migrate

# File activerecord/lib/active_record/migration.rb, line 338
      def migrate(migrations_path, target_version = nil)
        case
          when target_version.nil?              then up(migrations_path, target_version)
          when current_version > target_version then down(migrations_path, target_version)
          else                                       up(migrations_path, target_version)
        end
      end