在Django FlatPage代理模型中添加一个字段

Question

这是我的模型.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()

当我做makemigrations时，我得到了这个错误：

./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，这样我就只能在未来的某个日期显示帖子。

编辑

我现在了解到，代理模型在定义上不接受新字段。那么，我的下一个问题是：我如何将现有的代理模型"转换"为其他模型(当然不会丢失现有数据(，这样我就可以有一个额外的published字段？

Answer 1

如果设置proxy=True，则可以调整/增强Python级别的行为。不能向代理模型添加其他字段。但是，您可以像设置函数或方法一样设置自定义对象管理器。

文档

看看模型继承#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

如果使用新字段扩展FlatPage，则不会丢失数据。如果您想在致电python manage.py dumpdata > db.json之前保存数据

第二次更新

型号.py

from django.contrib.flatpages.models import FlatPage
from django.db import models
class MyCustomFlatePage(FlatPage):
published = models.DateTimeField(auto_now_add=True)

形式.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)