id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
13083	Add foreignkey_id field resolving to queryset filter function	anonymous	nobody	"Hi,

When selecting a model instance using a field that is a foreign key to a model, I expected this to work:
{{{
>>> AModel.objects.get(somemodel_id=4)
Traceback (most recent call last):
  File ""<console>"", line 1, in <module>
  File ""d:\code\env\src\django\django\db\models\manager.py"", line 132, in get
    return self.get_query_set().get(*args, **kwargs)
  File ""d:\code\env\src\django\django\db\models\query.py"", line 331, in get
    clone = self.filter(*args, **kwargs)
  File ""d:\code\env\src\django\django\db\models\query.py"", line 545, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File ""d:\code\env\src\django\django\db\models\query.py"", line 563, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File ""d:\code\env\src\django\django\db\models\sql\query.py"", line 1109, in add_q
    can_reuse=used_aliases)
  File ""d:\code\env\src\django\django\db\models\sql\query.py"", line 1003, in add_filter
    negate=negate, process_extras=process_extras)
  File ""d:\code\env\src\django\django\db\models\sql\query.py"", line 1171, in setup_joins
    ""Choices are: %s"" % (name, "", "".join(names)))
FieldError: Cannot resolve keyword 'somemodel_id' into field. Choices are: a, b, c, id, somemodel
}}}
I understand why it doesn't - you need two underscores to follow references:
{{{
>>> AModel.objects.get(somemodel__id=4)
<AModel: TheModelIWanted>
}}}
But this feels like an asymmetry, since after you get the model, you can read / assign to the foreignkey's id:

{{{
>>> obj = AModel.objects.get(somemodel__id=4)
>>> obj.somemodel
<SomeModel: OtherModel>
>>> obj.somemodel_id #Specifically this - why does this work, but I can't query for it without the JOIN to the related table?
4L
>>> obj.somemodel.id
4L
}}}
This asymmetry also /not/ around for the creation of a new instance:
{{{
>>> AModel(somemodel_id=4)
<AModel: UnsetPlaceholder>
}}}

Is this a design decision? Implementation detail?"		closed	Database layer (models, ORM)	dev		duplicate	foreignkey, filter		Unreviewed	0	0	0	0	0	0