$type = $_GET['type'];

      echo "<table>";
      echo "<table><tr><th><a href=file.php?type="' . $result['Alphabetic'] .'"></a>Alphabetic</th><th>Numeric</th><th>Date</th><th>Unsortable</th></tr>";
      $sql = mysqli_query($db, "SELECT * FROM test_table2 GROUP BY $type DESC");
      while ($result = mysqli_fetch_array($sql))
      {
      echo '<tr><td>' . "'.$result['Alphabetic']."</td></tr>";
      }
      echo "</table>";