Fixed #23646 -- Added QuerySet.bulk_update() to efficiently update many models.

tests/postgres_tests/test_bulk_update.py

@@ -0,0 +1,34 @@
+from datetime import date
+
+from . import PostgreSQLTestCase
+from .models import (
+    HStoreModel, IntegerArrayModel, JSONModel, NestedIntegerArrayModel,
+    NullableIntegerArrayModel, OtherTypesArrayModel, RangesModel,
+)
+
+try:
+    from psycopg2.extras import NumericRange, DateRange
+except ImportError:
+    pass  # psycopg2 isn't installed.
+
+
+class BulkSaveTests(PostgreSQLTestCase):
+    def test_bulk_update(self):
+        test_data = [
+            (IntegerArrayModel, 'field', [], [1, 2, 3]),
+            (NullableIntegerArrayModel, 'field', [1, 2, 3], None),
+            (JSONModel, 'field', {'a': 'b'}, {'c': 'd'}),
+            (NestedIntegerArrayModel, 'field', [], [[1, 2, 3]]),
+            (HStoreModel, 'field', {}, {1: 2}),
+            (RangesModel, 'ints', None, NumericRange(lower=1, upper=10)),
+            (RangesModel, 'dates', None, DateRange(lower=date.today(), upper=date.today())),
+            (OtherTypesArrayModel, 'ips', [], ['1.2.3.4']),
+            (OtherTypesArrayModel, 'json', [], [{'a': 'b'}])
+        ]
+        for Model, field, initial, new in test_data:
+            with self.subTest(model=Model, field=field):
+                instances = Model.objects.bulk_create(Model(**{field: initial}) for _ in range(20))
+                for instance in instances:
+                    setattr(instance, field, new)
+                Model.objects.bulk_update(instances, [field])
+                self.assertSequenceEqual(Model.objects.filter(**{field: new}), instances)