fixes bug with custom fields in _identifiers

nautobot_ssot/contrib.py

@@ -280,8 +280,25 @@ def _check_field(cls, name):
             raise ValueError(f"Field {name} is not defined on the model.")
 
     def get_from_db(self):
-        """Get the ORM object for this diffsync object from the database using the identifiers."""
-        return self._model.objects.get(**self.get_identifiers())
+        """Get the ORM object for this diffsync object from the database using the identifiers.
+
+        TODO: Currently this does not support many to many relationships.
+        """
+        parameters = {}
+        custom_field_lookup = {}
+        type_hints = get_type_hints(self, include_extras=True)
+        is_custom_field = False
+        for key, value in self.get_identifiers().items():
+            metadata_for_this_field = getattr(type_hints[key], "__metadata__", [])
+            for metadata in metadata_for_this_field:
+                if isinstance(metadata, CustomFieldAnnotation):
+                    custom_field_lookup[metadata.name] = value
+                    is_custom_field = True
+            if not is_custom_field:
+                parameters[key] = value
+        if custom_field_lookup:
+            parameters["_custom_field_data__contains"] = custom_field_lookup
+        return self._model.objects.get(**parameters)
 
     def update(self, attrs):
         """Update the ORM object corresponding to this diffsync object."""

nautobot_ssot/tests/test_contrib.py

@@ -387,11 +387,34 @@ def test_basic_deletion(self):
 class BaseModelCustomFieldTest(TestCase):
     """Test for manipulating custom field content through the shared case model code."""
 
+    @classmethod
+    def setUpTestData(cls):
+        cls.custom_field_name = "Is Global"
+        cls.custom_field = CustomField.objects.create(
+            key=cls.custom_field_name, label=cls.custom_field_name, type="boolean"
+        )
+        cls.custom_field.content_types.set([ContentType.objects.get_for_model(Provider)])
+
+    def test_custom_field_get(self):
+        """Test whether loading a model with a custom field set as the identifier works."""
+
+        class ProviderModel(NautobotModel):
+            """Test model for testing custom field functionality."""
+
+            _model = Provider
+            _identifiers = (
+                "name",
+                "is_global",
+            )
+
+            name: str
+            is_global: Annotated[bool, CustomFieldAnnotation(name="Is Global")] = False
+
+        provider = Provider.objects.create(name="Test", _custom_field_data={"Is Global": True})
+        self.assertEqual(provider, ProviderModel(name="Test", is_global=True).get_from_db())
+
     def test_custom_field_set(self):
         """Test whether setting a custom field value works."""
-        custom_field_name = "Is Global"
-        custom_field = CustomField.objects.create(key=custom_field_name, label=custom_field_name, type="boolean")
-        custom_field.content_types.set([ContentType.objects.get_for_model(Provider)])
 
         class ProviderModel(NautobotModel):
             """Test model for testing custom field functionality."""
@@ -402,7 +425,7 @@ class ProviderModel(NautobotModel):
 
             name: str
 
-            is_global: Annotated[bool, CustomFieldAnnotation(name=custom_field_name)] = False
+            is_global: Annotated[bool, CustomFieldAnnotation(name="Is Global")] = False
 
         provider_name = "Test Provider"
         provider = Provider.objects.create(name=provider_name)
@@ -413,7 +436,7 @@ class ProviderModel(NautobotModel):
 
         provider.refresh_from_db()
         self.assertEqual(
-            provider.cf[custom_field_name],
+            provider.cf[self.custom_field_name],
             updated_custom_field_value,
             "Setting a custom field through 'NautobotModel' does not work.",
         )