[Firebird-devel] Re: First & Limit

[Mark O'D. <mar...@lu...>]

Hi Ann + others

I've had a reasonable look back at news etc, but can't find and posting 
of sample code for a partial limit,  I saw some pseudo code for a stored 
procedure.  I remember seeing something flash by when I didn't have time 
to look, but may have been mistaken (or perhaps it's hidden  by being 
posted as a reply and the title doesn't spring out at me)..  

However, if there is one I'd like to see it, since from the code sample 
below it looks like the discussion is fairly well advanced along these 
lines.

Cheers


Mark

PS: I've kept up the

Ann W. Harrison wrote:

>
>>
>> On Thursday, July 19, 2001, at 01:24 PM, Ann W. Harrison wrote:
>>
>>> ->          case rsb_skip:
>>> ->              if ((--((IRSB_SKIP) impure)->irsb_number) > 0)
>>> ->                  return FALSE;
>>> ->              if (!get_record (tdbb, rsb->rsb_next, NULL, mode))
>>> ->                  return FALSE;
>>> ->              break;
>>
>
> At 07:01 PM 7/20/2001 -0700, John Bellardo wrote:
>
>> Forgive my ignorance,
>
>
> I assure you, the ignorance was all mine.  For reasons totally obscure
> now, I thought that returning false meant that this particular row didn't
> make the cut, not that the stream was exhausted.
>
>> What I was expecting was more along the lines of:
>>
>>             case rsb_skip:
>>                 if (((IRSB_SKIP) impure)->irsb_number > 0)
>>          {
>>              temp = ((IRSB_SKIP) impure)->irsb_number;
>>              ((IRSB_SKIP) impure)->irsb_number = 0;
>>              for (;temp > 0; temp--)
>>              {
>>                         if (!get_record (tdbb, rsb->rsb_next, NULL, 
>> mode))
>>                         return FALSE;
>>              }
>>           }
>>                 if (!get_record (tdbb, rsb->rsb_next, NULL, mode))
>>                     return FALSE;
>>                 break;
>>
>> Where have I gone wrong?  Thanks.
>
>
> Give or take the way your tabs show up in my mail program, I think
> you're right.  I might do it this way...
>
>         /*  skip over some specified number of rows */
>
>         case rsb_skip:
>             while((--((IRSB_SKIP) impure)->irsb_number))
>                 if (!get_record (tdbb, rsb->rsb_next, NULL, mode))
>                     return FALSE;
>
>             if (!get_record (tdbb, rsb->rsb_next, NULL, mode))
>                 return FALSE;
>             break;
>
> With the usual caveats about boundary conditions and my lack of
> mastery thereof.
>
>
> Regards,
>
> Ann
> www.ibphoenix.com
> We have answers.



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