如何訪問 urls.py 中的外鍵？################models.py...class Category(models.Model):    title = models.CharField(verbose_name='TITLE', max_length=200)    slug = models.SlugField('SLUG', unique=True, allow_unicode=True, help_text='one word for title alias.')    ...    def __str__(self):        return self.titleclass Episode(models.Model):    category = models.ForeignKey("Category", verbose_name=("CATEGORY"), on_delete=models.CASCADE)    number = models.IntegerField()....    meta:    ...    def __str__(self):    ...    def get_absolute_url(self):        return reverse("manga:episode_detail", kwargs={"slug": self.category.slug, "number": self.number})#####################urls.py...    # path('category/<slug:category.slug>/<int:number>', views.EpisodeDetailView.as_view(), name="episode_detail"),]#################views.py...class EpisodeDetailView(DetailView):    model = Episode    template_name = 'manga/episode_detail.html'    context_object_name = 'episode'** **它拋出了“必須使用 URLconf 中的對象 pk 或 slug 來調用通用詳細信息視圖 EpisodeDetailView?！?*我想看情節的細節。但我不能...我嘗試過拋出查詢集，但它不起作用......如何訪問 urls.py 中的外鍵？**  # def get_queryset(self):        # return Episode.objects.filter(category__slug=self.kwargs['lab'])    def get_queryset(self):        employee = Category.objects.get(slug=self.kwargs['slug'])        print(employee)        return Episode.objects.get(category=employee, number=self.kwargs['number'])