Django - 指定Django管理员应该使用哪个模型管理器

Question

I've created a custom Manager for a Django model which returns a QuerySet holding a subset of objects.all(). I need this to be the model's default Manager, since I am also creating a custom tag which will retrieve content from any model (specified by an argument), and needs to use the default Manager for the specified model. All that works fine, except - Django Admin is ALSO using the default Manager for this particular model, which means that not all model instances appear in the admin.

The Django docs don't help:

If you use custom Manager objects, take note that the first Manager Django encounters (in the order in which they're defined in the model) has a special status. Django interprets this first Manager defined in a class as the "default" Manager, and several parts of Django ( though not the admin application ) will use that Manager exclusively for that model. (Django Managers documentation)

The admin isn't supposed to use the default Manager, but it seems to be in my case. Note that I have also explicitly add the default Manager objects :

subset = CustomManager() # the default manager
objects = models.Manager() # the one I want admin to use

How can I specify which Manager the admin should use?

Answer 1

You can choose the manager by overriding the queryset method in your ModelAdmin subclass.

def get_queryset(self, request):
    # use our manager, rather than the default one
    qs = self.model.objects.get_queryset()

    # we need this from the superclass method
    ordering = self.ordering or () # otherwise we might try to *None, which is bad ;)
    if ordering:
        qs = qs.order_by(*ordering)
    return qs

Answer 2

Updated code:

def get_queryset(self, request):
    """
    Returns a QuerySet of all model instances that can be edited by the
    admin site. This is used by changelist_view.
    """
    qs = self.model._default_manager.get_queryset()
    # TODO: this should be handled by some parameter to the ChangeList.
    ordering = self.get_ordering(request)
    if ordering:
        qs = qs.order_by(*ordering)
    return qs

_default_manager can be replaced...

Answer 3

As we expect objects to be the sole manager, the admin will use manager in self.Admin.manager .

From the ticket https://code.djangoproject.com/ticket/4754 opened by troy.simpson

class filterManager(models.Manager):
  def get_query_set(self):
    return super(filterManager, self).get_query_set().filter(name='troy')

class Blah(models.Model):
  name = models.CharField(maxlength=100)
  objects = filterManager()
  class Admin:
    manager = filterManager()

Tested with Django 1.11