ORA-01403: no data found

ORA-01403: no data found
触发器一旦使用到select into赋值就会可能产生找不到数据赋值，使用异常处理机制。
begin
      select P into v_rate from classpoint    where rtrim(classcode) =:new.code;

exception
when no_data_found then

       v_rate := 1;
end;