Routing via Database?

[eluser]JasonS[/eluser]
Hello, I am making a small CMS, it has a page system which currently routes as follows.

app/page/page_name

Is there a way to set custom routing without using php to write a new routing file?

I was under the impression that routing is activated before any custom app code kicks in? Ideally I would like the site to query the db to check for pages. I.e. if the url is.

app/page_name

The page_name controller doesn't exist, as a result the page queries the db and if the page exists it will route to.. app/page/page_name

I hope that makes sense.