Django ValueError: Cannot use QuerySet for "": Use a QuerySet for "User"

Question

我正在 CS50w 中处理一个项目，我必须显示我关注的用户的帖子，但我收到以下错误

ValueError: Cannot use QuerySet for "Following": Use a QuerySet for "User".

models.py:

class Post(models.Model):
    """Tracks all the posts"""
    text = models.TextField(max_length=256)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    date_posted = models.DateTimeField(auto_now_add=True)

class Following(models.Model):
    """Tracks the following of a user"""
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    following = models.ForeignKey(User, on_delete=models.CASCADE, related_name="followers")

这就是我尝试检索我关注的用户的帖子的方式： views.py

# Gets all the posts from the users the current user is following
followings_usernames = Following.objects.filter(user=request.user)
posts = Post.objects.filter(user=followings_usernames)

感谢任何帮助。

Answer 1

尝试使用这个，它可能会有所帮助

  # Gets all the posts from the users the current user is following
    followings_usernames = list(Following.objects.filter(user=request.user).values_list('user', flat=True))
    posts = Post.objects.filter(user__in=followings_usernames)

Answer 2

您可以通过Post.user字段通过反向关系（followers）基于字段（Following.user）进行过滤：

posts = Post.objects.filter(user__followers__user=request.user)

有关 lookups that span relationships 以及双下划线分隔模型和字段的用法，请参阅 Django 文档。

Django ValueError: Cannot use QuerySet for "": Use a QuerySet for "User"

Django ValueError: Cannot use QuerySet for "": Use a QuerySet for "User"

django

cs50