migrate

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 254
      def migrate(version = nil)
        check_target_version

        scope = ENV["SCOPE"]
        verbose_was, Migration.verbose = Migration.verbose, verbose?

        Base.connection.migration_context.migrate(target_version || version) do |migration|
          scope.blank? || scope == migration.scope
        end.tap do |migrations_ran|
          Migration.write("No migrations ran. (using #{scope} scope)") if scope.present? && migrations_ran.empty?
        end

        ActiveRecord::Base.clear_cache!
      ensure
        Migration.verbose = verbose_was
      end