You have to install the free "Database and Server Behaviors" extension from the Adobe Store. You can find it from the Dreamweaver main menu option:
Window-> Extensions-> Browse Extensions...
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.