def update(self, instance, validated_data):
raise_errors_on_nested_writes('update', self, validated_data)
ModelClass = self.Meta.model
relations = model_meta.get_relations_data(ModelClass, validated_data)
# Generate filter for getting existing object once more. Earlier,
# We generate query to the database, because we can get relationship
# objects, which attached to the existing object. But can't use this
# instance further. To avoid issues with it, just get object once more
filter_args = (getattr(ModelClass, field) == getattr(instance, field)
for field in model_meta.model_pk(ModelClass))
# Simply set each attribute on the instance, and then save it.
# Note that unlike `.create()` we don't need to treat many-to-many
# relationships as being a special case. During updates we already
# have an instance pk for the relationships to be associated with
session = settings.SQLALCHEMY_SESSION(expire_on_commit=False)
try:
instance = session.query(ModelClass).filter(*filter_args).first()
if not instance:
raise ValidationError("Object does not exist.")
for field_name, value in validated_data.items():
setattr(instance, field_name, value)
# Update relation objects
if relations:
session.enable_relationship_loading(instance)
for field_name, value in relations.items():
setattr(instance, field_name, [])
session.refresh(instance)
if value:
setattr(instance, field_name, value)
session.commit()
finally:
session.close()
return instance
def test_model_pk_from_model_with_composite_pk(self):
self.assertEqual(
set(model_pk(self.TestModelPkWithCompositePkModel)),
{'id', 'username'}
)
def test_model_pk_from_model_with_one_pk(self):
self.assertEqual(
set(model_pk(self.TestModelPkWithSinglePkModel)),
{'id', }
)
def test_model_pk_from_model_with_composite_pk(self):
self.assertEqual(set(model_pk(self.TestModelPkWithCompositePkModel)),
{'id', 'username'})
def test_model_pk_from_model_with_one_pk(self):
self.assertEqual(set(model_pk(self.TestModelPkWithSinglePkModel)), {
'id',
})
def _get_object_pk(self, obj):
mapper = obj.__mapper__
model = mapper.class_
pk_fields = model_pk(model)
data = {str(field): getattr(obj, field) for field in pk_fields}
return data if len(pk_fields) > 1 else data[pk_fields[0]]
def _get_filter_args(self, query, data):
mapper = query._bind_mapper()
model = mapper.class_
pk_fields = model_pk(model)
return (getattr(model, field) == data[field] for field in pk_fields)
def _get_object_pk(self, obj):
mapper = obj.__mapper__
model = mapper.class_
pk_fields = model_pk(model)
data = {str(field): getattr(obj, field) for field in pk_fields}
return data if len(pk_fields) > 1 else data[pk_fields[0]]
def _get_filter_args(self, query, data):
mapper = query._bind_mapper()
model = mapper.class_
pk_fields = model_pk(model)
return (getattr(model, field) == data[field] for field in pk_fields)