PHP - 3 variables en consulta

$id=((isset($_GET['id']) && !empty($_GET['id']))?$_GET['id']:false);

    $secret=((isset($_GET['secret']) && !empty($_GET['secret']))?$_GET['secret']:false);

    $secret2=((isset($_GET['secret2']) && !empty($_GET['secret2']))?$_GET['secret2']:false);

    $secret3=((isset($_GET['secret3']) && !empty($_GET['secret3']))?$_GET['secret3']:false);

    $lacosalink = mysqli_query($conexion, "SELECT * FROM cosa WHERE id = '".$id."' AND secret = '".$secret."' AND secret2 = '".$secret2."' AND secret3 = '".$secret3."'")or die("error 4");

    $compru = mysqli_query($conexion, "SELECT * FROM cosa WHERE secret = '".$secret."' AND secret2 = '".$secret2."' AND secret3 = '".$secret3."'")or die("error 5");

    $comprus = mysqli_query($conexion, "SELECT * FROM cosa WHERE ID = '".$id."'")or die("<meta http-equiv='Refresh' content='0;url=http://localhost/'>");

if(mysqli_num_rows($comprus) < 1){

            echo "error 1";

        }

        else if(mysqli_num_rows($compru) < 1){

            echo "error 2";

        }

$lacosalink = mysqli_query($conexion, "SELECT * FROM cosa WHERE id = '".$id."' AND secret = '".$secret."' AND secret2 = '".$secret2."' AND secret3 = '".$secret3."'")or die("error 4");

$lacosalink = mysqli_query($conexion, "SELECT * FROM cosa WHERE id = ".$id." AND secret = '".$secret."' AND secret2 = '".$secret2."' AND secret3 = '".$secret3."'")or die("error 4");

$compru = mysqli_query($conexion, $compru_query);

$compru_rows = mysqli_num_rows($compru);

$comprus = mysqli_query($conexion, $comprus_query);

$comprus_rows = mysqli_num_rows($comprus);

if($comprus_rows < 1)

{

    echo "error 1";

 }

if($compru_rows < 1)

{

 echo "error 2";

 }