class FixPositions < ActiveRecord::Migration def self.up ActiveRecord::Base.transaction do Story.find(:all, :conditions => "parent_id is NULL", :order => "project_id ASC, fixed_version_id ASC, position ASC").each_with_index do |s,i| s.position=i+1 s.save! end end end def self.down raise ActiveRecord::IrreversibleMigration end end