如何从抽象基类覆盖模型字段的默认值 [英] How to override the default value of a Model Field from an Abstract Base Class

问题描述

我有一些代码如下：

class BaseMessage(models.Model):
    is_public = models.BooleanField(default=False)
    # some more fields...

    class Meta:
        abstract = True

class Message(BaseMessage):
    # some fields...

我想覆盖Message模型中的 is_public 字段的默认值，因此该模型的 True

and I'd like to override the default value of the is_public field in the Message model so that it's True for that model.

我已经浏览了一些相关的Django文档，并围绕模型对象戳了一下，但是我找不到正确的地方找到了。任何建议？

I've looked through some relevant Django docs and poked around the model objects but I'm having trouble finding the right place to do this. Any suggestions?

推荐答案

你可以这样做：

class BaseMessage(models.Model):
    is_public = models.BooleanField(default=False)
    # some more fields...

    class Meta:
        abstract = True

class Message(BaseMessage):
    # some fields...
Message._meta.get_field('is_public').default = True

我已经做了一两次。它的作用是因为Message上的字段与BaseMessage上的字段不同。但是，我怀疑它是推荐的;-)这取决于很多django内部部件目前的工作，所以不能保证它将永远工作。

I have done this once or twice. It works, because the field on Message is a different instance than the field on BaseMessage. However, I doubt it's recommended ;-) It depends a lot on how django internals currently work, so there's no guarantee that it will work forever.

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