小编Moh*_*sen的帖子

我想要一个完全只读ModelSerializer,即只是列表/检索方法

最好的方法是什么？

我有一个 User 模型，每个 User 可以通过这个关系有很多 Post：

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

，并且每个帖子都有一个like_count（整数字段），我想让用户（沿着他们的帖子）拥有超过 n 个帖子，并且被喜欢的次数超过 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, allow_joins, reuse, summarize, for_save)
  File "/usr/local/lib/python3.4/dist-packages/django/db/models/expressions.py", line 463, in …