双向表和Django ORM

Question

Consider two django models 'User' and 'BoardGame', the latter has a ManyToMany field 'vote' defined with a custom through table:

class Vote(models.Model):
    user = models.ForeignKey(User)
    boardgame = models.ForeignKey(BoardGame)
    vote = models.IntegerField()

I need to print a two way table having users names on the top, boardgames names on the left column and votes in the middle.

Is there a way to obtain this using django? (Remember that a user might not have voted every single boardgame.)

UPDATE: MORE DETAILS

1) Clearly this can be work out using some lines of python (which probably would result in many queries to the database), but I'm more interested in discovering if there is something directly implemented in django that could do the work. After all a ManyToMany field is nothing but a two way table (in this case with some data associated).

2) A possible 'solution' would be a FULL OUTER JOIN using a raw query, but, again, I am looking for something built-in inside django.

3) More specifically I'm using Class Based View and I was wondering if there exists an appropriate query to associate to queryset parameter of ListView.

Answer 1

Assuming:

class User(models.Model):
    ...

class BoardGame(models.Model):
    users = models.ManyToManyField(User, through='Vote')
    ...

class Vote(models.Model):
    user = models.ForeignKey(User)
    boardgame = models.ForeignKey(BoardGame)
    vote = models.IntegerField()

would work like this:

from django.db import connections, reset_queries
reset_queries()

users = User.objects.all().prefetch_related('vote_set')
table = []
table.append([''] + list(users))
for board_game in BoardGame.objects.all().prefetch_related('vote_set'):
    row = [board_game]
    for user in users:
        for vote in user.vote_set.all():
            if vote in board_game.vote_set.all():
                row.append(vote)
                break
        else:
            row.append('')
    table.append(row)

len(connection.queries)  # Returns always 4

This is not the solution you wanted, but it shows a way to get the table from the database with only 4 queries no matter how many objects you have.

Answer 2

我认为Django核心或基于类的通用视图中没有任何东西可以为您呈现表，但请尝试django-tables2