Fixed #36748 -- Filtered non-standard placeholders from UNNEST queries.

Author: CharString

django/db/backends/postgresql/compiler.py

@@ -36,6 +36,11 @@ def assemble_as_sql(self, fields, value_rows):
             # Lack of fields denote the usage of the DEFAULT keyword
             # for the insertion of empty rows.
             or any(field is None for field in fields)
+            # Field.get_placeholder takes value as an argument, so the
+            # resulting placeholder might be dependent on the value.
+            # in UNNEST requires a single placeholder to "fit all values" in
+            # the array.
+            or any(hasattr(field, "get_placeholder") for field in fields)
             # Fields that don't use standard internal types might not be
             # unnest'able (e.g. array and geometry types are known to be
             # problematic).

docs/releases/5.2.9.txt

@@ -13,3 +13,6 @@ Bugfixes
   ``django.utils.feedgenerator.Stylesheet.__str__()`` did not escape
   the ``url``, ``mimetype``, and ``media`` attributes, potentially leading
   to invalid XML markup (:ticket:`36733`).
+
+* Fixed a bug in Django 5.2 on PostgreSQL where ``bulk_create()`` did not apply
+  a field's custom query placeholders (:ticket:`36748`).

tests/postgres_tests/fields.py

@@ -57,3 +57,8 @@ def deconstruct(self):
 class EnumField(models.CharField):
     def get_prep_value(self, value):
         return value.value if isinstance(value, enum.Enum) else value
+
+
+class OffByOneField(models.IntegerField):
+    def get_placeholder(self, value, compiler, connection):
+        return "(%s + 1)"

tests/postgres_tests/migrations/0002_create_test_models.py

@@ -9,6 +9,7 @@
     EnumField,
     HStoreField,
     IntegerRangeField,
+    OffByOneField,
     SearchVectorField,
 )
 from ..models import TagField
@@ -565,4 +566,26 @@ class Migration(migrations.Migration):
                 "required_db_vendor": "postgresql",
             },
         ),
+        migrations.CreateModel(
+            name="OffByOneModel",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                (
+                    "one_off",
+                    OffByOneField(),
+                ),
+            ],
+            options={
+                "required_db_vendor": "postgresql",
+            },
+            bases=(models.Model,),
+        ),
     ]

tests/postgres_tests/models.py

@@ -9,6 +9,7 @@
     EnumField,
     HStoreField,
     IntegerRangeField,
+    OffByOneField,
     SearchVectorField,
 )
 
@@ -207,3 +208,7 @@ class HotelReservation(PostgreSQLModel):
     end = models.DateTimeField()
     cancelled = models.BooleanField(default=False)
     requirements = models.JSONField(blank=True, null=True)
+
+
+class OffByOneModel(PostgreSQLModel):
+    one_off = OffByOneField()

tests/postgres_tests/test_bulk_update.py

@@ -6,6 +6,7 @@
     IntegerArrayModel,
     NestedIntegerArrayModel,
     NullableIntegerArrayModel,
+    OffByOneModel,
     OtherTypesArrayModel,
     RangesModel,
 )
@@ -44,3 +45,10 @@ def test_bulk_update(self):
                 self.assertSequenceEqual(
                     Model.objects.filter(**{field: new}), instances
                 )
+
+    def test_bulk_create(self):
+        OffByOneModel.objects.bulk_create(OffByOneModel(one_off=0) for _ in range(20))
+
+        self.assertSequenceEqual(
+            [m.one_off for m in OffByOneModel.objects.all()], 20 * [1]
+        )