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POdjango - how to get a queryset based on a count of references to foreign field
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  1. POdjango - how to get a queryset based on a count of references to foreign field
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    copied!<p>Question about how to perform a django query. I have a Game model with a 'through' ManyToManyField to the User model.</p> <pre><code>class Game(models.Model): # other misc game-description fields... players = models.ManyToManyField(User, through='PlayerGameResult', blank=True, null=True) class PlayerGameResult(models.Model): game = models.ForeignKey(Game) player = models.ForeignKey(User) dtime_played = models.DateTimeField(default=datetime.now) # ... </code></pre> <p>If a particular game has been played by 1+ players, then the players field in the Game model will have 1+ references. Otherwise players is null. For the query question please refer to the ?????? below....</p> <pre><code># all games not yet played by this user... games_qset = Game.objects.exclude(players__username=request.user.username) # out of all the games not played by this user, extract the ones not # yet played by anyone else either (this user would be the 1st player) games_unplayed_qset = games_qset.filter(players__isnull=True) # here's the question: out of all the games that have not been played by # this user, get a queryset that extracts only the games that have been # played by more than 10 (GAME_WITH_FEW_PLAYERS_THRESHOLD) players # ?????? this is the query I don't know how to make... ????? # # in the following example, I want to get back a queryset that includes only # Game Ids 6 and 19, because they have players count 20 and 12 (&gt; threshold 10) # # (Pdb) for rec in games_qset: print rec # Game id 6, Num players: 20 # Game id 7, Num players: 5 # Game id 13, Num players: 0 # Game id 19, Num players: 12 # # for a count of all games that have been played by at least one player: # (Pdb) games_qset.filter(players__isnull=False).count() # 3 # </code></pre> <p>Any ideas? Thank you. Juan</p>
 

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