code: def build_rdn(self):
          
          bits = []
          for field in self._meta.fields:
              if field.db_column and field.primary_key:
                  bits.append("%s=%s" % (field.db_column,
                                         getattr(self, field.name)))
          if not len(bits):
              raise Exception("Could not build Distinguished Name")
          return '+'.join(bits)
docs: Build the Relative Distinguished Name for this entry.