You need to have your DB value in a process variable. This process variable can be passed to an input parameter of a human task. Then you can display your data in a task form of the human task. See http://docs.jboss.org/jbpm/v5.3/userguide/ch.human-tasks.html#d0e5071
Your "DB value" can be passed to your business process as a process variable when starting business process, or you can get the value from a service task.
Thans Jiri for your reply