delimiter $$
use `t_girl`$$MYSQL入門

drop function if exists `func_rand_string`$$MYSQL入門

create definer=`root`@`localhost` function `func_rand_string`(f_num tinyint unsigned,f_type tinyint unsigned) returns varchar(32) charset utf8
begin
????? -- translate the number to letter.
????? -- no 1 stands for string only.
????? -- no 2 stands for number only.
????? -- no 3 stands for combination of the above.
????? declare i int unsigned default 0;
????? declare v_result varchar(255) default '';
????? while i < f_num do
??????? if f_type = 1 then
????????? set v_result = concat(v_result,char(65+32*(ceil(rand()*2)-1)+ceil(rand()*25)));
??????? elseif f_type=2 then
????????? set v_result = concat(v_result,ceil(rand()*9));
??????? elseif f_type=3 then
????????? if (ceil(rand()*2)-1) = 1 then
??????????? set v_result = concat(v_result,substring(replace(uuid(),'-',''),i+1,1));
????????? else
??????????? set v_result = concat(v_result,upper(substring(replace(uuid(),'-',''),i+1,1)));
????????? end if;
??????? end if;
??????? set i = i + 1;
????? end while;
????? return v_result;
??? end$$MYSQL入門

delimiter ;MYSQL入門