向 Django FlatPage 代理模型添加一个字段

Add a field to a Django FlatPage proxy model

这是我的 models.py:

from django.contrib.flatpages.models import FlatPage

class FlatPageManager(models.Manager):
    def search(self, query=None):
        qs = self.get_queryset()
        if query is not None:
            or_lookup = (Q(title__icontains=query) |
                         Q(content__icontains=query)
                        )
            qs = qs.filter(or_lookup).distinct()
        return qs

class MyFlatPage(FlatPage):
    class Meta:
        proxy = True

    published = models.DateTimeField() # <- this is the field I want to add
    objects = FlatPageManager()

当我执行 makemigrations 时出现此错误:

./manage.py makemigrations
SystemCheckError: System check identified some issues:

ERRORS:
?: (models.E017) Proxy model 'MyFlatPage' contains model fields.

我做错了什么?我想做的就是添加一个 published 字段,这样我就可以在将来的某个日期只显示 post。

编辑

我现在了解到,根据定义,代理模型不接受新字段。那么我的下一个问题是:我怎样才能 'convert' 我现有的代理模型到其他东西(当然不会丢失我现有的数据)以便我可以有一个额外的 published 字段?

如果设置 proxy=True,则可以 adjust/enhance Python 级别的行为。您不能向代理模型添加其他字段。但是,您可以像以前一样设置自定义对象管理器以及函数或方法。

doc

take a look a model-inheritance #3

您可以将默认行为添加到 published

class FlatPage(models.Model):
   published = models.DateTimeField(auto_now_add=True)
   ...

第一次更新

如果您使用新字段扩展 FlatPage,您将不会丢失数据。如果您想保存数据,请致电 python manage.py dumpdata > db.json

第二次更新

models.py

from django.contrib.flatpages.models import FlatPage
from django.db import models

class MyCustomFlatePage(FlatPage):
   published = models.DateTimeField(auto_now_add=True)

forms.py

from django.contrib.flatpages.forms import FlatpageForm

class MyFlatPageForm(FlatpageForm):
    class Meta:
        model = MyFlatPage
        fields = '__all__'

admin.py

class MyFlatPageAdmin(FlatPageAdmin):
    form = MyFlatPageForm
    fieldsets = (
        (None, {'fields': ('url', 'title', 'content', 'published', 'sites')}),
        (_('Advanced options'), {
            'classes': ('collapse',),
            'fields': (
                'enable_comments',
                'registration_required',
                'template_name',
            ),
        }),
    )
admin.site.unregister(FlatPage)
admin.site.register(MyFlatPage, MyFlatPageAdmin)