PDO rowCount() 适用于 MySQL，但不适用于 SQL Server 2008 R2

I have a problem when I get number of rows in SQL Server 2008 because my code works fine using MySQL but not in SQL Server.

$sql = "SELECT TOP 1 U.Id , U.Name, U.Profile,  P.Name NameProfile
        FROM sa_users U
        INNER JOIN sa_profiles P ON P.Id = U.Profile
        WHERE User = :user  AND Pass = :pass";

$result = $this->dbConnect->prepare($sql) or die ($sql);
$result->bindParam(':user',$this->data['username'],PDO::PARAM_STR);
$result->bindParam(':pass',$this->data['password'],PDO::PARAM_STR);

if (!$result->execute()) {
    return false;
}

$numrows = $result->rowCount();
$jsonLogin = array();

var_dump($numrows);

if($numrows > 0) {
    while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
        $jsonLogin = array( 
            'name' => $row['Name'],
            'id' => $row['Id'],
            'profile' => $row['Profile'],
            'n_profile' => $row['NameProfile']
        );
    }

    $jsonLogin['area'] = 'another';
    return $jsonLogin;
} else {
    return false;
}

var_dump($result->fetch()) 在 MySQL 和 SQL Server 中

array(8) {
["Id"]=>
string(1) "1"
[0]=>
string(1) "1"
["Nombre"]=>
string(13) "Administrador"
[1]=>
string(13) "Administrador"
["Perfil"]=>
string(1) "1"
[2]=>
string(1) "1"
["NomPerfil"]=>
string(13) "Administrador"
[3]=>
string(13) "Administrador"
}

int(-1)

int(1)