在子类unique_together元选项中使用基类字段时出错

Using the following code:

使用以下代码：

class Organization(models.Model):
    name = models.CharField(max_length="100",)
    alias = models.SlugField()
    ...

class Division(Organization):
    parent_org = models.ForeignKey(Organization)

    class Meta:
        unique_together=['parent_org', 'alias']
        ...
class Org