edits

django_mongodb/compiler.py

@@ -442,6 +442,8 @@ def collection_name(self):
                 if isinstance(v, BaseTable) and self.query.alias_refcount[k]
             )
         except StopIteration:
+            # Use a dummy collection if the query doesn't specify a table
+            # (such as Constraint.validate() with a condition).
             query = self.query_class(self)
             query.aggregation_pipeline = [{"$facet": {"__null": []}}]
             self.subqueries.insert(0, query)

django_mongodb/features.py

@@ -23,7 +23,10 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     supports_expression_indexes = False
     supports_foreign_keys = False
     supports_ignore_conflicts = False
+    # Before MongoDB 6.0, $in cannot be used in partialFilterExpression.
     supports_in_index_operator = property(operator.attrgetter("is_mongodb_6_0"))
+    # Before MongoDB 6.0, $or cannot be used in partialFilterExpression.
+    supports_or_index_operator = property(operator.attrgetter("is_mongodb_6_0"))
     supports_json_field_contains = False
     # BSON Date type doesn't support microsecond precision.
     supports_microsecond_precision = False
@@ -97,7 +100,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "expressions.tests.ExpressionOperatorTests.test_lefthand_bitwise_xor_right_null",
         "expressions.tests.ExpressionOperatorTests.test_lefthand_transformed_field_bitwise_or",
     }
-    # Before MongoDB 6.0, $in cannot be used in partialFilterExpression.
     _django_test_expected_failures_partial_expression_in = {
         "schema.tests.SchemaTests.test_remove_ignored_unique_constraint_not_create_fk_index",
     }
@@ -106,7 +108,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     def django_test_expected_failures(self):
         expected_failures = super().django_test_expected_failures
         expected_failures.update(self._django_test_expected_failures)
-        if not self.is_mongodb_6_0:
+        if not self.supports_in_index_operator:
             expected_failures.update(self._django_test_expected_failures_partial_expression_in)
         if not self.is_mongodb_6_3:
             expected_failures.update(self._django_test_expected_failures_bitwise)

django_mongodb/indexes.py

@@ -9,7 +9,7 @@
 
 from .query_utils import process_rhs
 
-mongo_operators_idx = {
+MONGO_INDEX_OPERATORS = {
     "exact": "$eq",
     "gt": "$gt",
     "gte": "$gte",
@@ -33,7 +33,7 @@ def builtin_lookup_idx(self, compiler, connection):
     lhs_mql = self.lhs.target.column
     value = process_rhs(self, compiler, connection)
     try:
-        operator = mongo_operators_idx[self.lookup_name]
+        operator = MONGO_INDEX_OPERATORS[self.lookup_name]
     except KeyError:
         raise NotSupportedError(
             f"MongoDB does not support the '{self.lookup_name}' lookup in indexes."
@@ -44,7 +44,7 @@ def builtin_lookup_idx(self, compiler, connection):
 def in_idx(self, compiler, connection):
     if not connection.features.supports_in_index_operator:
         raise NotSupportedError(
-            f"MongoDB < 6.0 does not support the {self.lookup_name} lookup in indexes."
+            f"MongoDB < 6.0 does not support the '{self.lookup_name}' lookup in indexes."
         )
     return builtin_lookup_idx(self, compiler, connection)
 

django_mongodb/lookups.py

@@ -51,9 +51,7 @@ def is_null(self, compiler, connection):
     if not isinstance(self.rhs, bool):
         raise ValueError("The QuerySet value for an isnull lookup must be True or False.")
     if isinstance(self.lhs, Value):
-        if self.lhs.value is None or (
-            self.lhs.value == "" and connection.features.interprets_empty_strings_as_nulls
-        ):
+        if self.lhs.value is None:
             result_exception = FullResultSet if self.rhs else EmptyResultSet
         else:
             result_exception = EmptyResultSet if self.rhs else FullResultSet

tests/indexes_/test_mql.py → tests/indexes_/test_condition.py

@@ -35,9 +35,9 @@ def test_xor_not_supported(self):
                 condition=Q(pk=True) ^ Q(pk=False),
             )._get_condition_mql(Article, schema_editor=editor)
 
-    @skipIfDBFeature("supports_in_index_operator")
+    @skipIfDBFeature("supports_or_index_operator")
     def test_or_not_supported(self):
-        msg = "MongoDB does not support the 'Or' lookup in indexes."
+        msg = "MongoDB < 6.0 does not support the '|' operator in indexes."
         with self.assertRaisesMessage(NotSupportedError, msg), connection.schema_editor() as editor:
             Index(
                 name="test",
@@ -47,7 +47,7 @@ def test_or_not_supported(self):
 
     @skipIfDBFeature("supports_in_index_operator")
     def test_in_not_supported(self):
-        msg = "MongoDB does not support the 'in' lookup in indexes."
+        msg = "MongoDB < 6.0 does not support the 'in' lookup in indexes."
         with self.assertRaisesMessage(NotSupportedError, msg), connection.schema_editor() as editor:
             Index(
                 name="test",
@@ -90,7 +90,7 @@ def test_composite_op_index(self):
                 (operator.or_, "$or"),
                 (operator.and_, "$and"),
             )
-            if connection.features.supports_in_index_operator
+            if connection.features.supports_or_index_operator
             else ((operator.and_, "$and"),)
         )
         for op, mongo_operator in operators: