Yeah, for MySQLi, you should probably do a premiere support session.
but using Data Assist and MySQL, yes, the navigation can be used in conjunction with data assist search.
Think of it this way, you have a search from that lists categories and when it submits to the results page using Data Assist the URL would look like:
results.php?CatID=3&search=search
you can do the same thing with you dynamic navigation: Pass the category ID as a URL variable and include the trigger URL Variable also to trigger the Saerch behavior
a form using the get method just passes the information using URL variables, it's no different than passing those same URL variables using a link.
