CREATE TABLE zTest_TBL (
	TestID int NULL 
) 
INSERT INTO zTest_TBL (TestID) Values (1)

<?php
$iTestID=1;
$oConnection = new PDO($dsn);
$oStatement = $oConnection->prepare('SELECT TestID FROM zTest_TBL WHERE TestID IN (SELECT TestID FROM zTest_TBL WHERE TestID = :TestID)');
$oStatement->bindParam(':TestID', $iTestID,PDO::PARAM_INT );
$oStatement->execute() or print_r($oStatement->errorInfo());


$connection = sqlsrv_connect($dsn);
$statement = sqlsrv_prepare($connection,
	'SELECT TestID FROM zTest_TBL WHERE TestID IN (SELECT TestID FROM zTest_TBL WHERE TestID = ?)',
	array($iTestID));
$value = sqlsrv_execute($statement);
print_r(sqlsrv_errors());
?>