#216 Use self._state.db instead of `using` kwarg in model methods.

Thanks to @vdboor for the suggestion.

Also:
- Add missing `using` kwargs in query_translate functions.
- Add a couple unit tests for non-default database functionality.

polymorphic/models.py

@@ -87,12 +87,12 @@ class PolymorphicModel(six.with_metaclass(PolymorphicModelBase, models.Model)):
     def save(self, *args, **kwargs):
         """Overridden model save function which supports the polymorphism
         functionality (through pre_save_polymorphic)."""
-        using = kwargs.get('using', DEFAULT_DB_ALIAS)
+        using = kwargs.get('using', self._state.db or DEFAULT_DB_ALIAS)
         self.pre_save_polymorphic(using=using)
         return super(PolymorphicModel, self).save(*args, **kwargs)
     save.alters_data = True
 
-    def get_real_instance_class(self, using=DEFAULT_DB_ALIAS):
+    def get_real_instance_class(self):
         """
         Normally not needed.
         If a non-polymorphic manager (like base_objects) has been used to
@@ -105,7 +105,7 @@ class PolymorphicModel(six.with_metaclass(PolymorphicModelBase, models.Model)):
         # Note that model_class() can return None for stale content types;
         # when the content type record still exists but no longer refers to an existing model.
         try:
-            model = ContentType.objects.db_manager(using).get_for_id(self.polymorphic_ctype_id).model_class()
+            model = ContentType.objects.db_manager(self._state.db).get_for_id(self.polymorphic_ctype_id).model_class()
         except AttributeError:
             # Django <1.6 workaround
             return None
@@ -120,28 +120,28 @@ class PolymorphicModel(six.with_metaclass(PolymorphicModelBase, models.Model)):
             ))
         return model
 
-    def get_real_concrete_instance_class_id(self, using=DEFAULT_DB_ALIAS):
+    def get_real_concrete_instance_class_id(self):
-        model_class = self.get_real_instance_class(using=using)
+        model_class = self.get_real_instance_class()
         if model_class is None:
             return None
-        return ContentType.objects.db_manager(using).get_for_model(model_class, for_concrete_model=True).pk
+        return ContentType.objects.db_manager(self._state.db).get_for_model(model_class, for_concrete_model=True).pk
 
-    def get_real_concrete_instance_class(self, using=DEFAULT_DB_ALIAS):
+    def get_real_concrete_instance_class(self):
-        model_class = self.get_real_instance_class(using=using)
+        model_class = self.get_real_instance_class()
         if model_class is None:
             return None
-        return ContentType.objects.db_manager(using).get_for_model(model_class, for_concrete_model=True).model_class()
+        return ContentType.objects.db_manager(self._state.db).get_for_model(model_class, for_concrete_model=True).model_class()
 
-    def get_real_instance(self, using=DEFAULT_DB_ALIAS):
+    def get_real_instance(self):
         """Normally not needed.
         If a non-polymorphic manager (like base_objects) has been used to
         retrieve objects, then the complete object with it's real class/type
         and all fields may be retrieved with this method.
         Each method call executes one db query (if necessary)."""
-        real_model = self.get_real_instance_class(using=using)
+        real_model = self.get_real_instance_class()
         if real_model == self.__class__:
             return self
-        return real_model.objects.db_manager(using).get(pk=self.pk)
+        return real_model.objects.db_manager(self._state.db).get(pk=self.pk)
 
     def __init__(self, * args, ** kwargs):
         """Replace Django's inheritance accessor member functions for our model

polymorphic/query.py

@@ -112,8 +112,8 @@ class PolymorphicQuerySet(QuerySet):
 
     def _filter_or_exclude(self, negate, *args, **kwargs):
         "We override this internal Django functon as it is used for all filter member functions."
-        translate_polymorphic_filter_definitions_in_args(self.model, args)  # the Q objects
+        translate_polymorphic_filter_definitions_in_args(self.model, args, using=self._db)  # the Q objects
-        additional_args = translate_polymorphic_filter_definitions_in_kwargs(self.model, kwargs)  # filter_field='data'
+        additional_args = translate_polymorphic_filter_definitions_in_kwargs(self.model, kwargs, using=self._db)  # filter_field='data'
         return super(PolymorphicQuerySet, self)._filter_or_exclude(negate, *(list(args) + additional_args), **kwargs)
 
     def order_by(self, *args, **kwargs):
@@ -325,8 +325,8 @@ class PolymorphicQuerySet(QuerySet):
                     results[base_object.pk] = base_object
 
                 else:
-                    real_concrete_class = base_object.get_real_instance_class(using=self._db)
+                    real_concrete_class = base_object.get_real_instance_class()
-                    real_concrete_class_id = base_object.get_real_concrete_instance_class_id(using=self._db)
+                    real_concrete_class_id = base_object.get_real_concrete_instance_class_id()
 
                     if real_concrete_class_id is None:
                         # Dealing with a stale content type
@@ -345,7 +345,7 @@ class PolymorphicQuerySet(QuerySet):
         # Then we copy the extra() select fields from the base objects to the real objects.
         # TODO: defer(), only(): support for these would be around here
         for real_concrete_class, idlist in idlist_per_model.items():
-            real_objects = real_concrete_class.base_objects.filter(**{
+            real_objects = real_concrete_class.base_objects.db_manager(self._db).filter(**{
                 ('%s__in' % pk_name): idlist,
             })
             real_objects.query.select_related = self.query.select_related  # copy select related configuration to new qs
@@ -372,7 +372,7 @@ class PolymorphicQuerySet(QuerySet):
 
             for real_object in real_objects:
                 o_pk = getattr(real_object, pk_name)
-                real_class = real_object.get_real_instance_class(using=self._db)
+                real_class = real_object.get_real_instance_class()
 
                 # If the real class is a proxy, upcast it
                 if real_class != real_concrete_class:

polymorphic/query_translate.py

@@ -36,7 +36,7 @@ from functools import reduce
 # functionality to filters and Q objects.
 # Probably a more general queryset enhancement class could be made out of them.
 
-def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs):
+def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs, using=DEFAULT_DB_ALIAS):
     """
     Translate the keyword argument list for PolymorphicQuerySet.filter()
 
@@ -51,7 +51,6 @@ def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs):
     Returns: a list of non-keyword-arguments (Q objects) to be added to the filter() query.
     """
     additional_args = []
-    using = kwargs.get('using', DEFAULT_DB_ALIAS)
     for field_path, val in kwargs.copy().items():  # Python 3 needs copy
 
         new_expr = _translate_polymorphic_filter_definition(queryset_model, field_path, val, using=using)
@@ -90,7 +89,7 @@ def translate_polymorphic_Q_object(queryset_model, potential_q_object, using=DEF
     return potential_q_object
 
 
-def translate_polymorphic_filter_definitions_in_args(queryset_model, args):
+def translate_polymorphic_filter_definitions_in_args(queryset_model, args, using=DEFAULT_DB_ALIAS):
     """
     Translate the non-keyword argument list for PolymorphicQuerySet.filter()
 
@@ -104,7 +103,7 @@ def translate_polymorphic_filter_definitions_in_args(queryset_model, args):
     """
 
     for q in args:
-        translate_polymorphic_Q_object(queryset_model, q)
+        translate_polymorphic_Q_object(queryset_model, q, using=using)
 
 
 def _translate_polymorphic_filter_definition(queryset_model, field_path, field_val, using=DEFAULT_DB_ALIAS):

polymorphic/tests.py

@@ -430,6 +430,8 @@ class PolymorphicTests(TestCase):
     The test suite
     """
 
+    multi_db = True
+
     def test_annotate_aggregate_order(self):
         # create a blog of type BlogA
         # create two blog entries in BlogA
@@ -1162,6 +1164,45 @@ class PolymorphicTests(TestCase):
         result = DateModel.objects.annotate(val=DateTime('date', 'day', utc))
         self.assertEqual(list(result), [])
 
+    def test_save_to_non_default_database(self):
+        Model2A.objects.db_manager('secondary').create(field1='A1')
+        Model2C(field1='C1', field2='C2', field3='C3').save(using='secondary')
+        Model2B.objects.create(field1='B1', field2='B2')
+        Model2D(field1='D1', field2='D2', field3='D3', field4='D4').save('secondary')
+        
+        default_objects = list(Model2A.objects.order_by('id'))
+        self.assertEqual(len(default_objects), 2)
+        self.assertEqual(repr(default_objects[0]), '<Model2B: id 1, field1 (CharField), field2 (CharField)>')
+        self.assertEqual(repr(default_objects[1]), '<Model2D: id 2, field1 (CharField), field2 (CharField), field3 (CharField), field4 (CharField)>')
+
+        secondary_objects = list(Model2A.objects.db_manager('secondary').order_by('id'))
+        self.assertEqual(len(secondary_objects), 2)
+        self.assertEqual(repr(secondary_objects[0]), '<Model2A: id 1, field1 (CharField)>')
+        self.assertEqual(repr(secondary_objects[1]), '<Model2C: id 2, field1 (CharField), field2 (CharField), field3 (CharField)>')
+
+    def test_instance_of_filter_on_non_default_database(self):
+        Base.objects.db_manager('secondary').create(field_b='B1')
+        ModelX.objects.db_manager('secondary').create(field_b='B', field_x='X')
+        ModelY.objects.db_manager('secondary').create(field_b='Y', field_y='Y')
+
+        objects = Base.objects.db_manager('secondary').filter(instance_of=Base)
+        self.assertEqual(len(objects), 3)
+        self.assertEqual(repr(objects[0]), '<Base: id 1, field_b (CharField)>')
+        self.assertEqual(repr(objects[1]), '<ModelX: id 2, field_b (CharField), field_x (CharField)>')
+        self.assertEqual(repr(objects[2]), '<ModelY: id 3, field_b (CharField), field_y (CharField)>')
+
+        objects = Base.objects.db_manager('secondary').filter(instance_of=ModelX)
+        self.assertEqual(len(objects), 1)
+        self.assertEqual(repr(objects[0]), '<ModelX: id 2, field_b (CharField), field_x (CharField)>')
+
+        objects = Base.objects.db_manager('secondary').filter(instance_of=ModelY)
+        self.assertEqual(len(objects), 1)
+        self.assertEqual(repr(objects[0]), '<ModelY: id 3, field_b (CharField), field_y (CharField)>')
+
+        objects = Base.objects.db_manager('secondary').filter(Q(instance_of=ModelX) | Q(instance_of=ModelY))
+        self.assertEqual(len(objects), 2)
+        self.assertEqual(repr(objects[0]), '<ModelX: id 2, field_b (CharField), field_x (CharField)>')
+        self.assertEqual(repr(objects[1]), '<ModelY: id 3, field_b (CharField), field_y (CharField)>')
 
 class RegressionTests(TestCase):
 

runtests.py

@@ -25,6 +25,10 @@ if not settings.configured:
             'default': {
                 'ENGINE': 'django.db.backends.sqlite3',
                 'NAME': ':memory:'
+            },
+            'secondary': {
+                'ENGINE': 'django.db.backends.sqlite3',
+                'NAME': ':memory:'
             }
         },
         TEMPLATE_LOADERS=(