So, now I've got both ends of the process chain; a database schema and the RFID hardware. The fun part, remaining to be done, is to get the two to communicate. I had been planning to use an HTTP server to host the client components; then I realized that the transactions I'm planning to support fall right into HTTP, so now I'm going to use HTTP for all intermachine communications. I'll produce some XML bodies for the transactions that need extra information and send them across with PUT or POST.
I told rabidkitten about my patron management system the other day; she thinks it smacks of Big Brother. I think she's just insufficiently assimilated.