hmmmmmmmmmm... I mix form data with files all the time in my forms, and it always behaves the way I would expect it to (i.e., the file goes into my /tmp folder, and the other form elements become variables). So I seriously think enctype isn't the problem.
It's possible that your form data isn't being registered as variables at all. Make sure your php.ini has register_globals set to 1. If you have no control over the php.ini file, and register_globals is set to 0, you can still access the form data using an array called $HTTP_POST_VARS. But if you're doing something as advanced as handling file uploads and throwing them into database fields, you probably already thought of that 🙂
when you say "fields relative to the upload file" being added to the database, what do you mean?
HTH
Paul