提交喜欢按钮后表格没有更新

Question

在单击后提交按钮时，就像创建对象成功一样，但是像字段正在更新为空值，而django则收到错误302。有人可以帮我这个忙。

编辑后

我已经从 SongVoteUpdateView 中删除了 form_valid 函数，现在更新部分工作正常，但是如果我从 SongVoteCreatView中删除了 form_valid 函数， / strong>会引发类似NOT NULL constraint failed: album_vote.song_id的虚假错误。 For trace back please refer this link，如果未删除，将创建空白的空白对象。

models.py

models.py中的代码

class VoteManager(models.Manager):
    def get_vote_or_unsaved_blank_vote(self,song,user):
        try:
            return Vote.objects.get(song=song,user=user)

        except ObjectDoesNotExist:
            return Vote(song=song,user=user)

class Vote(models.Model):
    UP = 1
    DOWN = -1
    VALUE_CHOICE = ((UP, "?️"),(DOWN, "?️"),)


    like = models.SmallIntegerField(null=True, blank=True, choices=VALUE_CHOICE)
    user = models.ForeignKey(User,on_delete=models.CASCADE)
    song = models.ForeignKey(Song, on_delete=models.CASCADE)
    voted_on = models.DateTimeField(auto_now=True)

    objects = VoteManager()

    class Meta:
        unique_together = ('user', 'song')

views.py

views.py中的代码

class SongDetailView(DetailView):
    model = Song
    template_name = 'song/song_detail.html'

    def get_context_data(self,**kwargs):
        ctx = super().get_context_data(**kwargs)
        if self.request.user.is_authenticated:
           vote = Vote.objects.get_vote_or_unsaved_blank_vote(song=self.object, user = self.request.user)
            if vote.id:
                vote_url = reverse('music:song_vote_update', kwargs={'song_id':vote.song.id,'pk':vote.id}) #'pk':vote.id
            else:
                vote_url = reverse('music:song_vote_create', kwargs={'song_id':vote.song.id})

            vote_form = SongVoteForm(instance=vote)
            ctx['vote_form'] = vote_form
            ctx['vote_url'] = vote_url
        return ctx

class SongVoteCreateView(CreateView):
    form_class = SongVoteForm
    model = Vote

    def get_success_url(self,**kwargs):
        song_id = self.kwargs.get('song_id')
        return reverse('music:song_detail', kwargs={'pk':song_id})

    def form_valid(self, form):
        user = self.request.user
        song_obj = Song.objects.get(pk=self.kwargs['song_id'])
        vote_obj, created = Vote.objects.get_or_create(song = song_obj, user = user) 
        form.instance = vote_obj
        return super(SongVoteCreateView).form_valid(form)

class SongUpdateVoteView(UpdateView):
    form_class = SongVoteForm
    model = Vote

    # def form_valid(self, form):
#     user = self.request.user
#     song_obj = Song.objects.get(pk=self.kwargs['song_id'])
#     vote_obj, created = Vote.objects.get_or_create(song = song_obj, user = user) 
#     form.instance = vote_obj
#     print(form)
#     return super().form_valid(form)

    def get_success_url(self):
        song_id = self.kwargs.get('song_id')
        return reverse('music:song_detail', kwargs={'pk':song_id})

urls.py

网址映射

    path('album/song/<int:pk>/',views.SongDetailView.as_view(), name='song_detail'),
    path('album/song/create/<int:song_id>/',views.SongVoteCreateView.as_view(), name='song_vote_create'),
    path('album/song/update/<int:song_id>/<int:pk>/', views.SongUpdateView.as_view(), name='song_vote_update')

song_detail.html

html页面中的代码

 <div>
     <form action="{{vote_url}}" method="post" enctype="multipart/form-data">
            {% csrf_token %}
            {{ vote_form.as_p }}
            <button class="btn btn-primary" type="submit" >Vote</button>
     </form>
 </div>

forms.py

forms.py中的代码

class SongVoteForm(forms.ModelForm):
    like = forms.ChoiceField(widget=forms.RadioSelect,choices=Vote.VALUE_CHOICE)

    class Meta:
        model = Vote
        fields = ['like',]

错误代码

响应进入控制台。

[31/Oct/2019 04:15:19] "GET /album/song/1/ HTTP/1.1" 200 3560
**[31/Oct/2019 04:15:21] "POST /album/song/update/1/8/ HTTP/1.1" 302 0**
[31/Oct/2019 04:15:21] "GET /album/song/1/ HTTP/1.1" 200 3560

Answer 1

我已经在SongVoteCreateView中的form_valid中明确提到过，如下所示。现在，表单不再创建空白对象，而是重定向到正确的页面。

def form_valid(self, form):
        like = form.cleaned_data.get('like')
        user = self.request.user
        song_obj = Song.objects.get(pk=self.kwargs['song_id'])
        vote_obj, created = Vote.objects.get_or_create(song = song_obj, user = user, like=like) 
        form.instance = vote_obj
        return super().form_valid(form)