Martin Evans wrote:
Most likely you are running into the problem of lob locater state
A lob field can have two states
1) Null meaning no Lob locater present
2) Lob Locater present (it might point to a null LOB of course)
You might try and change your code so that is tests for null in the lob
field before you try and fetch it
Hope this helps?
Hi,
I'm experiencing a problem in DBD::Oracle calling a procedure which
returns a lob but sometimes the lob is not set. We use ora_auto_lob = 0
so we can retrieve the lob ourselves but I cannot see how to know the
lob is empty and calling ora_lob_length returns an error:
DBD::Oracle::db ora_lob_length failed: (DBD INVALID_HANDLE:
OCILobGetLength) at empty_lob.pl line 26.
The following code illustrates the problem:
use strict;
use warnings;
use DBI;
use DBD::Oracle qw(:ora_types);
use Data::Dumper;
my $h = DBI->connect;
$h->do(<<'EOT');
create procedure p_mje(plob OUT NOCOPY clob) AS
BEGIN
NULL;
END;
EOT
my $s = $h->prepare(<<'EOT', {ora_auto_lob => 0, ora_check_sql => 0});
begin p_mje(?); end;
EOT
my $lob;
$s->bind_param_inout(1, \$lob, 20, {ora_type => ORA_CLOB});
$s->execute;
print Dumper([$lob]);
# following line errors
my $len = $h->ora_lob_length($lob);
END {
$h->do(q{drop procedure p_mje});
}
The output is:
$ perl empty_lob.pl
$VAR1 = [
bless( do{\(my $o = 168781336)}, 'OCILobLocatorPtr' )
];
DBD::Oracle::db ora_lob_length failed: (DBD INVALID_HANDLE:
OCILobGetLength) at empty_lob.pl line 26.
Any ideas how to detect an empty lob in this case?
BTW, there are 3 typos in the pod in the following sentence:
"A word of catution when using the data retruned from an ora_lob_read in
a condtional statement. for example if the code below;"
Martin
