PHP & MySQL url rewriting question - php

Question

Can I rewrite a url by using the value 6 from ?cat for example, and checking my MySQL database for the value 6 category name html using PHP & MySQL if so how?
Current url.
http://localhost/index.php?cat=6&sub1=8&sub2=24&sub3=81
New search friendly URL displayed in browser.
http://localhost/html/basics/forms/select-tag/

Answer 1

Check out mod_rewrite.
You need to open up the .htaccess file(if it does not exist, create it) and include the following lines. Note that RewriteEngine On should be only written once.
RewriteEngine On # Turn on the rewriting engine
RewriteRule ^html/basics/forms/select-tag/([0-9]+)/?$ index.php?cat=$1 [NC,L]

Answer 2

Yes. Basically you will want to pass the entire url through a router script using mod_rewrite. The .htaccess file should have something like this:
RewriteEngine On
RewriteBase /
#if it's an existing directory
RewriteCond %{REQUEST_FILENAME} -d [OR]
#...or an existing file
RewriteCond %{REQUEST_FILENAME} -f
#serve it up
RewriteRule ^(.+) - [PT,L]
#else, direct to index.php
RewriteRule ^(.*)$ index.php?url=$1 [QSA,L]
Then, in index.php you can have something like this:
$request = explode('/', $_GET['url']);
Which would have all your clean url segments in the $request array. Once you have those values, you can connect to the database, find what the url represents, and output the page. If it's not found, you can send a 404 header with a "Page not found" message.
header('HTTP/1.0 404 Not Found');
echo '<p>Page not found</p>';
So that's the basic clean url technique. If the url is the earlier, messy one, you would just add some logic to check for that, and redirect to the correct clean url:
if(isset($_GET['cat'])){
//put some logic here
header("Location: http://localhost/".$the_clean_url);
}
This basic technique should solve your problem with some tinkering.