arel_column

# File activerecord/lib/active_record/relation/query_methods.rb, line 1068
      def arel_column(field)
        field = klass.attribute_alias(field) if klass.attribute_alias?(field)
        from = from_clause.name || from_clause.value

        if klass.columns_hash.key?(field) && (!from || table_name_matches?(from))
          arel_attribute(field)
        else
          yield
        end
      end