[Django]-Override default queryset in Django admin

Konrad is correct, but this is more difficult than the example given in the documentation.

Deleted conversations can’t be included in a queryset that already excludes them. So I don’t see an option other than re-implementing admin.ModelAdmin.queryset entirely.

class ConversationAdmin (admin.ModelAdmin):

    def queryset (self, request):
        qs = Conversation.all_conversations
        ordering = self.get_ordering(request)
        if ordering:
            qs = qs.order_by(*ordering)
        return qs

You can do this with a Django proxy model.

# models.py
class UnfilteredConversation(Conversation):
    class Meta:
        proxy = True

    # this will be the 'default manager' used in the Admin, and elsewhere
    objects = models.Manager() 

# admin.py
@admin.register(UnfilteredConversation)
class UnfilteredConversationAdmin(Conversation):
    # regular ModelAdmin stuff here
    ...

Or, if you have an existing ModelAdmin class you want to re-use:

admin.site.register(UnfilteredConversation, ConversationAdmin)

This approach avoids issues that can arise with overriding the default manager on the original Conversation model – because the default manager is also used in ManyToMany relationships and reverse ForeignKey relationships.

What would be so wrong with the following:

class Conversation(BaseModel):
    ...
    deleted = models.BooleanField(default=False)
    objects = models.Manager() # includes deleted conversations
    nondeleted_conversations = NondeletedManager()

So in your own apps/projects, you use Conversation.nondeleted_conversations() and let the built-in admin app do it’s thing.

Natan Yellin is correct, but you can change the managers order and the first will be the default, then it is the used by the admin:

class Conversation(BaseModel):
    ...
    deleted = models.BooleanField(default=False)

    all_conversations = models.Manager() # includes deleted conversations
    objects = NondeletedManager()

The admin implementation of get_queryset() use ._default_manager instead .objects, as show next

qs = self.model._default_manager.get_queryset()

ref Django github BaseModelAdmin implementation

This only ensures that every time you use YourModel.objects, you will not include deleted objects, but the generic views and others uses ._default_manager too. Then if you don’t override get_queryset is not a solution. I’ve just check on a ListView and admin.

The accepted solution works great for me but I needed a little bit more flexibility, so I ended up extending the changelist view to add in a custom queryset parameter. I can now configure my default queryset/filter as such and it can still be modified by using a different filter (get parameters):

def changelist_view(self, request, extra_context=None):
    if len(request.GET) == 0 :
        q = request.GET.copy()
        q['status__gt'] = 4
        request.GET = q
        request.META['QUERY_STRING'] = request.GET.urlencode()

    return super(WorksheetAdmin,self).changelist_view(request, extra_context=extra_context)

To extend on some of these answers with what I found most concise and useful.

I’ve made the assumption you have a field like "name" to show the entries.

# admin.py

from django.contrib import admin

@admin.register(Conversation)
class ConversationAdmin(admin.ModelAdmin):
    list_display = ('name', '_is_deleted')


    # Nice to have but indicates that an object is deleted
    @admin.display(
        boolean=True,
        ordering='deleted'
    )
    def _is_deleted(self, obj):
        return obj.deleted

    def get_queryset(self, request):
        return Conversation.all_conversations

Which will give you an interface like:

The problem I found with subclassing a model was that it caused issues with meta inheritance and reverse-path lookups.