确保你的应用在settings.py中的installed_apps中被提及 确保建模类扩展了模型。模型

我从django外部复制了一个表，Meta类默认为“managed = false”。例如:

class Rssemailsubscription(models.Model):
    id = models.CharField(primary_key=True, max_length=36)
    ...
    area = models.FloatField('Area (Sq. KM)', null=True)

    class Meta:
        managed = False
        db_table = 'RSSEmailSubscription'

通过将managed改为True, makemig开始发生变化。

我这样解决了这个问题:

Erase the "db.sqlite3" file. The issue here is that your current data base will be erased, so you will have to remake it again. Inside the migrations folder of your edited app, erase the last updated file. Remember that the first created file is: "0001_initial.py". For example: I made a new class and register it by the "makemigrations" and "migrate" procedure, now a new file called "0002_auto_etc.py" was created; erase it. Go to the "pycache" folder (inside the migrations folder) and erase the file "0002_auto_etc.pyc". Finally, go to the console and use "python manage.py makemigrations" and "python manage.py migrate".

可能的原因是删除了现有的db文件和migrations文件夹 你可以使用python manage.py makemigrations <app_name>这应该可以工作。我曾经遇到过类似的问题。

对于这个错误，我的问题在于我包含了:

class Meta:
   abstract = True

里面的模型，我想创建迁移。

还有一个非常愚蠢的问题是在模型中定义两个类Meta。在这种情况下，在运行makemigrations时，对第一个的任何更改都不会应用。

class Product(models.Model):
    somefield = models.CharField(max_length=255)
    someotherfield = models.CharField(max_length=255)

    class Meta:
        indexes = [models.Index(fields=["somefield"], name="somefield_idx")]

    def somefunc(self):
        pass

    # Many lines...

    class Meta:
        indexes = [models.Index(fields=["someotherfield"], name="someotherfield_idx")]