Fixed #12152. DoesNotExist and MultipleObjectsReturned now subclass their parent model's exceptions. Thanks, mattmcc and Alex Gaynor.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12567 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/base.py

@@ -52,10 +52,14 @@ class ModelBase(type):
 
         new_class.add_to_class('_meta', Options(meta, **kwargs))
         if not abstract:
-            new_class.add_to_class('DoesNotExist',
+            new_class.add_to_class('DoesNotExist', subclass_exception('DoesNotExist',
-                    subclass_exception('DoesNotExist', ObjectDoesNotExist, module))
+                    tuple(x.DoesNotExist
-            new_class.add_to_class('MultipleObjectsReturned',
+                            for x in parents if hasattr(x, '_meta') and not x._meta.abstract)
-                    subclass_exception('MultipleObjectsReturned', MultipleObjectsReturned, module))
+                                    or (ObjectDoesNotExist,), module))
+            new_class.add_to_class('MultipleObjectsReturned', subclass_exception('MultipleObjectsReturned',
+                    tuple(x.MultipleObjectsReturned
+                            for x in parents if hasattr(x, '_meta') and not x._meta.abstract)
+                                    or (MultipleObjectsReturned,), module))
             if base_meta and not base_meta.abstract:
                 # Non-abstract child classes inherit some attributes from their
                 # non-abstract parent (unless an ABC comes before it in the
@@ -919,8 +923,8 @@ model_unpickle.__safe_for_unpickle__ = True
 
 if sys.version_info < (2, 5):
     # Prior to Python 2.5, Exception was an old-style class
-    def subclass_exception(name, parent, unused):
+    def subclass_exception(name, parents, unused):
-        return types.ClassType(name, (parent,), {})
+        return types.ClassType(name, parents, {})
 else:
-    def subclass_exception(name, parent, module):
+    def subclass_exception(name, parents, module):
-        return type(name, (parent,), {'__module__': module})
+        return type(name, parents, {'__module__': module})

tests/modeltests/model_inheritance/models.py

@@ -38,6 +38,9 @@ class Student(CommonInfo):
     class Meta:
         pass
 
+class StudentWorker(Student, Worker):
+    pass
+
 #
 # Abstract base classes with related models
 #
@@ -176,6 +179,32 @@ Traceback (most recent call last):
     ...
 AttributeError: type object 'CommonInfo' has no attribute 'objects'
 
+# A StudentWorker which does not exist is both a Student and Worker which does not exist.
+>>> try:
+...     StudentWorker.objects.get(id=1)
+... except Student.DoesNotExist:
+...     pass
+>>> try:
+...     StudentWorker.objects.get(id=1)
+... except Worker.DoesNotExist:
+...     pass
+
+# MultipleObjectsReturned is also inherited.
+>>> sw1 = StudentWorker()
+>>> sw1.name = 'Wilma'
+>>> sw1.age = 35
+>>> sw1.save()
+>>> sw2 = StudentWorker()
+>>> sw2.name = 'Betty'
+>>> sw2.age = 34
+>>> sw2.save()
+>>> try:
+...     StudentWorker.objects.get(id__lt=10)
+... except Student.MultipleObjectsReturned:
+...     pass
+... except Worker.MultipleObjectsReturned:
+...     pass
+
 # Create a Post
 >>> post = Post(title='Lorem Ipsum')
 >>> post.save()
@@ -267,6 +296,18 @@ Traceback (most recent call last):
     ...
 DoesNotExist: ItalianRestaurant matching query does not exist.
 
+# An ItalianRestaurant which does not exist is also a Place which does not exist.
+>>> try:
+...     ItalianRestaurant.objects.get(name='The Noodle Void')
+... except Place.DoesNotExist:
+...     pass
+
+# MultipleObjectsReturned is also inherited.
+>>> try:
+...     Restaurant.objects.get(id__lt=10)
+... except Place.MultipleObjectsReturned:
+...     pass
+
 # Related objects work just as they normally do.
 
 >>> s1 = Supplier(name="Joe's Chickens", address='123 Sesame St')

tests/modeltests/proxy_models/models.py

@@ -206,6 +206,26 @@ False
 >>> MyPersonProxy.objects.all()
 [<MyPersonProxy: Bazza del Frob>, <MyPersonProxy: Foo McBar>, <MyPersonProxy: homer>]
 
+# Proxy models are included in the ancestors for a model's DoesNotExist and MultipleObjectsReturned
+>>> try:
+...     MyPersonProxy.objects.get(name='Zathras')
+... except Person.DoesNotExist:
+...     pass
+>>> try:
+...     MyPersonProxy.objects.get(id__lt=10)
+... except Person.MultipleObjectsReturned:
+...     pass
+>>> try:
+...     StatusPerson.objects.get(name='Zathras')
+... except Person.DoesNotExist:
+...     pass
+>>> sp1 = StatusPerson.objects.create(name='Bazza Jr.')
+>>> sp2 = StatusPerson.objects.create(name='Foo Jr.')
+>>> try:
+...     StatusPerson.objects.get(id__lt=10)
+... except Person.MultipleObjectsReturned:
+...     pass
+
 # And now for some things that shouldn't work...
 #
 # All base classes must be non-abstract