Can avi files be used here?

I want to create an online store for users to view avi. files and be able to add toshopping cart and download.
QUESTION: can I use MySQL for this? If so, how do I do link the files in the datbase?? I have searched everywhere on this and can't find any code. New obviousely to this all, but I did have someone write the program using MySql and PHP, however they used thought I meant flash files and not avi.
any solutions?? I have seen sites that do this.

If you plan on having lots (and I mean lots as in thousands) of files then using a database is essential. But I wouldn't store the files in the database, just their location and other info.
I don't think it should make that much difference as to whether you're working with flash or avi or anything else for that matter. See if you can modify the script by changing the file extension. Unless it was storing the actual files in the database as binary blobs it should be fairly easy (relatively speaking). And even if it was, it shouldn't be impossible to modify it.