveUsersMail < ActiveRecord::Migration[4.2] def self.up remove_column :users, :mail end def self.down add_column :users, :mail, :string, :limit => 60, :default => '', :null => false EmailAddress.where(:is_default => true).each do |a| User.where(:id => a.user_id).update_all(:mail => a.address) end end end