Method save_deferred_fields

django/core/serializers/base.py:303–328

(self, using=None)

        self.m2m_data = None

    def save_deferred_fields(self, using=None):
        self.m2m_data = {}
        for field, field_value in self.deferred_fields.items():
            opts = self.object._meta
            label = opts.app_label + "." + opts.model_name
            if isinstance(field.remote_field, models.ManyToManyRel):
                try:
                    values = deserialize_m2m_values(
                        field, field_value, using, handle_forward_references=False
                    )
                except M2MDeserializationError as e:
                    raise DeserializationError.WithData(
                        e.original_exc, label, self.object.pk, e.pk
                    )
                self.m2m_data[field.name] = values
            elif isinstance(field.remote_field, models.ManyToOneRel):
                try:
                    value = deserialize_fk_value(
                        field, field_value, using, handle_forward_references=False
                    )
                except Exception as e:
                    raise DeserializationError.WithData(
                        e, label, self.object.pk, field_value
                    )
                setattr(self.object, field.attname, value)
        self.save()


def build_instance(Model, data, db):