如何在 Django 上使用查询集进行搜索

Question

我有主题模型和 Post 模型。

我想使用查询集进行搜索。当 q 有字符串时它工作得很好，但是当 q = '' （这意味着 All ）它不显示所有 post.

我该如何解决这个问题？

models.py

class Topic(models.Model):
    name = models.CharField(max_length=200)

    def __str__(self):
        return self.name


class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(default=timezone.now)
    author = models.ForeignKey(User,on_delete=models.CASCADE)
    topic = models.ForeignKey(Topic,on_delete=models.SET_NULL,null=True)

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('post-detail',kwargs={'pk':self.pk})

views.py

class PostListView(ListView):
    model = Post
    template_name = 'blog/home.html'
    context_object_name = 'posts'
    ordering = ['-date_posted']
    paginate_by = 5

    def get_context_data(self, **kwargs):
        context = super(PostListView, self).get_context_data(**kwargs)
        context["topics"] = Topic.objects.all() 
        return context

    def get_queryset(self):
        if self.request.GET.get('q') != None:
            q = self.request.GET.get('q')
        else:
            q = ''
        # q = self.request.GET.get('q') if self.request.GET.get('q') != None else ''
        
        return Post.objects.filter(topic__name__icontains=q).order_by('-date_posted')

Answer 1

你检查真实性 return Post.objects.none() 以防 q 真实 False:

def get_queryset(self):
    q = self.request.GET.get('q')
    if q:
        return Post.objects.filter(topic__name__icontains=q).order_by('-date_posted')
    else:
        return Post.objects<strong>.none()</strong>

Answer 2

也许可以将 PostListView 中的 get_queryset 方法更改为：

def get_queryset(self):
    q_param = self.request.GET.get('q')

    if q_param:
        return Post.objects.filter(topic__name__icontains=q_param).order_by('-date_posted')

    # if q is empty this will return all objects
    return Post.objects.all().order_by('-date_posted')

解决了您的问题。

Answer 3

试试这个

        q = request.GET.get('search')
        if q is not None and q != u"":
            q = request.GET.get('search')
            Post.objects.filter(topic__name__icontains=q).order_by('date_posted')
        else: 
            Post.objects.all().order_by('date_posted')

如何在 Django 上使用查询集进行搜索

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