Django 1.8 - FieldError：无法将关键字解析为字段

I recently upgraded from Django 1.6 to Django 1.8. When I did, I found that I was no longer able to to do a lookup back through a foreign key relationship as described in: https://docs.djangoproject.com/en/1.8/topics/db/queries/#lookups-that-span-relationships.

我最近从Django 1.6升级到Django 1.8。当我这样做时，我发现我无法再通过外键关系进行查找，如下所述：https：//docs.djangoproject.com/en/1.8/topics/db/queries/#lookups-该跨度的关系。

The system is set up so that there are two projects which use the same database. (Not my idea, but not something I would like to change right now.) The project where the models were initially created and migrated works just fine after the upgrade, but the other one does not. The models file for each is identical.

设置系统，以便有两个项目使用相同的数据库。（不是我的想法，而是我现在想要改变的东西。）最初创建和迁移模型的项目在升级后工作得很好，但另一个没有。每个模型文件都是相同的。

Models.py:

Models.py：

class Site(models.Model):
    name = models.CharField(max_length=255)

    class Meta:
        app_label = 'project1'

class Page(models.Model):
    title = models.CharField(max_length=255)
    site = models.ForeignKey('Site')

    class Meta:
        app_label = 'project1'

Error traceback from the Django Shell:

Django Shell的错误回溯：

>>> x = models.Site.objects.filter(page__id=1000)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/manager.py", line 127, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 679, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 697, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1314, in add_q
    clause, require_inner = self._add_q(where_part, self.used_aliases)
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1342, in _add_q
    allow_joins=allow_joins, split_subq=split_subq,
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1154, in build_filter
    lookups, parts, reffed_expression = self.solve_lookup_type(arg)
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1035, in solve_lookup_type
    _, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
  File "/home/user_name/project2/venv/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1401, in names_to_path
    "Choices are: %s" % (name, ", ".join(available)))
FieldError: Cannot resolve keyword 'page' into field. Choices are: name, id

In the first project, the same query works as expected:

在第一个项目中，相同的查询按预期工作：

>>> x = models.Site.objects.filter(page__id=1000)
[<Site: http://*.com>]

1 个解决方案

#1

What if you set a related_name on the `ForeignKey ?

如果在`ForeignKey上设置related_name怎么办？

class Page(models.Model):
    site = models.ForeignKey('Site', related_name="pages")  # Note the related_name here

I tried it on another project and it work as axpected:

我在另一个项目上尝试了它，它的工作原理是有道理的：

>>> Site.objects.filter(pages__pk=42)
[<Site: http://*.com>]

If you don't set a related_name, I think the default is <model>_set. So it should be page_set.

如果您没有设置related_name，我认为默认值是 _set。所以它应该是page_set。

#1