How to use Turtle sparql php

I'm trying to filter this database written in Turtle

@prefix : <http://www.essepuntato.it/resource/> .

@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .

@prefix cs: <http://cs.unibo.it/ontology/> .        

:pt0001

     vcard:category "Poste e Telegrafi"

    ; vcard:fn "Ufficio Bologna 1"

    ; vcard:extended-address "Via Cairoli 9, Bologna BO, Italy"

    ; vcard:latitude "44.504192"

    ; vcard:longitude "11.338661"

    ; vcard:tel "051 243425"

    ; vcard:fax "051 244459"

    ; cs:opening "Mon, Tue, Wed, Thu, Fri: 0800-1330. Sat: 0800-1230."

    ; cs:closing "01-01, 01-06, P, LA, 04-25, 05-01, 06-02, 08-15, 11-01, 12-08, 12-25,     12-26: .".

I use arc2 api beacause the RAP doesn't work. I wrote this code but it won't work:

<?php

/* ARC2 static class inclusion */ 

include_once('./arc2/ARC2.php');



/* MySQL and endpoint configuration */ 

$config = array(

  /* db */

  'db_host' => 'localhost', /* optional, default is localhost */

  'db_name' => 'my_db',

  'db_user' => 'user',

  'db_pwd' => 'secret',



  /* store name */

  'store_name' => 'my_endpoint_store',



  /* endpoint */

  'endpoint_features' => array(

    'select', 'construct', 'ask', 'describe', 

 'load', 'insert', 'delete', 

 'dump' /* dump is a special command for streaming SPOG export */

),

'endpoint_timeout' => 60, /* not implemented in ARC2 preview */

'endpoint_read_key' => '', /* optional */

'endpoint_write_key' => 'somekey', /* optional */

'endpoint_max_limit' => 250, /* optional */

);



/* instantiation */



/* instantiation */

$ssp = ARC2::getSPARQLScriptProcessor($config);



/* script evaluation */

$scr = '

  PREFIX vcard: <http://www.w3.org/2006/vcard/ns#> 

  PREFIX dbpedia2: <http://dbpedia.org/property/> 



  ENDPOINT "database.ttl"



  $rows = SELECT ?x ?y WHERE { 

    ?x vcard: ?y.

  }

';



$ssp->processScript($scr);

echo $ssp->env['output'];

?>

The script returns no error and not a result. Could you please find the error? I can't figure it out.

Source: Tips4all