SQL query help: multiple rules

[suvatyyp]

PostgreSQL
I have problems with the following situation. Can this even be done in one query?

I have 3 tables - 'results_of_game' and (less important) 'games' and 'players'.
'results_of_game' table has fields 'game_id', 'player_id', 'position', 'result'.

Now comes the problem:
I want to find all game_id's where:
* player in first position (results_of_game.position=1) has result='A'
AND
* player in second position has result='B'
AND
* all the remaining players have result='C'

(A/B/C are 3 different numeric values). Number of players in every game is an unknown number between 3 and 10 (and if it makes things any easier then table 'games' includes 'number_of_players' field). How to receive list of game_id's that fulfill these requirements?

[r937]

SELECT game_id
  FROM results_of_game 
GROUP
    BY game_id
HAVING SUM(CASE WHEN position = 1
                 AND result = 'A'
                THEN 1 ELSE 0 END) = 1
   AND SUM(CASE WHEN position = 2
                 AND result = 'B'
                THEN 1 ELSE 0 END) = 1
   AND SUM(CASE WHEN position > 2
                 AND result <> = 'C'
                THEN 1 ELSE 0 END) < 1

[suvatyyp]

Yes, this is exactly what I needed. Thank you