/* Set username and password here */
$client->username = 'username';
$client->password = 'password';

$qd = new ExactTarget_QueryDefinition();
$qd->ObjectID = 'Query External KEY';
$qd->TargetUpdateType = "Overwrite";
$qd->TargetType = "DE";
$qd->QueryText = "SELECT * FROM ent.Active";

$ibo = new ExactTarget_InteractionBaseObject();
$ibo->CustomerKey = 'Target DE External Key';
$ibo->Name = 'Target DE Name';
$qd->DataExtensionTarget = $ibo;


$object = new SoapVar($qd, SOAP_ENC_OBJECT, 'QueryDefinition', "http://exacttarget.com/wsdl/partnerAPI");
$request = new ExactTarget_UpdateRequest();
$request->Options = NULL;
$request->Objects = array($object);
$results = $client->Update($request);