Dynamic graphics generation inside plperlu query, odbc and MS Access display

["Philippe Lang" <philippe(dot)lang(at)attiksystem(dot)ch>]

Hi,

I'm trying to generate an image inside a plperlu function (PG 8.1.4), and to display it in a MS Access form, through ODBC.
I'm using the GD library for this. Here is the test code:

----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION test_gd
(
    IN a			int4,
    IN b			int4, 

    OUT val                     int4,
    OUT image			bytea
)
RETURNS SETOF record
AS

$$
    #----------------------------------------------------------------------------
    #-- Configuration des paramètres de la fonction
    #----------------------------------------------------------------------------
    @i = ('a', 'b');
    @io = ();
    @o = ('val','image');

    #----------------------------------------------------------------------------
    #-- Préparation des paramètres de la fonction
    #----------------------------------------------------------------------------
    &start_sub(@_);

    #----------------------------------------------------------------------------
    #-- Test GD
    #----------------------------------------------------------------------------
    use GD;

    # create a new image
    $im = new GD::Image(100,100);

    # allocate some colors
    $white = $im->colorAllocate(255,255,255);
    $black = $im->colorAllocate(0,0,0);       

    # make the background transparent and interlaced
    $im->transparent($white);


    # Put a black frame around the picture
    $im->rectangle(0,0,99,99,$black);

    # Draw a blue oval
    $im->arc(50,50,95,75,0,360,$black);

    # And fill it with red
    $im->fill(50,50,$black);

    $output{'image'} = $im->gif;
    $output{'val'} = $input{'a'} + $input{'b'};
    ret(@_);

    #----------------------------------------------------------------------------
    #-- Helper functions
    #----------------------------------------------------------------------------
    end_sub(@_);

    sub start_sub
    {
        init(@_);
    }

    sub end_sub
    {
        return undef;
    }

    sub init
    {
	$c = 0;
        foreach $i (@i) {$input{$i} = @_[$c++]};
        foreach $io (@io) {$input{$io} = @_[$c]; $output{$io} = @_[$c++]};
        foreach $o (@o) {$output{$o} = @_[$c++]};
    }

    sub ret
    {
	while (($key, $value) = each %output) {if (!defined($value)) {elog(ERROR, 'Valeur indéfinie pour ' . $key)}}; 
	return_next \%output;
	init(@_);
    }

$$

LANGUAGE 'plperlu';
----------------------------------------------------------------------------


The function looks good. If I run inside pgAdmin:

   select * from test_gd('7', '3');

I get:

   val    image
   --------------
   10     GIF89ad


The problem is that I'm unable to display anything in a MS Access form, and I'm not quite sure how to do it. I've been using a "bytea" column type, is that correct?

In Ms Access, I've created a pass-through query, linked it to a form with an OLE Dependant Control. But... Nothing. Same Problem id I try wbmp or jpeg images.

Does anyone have an idea how to do this?

Thanks.


Note: I'm using the latest driver: psqlodbc-08_02_0002.zip

----------------------------------
Philippe Lang, Ing. Dipl. EPFL
Attik System
rte de la Fonderie 2
1700 Fribourg
Switzerland
http://www.attiksystem.ch

Tel:  +41 (26) 422 13 75
Fax:  +41 (26) 422 13 76

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