class SingleGroupForGuidance < ActiveRecord::Migration def change unless Rails.env.test? Guidance.class_eval do belongs_to :guidance_group, class_name: "GuidanceGroup", foreign_key: "guidance_group_id" end if Object.const_defined?('Guidance') Guidance.includes( :guidance_groups).all.each do |guidance| guidance.guidance_group_id = guidance.guidance_groups.first.id unless guidance.guidance_groups.empty? if guidance.guidance_group_id.nil? guidance.destroy else guidance.save! end end end end drop_table :guidance_in_group end end