保存 ModelForm 时 NOT NULL 约束失败

Question

我是 Django (1.9) 的新手

当我保存我的 ModelForm 时，我有一个 NOT NULL 约束失败，我不明白为什么......

我向用户建议一个表单来 post 评论，表单中包含的唯一字段是 "text"，我想在验证之后和之前在我的视图中设置排除的字段保存在数据库中

Models.py :

class Commentaire(models.Model):
    text = RichTextField()
    pub_date = models.DateTimeField()
    author = models.ForeignKey(User)
    post = models.ForeignKey(Post)
    publish = models.BooleanField()

    def __str__(self):
        return "/%s/%s" % (self.pub_date,self.author.username)

    class Meta:
        ordering = ["-pub_date"]

Forms.py :

class CommentaireForm(forms.ModelForm):
    class Meta:
        model = Commentaire
        fields = ['text']

Views.py :

class PostDetail(View):

    def get(self, request, *args, **kwargs):
        view = PostDisplay.as_view()
        return view(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        view = PostComment.as_view()
        return view(request, *args, **kwargs)

class PostDisplay(DetailView):
    model = Post

    def get_context_data(self, **kwargs):
        context = super(PostDisplay, self).get_context_data(**kwargs)

        context['form'] = CommentaireForm()
        return context

class PostComment(SingleObjectMixin, FormView):
    template_name = 'blogengine/post_detail.html'
    form_class = CommentaireForm
    model = Post

    def post(self, request, *args, **kwargs):
        #if not request.user.is_authenticated():
        #    return HttpResponseForbidden()

        self.object = self.get_object()        
        form = self.get_form()

        if form.is_valid():
            return self.form_valid(form)
        else:
            return self.form_invalid(form)


    def form_valid(self, form):
        """
        If the form is valid, redirect to the supplied URL
        """
        form.save(commit=False)
        form.post = self.object
        form.author = self.request.user
        form.pub_date = datetime.now()
        form.publish = True
        form.save()

        return HttpResponseRedirect(self.get_success_url())

当 Django 保存表单时，出现以下异常：

NOT NULL constraint failed: blogengine_commentaire.pub_date

我在 "form_valid" 中为排除字段（作者，post，pub_date）设置的值未被考虑在内，它们似乎保持为 NULL

你能解释一下为什么我迷路了吗？

谢谢

Answer 1

你需要像那样重写 form_valid 方法

def form_valid(self, form):
    """
    If the form is valid, redirect to the supplied URL
    """
    model_instance = form.save(commit=False)
    model_instance.post = self.object
    model_instance.author = self.request.user
    model_instance.pub_date = datetime.now()
    model_instance.publish = True
    model_instance.save()
    return HttpResponseRedirect(self.get_success_url())

因为 save(commit=False) 会 return 你一个 Post 实例然后你需要填充和保存。

保存 ModelForm 时 NOT NULL 约束失败

NOT NULL constraint failed when save ModelForm

django

modelform