獲取類別的最新日誌

Question

我試圖在我的論壇應用程序中獲取每個類別的最新帖子。我一直在嘗試諸如Category.objects.order_by('catID').annotate(latestpost=Post.objects.order_by('-pub_date')[:1]) 我希望能夠在我的模板中使用值：postID，title，user和pub_date。

models.py：

class Category(models.Model): 
    catID = models.CharField(max_length=20, primary_key=True) 
    title = models.CharField(max_length=200) 
    description = models.CharField(max_length=200) 

class Post(models.Model): 
    postID = models.CharField(max_length=10, primary_key=True) 
    catID = models.ForeignKey(Category) 
    user = models.CharField(max_length=100) 
    title = models.CharField(max_length=200) 
    content = models.TextField() 
    pub_date = models.DateTimeField(auto_now=True) 

views.py：

def index(request): 
    cats = Category.objects.order_by('catID').annotate(latestpost=Post.objects.order_by('-pub_date')[:1]) 
    context = {'forum_cats': cats} 
    return render(request, 'forums/index.html', context) 

Answer 1

一種方法是

class Category(models.Model): 
    catID = models.CharField(max_length=20, primary_key=True) 
    title = models.CharField(max_length=200) 
    description = models.CharField(max_length=200) 

    def latest_post(self): 
     post = self.post_set.order_by('-pub_date') 
     if post: 
      return post[0] 
     return None 

，並在模板中，

{% for cat in forum_cats %} 
    {% if cat.latest_post %} 
     {{cat.latest_post.title}} 
    {% endif %} 
{% endfor %}