为什么调用这个存储过程会死循环?

u332744

delimiter $$

CREATE procedure sett93c(in apid int,in adesignation varchar(30),in areference varchar(30),in apic varchar(30),in amnote varchar(850),in amark varchar(20))

begin

loop_label: loop

If apid<0 then

        leave loop_label;

else

insert into t93c(pid,name,reference,pic,mnote,mark) values(apid,adesignation,areference,apic,amnote,amark);

leave loop_label;

end if;

end loop;

end

$$

u332744

没人知道吗?