This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
From what little I know about AJAX, it is more a presentation technology (the View in MVC (model 2) archetecture). You will still need a servlet (or something) on the server side to interact with the database.