Site developed with mysql stored coding

Sounds about right.
I'm considering altering the way I'm coding my current clients website to include an (almost) entirely mysql driven website. This includes the code as well, and its simply extracted from the database and processed as nessessary. I have good reason for doing it this way btw, its not just a 'try out' sort of idea. I'm good to go as well, I've got it mostly layed out and developed, but I'm wondering if anyone else has ever tried something out like this. Any security risks they would watch out for? Any errors or difficulties in creation or initialization? If you've tried this, or know of any system which has, it would be great if you can give me a heads up on what to watch for.

Advanced poll uses some of it, you have to be careful because it is difficult to remember what tags you are inside (html and php), it can lead to many stuff ups.

Thanx for your input. I hear you there, templates can be tough enough to put together, let alone scripts requiring specific ordering to call the templates as well. Its a wip but I've got a working model to use, so its not the remembering I'm worried about so much as the security. Any known issues with this? I'm not using an include BTW, its a complete db call for anyone thats thinking I'm working through files.