So the goal is to have a live, interactive, form in your publication that sends the data to a database?
Why does it have to be a "PDF" form? Or do you just mean an interactive form designed to look like it was an interactive PDF?
I've used Adobe FormsCentral to do this. You'd make a web form and then put the HTML in your DPS publication. Works like a charm. Of course you'd have to be online to be able to send the data through (which makes sense). And then FormsCentral will keep everything in a database from which you can export to Excel and do other funky things. Also, email messages will be triggered when submitting new data.
Give it a try I think it'll be your best bet.