python - 错误 : "You are trying to add a non-nullable field"

Question

我定义了下面的模型并得到

错误:您正在尝试在没有默认值的情况下向 videodata 添加不可为空的字段“用户”；我们不能这样做

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'

我哪里做错了？？？？

Answer 1

正如错误所说，您在 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>)