INTPYTHON-602 Fix QuerySet results of embedded model fields that use database converters

Author: timgraham

django_mongodb_backend/operations.py

@@ -107,6 +107,8 @@ def get_db_converters(self, expression):
                 converters.append(self.convert_datetimefield_value)
         elif internal_type == "DecimalField":
             converters.append(self.convert_decimalfield_value)
+        elif internal_type == "EmbeddedModelField":
+            converters.append(self.convert_embeddedmodelfield_value)
         elif internal_type == "JSONField":
             converters.append(self.convert_jsonfield_value)
         elif internal_type == "TimeField":
@@ -150,6 +152,16 @@ def convert_durationfield_value(self, value, expression, connection):
                 value = datetime.timedelta(milliseconds=int(str(value)))
         return value
 
+    def convert_embeddedmodelfield_value(self, value, expression, connection):
+        if value is not None:
+            # Apply database converters to each field of the embedded model.
+            for field in expression.output_field.embedded_model._meta.fields:
+                field_expr = Expression(output_field=field)
+                converters = connection.ops.get_db_converters(field_expr)
+                for converter in converters:
+                    value[field.attname] = converter(value[field.attname], field_expr, connection)
+        return value
+
     def convert_jsonfield_value(self, value, expression, connection):
         """
         Convert dict data to a string so that JSONField.from_db_value() can

docs/source/releases/5.1.x.rst

@@ -13,6 +13,9 @@ Django MongoDB Backend 5.1.x
 - Fixed the results of queries that use the ``tzinfo`` parameter of the
   ``Trunc`` database functions.
 - Added support for ``QuerySet.dates()`` and ``datetimes()``.
+- Fixed loading of ``QuerySet`` results for embedded models that have fields
+  that use database converters. For example, a crash for ``DecimalField``:
+  ``ValidationError: ['“1” value must be a decimal number.']``).
 
 .. _django-mongodb-backend-5.1.0-beta-2:
 

tests/model_fields_/models.py

@@ -104,6 +104,12 @@ class Data(EmbeddedModel):
     auto_now = models.DateTimeField(auto_now=True)
     auto_now_add = models.DateTimeField(auto_now_add=True)
     json_value = models.JSONField()
+    decimal = models.DecimalField(max_digits=9, decimal_places="2", null=True, blank=True)
+    nested_data = EmbeddedModelField("NestedData", null=True, blank=True)
+
+
+class NestedData(EmbeddedModel):
+    decimal = models.DecimalField(max_digits=9, decimal_places="2", null=True, blank=True)
 
 
 class Address(EmbeddedModel):

tests/model_fields_/test_embedded_model.py

@@ -24,6 +24,7 @@
     Data,
     Holder,
     Library,
+    NestedData,
 )
 from .utils import truncate_ms
 
@@ -93,7 +94,16 @@ def test_pre_save(self):
 class QueryingTests(TestCase):
     @classmethod
     def setUpTestData(cls):
-        cls.objs = [Holder.objects.create(data=Data(integer=x)) for x in range(6)]
+        cls.objs = [
+            Holder.objects.create(
+                data=Data(
+                    integer=x,
+                    decimal=f"{x}.5",
+                    nested_data=NestedData(decimal=f"{x}.5"),
+                )
+            )
+            for x in range(6)
+        ]
 
     def test_exact(self):
         self.assertCountEqual(Holder.objects.filter(data__integer=3), [self.objs[3]])
@@ -113,6 +123,19 @@ def test_gte(self):
     def test_range(self):
         self.assertCountEqual(Holder.objects.filter(data__integer__range=(2, 4)), self.objs[2:5])
 
+    def test_exact_decimal(self):
+        # EmbeddedModelField lookups call
+        # DatabaseOperations.adapt__<foo>field_value().
+        self.assertCountEqual(Holder.objects.filter(data__decimal="3.5"), [self.objs[3]])
+
+    def test_lt_decimal(self):
+        self.assertCountEqual(Holder.objects.filter(data__decimal__lt="3"), self.objs[0:3])
+
+    def test_exact_decimal_nested(self):
+        self.assertCountEqual(
+            Holder.objects.filter(data__nested_data__decimal="3.5"), [self.objs[3]]
+        )
+
     def test_order_by_embedded_field(self):
         qs = Holder.objects.filter(data__integer__gt=3).order_by("-data__integer")
         self.assertSequenceEqual(qs, list(reversed(self.objs[4:])))