Override default queryset in Django admin

One of my models has a deleted flag, which is used to hide objects globally:

class NondeletedManager(models.Manager):
    """Returns only objects which haven't been deleted"""

    def get_query_set(self):
        return super(NondeletedManager, self).get_query_set().exclude(deleted=True)

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

How can I override the default queryset used by Django admin module to include deleted conversations?

You can [override][1] get_queryset method in your model admin class.

class MyModelAdmin(admin.ModelAdmin):
    def get_queryset(self, request):
        qs = super(MyModelAdmin, self).get_queryset(request)
        if request.user.is_superuser:
            return qs
        return qs.filter(author=request.user)

Note in Django<=1.5 the method was named just queryset. [1]: https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.get_queryset

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

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.

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.

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)

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.

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.