PHP/MySQL URL Strings

[Anon]

I am still fairly new to PHP and MySQL. I am trying to pull an ending of a URL such as www.blahblah.com/index.php?id=3 and only display what I have placed within the row for id 3 in MySQL. At the same time, having a URL in the database that someone can follow (not just to another database, but to a whole new site).

Thank you for any replies ahead of time.

[bretticus]

www.blahblah.com/index.php:

<?
...read manual...
$sql = "SELECT url FROM table WHERE id = $id";
...read manual...
?>

[Anon]

OK. I have placed the following within my script:

$result = mysql_query( "SELECT url FROM table WHERE id = $id" );

I am now getting an error on the line that states the following:

while ( $a_row = mysql_fetch_row( $result ) ) {

Any suggestions? This is the exact error code:

Warning: Supplied argument is not a valid MySQL result resource in /home/mastero4/public_html/verify2.php on line 129

Thanks,