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);