checks.py 文件源码

def _check_raw_id_fields_item(self, obj, model, field_name, label):
        """ Check an item of `raw_id_fields`, i.e. check that field named
        `field_name` exists in model `model` and is a ForeignKey or a
        ManyToManyField. """

        try:
            field = model._meta.get_field(field_name)
        except FieldDoesNotExist:
            return refer_to_missing_field(field=field_name, option=label,
                                          model=model, obj=obj, id='admin.E002')
        else:
            if not isinstance(field, (models.ForeignKey, models.ManyToManyField)):
                return must_be('a ForeignKey or ManyToManyField',
                               option=label, obj=obj, id='admin.E003')
            else:
                return []