mysql stored procedure instance

mysql stored procedure

delimiter $
DROP FUNCTION IF EXISTS `fun_convert`$
CREATE DEFINER=`root`@`%` FUNCTION   `fun_convert`(para varchar(255))
 RETURNS varchar(255) CHARSET gbk
BEGIN
         declare   result varchar(255) default '';
         declare   cnt int default 0;
         declare   i int default 0;
         declare   id BIGINT default 0;
         set   cnt = length(para) - length(replace(para,',',''))-1;
         WHILE   i < cnt DO
      select c.id into id from company c where c.code =   SUBSTRING(para,i*3+2,2);
                   set   result = CONCAT(result, ",",id);
                   set   i = i+1;
         end   WHILE;
         set   result = CONCAT(result, ",");
         RETURN   result;
END
$
delimiter ;
 
update users u set u.company =   fun_convert(u.COMPANY);