Python Django抽象模型南移错误

我有以下型号：

class MemberCategory(BaseModel):

    """
    Contains Predfined Category Types
    """
    title = models.CharField(null=True, blank=True, max_length=100)
    description = models.TextField(null=True, blank=True)
    slug = models.SlugField(null=True, blank=True)

基本模型如下所示：

class BaseModel(models.Model):

    """
    An abstract base class model that provides self-managed "created" and
    "modified" multi tenant fields.
    """
    creation_date = models.DateTimeField(auto_now_add=True)
    modification_date = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

class MemberCategory(BaseModel):

    """
    Contains Predfined Category Types
    """
    title = models.CharField(null=True, blank=True, max_length=100)
    description = models.TextField(null=True, blank=True)
    slug = models.SlugField(null=True, blank=True)
    orgs = models.ForeignKey(Org, null=True, blank=True)

现在，我在我的MemberCategory中添加一个字段

org

，这样新模型如下所示：

class BaseModel(models.Model):

    """
    An abstract base class model that provides self-managed "created" and
    "modified" multi tenant fields.
    """
    creation_date = models.DateTimeField(auto_now_add=True)
    modification_date = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

class MemberCategory(BaseModel):

    """
    Contains Predfined Category Types
    """
    title = models.CharField(null=True, blank=True, max_length=100)
    description = models.TextField(null=True, blank=True)
    slug = models.SlugField(null=True, blank=True)
    orgs = models.ForeignKey(Org, null=True, blank=True)

在此之后，我执行-

python manage.py模式迁移--auto

无错误，一切正常

然后我执行

python manage.py migrate

，这会引发以下错误-

KeyError: u'creation_date'

---

有什么原因导致我出现这个错误吗？

只是为了确定一下。您第一次使用python manage.py模式迁移了吗？只有当数据库中已经存在表时，--auto选项才起作用。是否有可能在粘贴箱中删除最后两次迁移？