migrate

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 237
      def migrate(version = nil)
        scope = ENV["SCOPE"]
        verbose_was, Migration.verbose = Migration.verbose, verbose?

        check_target_version

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

        migration_connection.schema_cache.clear!
      ensure
        Migration.verbose = verbose_was
      end