I currently got this code, it updates the database when a form is submitted. It currently updates the row id 3 with this code:

PHP Code:

$id = 3; 


and

PHP Code:

   WHERE `id` = '".$id."' 


How do I do it so it automatically picks every single row that's there?

PHP Code:

<?php
if (isset ($_POST['submit'])) // if the form was submitted, display their name
{
require_once ('inc/config.php');
$title = mysql_real_escape_string ($_POST['title']);
$url = mysql_real_escape_string ($_POST['url']);

$mainnewstitle = mysql_real_escape_string ($_POST['mainnewstitle']);
$mainnewsdate = mysql_real_escape_string ($_POST['mainnewsdate']);
$mainnewsimage = mysql_real_escape_string ($_POST['mainnewsimage']);
$mainnewsmessage = mysql_real_escape_string ($_POST['mainnewsmessage']);
$mainnewslink = mysql_real_escape_string ($_POST['mainnewslink']);

$firstnewstitle = mysql_real_escape_string ($_POST['firstnewstitle']);
$firstnewsdate = mysql_real_escape_string ($_POST['firstnewsdate']);
$firstnewsmessage = mysql_real_escape_string ($_POST['firstnewsmessage']);

$secondnewstitle = mysql_real_escape_string ($_POST['secondnewstitle']);
$secondnewsdate = mysql_real_escape_string ($_POST['secondnewsdate']);
$secondnewsmessage = mysql_real_escape_string ($_POST['secondnewsmessage']);

$thirdnewstitle = mysql_real_escape_string ($_POST['thirdnewstitle']);
$thirdnewsdate = mysql_real_escape_string ($_POST['thirdnewsdate']);
$thirdnewsmessage = mysql_real_escape_string ($_POST['thirdnewsmessage']);

$id = 3;  
$sql = mysql_query ("
   UPDATE `news` SET 
      `title` = '".$title."', 
      `url` = '".$url."',
 
      `mainnewstitle` = '".$mainnewstitle."',
      `mainnewsdate` = '".$mainnewsdate."',
      `mainnewsimage` = '".$mainnewsimage."',
      `mainnewsmessage` = '".$mainnewsmessage."',
      `mainnewslink` = '".$mainnewslink."',

      `firstnewstitle` = '".$firstnewstitle."',
      `firstnewsmessage` = '".$firstnewsmessage."',  
      `firstnewsdate` = '".$firstnewsdate."',
      
      `secondnewstitle` = '".$secondnewstitle."',
      `secondnewsmessage` = '".$secondnewsmessage."',      
      `secondnewsdate` = '".$secondnewsdate."',      

      `thirdnewstitle` = '".$thirdnewstitle."',
      `thirdnewsmessage` = '".$thirdnewsmessage."',
      `thirdnewsdate` = '".$thirdnewsdate."'    
   WHERE `id` = '".$id."'
")
OR die (mysql_error());
echo "Your website news have been updated. <hr>";
}

require_once ('inc/config.php');
$query = "SELECT * FROM `news`";
$result = mysql_query($query) or die(mysql_error());
while ($row = mysql_fetch_array ($result))
{
?>

leave off the where clause and every single row will be updated. They will of course all be identical, but if that's what you need, it will do that.