Question

大家早上好我写这段代码来检查数据库中的记录并返回错误或为空但问题总会重现当我在数据库中测试时，它拒绝检查是否声明并直接进入异常

 begin

l_CURRENT_DATE := P_FROM_DATE;
select P_TO_DATE - P_FROM_DATE into l_DAY_COUNT from dual;

--   while l_CURRENT_DATE between P_FROM_DATE and P_TO_DATE loop
for i in 0 .. l_DAY_COUNT loop
  --  l_CURRENT_DATE := P_FROM_DATE + i;

  select to_number(to_char(l_CURRENT_DATE, 'd'))
    into l_DAY_NUMBER
    from dual;

  -------------------------------------
  if l_DAY_NUMBER = 1 and P_DAY1 = 1 then

    select 1
      into l_DUMMY
      from dual
     where exists (select *
              from PBG_PARK_BOOKING
             where BOOKING_DATE = l_CURRENT_DATE
               and NUM1 = P_PARK
               and FROM_TIME = P_FROM_TIME
               and TO_TIME = P_TO_TIME);

    if l_DUMMY is not null then
      return('PBG-ERROR410:Please Inform there is an Conflict with other Resevation..');
    end if;
  end if;

  l_DUMMY := '';

  --------------------------------------
  if l_DAY_NUMBER = 2 and P_DAY2 = 2 then

    select 1
      into l_DUMMY
      from dual
     where exists (select *
              from PBG_PARK_BOOKING
             where BOOKING_DATE = l_CURRENT_DATE
               and NUM1 = P_PARK
               and FROM_TIME = P_FROM_TIME
               and TO_TIME = P_TO_TIME);

    if l_DUMMY is not null then
      return('PBG-ERROR410:Please Inform there is an Conflict with other Resevation..');
    end if;
  end if;

  l_DUMMY := '';


end loop
exception
  when no_data_found then
  return null;

end ;

Answer 1

您发布的代码不完整；有一些从未声明过的变量（或参数）（例如P_TO_DATE，P_FROM_DATE等）。

无论如何：说该代码“拒绝”检查IF语句（我相信您是说它实际上是执行 IF，但在{{1 }}中的内容并直接进入异常处理部分，意味着SELECT不返回任何内容（即引发SELECT）。

如果您不希望发生这种情况，请确保NO_DATA_FOUND返回某物。

另一方面，看到您编写了一个循环，也许您想检查所有SELECT索引，即，如果它在第一个索引上失败了，那就好了-请检查第二个索引，依此类推。 / p>

如果是这样，则应将循环内的代码包含在其自己的FOR LOOP块中：

BEGIN-EXCEPTION-END

功能始终返回null pl-sql

1 个答案: