带有 if 语句的 url 的 Python Django request.GET.get 方法

Question

我想按学校和类别这两个不同的类别过滤帖子。

models.py

class Category(models.Model):
    name = models.CharField(max_length=100)
    slug = models.SlugField(max_length=100, unique=True)

    class Meta:
        ordering = ('name',)
        verbose_name = 'category'
        verbose_name_plural = 'categories'

    def __str__(self):
        return self.name

class School(models.Model):
    name = models.CharField(max_length=100)
    slug = models.SlugField(max_length=100, unique=True)

    class Meta:
        ordering = ('name',)
        verbose_name = 'school'
        verbose_name_plural = 'schools'

    def __str__(self):
        return self.name


class VideoPost(models.Model):
    category = models.ForeignKey('Category', on_delete=models.CASCADE)
    school = models.ForeignKey('School', on_delete=models.CASCADE)
    title = models.CharField(max_length=100)
    slug = models.SlugField(max_length=100, unique = True)
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    video = models.CharField(max_length=100, blank=True)
    content = RichTextUploadingField()
    image = models.ImageField(upload_to='images', null=True, blank=True)
    date_posted = models.DateTimeField(default=timezone.now)

    def _get_unique_slug(self, *args, **kwargs):
        self.slug = slugify(self.title)
        super(VideoPost, self).save(*args, **kwargs)

    def __unicode__(self):
        return self.title

School 和 Category 是 VideoPost 的外键。因此，在 db 中它只有它的 id，而不是 slug 或名称。是category_id & school_id

views.py

def post_list(request):
    school = request.GET.get('school', None)
    category = request.GET.get('category', None)

    posts = VideoPost.objects.all()

    if school:
        posts.filter(school=school).order_by('-date_posted')

    elif category:
        posts.filter(category=category).order_by('-date_posted')

    elif school & category:
         posts.filter(school=school).filter(category=category).order_by('-date_posted')
    else:
        posts.order_by('-date_posted')

## I wanted to filter them in multiple ways where the posts are filtered by either one of the category, or both, but It doesn't work.
## The only way I found that's working is:

   posts = VideoPost.objects.all().filter(school=school).filter(category=category)
##This way, it filtered the posts with its school and category id specified.

    return render(request, 'stories/browse.html', {'posts': posts})

模板.html

<a href="{% url 'post_list' %}?school=1&category=4">Link</a>

所以，我的问题是

1. 是否可以在数据库中为外键提供文本？这样该 url 可以更具可读性，并且我可以在 url 标签中使用文本。 喜欢<a href="{%url 'post_list' %}?school=MIT&category=sports">Link</a>

2. 如何正确使用带有 IF 语句的 request.GET.get() 方法？

Answer 1

1. 您可以按学校 slug 和类别 slug 过滤VideoPost，您不需要使 slug 字段主键，通常这是一个糟糕的设计。您可以做的是使 slug 字段唯一，这样您就知道没有具有相同 slug 的条目。

2. 请记住，每个应用于 QuerySet 的过滤器都会返回一个新的 QuerySet，因此您可以创建一个 QuerySet 链。

以下代码应按预期工作

school_slug = request.query_params.get('school', None)
category_slug = request.query_params.get('category', None)   

posts = VideoPost.objects.all()

if school:
    # If we have school, filter by school slug
    posts = posts.filter(school__slug=school_slug)
if category:
    # If we have category, filter by category slug
    posts = posts.filter(category__slug=category_slug)

# Always order the posts by date_posted
posts = posts.order_by('-date_posted')

return render(request, 'stories/browse.html', {'posts': posts})

如果 school 和 category 都通过了，那么我们将 2 个过滤器应用于查询集

另外，将来我建议在此用例中使用django-filter。