计算外键关系中出现的次数

Question

我设置了以下模型：

class Team(models.Model):
    # stuff

class Alliance(models.Model):
    # an alliance is made up of 3 teams
    teams = models.ManyToManyField(Team)

class Match(models.Model):
    # 2 alliances per match
    alliances = models.ManyToManyField(Alliance)
    # 1 winner per match
    winner = models.ForeignKey(Alliance, related_name='winner')

我正在尝试找出哪些球队和联盟的胜利次数最多。我已经成功地获得联盟来解决这个问题：

from collections import Counter
def most_alliance_wins():
    matches = Match.objects.all()
    count = Counter()
    for m in matches:
        count[m.winner] += 1
    # Remove ties
    del count[None]
    return count.most_common(5)

但是，我的团队 wins 方法不起作用，说我无法访问模型的管理器，但我不确定我实际上在代码中的哪个位置尝试访问管理器，所以我有点迷路了。

from collections import Counter
def most_team_wins():
    matches = Match.objects.all()
    count = Counter()
    for m in matches:
        for team in m.winner.objects.all():
            count[team] += 1
    return count.most_common(5)

任何帮助将不胜感激

Answer 1

啊，我傻了。已解决！

这是解决方案：

def most_wins():
    matches = Match.objects.all()
    count = Counter()
    for m in matches:
        if m.winner is None:
            continue
        for team in m.winner.teams.all():
            count[team] += 1
    return count.most_common(5)

我应该引用 m.winner.teams.all() 而不是 m.winner.objects.all()。

计算外键关系中出现的次数

Counting number of occurrences in Foreign Key relationships

python

django

count

django-queryset

python-3.x