Django建表ForeignKey提示错误

TypeError: __init__() missing 1 required positional argument: 'on_delete'

b = models.ForeignKey(to='Business', to_field='id')

此处查询文件，缺少属性 on_delete=models.DO_NOTHING，只需在后面加上即可

b = models.ForeignKey(to='Business', to_field='id',on_delete=models.DO_NOTHING)