错误:"您正在尝试添加不可为空的字段"

Question

我在下面定义了模型和获取

错误: You are trying to add a non-nullable field 'user' to videodata without a default; we can't do that

models.py

class User(Model):
    userID = models.IntegerField()
    userName = models.CharField(max_length=40)
    email = models.EmailField()
    class Meta:
        ordering = ['userName']
        verbose_name = 'User MetaData'
        verbose_name_plural = 'Users MetaData'
    def __unicode__(self):
        return str(self.userName)

class VideoData(Model):
    video = models.CharField(max_length=40)
    time  = models.IntegerField()
    user = models.ForeignKey(User, related_name='User')
    class Meta:
        verbose_name = 'User_Video MetaData'

我做错了哪里????

Answer 1

如错误所示,VideoData上的用户字段不允许空值,因此您需要为其提供默认用户或允许空值.最简单的方法是允许空值.

user = models.ForeignKey(User, related_name='User', null=True)

或者有一个默认用户

user = models.ForeignKey(User, related_name='User', default=<have your default user id here>)

Answer 2

我的OneToOneField遇到了同样的问题.而且,我所做的是删除所有迁移文件(migrations位于您的应用程序下的目录下),并运行:

python manage.py makemigrations

和

python manage.py migrate

我不知道为什么,但它在我的情况下起作用.尝试上面写的内容不会对你造成伤害.

祝好运!