Question

我已经将memcached作为我在django项目上的缓存后端。运行python manage.py test时，出现以下错误：

AttributeError: type object 'FakeModel' has no attribute '_deferred'

详细日志如下：

 File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/django/core/cache/backends/memcached.py", line 82, in set
    self._cache.set(key, value, self._get_memcache_timeout(timeout))
  File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/memcache.py", line 584, in set
    return self._set("set", key, val, time, min_compress_len)
  File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/memcache.py", line 835, in _set
    return _unsafe_set()
  File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/memcache.py", line 812, in _unsafe_set
    store_info = self._val_to_store_info(val, min_compress_len)
  File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/memcache.py", line 782, in _val_to_store_info
    pickler.dump(val)
  File "/home/my_project/virtualenv_my_project/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 186, in __reduce__
    if self.model._deferred:
AttributeError: type object 'FakeModel' has no attribute '_deferred'

每当缓存超时并且需要在缓存中存储某些内容时，就会发生错误。如果我运行我的开发服务器并再次运行测试，则会显示错误。

更新

Memcached设置：

CACHES = {
    'default': {
        'BACKEND':'django.core.cache.backends.memcached.MemcachedCache',
        'LOCATION':'127.0.0.1:11211',
    }
}

我用于缓存的一件事是查询集返回的输出：

top_students = Student.objects.filter(.....).filter(
            ..........
        ).annotate(
            .........
        ).all().order_by(........)[:3]

学生模型是这样的：

class Student(models.Model):

    user = models.ForeignKey(User, unique=True, null=True,
                             blank=True, related_name="student")
    description = models.CharField(max_length=1000, null=True, blank=True)
    rollno = models.CharField(max_length=20)
    phoneno = models.CharField(max_length=15, null=True, blank=True)
    enrollYear = models.ForeignKey(EnrollYear, null=True)
    college = models.ForeignKey(College, null=True, blank=True)
    faculty = models.ForeignKey(Faculty, null=True, blank=True)
    verification = models.ManyToManyField(VerifyStudent)

使用Memcached测试Django时出错

0 个答案: