用石墨烯Django计算喜欢

Question

我正在尝试用graphene django制作一个字段，以便能够计算出我在每篇文章中得到的喜欢的总数，我该如何做，我尝试做的如下

class PostType(DjangoObjectType):
    class Meta:
        model = Post

    likes = graphene.List()

    def resolve_count_like(self, info, id):
        post_id = Post.objects.filter(id=id)
        n = Likes.objects.filter(post_id=post_id)
        return len(n)

Answer 1

可以使用根目录访问当前对象的属性，因此您无需手动传递帖子id。请尝试以下操作：

class PostType(DjangoObjectType):
    class Meta:
        model = Post

    likes = graphene.List()
    count_like = graphene.Int()

    def resolve_count_like(self, root, info, **kwargs):
        return Likes.objects.filter(post_id=root.id).count()

通过在查询集上链接count()，可以跳过通过len检查长度。这将更快，因为查询执行SELECT COUNT(*)