Fixed #17602 -- Stopped the XML serializer from doing unneeded queries. Thanks, gnosek. (62efdcb0) · Commits · Dom Sekotill / django

django/core/serializers/python.py

+6 −12

Original line number	Diff line number	Diff line
		@@ -45,18 +45,12 @@ class Serializer(base.Serializer):
		self._current[field.name] = field.value_to_string(obj)

		def handle_fk_field(self, obj, field):
		if self.use_natural_keys and hasattr(field.rel.to, 'natural_key'):
		related = getattr(obj, field.name)
		if related is not None:
		if self.use_natural_keys and hasattr(related, 'natural_key'):
		related = related.natural_key()
		else:
		if field.rel.field_name == related._meta.pk.name:
		# Related to remote object via primary key
		related = related._get_pk_val()
		value = related.natural_key()
		else:
		# Related to remote object via other field
		related = smart_unicode(getattr(related, field.rel.field_name), strings_only=True)
		self._current[field.name] = related
		value = getattr(obj, field.get_attname())
		self._current[field.name] = value

		def handle_m2m_field(self, obj, field):
		if field.rel.through._meta.auto_created:

+5 −10

Original line number	Diff line number	Diff line
		@@ -85,9 +85,10 @@ class Serializer(base.Serializer):
		differently from regular fields).
		"""
		self._start_relational_field(field)
		related_att = getattr(obj, field.get_attname())
		if related_att is not None:
		if self.use_natural_keys and hasattr(field.rel.to, 'natural_key'):
		related = getattr(obj, field.name)
		if related is not None:
		if self.use_natural_keys and hasattr(related, 'natural_key'):
		# If related object has a natural key, use it
		related = related.natural_key()
		# Iterable natural keys are rolled out as subelements
		@@ -96,13 +97,7 @@ class Serializer(base.Serializer):
		self.xml.characters(smart_unicode(key_value))
		self.xml.endElement("natural")
		else:
		if field.rel.field_name == related._meta.pk.name:
		# Related to remote object via primary key
		related = related._get_pk_val()
		else:
		# Related to remote object via other field
		related = getattr(related, field.rel.field_name)
		self.xml.characters(smart_unicode(related))
		self.xml.characters(smart_unicode(related_att))
		else:
		self.xml.addQuickElement("None")
		self.xml.endElement("field")

+13 −0

Original line number	Diff line number	Diff line
		@@ -178,6 +178,19 @@ class SerializersTestBase(object):
		mv_obj = obj_list[0].object
		self.assertEqual(mv_obj.title, movie_title)

		def test_serialize_superfluous_queries(self):
		"""Ensure no superfluous queries are made when serializing ForeignKeys

		#17602
		"""
		ac = Actor(name='Actor name')
		ac.save()
		mv = Movie(title='Movie title', actor_id=ac.pk)
		mv.save()

		with self.assertNumQueries(0):
		serial_str = serializers.serialize(self.serializer_name, [mv])

		def test_serialize_with_null_pk(self):
		"""
		Tests that serialized data with no primary key results