PokerTracker

Can anyone give me the query/expression that will tell me the table types in cash games (6 handed, 9 handed, or HU)?

You can tell how many players were in a hand using the database field holdem_hand_summary.cnt_players or holdem_hand_player_statistics.cnt_players, but to find the table size you need to look at the limit name using:
holdem_limit.limit_name

e.g.
holdem_limit.limit_name LIKE '%(6 max)'
..depending on how the limit names are defined at your site.

it will work only if in preferences of import, you set adjust limits - >adjust qualyfing table limits limits

Some sites can adjust those things automatically, though yes some cannot and for those sites you do need that box checked.