instance method column_references

# File activerecord/lib/active_record/relation/query_methods.rb, line 1911
      def column_references(order_args)
        order_args.flat_map do |arg|
          case arg
          when String, Symbol
            extract_table_name_from(arg)
          when Hash
            arg
              .map do |key, value|
                case value
                when Hash
                  key.to_s
                else
                  extract_table_name_from(key) if key.is_a?(String) || key.is_a?(Symbol)
                end
              end
          when Arel::Attribute
            arg.relation.name
          when Arel::Nodes::Ordering
            if arg.expr.is_a?(Arel::Attribute)
              arg.expr.relation.name
            end
          end
        end.compact
      end