python - "' 反向ManyToOneDescriptor ' object has no attribute ' 全部 '"

Question

我自己找到了答案，但认为这个问题可能对其他人有益:

每当我打电话时，我都会收到以下错误:

Schema.objects.all() 

或

Schema.objects.filter(url=some_url)

或类似的..

错误:“'ReverseManyToOneDescriptor'对象没有属性'all'”

class Schema(models.Model):

    label = models.TextField()
    description = models.TextField()
    url = models.URLField(unique=True)

    def __str__(self):
        return self.label

    class Meta:
        app_label = 'metadata'


class Object(models.Model):
    label = models.TextField()
    description = models.TextField()
    # related name should not be objects, because that will cause problems
    schema = models.ForeignKey(
        Schema, related_name='objects', on_delete=models.CASCADE)

    def __str__(self):
        return "%s.%s" % (self.schema.label, self.label)

    class Meta:
        app_label = 'metadata'

Answer 1

问题是 related_name 不能是“objects”，它与 Schema.objects 冲突

因此，通过重命名 related_name，例如:

class Object(models.Model):
    label = models.TextField()
    description = models.TextField()
    # related name should not be objects, because that will cause problems
    schema = models.ForeignKey(
        Schema, related_name='object_list', on_delete=models.CASCADE)

    def __str__(self):
        return "%s.%s" % (self.schema.label, self.label)

    class Meta:
        app_label = 'metadata'

解决了我的问题。