InfoPath Dev

Hi,

I'm using qRules for creating a form for editing two lists with parent/child relationship. I created the first part where it saves data to list, but I'm not sure how to complete the second part where it edits existing data in the lists. The PDF guide describes how to complete this by adding a dropdown for querying the secondary source and a button for a rule that will trigger the query. But, what I'm looking for is a way where the form is prepopulated for editing, maybe with specific query string. Is it possible?

Thanks, RM

Also, I have a repeating table in the form for the child list. It saves data fine. But, how do I populate the table based on ID of a parent list item when the form opens?