The QuerySet value for an exact lookup must be limited to one result using slicing-Django

问题

I'm building a news website.While I tried to get the list of relative news which have the same tags.The error said:The QuerySet value for an exact lookup must be limited to one result using slicing-Django.

I have two models News and Tag,Tag is a many to many foreign key of News.

News model:

class News(models.Model):

    tag = models.ManyToManyField(Tag, blank=True, verbose_name='tag')

Tag model:

class Tag(models.Model):

    name = models.CharField(max_length=40)

View:

def newsDetailView(request, news_pk):
    news = get_object_or_404(News, id=news_pk)
    tags = news.tag.annotate(news_count=Count('news'))
    relative_news = News.objects.filter(tag=tags)

    return render(request, "news_detail.html", {
        'news': news,
        'tags': tags,
        'relative_news': relative_news
    })

Any friend can help?Thank you so much!

回答1:

The following will work:

def newsDetailView(request, news_pk):
    news = get_object_or_404(News, id=news_pk)
    relative_news = News.objects.filter(tag__id__in=news.tag.all())

来源：https://stackoverflow.com/questions/50431810/the-queryset-value-for-an-exact-lookup-must-be-limited-to-one-result-using-slici