redmine/db/migrate/20091010093521_fix_users_custom_values.rb

class FixUsersCustomValues < ActiveRecord::Migration[4.2]
  def self.up
    CustomValue.where("customized_type = 'User'").
      update_all("customized_type = 'Principal'")
  end

  def self.down
    CustomValue.where("customized_type = 'Principal'").
      update_all("customized_type = 'User'")
  end
end