code: def _getOneMatchingRowNoRetries(self, tableInfo, conn, fieldsToMatch,
                                    selectFieldNames):
      
      rows = self._getMatchingRowsNoRetries(tableInfo, conn, fieldsToMatch,
                                            selectFieldNames, maxRows=1)
      if rows:
        assert len(rows) == 1, repr(len(rows))
        result = rows[0]
      else:
        result = None
  
      return result
docs: Return a single matching row with the requested field values from the
      the requested table or None if nothing matched.
  
      tableInfo:       Table information: a ClientJobsDAO._TableInfoBase  instance
      conn:            Owned connection acquired from ConnectionFactory.get()
      fieldsToMatch:   Dictionary of internal fieldName/value mappings that
                       identify the desired rows. If a value is an instance of
                       ClientJobsDAO._SEQUENCE_TYPES (list/set/tuple), then the
                       operator 'IN' will be used in the corresponding SQL
                       predicate; if the value is bool: "IS TRUE/FALSE"; if the
                       value is None: "IS NULL"; '=' will be used for all other
                       cases.
      selectFieldNames:
                       list of fields to return, using internal field names
  
      retval:          A sequence of field values of the matching row in the order
                        of the given field names; or None if there was no match.