PHP: .htaccess 301 redirect not working

Question

I have a basic CMS in PHP/MySQL where content managers can create pages to the system for public viewing. Each page is then available at an url such as http://www.example.com/pages.php?pid=123 Now, I want to redirect requests to http://www.example.com/pages.php?pid=123 to http://www.example.com/pages.php?pid=456.

I've already removed the pid=123 page from the db but because of the cms code the site still returns a 202 when some one tries to access the page. I thought I could use a 301 redirect in .htaccess to make the redirect work, i.e.:

redirect 301 pages.php?pid=123 http://www.example.com/pages.php?pid=456

but this doesn't work, Apache still return 202 when trying to fetch the pid=123 page. Also, I've tried using mod_rewrite, but it doesn't work:

RewriteRule ^pages.php?pid=123$ pages.php?pid=456 [R=301,L]

Any ideas what could be wrong and how I can fix the 301 redirect?

Answer 1

You can perform the redirect in PHP (which probably knows more about what to redirect where) using header().

Please note that ? is a special character used by regular expressions, so your regex matches pages.phppid=123 and pages.phppid=123.

Even then, I don't think the query string (including the ?pid=123 part) is used in the URL handled by RewriteRule, so you would need to use something like:

RewriteCond %{QUERY_STRING} ^pid=123$
RewriteRule ^pages.php$ pages.php?pid=456 [R=301,L]

This shouldn't work as is, but it should give you some ideas.

Answer 2

Both the Redirect and RewriteRule directive work just on the URL path. In mod_alias (Redirect directive) you can not test the query and in mod_rewrite (RewriteRule directive) you need an additional RewriteCond directive:

RewriteCond %{QUERY_STRING} (^|&)pid=123(&|$)
RewriteRule ^pages\.php$ /pages.php?pid=456 [R=301,L]

But it would certainly be better if your CMS can handle such redirects since it’s your CMS that knows best what URLs are valid and what are not.