`select_related()` doesn't work with proxy models.

[Tai Lee]

I get a traceback if I call get() on a queryset for a proxy model which is using select_related(), or simply no objects if I try to access the queryset itself.

# models

class Country(models.Model):
	name = models.CharField(max_length=50, unique=True)

class State(models.Model):
	name = models.CharField(max_length=50)
	country = models.ForeignKey(Country)

	def __unicode__(self):
		return self.name

class StateProxy(State):
	class Meta:
		proxy = True

# interactive shell

>>> country = Country.objects.create(name='Australia')
>>> state = State.objects.create(name='New South Wales', country=country)

>>> State.objects.select_related()
[<State: New South Wales>]

>>> StateProxy.objects.select_related()
[]

# should have got [<State: New South Wales>]

>>> StateProxy.objects.get(name='New South Wales')
<StateProxy: New South Wales>

>>> StateProxy.objects.select_related().get(name='New South Wales')
Traceback (most recent call last):
  File "<console>", line 1, in ?
  File "/path/to/django/db/models/manager.py", line 120, in get
    return self.get_query_set().get(*args, **kwargs)
  File "/path/to/django/db/models/query.py", line 269, in get
    num = len(clone)
  File "/path/to/django/db/models/query.py", line 68, in __len__
    self._result_cache = list(self.iterator())
  File "/path/to/django/db/models/query.py", line 207, in iterator
    for row in self.query.results_iter():
  File "/path/to/django/db/models/sql/query.py", line 276, in results_iter
    for rows in self.execute_sql(MULTI):
  File "/path/to/django/db/models/sql/query.py", line 2301, in execute_sql
    sql, params = self.as_sql()
  File "/path/to/django/db/models/sql/query.py", line 384, in as_sql
    self.pre_sql_setup()
  File "/path/to/django/db/models/sql/query.py", line 571, in pre_sql_setup
    self.fill_related_selections()
  File "/path/to/django/db/models/sql/query.py", line 1361, in fill_related_selections
    lhs_col = int_opts.parents[int_model].column
AttributeError: 'NoneType' object has no attribute 'column'

# should have got <StateProxy: New South Wales>

[Clément Nodet]

initial patch, fixes select_related + filter on proxy, and type issue on subproxy

[Clément Nodet]

There was a possible bug on subproxy (proxy of proxy) manager creation, giving the following results on the API tests:

>>> MyPersonProxy.objects.all() 
[<MyPerson: Bazza del Frob>, <MyPerson: Foo McBar>, <MyPerson: homer>]

bypassed that by forcing manager inheritance (of abstract and concrete managers) from the model base (before skipping proxy for populating fields), but not sure this is the needed behaviour here.

Patch mostly adresses proxy skipping when joining fields (traversing multiple levels of nested proxies) and ancestors chain when populating select fields on proxy models. Added also some regression tests on proxy + model inheritance, subproxy select_related().filter(...), and ForeignKey( proxy / subproxy )

[Alex Gaynor]

I have a patch on another issue (I forget the number) that solves the manager issue.

[Clément Nodet]

patch without manager fix (covered by #10953)

[Clément Nodet]

@Alex:

I suppose #10953 , attached a new patch with no modifications in django.models.base.ModelBase

[Armin Ronacher]

The patch for this and #10953 is attached to my github repo: ​http://github.com/mitsuhiko/django/tree/ticket-10953

[Jacob]

(In [10738]) Fixed #10953, #10955: proxies of proxies now work correctly, though I still don't quite understand why you'd want to do such a thing. Thanks, Armin Ronacher.

[Jacob]

Milestone 1.1 deleted