Un esempio con XMLWriter .
mysql_connect('server', 'user', 'pass');
mysql_select_db('database');
$sql = "SELECT udid, country FROM table ORDER BY udid";
$res = mysql_query($sql);
$xml = new XMLWriter();
$xml->openURI("php://output");
$xml->startDocument();
$xml->setIndent(true);
$xml->startElement('countries');
while ($row = mysql_fetch_assoc($res)) {
$xml->startElement("country");
$xml->writeAttribute('udid', $row['udid']);
$xml->writeRaw($row['country']);
$xml->endElement();
}
$xml->endElement();
header('Content-type: text/xml');
$xml->flush();
Uscita:
<?xml version="1.0"?>
<countries>
<country udid="1">Country 1</country>
<country udid="2">Country 2</country>
...
<country udid="n">Country n</country>
</countries>