Django ORM查询用户的朋友

Question

我无法让Django ORM查询正常工作.我有这个友谊模型:

class Friendship(models.Model):
    user1 = models.ForeignKey(User, related_name='friendships1')
    user2 = models.ForeignKey(User, related_name='friendships2')
    class Meta:
        unique_together = ('user1', 'user2',)

要查找给定用户的朋友,我们必须检查user1和user2,因为我们永远无法确定他们将在哪个方面建立关系.因此,为了获得给定用户的所有朋友,我使用以下查询:

user = request.user
User.objects.filter(
    Q(friendships1__user2=user, friendships1__status__in=statuses) |
    Q(friendships2__user1=user, friendships2__status__in=statuses)
)

在我看来,这似乎应该有效,但事实并非如此.它给了我重复.这是它生成的SQL:

SELECT auth_user.*
FROM auth_user
LEFT OUTER JOIN profile_friendship ON (auth_user.id = profile_friendship.user1_id)
LEFT OUTER JOIN profile_friendship T4 ON (auth_user.id = T4.user2_id)
WHERE (
    (profile_friendship.status IN ('Accepted') AND profile_friendship.user2_id = 1 )
    OR (T4.user1_id = 1 AND T4.status IN ('Accepted'))
);

这是我想要的SQL,它产生了正确的结果:

SELECT f1.id as f1id, f2.id AS f2id, u.*
FROM auth_user u
LEFT OUTER JOIN profile_friendship f1 ON (u.id = f1.user1_id AND f1.user2_id = 1 AND f1.status IN ('Accepted'))
LEFT OUTER JOIN profile_friendship f2 ON (u.id = f2.user2_id AND f2.user1_id = 1 AND f2.status IN ('Accepted'))
WHERE f1.id IS NOT NULL OR f2.id IS NOT NULL

我知道我可以在原始查询中执行此操作,但后来我认为我无法链接.有没有一个很好的清洁方式来做到这一点,而不是生吃？

Answer 1

简单的解决方案：

user = request.user
User.objects.filter(
    Q(friendships1__user2=user, friendships1__status__in=statuses) |
    Q(friendships2__user1=user, friendships2__status__in=statuses)
).distinct()

有人知道有什么缺点吗？