I attached a screenshot of the results from the first query (with the bridge_event_room.event_id added). Also, I've broken it down to the absolute minimum of what I'm trying to do, but still get the same results. I've also tried changing the sql in the second query with all variations of !=, <>, NOT IN. I think NOT IN is probably the most accurate for what I'm doing, but not really sure.
$Existing_Rooms_Test = new WA_MySQLi_RS("Existing_Rooms_Test",$local_i,0);
$Existing_Rooms_Test->setQuery("SELECT bridge_event_room.* FROM bridge_event_room WHERE bridge_event_room.event_id = 5 GROUP BY bridge_event_room.room_id");
As you can see from the screenshot, this outputs room_id's 1, 2, 33
$Available_Rooms_Test = new WA_MySQLi_RS("Available_Rooms_Test",$local_i,0);
$Available_Rooms_Test->setQuery("SELECT 7_room.* FROM 7_room WHERE 7_room.room_id NOT IN (?)");
$Available_Rooms_Test->bindParam("il", "".($Existing_Rooms_Test->getColumnVal("room_id")) ."", "-1"); //WAQB_Param1
This one still gives me the same result as before. It filters the first room_id (#1) correctly, but displays everything else.