def _update_sdss_coverage(
            self):
        """ update sdss coverage

        .. todo ::

            - update key arguments values and definitions with defaults
            - update return values and definitions
            - update usage examples and text
            - update docstring text
            - check sublime snippet exists
            - clip any useful text to docs mindmap
            - regenerate the docs and check redendering of this docstring
        """
        self.log.debug('starting the ``_update_sdss_coverage`` method')

        tableName = self.dbTableName

        # SELECT THE LOCATIONS NEEDING TO BE CHECKED
        sqlQuery = u"""
            select primary_ned_id, primaryID, raDeg, decDeg, sdss_coverage from %(tableName)s where sdss_coverage is null and master_row = 1 and in_ned = 1 order by dist_mpc;
        """ % locals()
        rows = readquery(
            log=self.log,
            sqlQuery=sqlQuery,
            dbConn=self.cataloguesDbConn,
            quiet=False
        )

        totalCount = len(rows)
        count = 0
        for row in rows:
            count += 1
            if count > 1:
                # Cursor up three lines and clear
                sys.stdout.write("\x1b[1A\x1b[2K")
                sys.stdout.write("\x1b[1A\x1b[2K")
                sys.stdout.write("\x1b[1A\x1b[2K")

            if count > totalCount:
                count = totalCount
            percent = (float(count) / float(totalCount)) * 100.

            primaryID = row["primaryID"]
            raDeg = float(row["raDeg"])
            decDeg = float(row["decDeg"])
            primary_ned_id = row["primary_ned_id"]

            # SDSS CAN ONLY ACCEPT 60 QUERIES/MIN
            time.sleep(1.1)
            print "%(count)s / %(totalCount)s (%(percent)1.1f%%) NED galaxies checked for SDSS coverage" % locals()
            print "NED NAME: ", primary_ned_id

            # covered = True | False | 999 (i.e. not sure)
            sdss_coverage = check_coverage(
                log=self.log,
                ra=raDeg,
                dec=decDeg
            ).get()

            if sdss_coverage == 999:
                sdss_coverage_flag = "null"
            elif sdss_coverage == True:
                sdss_coverage_flag = 1
            elif sdss_coverage == False:
                sdss_coverage_flag = 0
            else:
                self.log.error('cound not get sdss coverage' % locals())
                sys.exit(0)

            # UPDATE THE DATABASE FLAG
            sqlQuery = u"""
                update %(tableName)s set sdss_coverage = %(sdss_coverage_flag)s where primaryID = %(primaryID)s
            """ % locals()
            writequery(
                log=self.log,
                sqlQuery=sqlQuery,
                dbConn=self.cataloguesDbConn,
            )

        self.log.debug('completed the ``_update_sdss_coverage`` method')
        return None
update sdss coverage

        .. todo ::

            - update key arguments values and definitions with defaults
            - update return values and definitions
            - update usage examples and text
            - update docstring text
            - check sublime snippet exists
            - clip any useful text to docs mindmap
            - regenerate the docs and check redendering of this docstring