sybperl-l Archive

From: michael dot peppler at bnpparibas dot com
Subject: Re: I must be doing something wrong... (reading image data with DBD::Sybase)
Date: Jun 1 2007 9:26AM

Weird.

I just tried it here (using the test script t/xblob.t as a sample) with no 
problems:

$dbh->{LongReadLen} = 100000;
$sth = $dbh->prepare("select id, data from blob_test");
$sth->{syb_no_bind_blob} = 1;
$sth->execute;
while(my $d = $sth->fetch) {
    my $data;
    my $read = $sth->syb_ct_get_data(2, \$data, 0);
    print "read = $read\n";

}


And I get:

[pepm01a@gvas1tkc6001 DBD-Sybase-1.08]$ perl test/readimg.pl
read = 96804

Maybe a run with DBI->trace(5) could give us some more information...

Michael




Internet
rob@sypron.nl@peppler.org - 01.06.2007 10:41
 
Please respond to rob@sypron.nl
Sent by:        owner-sybperl-l@peppler.org
To:     sybperl-l
cc: 
Subject:        I must be doing something wrong... (reading image data 
with DBD::Sybase)

Folks, I've looked everywhere but I cannot find the error I'm no doubt
making.
In short, I'm unable to read more than 32768 bytes from an image column,
although I've followed -afaik- all the required steps.

I've verified that the image stored in the image column is indeed bigger
than 32Kb (with datalength()). However, I'm getting only the first 32KB
returned.

My code:

$dbh->{LongReadLen} = 10000000;

$sth = $dbh->prepare("select img_col from my_table where id = 12345 ");
$sth->{syb_no_bind_blob} = 1;
$sth->execute;

while(my $d = $sth->fetch) {
$size = $sth->syb_ct_get_data(1, \$my_img, 0);
}


....which returns only 32KB.

However, when I select @@textsize prior to the prepare(), this returns
32768. In fact, I replaced setting LongReadLen with 'set textsize
10000000', and this does not change things: select @@textsize then still
returns only the first 32KB. I've verified through the MDA table
monSysSQLText that 'set textsize 10000000' is actually executed, so it
beats why @@textsize is still set to 32768.

Any hints appreciated!

Thanks,

Rob V.
rob@sypron.nl



This message and any attachments (the "message") is
intended solely for the addressees and is confidential. 
If you receive this message in error, please delete it and 
immediately notify the sender. Any use not in accord with 
its purpose, any dissemination or disclosure, either whole 
or partial, is prohibited except formal approval. The internet
can not guarantee the integrity of this message. 
BNP PARIBAS (and its subsidiaries) shall (will) not 
therefore be liable for the message if modified. 

                ---------------------------------------------

Ce message et toutes les pieces jointes (ci-apres le 
"message") sont etablis a l'intention exclusive de ses 
destinataires et sont confidentiels. Si vous recevez ce 
message par erreur, merci de le detruire et d'en avertir 
immediatement l'expediteur. Toute utilisation de ce 
message non conforme a sa destination, toute diffusion 
ou toute publication, totale ou partielle, est interdite, sauf 
autorisation expresse. L'internet ne permettant pas 
d'assurer l'integrite de ce message, BNP PARIBAS (et ses
filiales) decline(nt) toute responsabilite au titre de ce 
message, dans l'hypothese ou il aurait ete modifie.