石墨烯突变未映射 SQLAlchemy 中的模型

Posted 2023-03-08

【中文标题】石墨烯突变未映射 SQLAlchemy 中的模型

【英文标题】：Graphene mutation not mapping Models in SQL Alchemy

【发布时间】：2017-08-25 14:41:09

【问题描述】：

我正在尝试对使用 SQL ALCHEMY 声明的用户模型执行突变。 这是我的 models.py 文件的代码

# blog/models.py
from sqlalchemy import *
from sqlalchemy.orm import (scoped_session, sessionmaker, relationship,
                            backref)
from sqlalchemy.ext.declarative import declarative_base    
engine = create_engine('sqlite:///database.sqlite3', convert_unicode=True)
db_session = scoped_session(sessionmaker(autocommit=False,
                                         autoflush=False,
                                         bind=engine))
Base = declarative_base()
# We will need this for querying
Base.query = db_session.query_property()

class User(Base):
    __tablename__ = 'user'
    id = Column(Integer, primary_key= True)
    name = Column(String)
    email = Column(String)
    posts = relationship("Post", backref="user")

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

这是 Schema.py 文件

import graphene
from graphene import relay
from graphene_sqlalchemy import SQLAlchemyObjectType, SQLAlchemyConnectionField
from models import db_session,User as UserModel, Post as PostModel
from sqlalchemy import *

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

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

class CreateUser(graphene.Mutation):
    class Input:
        name = graphene.String()

    ok = graphene.Boolean()
    user = graphene.Field(User)

    @classmethod
    def mutate(cls, instance, args, context, info):
        new_user = User(name=args.get('name'))

        db_session.add(new_user)
        db_session.commit()
        ok = True
        return CreateUser(user=new_user, ok=ok)

class Query(graphene.ObjectType):
    node = relay.Node.Field()
    user = relay.Node.Field(User)
    allUsers = SQLAlchemyConnectionField(User)

class MyMutations(graphene.ObjectType):
    create_user = CreateUser.Field()

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

当我尝试执行以下突变时，这是我得到的错误：

--Query--
    mutation Test
      createUser(name:"tess")
        ok
        user
          name
        
      
    

    --Result--
    
      "errors": [
        
          "message": "Class 'schema2.User' is not mapped",
          "locations": [
            
              "line": 2,
              "column": 3
            
          ]
        
      ],
      "data": 
        "createUser": null
      
    

【参考方案1】：

您正在尝试使用错误的类创建用户。当您调用 User(name=args.get('name'))

行时，您的意思似乎是 UserModel

错误是正确的，SQLAlchemyObjectType 用户未映射，您作为 UserModel 导入的模型用户是。

【讨论】：

谢谢，我真的很想念。花了几个小时找出问题所在。