如何在石墨烯烧瓶中进行多个查询过滤器？

Posted 2023-03-08

【中文标题】如何在石墨烯烧瓶中进行多个查询过滤器？

【英文标题】：How to make multiple queries filters in graphene flask?

【发布时间】：2018-07-08 01:30:44

【问题描述】：

我是 GraphQL 的新手，我正在尝试进行这样的查询

   user(username: "Jon")  
     name
     last_lame
     username
     posts(in_draft : true)  
       title
       text
       in_draft
       update_at      
     
   

我想过滤用户在草稿中的帖子列表

我可以进行查询的唯一方法是通过模型的关系，但无法过滤草稿中的帖子。 一对多

class User(Base):
  __tablename__ = 'user'
  id = Column(Integer, primary_key=True)
  name = Column(String)
  last_lame = Column(String)
  username = Column(String)


class Post(Base):
  __tablename__ = 'post'
  id = Column(Integer, primary_key=True)
  title = Column(String)
  text = Column(String)
  in_draft = Column(Boolean) 
  post_id = Column(Integer, ForeignKey('user.id'))

  posts = relationship("User", backref='posts')

有了这种关系，我用“backref = 'posts'”显示帖子节点

我的对象：

class User(SQLAlchemyObjectType):
  """User Object."""
  class Meta:
    model = UserModel
    interfaces = (relay.Node, )


class Post(SQLAlchemyObjectType):
  """Post Object."""
   class Meta:
      model = PostModel
      # interfaces = (relay.Node, )

查询：

class Query(graphene.ObjectType):

    user = graphene.Field(lambda: User, username=graphene.String())
    def resolve_user(self, info, username):
       query = User.get_query(info)
       return query.filter(UserModel.username == username).first()

我想让帖子的查询属于用户

   posts = graphene.List(lambda: Post, in_draft=graphene.Boolean())
   def resolve_posts(self, info, in_draft):
      query = Post.get_query(info)
      return query.filter(PostModel.in_draft == in_draft).all()

schema = graphene.Schema(
   query=Query,
   types=[User, Post])

有什么想法或建议吗？

【参考方案1】：

老实说，鉴于 User 和 Post 之间的关系已经定义，我将创建一个解析器来让这些组合结果同时传递两个参数，如下所示：

class Query(graphene.ObjectType):
    filter_user_posts = graphene.List(
        lambda: User,
        username=graphene.String,
        in_draft=graphene.Boolean,
    )
    def resolve_filter_user_posts(
        self, info, username, in_draft
    ):
        query = User.get_query(info=info)
        query = query.join(User.posts)
        query = query.filter(User.username == username)
        query = query.filter(Post.in_draft == in_draft)

        objs = query.all()

        return objs

然后您可以像这样简单地查询：

 filterUserPosts(username: "Jon", in_draft: true)  
   name
   last_lame
   username
   posts 
     title
     text
     in_draft
     update_at      
   
 

【讨论】：

对我有用，但需要进行一点更正或澄清。在 filter_user_posts 。该行应该是 username=graphene.String()。字符串是一个类