Subject Re: [ib-support] UDF with BLOB...
Author Claudio Valderrama C.
<liglezias2@...> wrote in message news:9q2kph+mi2l@......
> Hi all!
> Supose that I have an UDF that has a BLOB param.
> Is there a way to see only a specific byte of that BLOB?
> For ex: I want the last byte of that BLOB.
> I should do that WITHOUT reading ALL the blob (from the begining), as
> it is suggested by the function (in the BLOB structure):

In theory: create a stream blob (as opposed to typical segmented blobs) and
use the blobcallback structure definition that's in FB's ibase.h, then
you'll have a function to seek. The seek function in turn takes an arguments
that should allow you to seek from the end backwards. This is in fact the
full structure that both InterBase® and Firebird give to the UDF, but the
seek function is only available for stream blobs.

Now, the problem is whether you can create such stream blobs. I know they
are used internally for arrays.

Ann, are you reading?

Claudio Valderrama C. - -
Independent developer
Owner of the Interbase® WebRing