Sortier-Funktion einbauen in PHP-Script

<?php

  $query = "SELECT ...";  

  $columns = array(1 => 'column1', 2 => 'column2', 3 => 'column3' ...);  
  $sortOrders = array('ASC','DESC');  
  if(!empty($_GET['sort']) && array_key_exists($_GET['sort'], $columns) && in_array($_GET['order'], $sortOrders)) {  
    $query .= ' ORDER BY '.$columns[$_GET['sort']].' '.$_GET['order'];  
  }
  
  mysql_query($query);
  ...
?>

<?php

  for(...) {
    if(!empty($_GET['sort']) && $columns[$_GET['sort']] == $col_id) {  
      $order = ($_GET['order'] == 'ASC')? 'DESC' : 'ASC';  
      
      #url bauen...
    }
  }
  
?>