<?php
include 'inc/header.php';
$cars = $db->prepare("SELECT name, price FROM cars");
$cars->execute();
$cars = $cars->fetchAll(PDO::FETCH_ASSOC);
 ?>

<table>
   <thead>
     <tr>
       <th>Name</th>
       <th>
         <a href="?orderBy=price">Price</a>
       </th>
     </tr>
   </thead>
     <tbody>
       <?php  foreach($cars as $car):     ?>
      <tr>
       <td>
           <?php echo $car['name'];?>
       </td>
       <td>
          <?php echo $car['price'];?>€
       </td>
      </tr>
      <?php endforeach;?>
   </tbody>
 </table>

<?php
$orderBy = array('price');

$order = 'type';
if (isset($_GET['orderBy']) && in_array($_GET['orderBy'], $orderBy)) {
    $order = $_GET['orderBy'];
}

$query = 'SELECT * FROM cars ORDER BY '.$order;
)
?>