id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
36821	Asymmetry between exact and iexact when filtering for empty strings on Oracle	Clifford Gama	JaeHyuckSa	"[https://github.com/django/django/pull/19793#discussion_r2636417393 As pointed out by Jacob], the special-handling that the ORM does for empty strings on backends that `interpret_empty_strings_as_null=True` is not performed on `iexact` lookups. The [https://docs.djangoproject.com/en/6.0/ref/models/querysets/#iexact docs] on iexact and exact state that:

> If the value provided for comparison is None, it will be interpreted as an SQL NULL (see isnull for more details).

Which I would also expect to apply to empty strings on backends where they mean Null.

Failing test:
{{{#!diff
diff --git a/tests/queries/tests.py b/tests/queries/tests.py
index 51d1915c97..24e9c51593 100644
--- a/tests/queries/tests.py
+++ b/tests/queries/tests.py
@@ -2280,6 +2280,17 @@ class ComparisonTests(TestCase):
            [item_ab],
        )

+    @skipUnlessDBFeature(""interprets_empty_strings_as_nulls"")
+    def test_empty_string_is_null(self):
+        obj = NullableName.objects.create(name=None)
+        obj1 = NullableName.objects.create(name="""")
+        cases = [{""name__exact"": """"}, {""name__iexact"": """"}]
+        for lookup in cases:
+            with self.subTest(lookup):
+                self.assertSequenceEqual(
+                    NullableName.objects.filter(**lookup), [obj, obj1]
+                )
+

class ExistsSql(TestCase):
    def test_exists(self):
}}}

The query generated for the iexact case is as follows (note that it will never match anything):
{{{#!sql
SELECT ""queries_nullablename"".""id"",
       ""queries_nullablename"".""name""
FROM   ""queries_nullablename""
WHERE  Upper(""queries_nullablename"".""name"") = Upper()
ORDER  BY ""queries_nullablename"".""id"" ASC;  
}}}"	Bug	closed	Database layer (models, ORM)	6.0	Normal	fixed	iexact, interprets_empty_strings_as_null		Ready for checkin	1	0	0	0	0	0