如何修改Django模型? [英] How to modify a Django model?

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问题描述

如果我想更改例如Django的网站模块:

  from django.contrib.sites.models import Site 
/ pre>

我如何在我的项目中这样做?或者我要做什么来更改或添加一些代码?



或者我只是创建一个新的模型?

解决方案

您可以通过继承添加字段



如果您仍然需要保留对原始站点的引用对象/行,您可以使用多表继承

  from django.contrib.sites.models import Site 

class MySite(Site) :
new_field = models.CharField(...)

def new_method(self):
#做一些新的

这允许您定期的站点对象,可以通过 MySite 模型,在这种情况下,你可以例如通过 site.mysite 访问额外的字段和方法,例如 site.mysite.new_field



通过模型继承,您不能更改祖先字段



通过继承,您无法隐藏祖先字段,因为如果您覆盖任何祖先模型中的任何模型字段,Django将引发FieldError



而且我会因此,如果您更新Django,您可能会遇到与网站模型的模式冲突。



所以这里是我会做的如果我想存储祖先模型允许的更多信息:

  class SiteLongName(Site):
long_name = models .CharField(max_length = 60)


If I would like to change e.g. Django's Site module:

from django.contrib.sites.models import Site

How would I do that in my project? Do I subclass or what do I do to change or add some code to it?

Or do I just create a new model?

解决方案

You can add a field via inheritance

If you still need to keep a reference to the original Site object/row, you can use multi-table inheritance

from django.contrib.sites.models import Site

class MySite(Site):
    new_field = models.CharField(...)

    def new_method(self):
        # do something new

This allows you to have regular Site objects, that may be extended by your MySite model, in which case you can e.g. access the extra fields and methods through site.mysite, e.g. site.mysite.new_field.

Through model inheritance, you cannot alter an ancestor field

Through inheritance you cannot hide ancestor fields, because Django will raise a FieldError if you override any model field in any ancestor model.

And I wouldn't venture and write a custom DB migration for this, because then if you update Django, you may get schema conflicts with the Site model.

So here's what I would do if I wanted to store more info that the ancestor model allows:

class SiteLongName(Site):
    long_name = models.CharField(max_length=60)

这篇关于如何修改Django模型?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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