delimiter //
drop table if exists `t1`//
create table `t1`(`a` int,unique(`a`),`b` varchar(30))engine=myisam//
insert into `t1` (`a`,`b`) values (1,'1'),(2,'2');
drop procedure if exists `p1`//
create procedure `p1`(num int)
begin
        declare count1 int default '0';
        declare vb varchar(30);
        declare last_row int;
        
        while(num>=1) do
               set num=num-1;
        begin

                declare cur1 cursor for select `a` from `t1`;
                declare continue handler for not found set last_row = 1;
                set last_row:=0;
                open cur1;
                rep1:
                repeat
                        begin
                                declare exit handler for 1062 begin end;
                                fetch cur1 into vb;
                                if (last_row = 1) then
                                        leave rep1;
                                end if;
                        end;
                until last_row=1
                end repeat;
                close cur1;
        end;
        end while;
end//

delimiter ;
call p1(20);