如何正确上传图像以形成？

Question

这是我与表单关联的代码：

模型

class Date(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, null=True)
    place = models.ForeignKey('Place', on_delete=models.CASCADE, null=True)
    title = models.CharField(max_length=64, null=True)


class Photo(models.Model):
    date = models.ForeignKey('Date', on_delete=models.CASCADE)
    image = models.ImageField(verbose_name='Photos', upload_to='media/date/photos/')

# form

class DateForm(forms.ModelForm):
    image = forms.ImageField()
    class Meta:
        model = Date
        exclude = ('user',)

# view

class CreateDateView(LoginRequiredMixin, CreateView):
    template_name = 'app/date/form.html'
    form_class = DateForm

    def form_valid(self, form):
        form.instance.user = self.request.user
        form.save() # by the way why do I save this form? Is it okay to save it in 
form_valid method?
        photos = self.request.FILES.getlist('image')
        for photo in photos:
            Photo.objects.create(image=photo)
        return super().form_valid(form)

问题是，如果照片对象需要日期模型id，则如何保存它。它引发NULL约束失败:据我所知，app_photo.date_id必须编写如下内容：

Photo.objects.create(date=date_from_the_form, image=photo)

但是如何从日期模型中得到pk呢？希望你能理解我的问题，如果有任何问题，请在下面的评论部分写下来。提前感谢！

错误

Answer 1

当您调用form.save()时，它返回模型实例，这样您就可以像下面这样从它获得实例

def form_valid(self, form):
    form.instance.user = self.request.user
    date_instance = form.save() 
    photos = self.request.FILES.getlist('image')
    for photo in photos:
       Photo.objects.create(date=date_instance, image=photo)
    return super().form_valid(form)