Django在预取的过滤相关模型上进行注释

概述我有一个用户模型,每个用户可以通过这种关联有很多帖子： class Post(models.Model): ... user = models.ForeignKey('User', related_name='posts') ,每个帖子都有一个like_count(整数字段),我希望得到的用户(沿着他们的帖子)有更多的帖子,这些帖子多被m次,我这样做： User.objects.p 我有一个用户模型,每个用户可以通过这种关联有很多帖子：

class Post(models.Model):    ...    user = models.ForeignKey('User',related_name='posts')

,每个帖子都有一个like_count(整数字段),我希望得到的用户(沿着他们的帖子)有更多的帖子,这些帖子多被m次,我这样做：

User.objects.prefetch_related(Prefetch('posts',queryset=Post.objects.filter(like_count__gte=m),to_attr='top_posts')).annotate(top_post_count=Count('top_posts')).filter(top_post_count__gte=n)

但是,我得到：

Traceback (most recent call last):  file "<console>",line 1,in <module>  file "/usr/local/lib/python3.4/dist-packages/django/db/models/query.py",line 912,in annotate    clone.query.add_annotation(annotation,alias,is_summary=False)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/query.py",line 971,in add_annotation    summarize=is_summary)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/aggregates.py",line 19,in resolve_Expression    c = super(Aggregate,self).resolve_Expression(query,allow_joins,reuse,summarize)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/Expressions.py",line 513,in resolve_Expression    c.source_Expressions[pos] = arg.resolve_Expression(query,summarize,for_save)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/Expressions.py",line 463,in resolve_Expression    return query.resolve_ref(self.name,summarize)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/query.py",line 1462,in resolve_ref    self.get_initial_alias(),reuse)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/query.py",line 1402,in setup_joins    names,opts,allow_many,fail_on_missing=True)  file "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/query.py",line 1327,in names_to_path    "Choices are: %s" % (name,",".join(available)))django.core.exceptions.FIEldError: Cannot resolve keyword 'top_posts' into fIEld. Choices are: ...

解决方法 docs解释了它分配给一个属性,该属性是根据to_attr参数在querySet项上命名的.

我认为这并不意味着它可以作为模型字段访问,后续注释可以链接到该模型字段.

您可能需要将其分为两个步骤.

编辑：问题已评论说过滤器可以链接,但注释不能.

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