class Entry(models.Model):
    
    #引用数据库中的另一条记录
    topic = models.ForeignKey(Topic)
    text = models.TextField()
    date_added = models.DateTimeField(auto_now_add = True)

    class Mate:
        verbose_name_plural = 'entries'

        def __str__(self):

            #返回模型的字符串表示

            return self.text[:50]+"..."

上面是最初的代码，指定一个外键时 ，进行迁移时报错：TypeError: ForeignKey.__init__() missing 1 required positional argument: 'on_delete'

即 外键 丢失了一个需要的位置参数“on_delete”

解决办法： topic = models.ForeignKey(Topic,on_delete=models.CASCADE)

具体原因请查看下面的博客：

(100条消息) model.ForeignKey() TypeError: __init__() missing 1 required positional argument: 'on_delete'_再努力一点吧-CSDN博客https://blog.csdn.net/weixin_43424969/article/details/84478669