Обсуждение: Re: Large Objects

FROM test.pl of DBD-Pg-0.93.tar ...

######################### test large objects

# create large object from binary file

my ($ascii, $pgin);
foreach $ascii (0..255) {   $pgin .= chr($ascii);
};

my $PGIN = '/tmp/pgin';
open(PGIN, ">$PGIN") or die "can not open $PGIN";
print PGIN $pgin;
close PGIN;

# begin transaction
$dbh->{AutoCommit} = 0;

my $lobjId;
( $lobjId = $dbh->func($PGIN, 'lo_import') )   and print "\$dbh->func(lo_import) ...... ok\n"   or  print
"\$dbh->func(lo_import)...... not ok\n";
 

# end transaction
$dbh->{AutoCommit} = 1;

unlink $PGIN;


# blob_read

# begin transaction
$dbh->{AutoCommit} = 0;

$sth = $dbh->prepare( "" ) or die $DBI::errstr;

my $blob;
( $blob = $sth->blob_read($lobjId, 0, 0) )   and print "\$sth->blob_read ............ ok\n"   or  print
"\$sth->blob_read............ not ok\n";
 

$sth->finish or die $DBI::errstr;

# end transaction
$dbh->{AutoCommit} = 1;


# read large object using lo-functions

# begin transaction
$dbh->{AutoCommit} = 0;

my $lobj_fd; # may be 0
( defined($lobj_fd = $dbh->func($lobjId, $dbh->{pg_INV_READ}, 'lo_open')) )   and print "\$dbh->func(lo_open) ........
ok\n"  or  print "\$dbh->func(lo_open) ........ not ok\n";
 

( 0 == $dbh->func($lobj_fd, 0, 0, 'lo_lseek') )   and print "\$dbh->func(lo_lseek) ....... ok\n"   or  print
"\$dbh->func(lo_lseek)....... not ok\n";
 

my $buf = '';
( 256 == $dbh->func($lobj_fd, $buf, 256, 'lo_read') )   and print "\$dbh->func(lo_read) ........ ok\n"   or  print
"\$dbh->func(lo_read)........ not ok\n";
 

( 256 == $dbh->func($lobj_fd, 'lo_tell') )   and print "\$dbh->func(lo_tell) ........ ok\n"   or  print
"\$dbh->func(lo_tell)........ not ok\n";
 

( $dbh->func($lobj_fd, 'lo_close') )   and print "\$dbh->func(lo_close) ....... ok\n"   or  print
"\$dbh->func(lo_close)....... not ok\n";
 

( $dbh->func($lobjId, 'lo_unlink') )   and print "\$dbh->func(lo_unlink) ...... ok\n"   or  print
"\$dbh->func(lo_unlink)...... not ok\n";
 

# end transaction
$dbh->{AutoCommit} = 1;


# compare large objects

( $pgin cmp $buf and $pgin cmp $blob )   and print "compare blobs .............. not ok\n"   or  print "compare blobs
..............ok\n";
 

#########################


craig.may@s2.enthdimension.com.au writes:
>Hi,
>
>Could someone please provide a demo of creating the type "Lo".
>
>Regards,
>Craig May
>
>Enth Dimension
>http://www.enthdimension.com.au