DELIMITER //
CREATE FUNCTION DateWeek ( date VARCHAR(8) )
RETURNS VARCHAR(8)
SQL SECURITY INVOKER
BEGIN
   DECLARE month VARCHAR(5);
   DECLARE ret VARCHAR(8);
      set month = concat(substring(date, 3,2),'.',substring(date, 5,2)) ;
      set ret = concat(month,'-',week(date)- week(concat(substring(date, 1,6),'01'))+1);
   RETURN ret;
END; //
DELIMITER ;