小编Dom*_*nik的帖子

我有两个型号。当我尝试删除联系人时收到错误

Exception Value:    

("Cannot delete some instances of model 'GuestContact' because they are referenced through a protected foreign key: 'Reservation.res_company'", <QuerySet [<Reservation: Reservation object>, <Reservation: Reservation object>]>)

我不想看到 django 错误页面。我要发送信息“该记录无法删除，但该联系人已用于预订”

你能帮助我吗 ？

问候

模型：

class MyModel(model.Models)
   status = models.ForeignKey(Statuses, on_delete=models.PROTECT, null=True, blank=True)

观看次数：

class MyViewCreate(CreateView):
    model = MyModel
    form_class = MyFrom
    template_name = 'mymodel_form.html'

形式：

class MyForm(ModelForm):

    class Meta:
        model = MyModel
        fields = '__all__'

我如何在表单中设置选项列表上的默认值或第一个值>