Do you want to add the values in separate columns or joined in one column?

For all values joined you can just do something like this:
* * *
foreach($orders as $key=>$order) $orders[$key] = mysql_real_escape_string($order);
$orders = implode(', ', $orders);
$sql = "INSERT INTO orders (ORDER_DESC) VALUES ('$orders')";
mysql_query($sql) or die(mysql_error());