Replaced @no_oracle skips with DatabaseFeatures.allows_group_by_lob.

django/db/backends/base/features.py

@@ -4,6 +4,8 @@ from django.utils.functional import cached_property
 
 class BaseDatabaseFeatures:
     gis_enabled = False
+    # Oracle can't group by LOB (large object) data types.
+    allows_group_by_lob = True
     allows_group_by_pk = False
     allows_group_by_selected_pks = False
     empty_fetchmany_value = []

django/db/backends/oracle/features.py

@@ -4,6 +4,9 @@ from django.utils.functional import cached_property
 
 
 class DatabaseFeatures(BaseDatabaseFeatures):
+    # Oracle crashes with "ORA-00932: inconsistent datatypes: expected - got
+    # BLOB" when grouping by LOBs (#24096).
+    allows_group_by_lob = False
     interprets_empty_strings_as_nulls = True
     has_select_for_update = True
     has_select_for_update_nowait = True

tests/expressions_case/tests.py

@@ -5,6 +5,7 @@ from operator import attrgetter, itemgetter
 from uuid import UUID
 
 from django.core.exceptions import FieldError
+from django.db import connection
 from django.db.models import (
     BinaryField, BooleanField, Case, Count, DecimalField, F,
     GenericIPAddressField, IntegerField, Max, Min, Q, Sum, TextField, Value,
@@ -56,10 +57,13 @@ class CaseExpressionTests(TestCase):
         O2OCaseTestModel.objects.create(o2o=o, integer=1)
         FKCaseTestModel.objects.create(fk=o, integer=5)
 
-        # GROUP BY on Oracle fails with TextField/BinaryField; see #24096.
-        cls.non_lob_fields = [
+        cls.group_by_fields = [
             f.name for f in CaseTestModel._meta.get_fields()
-            if not (f.is_relation and f.auto_created) and not isinstance(f, (BinaryField, TextField))
+            if not (f.is_relation and f.auto_created) and
+            (
+                connection.features.allows_group_by_lob or
+                not isinstance(f, (BinaryField, TextField))
+            )
         ]
 
     def test_annotate(self):
@@ -197,7 +201,7 @@ class CaseExpressionTests(TestCase):
 
     def test_annotate_with_aggregation_in_value(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 min=Min('fk_rel__integer'),
                 max=Max('fk_rel__integer'),
             ).annotate(
@@ -212,7 +216,7 @@ class CaseExpressionTests(TestCase):
 
     def test_annotate_with_aggregation_in_condition(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 min=Min('fk_rel__integer'),
                 max=Max('fk_rel__integer'),
             ).annotate(
@@ -227,7 +231,7 @@ class CaseExpressionTests(TestCase):
 
     def test_annotate_with_aggregation_in_predicate(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 max=Max('fk_rel__integer'),
             ).annotate(
                 test=Case(
@@ -483,7 +487,7 @@ class CaseExpressionTests(TestCase):
 
     def test_filter_with_aggregation_in_value(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 min=Min('fk_rel__integer'),
                 max=Max('fk_rel__integer'),
             ).filter(
@@ -498,7 +502,7 @@ class CaseExpressionTests(TestCase):
 
     def test_filter_with_aggregation_in_condition(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 min=Min('fk_rel__integer'),
                 max=Max('fk_rel__integer'),
             ).filter(
@@ -513,7 +517,7 @@ class CaseExpressionTests(TestCase):
 
     def test_filter_with_aggregation_in_predicate(self):
         self.assertQuerysetEqual(
-            CaseTestModel.objects.values(*self.non_lob_fields).annotate(
+            CaseTestModel.objects.values(*self.group_by_fields).annotate(
                 max=Max('fk_rel__integer'),
             ).filter(
                 integer=Case(

tests/gis_tests/geoapp/test_regress.py

@@ -5,7 +5,6 @@ from django.contrib.gis.shortcuts import render_to_kmz
 from django.db.models import Count, Min
 from django.test import TestCase, skipUnlessDBFeature
 
-from ..utils import no_oracle
 from .models import City, PennsylvaniaCity, State, Truth
 
 
@@ -65,10 +64,7 @@ class GeoRegressionTests(TestCase):
         # .count() should not throw TypeError in __eq__
         self.assertEqual(cities_within_state.count(), 1)
 
-    # TODO: fix on Oracle -- get the following error because the SQL is ordered
-    # by a geometry object, which Oracle apparently doesn't like:
-    #  ORA-22901: cannot compare nested table or VARRAY or LOB attributes of an object type
-    @no_oracle
+    @skipUnlessDBFeature('allows_group_by_lob')
     def test_defer_or_only_with_annotate(self):
         "Regression for #16409. Make sure defer() and only() work with annotate()"
         self.assertIsInstance(list(City.objects.annotate(Count('point')).defer('name')), list)

tests/gis_tests/relatedapp/tests.py

@@ -222,10 +222,7 @@ class RelatedGeoModelTest(TestCase):
         self.assertIn('Aurora', names)
         self.assertIn('Kecksburg', names)
 
-    # TODO: fix on Oracle -- get the following error because the SQL is ordered
-    # by a geometry object, which Oracle apparently doesn't like:
-    #  ORA-22901: cannot compare nested table or VARRAY or LOB attributes of an object type
-    @no_oracle
+    @skipUnlessDBFeature('allows_group_by_lob')
     def test12a_count(self):
         "Testing `Count` aggregate on geo-fields."
         # The City, 'Fort Worth' uses the same location as Dallas.
@@ -247,10 +244,7 @@ class RelatedGeoModelTest(TestCase):
         self.assertEqual(1, len(vqs))
         self.assertEqual(3, vqs[0]['num_books'])
 
-    # TODO: fix on Oracle -- get the following error because the SQL is ordered
-    # by a geometry object, which Oracle apparently doesn't like:
-    #  ORA-22901: cannot compare nested table or VARRAY or LOB attributes of an object type
-    @no_oracle
+    @skipUnlessDBFeature('allows_group_by_lob')
     def test13c_count(self):
         "Testing `Count` aggregate with `.values()`.  See #15305."
         qs = Location.objects.filter(id=5).annotate(num_cities=Count('city')).values('id', 'point', 'num_cities')

tests/model_fields/test_jsonfield.py

@@ -355,7 +355,7 @@ class TestQuerying(TestCase):
             operator.itemgetter('key', 'count'),
         )
 
-    @skipIf(connection.vendor == 'oracle', "Oracle doesn't support grouping by LOBs, see #24096.")
+    @skipUnlessDBFeature('allows_group_by_lob')
     def test_ordering_grouping_by_count(self):
         qs = NullableJSONModel.objects.filter(
             value__isnull=False,