I have page that lists contact people (liaisons) for each state in the US.

In my database I have three tables that are associated with this:

'states' (state_id, state_name)
'staff' (staff_id, staff_name, etc)
'liaisons' (id, state_id, staff_id)

The liaisons table joins the states table to the staff table, and it's a simple query to fetch the states that each staff member is assigned to.

What's not so simple (for me at least) is to also select the remaining states - the ones that the member is not assigned to. I can do it in a second query, but I'd rather do it in the same query, if possible.