Subject | RE: [firebird-support] How to obtain isc_db_handle and isc_tr_handle |
---|---|
Author | Doug Chamberlin |
Post date | 2003-10-20T21:07:51Z |
At 10/20/2003 04:01 PM (Monday), Robert DiFalco wrote:
Blobs are blobs in the database - I don't think there is a distinction
between segmented BLOBs or BLOB streams in the database, itself. How you
access the BLOBs may differ but that depends on your client operating
environment. I stream to and from BLOB fields in my client application all
the time. I use Delphi under Win32.
UDFs are a supplement to SQL which enables clients to extend the
manipulation of fields beyond what the built-in SQL functions provide. SQL
provides almost no support for manipulating BLOB fields and that is where
the paucity of BLOB support you feel probably comes from. However, I think
some people have written UDFs which accept BLOB fields as parameters and
return modified BLOBs as results but I have not used those UDFs.
If you need to manipulate BLOBs within your SQL statements then I suggest
you look for those UDF libraries. If you want to stream BLOBs to/from your
client applications then that should be easier since I think all middleware
layers support it. Perhaps I'm wrong about that.
>That's kinda sad. I read all this great stuff about using blob streamsI don't what a bstream is. Sounds like something from embedded SQL?
>(i.e. bstreams) but we have no sanctioned way of using them in a UDF. I
>guess we can only use segmented blobs in UDFs?
>
>But I'm open to suggestions, how would you work with a streamed blob in
>a UDF?
Blobs are blobs in the database - I don't think there is a distinction
between segmented BLOBs or BLOB streams in the database, itself. How you
access the BLOBs may differ but that depends on your client operating
environment. I stream to and from BLOB fields in my client application all
the time. I use Delphi under Win32.
UDFs are a supplement to SQL which enables clients to extend the
manipulation of fields beyond what the built-in SQL functions provide. SQL
provides almost no support for manipulating BLOB fields and that is where
the paucity of BLOB support you feel probably comes from. However, I think
some people have written UDFs which accept BLOB fields as parameters and
return modified BLOBs as results but I have not used those UDFs.
If you need to manipulate BLOBs within your SQL statements then I suggest
you look for those UDF libraries. If you want to stream BLOBs to/from your
client applications then that should be easier since I think all middleware
layers support it. Perhaps I'm wrong about that.