pl/sql 过程中变量未初始化导致update语句失败

问题描述：

如下pl/sql 块一直处于执行状态

DECLARE

...

curr_distr_no varchar2(10);

BEGIN

   for rec in cur loop

    if rec.distr_no <> curr_distr_no then final_amount := 0;

    end if;

     final_amount := rec.amount + final_amount;

     update d set remain_amount = to_char(final_amount) where sn = rec.sn and distr_no = rec.distr_no;

     curr_distr_no := rec.distr_no;

  end loop;

END; 

解决方案：

curr_distr_no varchar2(10); 改为 curr_distr_no varchar2(10) :='';