Question

我是Django的新手，尤其是它的继承工具。我有以下架构：

   class BaseMixin(models.Model):
       effective_from = models.DateTimeField(blank = True, null = True)

       class Meta:
           abstract = True 
   class QuerySetManager(models.Manager):
       def get_queryset(self):
          # ...
       def __getattr__(self, attr, *args):
            return getattr(self.get_queryset(), attr, *args)
       def save(self, *args, **kwargs):
            # I want this method to be deployed for my_model_instance.save()

    class MyModel(BaseMixin):
       # ...
       objects = QuerySetManager()

       class Meta:
           managed = False
           db_table = 'my_model'

       class QuerySet(QuerySet):
           # ...

所以我的目标是在尝试保存对my_model_instance的更改时调用QuerySetManager的{{1}}方法。问题是，我应该在save中重载save方法吗？还是在BaseMixin？我绑两个，就像现在一样，Django在这两种情况下都忽略了我的自定义保存方法。

Answer 1

您的BaseMixin是您在其他地方继承的抽象类。

ModelManagers没有提供保存方法，它用于在查询特定模型时抽象出复杂的逻辑。

您需要在此处覆盖保存MyModel。就像是。

class MyModel(BaseMixin):
    # ...
    objects = QuerySetManager()

    class Meta:
        managed = False
        db_table = 'my_model'


    def save(self, force_insert=False, force_update=False, using=None,
         update_fields=None):
        print "In Save Method"
        return super(MyModel, self).save()

Save方法是模型实例的属性。

简单示例。

def my_view(request,pk):
    my_model = MyModel.object.get(id=pk)
    my_model.field_1 = "new value"
    ## When you call save method your custom save method is called first.
    my_model.save()

Django - 使子类继承其父抽象类

1 个答案: