Ticket #13781: select_related_subclass_patch_1.2.X.diff

django/db/models/query.py

@@ -1142 +1142 @@
 
 
 def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
-                   requested=None, offset=0, only_load=None, local_only=False):
+                   requested=None, offset=0, only_load=None, local_only=False,
+                   last_klass=None):
     """
     Helper function that recursively returns an object with the specified
     related attributes already populated.
@@ -1172 +1173 @@
        the full field list for `klass` can be assumed.
      * local_only - Only populate local fields. This is used when building
        following reverse select-related relations
+     * last_klass - the last class seen when following reverse
+       select-related relations
     """
     if max_depth and requested is None and cur_depth > max_depth:
         # We've recursed deeply enough; stop now.
@@ -1218 +1221 @@
     else:
         # Load all fields on klass
         if local_only:
-            field_names = [f.attname for f in klass._meta.local_fields]
+            parents = [p for p in klass._meta.get_parent_list()
+                       if p is not last_klass]
+            field_names = [f.attname for f in klass._meta.fields
+                           if f in klass._meta.local_fields
+                           or f.model in parents]
         else:
             field_names = [f.attname for f in klass._meta.fields]
         field_count = len(field_names)
@@ -1277 +1284 @@
             next = requested[f.related_query_name()]
             # Recursively retrieve the data for the related object
             cached_row = get_cached_row(model, row, index_end, using,
-                max_depth, cur_depth+1, next, only_load=only_load, local_only=True)
+                max_depth, cur_depth+1, next, only_load=only_load, local_only=True,
+                last_klass=klass)
             # If the recursive descent found an object, populate the
             # descriptor caches relevant to the object
             if cached_row:
@@ -1293 +1301 @@
                     # Now populate all the non-local field values
                     # on the related object
                     for rel_field,rel_model in rel_obj._meta.get_fields_with_model():
-                        if rel_model is not None:
+                        if rel_model is not None and isinstance(obj, rel_model):
                             setattr(rel_obj, rel_field.attname, getattr(obj, rel_field.attname))
                             # populate the field cache for any related object
                             # that has already been retrieved

django/db/models/sql/compiler.py

@@ -213 +213 @@
         return result
 
     def get_default_columns(self, with_aliases=False, col_aliases=None,
-            start_alias=None, opts=None, as_pairs=False, local_only=False):
+            start_alias=None, opts=None, as_pairs=False, local_only=False,
+            last_opts=None):
         """
         Computes the default columns for selecting every field in the base
         model. Will sometimes be called to pull in related models (e.g. via
@@ -237 +238 @@
 
         if start_alias:
             seen = {None: start_alias}
+        parents = [p for p in opts.get_parent_list() if p._meta is not last_opts]
         for field, model in opts.get_fields_with_model():
-            if local_only and model is not None:
+            if local_only and model is not None and model not in parents:
                 continue
             if start_alias:
                 try:
@@ -249 +251 @@
                     else:
                         link_field = opts.get_ancestor_link(model)
                         alias = self.query.join((start_alias, model._meta.db_table,
-                                link_field.column, model._meta.pk.column))
+                                link_field.column, model._meta.pk.column),
+                                promote=(model in parents))
                     seen[model] = alias
             else:
                 # If we're starting from the base model of the queryset, the
@@ -647 +650 @@
                 )
                 used.add(alias)
                 columns, aliases = self.get_default_columns(start_alias=alias,
-                    opts=model._meta, as_pairs=True, local_only=True)
+                    opts=model._meta, as_pairs=True, local_only=True,
+                    last_opts=opts)
                 self.query.related_select_cols.extend(columns)
                 self.query.related_select_fields.extend(model._meta.fields)
 

tests/regressiontests/select_related_onetoone/models.py

@@ -45 +45 @@
 class AdvancedUserStat(UserStat):
     karma = models.IntegerField()
 
+
 class Image(models.Model):
     name = models.CharField(max_length=100)
 
@@ -52 +53 @@
 class Product(models.Model):
     name = models.CharField(max_length=100)
     image = models.OneToOneField(Image, null=True)
+
+
+class Parent1(models.Model):
+    name1 = models.CharField(max_length=50)
+    def __unicode__(self):
+        return self.name1
+
+
+class Parent2(models.Model):
+    name2 = models.CharField(max_length=50)
+    def __unicode__(self):
+        return self.name2
+
+
+class Child1(Parent1, Parent2):
+    other = models.CharField(max_length=50)
+    def __unicode__(self):
+        return self.name1
+
+
+class Child2(Parent1):
+    parent2 = models.OneToOneField(Parent2)
+    other = models.CharField(max_length=50)
+    def __unicode__(self):
+        return self.name1

tests/regressiontests/select_related_onetoone/tests.py

@@ -3 +3 @@
 from django.test import TestCase
 
 from models import (User, UserProfile, UserStat, UserStatResult, StatDetails,
-    AdvancedUserStat, Image, Product)
+    AdvancedUserStat, Image, Product, Parent1, Parent2, Child1, Child2)
 
 class ReverseSelectRelatedTestCase(TestCase):
     def setUp(self):
@@ -25 +25 @@
         advstat = AdvancedUserStat.objects.create(user=user2, posts=200, karma=5,
                                                   results=results2)
         StatDetails.objects.create(base_stats=advstat, comments=250)
+        p1 = Parent1(name1="Only Parent1")
+        p1.save()
+        c1 = Child1(name1="Child1 Parent1", name2="Child1 Parent2")
+        c1.save()
+        p2 = Parent2(name2="Child2 Parent2")
+        p2.save()
+        c2 = Child2(name1="Child2 Parent1", parent2=p2)
+        c2.save()
 
         db.reset_queries()
 
@@ -92 +100 @@
         p2 = Product.objects.create(name="Talking Django Plushie")
 
         self.assertEqual(len(Product.objects.select_related("image")), 2)
+
+    def test_parent_only(self):
+        Parent1.objects.select_related('child1').get(name1="Only Parent1")
+
+    def test_multiple_subclass(self):
+        p = Parent1.objects.select_related('child1').get(name1="Child1 Parent1")
+        self.assertEqual(p.child1.name2, u'Child1 Parent2')
+        self.assertQueries(1)
+
+    def test_onetoone_with_subclass(self):
+        p = Parent2.objects.select_related('child2').get(name2="Child2 Parent2")
+        self.assertEqual(p.child2.name1, u'Child2 Parent1')
+        self.assertQueries(1)