Django:将公共字段存储在父模型中 [英] Django: store common fields in a parent model
问题描述
我有一些型号:
class Place(models.Model):
name = models.CharField(unique=True)
class Bar(Place):
drinks = models.ManyToManyField('Drink')
class Restaurant(Place):
meals = models.ManyToManyField('Meals')
这是一个多表继承的结构,其中每个酒吧仅提供饮料,而每个餐厅仅提供餐点.但是,我需要每个位置的名称在所有位置上都是唯一的-因此,父级Place
模型.
That's a multi-table inherited structure where each bar serves drinks only, and each restaurant serves meals only. I, though, need a name of each place to be unique across all the places - hence the parent Place
model.
现在,多表继承假定父级和子级是单独的实体.这意味着当我想创建一个新的Bar
时,我应该这样:
Now, multi-table inheritance presumes a parent and a child are separate entities. That means when I want to create a new Bar
, I should go like this:
>> parent = Place(name='Myplace')
>> parent.save()
>> child = Bar(place=parent, drinks=mydrinklist)
>> child.save()
但是在我的情况下,Place
不是一个单独的实体:它不应该单独存在.它只是一个共享存储,但有一些限制.我想要这样的东西:
But in my case, Place
is not a separate entity: it should not exists by itself. It's just a shared storage with some restrictions. I'd like to have something like this:
>> child = Bar(name='Myplace', drinks=mydrinklist)
>> child.save()
name
属性将自动传递给基础父模型,并且在调用save()
时以静默方式创建Place
模型. SQLAlchemy可以通过其多表继承来做到这一点.有没有办法在Django中实现相同的目标?
Where name
attribute is automatically passed to the underlying parent model and a Place
model is silently created when save()
is called. SQLAlchemy can do that via its multi-table inheritance. Is there a way to achieve the same in Django?
推荐答案
Django的抽象基类解决了在模型之间共享公共字段的问题:
Django's abstract base classes solve the problem of sharing common fields between models:
class Place(models.Model):
name = models.CharField(unique=True)
class Meta:
abstract = True
编辑:就像Daniel在评论中提到的那样,您建议的解决方案应该可以正常工作.有关 Django的多表继承的更多信息,
Edit: Having said that, as Daniel mentioned in the comments, the solution you propose should work just fine. Here's more on Django's multi-table inheritance
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