From 0e7a45fca09623e7bad9408a838e522b3cca8d65 Mon Sep 17 00:00:00 2001
From: Hannes Ljungberg <hannes.ljungberg@gmail.com>
Date: Mon, 19 Oct 2020 22:36:24 +0200
Subject: [PATCH] Fixed #32126 -- Fixed grouping by Case() annotation without
cases.
Co-authored-by: Simon Charette <charettes@users.noreply.github.com>
---
django/db/models/expressions.py | 5 +++++
tests/expressions_case/tests.py | 25 +++++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index 43b8920d95..13918467ee 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -1068,6 +1068,11 @@ class Case(Expression):
sql = connection.ops.unification_cast_sql(self.output_field) % sql
return sql, sql_params
+ def get_group_by_cols(self, alias=None):
+ if not self.cases:
+ return self.default.get_group_by_cols(alias)
+ return super().get_group_by_cols(alias)
+
class Subquery(Expression):
"""
diff --git a/tests/expressions_case/tests.py b/tests/expressions_case/tests.py
index 2a101eeee1..54c53ef4de 100644
--- a/tests/expressions_case/tests.py
+++ b/tests/expressions_case/tests.py
@@ -1148,6 +1148,31 @@ class CaseExpressionTests(TestCase):
lambda x: x[1:]
)
+ def test_aggregation_empty_cases(self):
+ tests = [
+ # Empty cases and default.
+ (Case(output_field=IntegerField()), None),
+ # Empty cases and a constant default.
+ (Case(default=Value('empty')), 'empty'),
+ # Empty cases and column in the default.
+ (Case(default=F('url')), ''),
+ ]
+ for case, value in tests:
+ with self.subTest(case=case):
+ self.assertQuerysetEqual(
+ CaseTestModel.objects.values('string').annotate(
+ case=case,
+ integer_sum=Sum('integer'),
+ ).order_by('string'),
+ [
+ ('1', value, 1),
+ ('2', value, 4),
+ ('3', value, 9),
+ ('4', value, 4),
+ ],
+ transform=itemgetter('string', 'case', 'integer_sum'),
+ )
+
class CaseDocumentationExamples(TestCase):
@classmethod