Re: [GENERAL] Picture with Postgres and Delphi

[Guy Fraser]

Thanks that is extremely helpfull.

Guy

Jonathan Bartlett wrote:

What is the size limit of bytea, I thought it was 8K?
     

No limit that I've found.  Some are several meg.

 

How do you dump your database when you have bytea, do you need to do a
binary dump?
     

Nope.  pg_dump automagically escapes everything.

 

What are you using to insert the binary data?
     

Perl example:

my $COMPLETED_TEMPLATE_VARS_INSERT = <<EOF; insert into
completed_template_vars (completed_template, name, value, binvalue) VALUES
(?, ?, ?, ?)
EOF
               $sth = $dbh->prepare($COMPLETED_TEMPLATE_VARS_INSERT);
               $value = undef;
               $binvalue = $field->{BINANS};
               $value = $field->{ANS} unless $binvalue;
               $sth->bind_param(1, $self->getOID);
               $sth->bind_param(2, $name);
               $sth->bind_param(3, $value);
               $sth->bind_param(4, $binvalue, DBI::SQL_BINARY);
               $sth->execute || die("DBERROR:${DBI::errstr}:");
Note that I explicityl set DBI::SQL_BINARY.

Now, for php, you do the following:

$logodata = pg_escape_bytea($tmpdata);
$tmpsql = "update advertisements set $column_name = '$logodata'::bytea where object_id = 
$advertisement_oid";
$tmp = $db->query($tmpsql);
I never got it to work with parameterized queries, but this works fine for
me.  To select it back out, you need to do:
$q = $db->query("select teaser_logo_gif_image from advertisements where
object_id = ?::int8", array($_GET['advertisement']));
$row = $q->fetchrow();
$data = pg_unescape_bytea($row[0]);
NOTE that many versions of PHP include pg_escape_bytea but NOT
pg_unescape_bytea.  Look in the docs to see which function appeared in
which version.
Jon
 



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