问无法查询类型\“突变”上的字段\“addWorkout”
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Stack Overflow用户

提问于 2020-02-16 07:52:52

回答 1查看 2.8K关注 0票数 0

我对GraphQL相当陌生，我之前的问题是关于我得到的一些参考错误，但是我最终解决了，但是现在我得到了这个错误。似乎我不能添加一个锻炼，因为它不认识到它是模式中的一个突变字段。

我一直在犯错误

Cannot query field \"addWorkout\" on type \"Mutation\

总之，在app.js上，这是我的代码

const express = require("express")
const app = express();
const userSchema = require("./graph-schema/userQueries")
const workoutSchema = require("./graph-schema/workoutQueries")
const mealSchema = require("./graph-schema/mealQueries")
const mongoose = require("mongoose")
const {mergeSchemas} = require("graphql-tools")

//connect to mongoDB atlase database
mongoose.connect("mongodb+srv://Zubair97:superman2008@cluster0-epauj.mongodb.net/test?retryWrites=true&w=majority")
mongoose.connection.once("open", () => {
    console.log("Connected to database")
})

const combinedSchemas = mergeSchemas({
    schemas: [
        userSchema,
        mealSchema,
        workoutSchema
    ],
})




//this module allows express to communicate with graphql ;
//we use it as a single endpoint
const graphqlHTTP = require("express-graphql")

app.use("/graphql" , graphqlHTTP({
    schema: combinedSchemas,
    graphiql: true


}))


app.listen(4000, () => {
    console.log(`Listening on port 4000`)
})

在我导出的名为workoutQueries.js的文件中定义了锻炼查询和突变，您可以看到我在解析器中定义了addWorkout。

const graphql = require("graphql")
const {WorkoutType} = require("./schema")
const Workout = require("../models/Workout.js")
const {GraphQLObjectType, GraphQLID, GraphQLString, GraphQLSchema, GraphQLInt, GraphQLList} = graphql;

const WorkoutQuery = new GraphQLObjectType({
    name: "WorkoutQuery",
    fields: () => ({
        workout: {
            type: WorkoutType,
            args: {id: {type: GraphQLID}},
            resolve(parent, args){
                //returns the workout instance from the database
                return Workout.findById(args.id)
            }

        },

        workouts: {
            type: new GraphQLList(WorkoutType),
            resolve(parent, args){
                //returns all workouts from the databse
                return Workout.find({})
            }
        }
    })

})

const WorkoutMutation = new GraphQLObjectType({
    name: "WorkoutMutation",
    addWorkout: {
        type: WorkoutType,
        args: {
            name: {type: GraphQLString},
            reps: {type: GraphQLInt},
            sets: {type: GraphQLInt},
            burnedCalories: {type: GraphQLInt},
            userId: {type: GraphQLID},

        },
        resolve(parent, args){
            let workout = new Workout({
                name: args.name,
                reps: args.reps,
                sets: args.sets,
                burnedCalories: args.burnedCalories,
                userId: args.userId
            })

            return workout.save();
        }
    },

})

module.exports = new GraphQLSchema({
    query: WorkoutQuery,
    mutation: WorkoutMutation
})

此外，即使我尝试添加一顿饭，查询和突变也会发生在一个名为mealQueries.js的文件中，我已经导出了该文件。

const graphql = require("graphql")
const {MealType, NutritionType} = require("./schema")
const Meal = require("../models/Meal.js")
const {GraphQLObjectType, GraphQLID, GraphQLString, GraphQLSchema, GraphQLInt, GraphQLList} = graphql;

const MealQuery = new GraphQLObjectType({
    name: "MealQueries",
    fields: () => ({
        meal: {
            type: MealType,
            args: {id: {type: GraphQLID}},
            resolve(parent, args){
                return Meal.findById(args.id)
            }
        },

        meals: {
            type: new GraphQLList(MealType),
            resolve(parent, args){
                return Meal.find({})
            }
        }

    })

})

const MealMutation = new GraphQLObjectType({
    name: "MealMutation",
    addMeal: {
        type: MealType,
        args: {
            name: {type: GraphQLString},
            servings: {type: GraphQLInt},
            calories: {type: GraphQLInt},
            nutrition: {type: NutritionType},
            userId: {type: GraphQLID}
        },
        resolve(parent, args){

            let meal = new Meal({
                userId: args.userId,
                name: args.name,
                servings: args.servings,
                calories: args.calories,
                nutrition: {
                    carbohydrates: args.nutrition.carbohydrates,
                    fats: args.nutrition.fats,
                    proteins: args.nutrition.proteins
                }
            })

            return meal.save();
        }
    }

})

module.exports = new GraphQLSchema({
    query: MealQuery,
    mutation: MealMutation
})

在创建用户和对用户进行身份验证时，我没有问题，在userQueries.js中定义的用户查询和变异是没有问题的。

const graphql = require("graphql")
const User = require("../models/User.js")
const bcrypt = require("bcrypt")
const jwt = require("jsonwebtoken")
const {AuthType, UserType} = require("./schema")
const {GraphQLObjectType, GraphQLID, GraphQLString, GraphQLSchema, GraphQLInt, GraphQLList} = graphql;


const UserQuery = new GraphQLObjectType({
    name: "UserQuery",
    fields: () => ({
        user: {
            type: UserType,
            args: {id: {type: GraphQLID}},
            resolve(parent, args){
                //returns the user from the database
                return User.findById(args.id)
            }
        },
        login: {
            type: AuthType,
            args: {email: {type: GraphQLString}, password: {type: GraphQLString}},
            resolve(parent, {email, password}){
                return User.findOne({email: email}).then((user) => {
                    const isEqual = bcrypt.compare(password, user.password)
                    if (!isEqual) {
                        throw new Error('Password is incorrect!');
                    }

                    const token = jwt.sign({
                        userId: user.id,
                        email: user.email},
                        "a_super_secret",
                        {expiresIn: "1h"}
                    )

                    return {token: token, userId: user.id}


                })

            }
        }


    })


})



const UserMutation = new GraphQLObjectType({
    name: "Mutation",
    fields: {
        addUser: {
            type: UserType,
            args: {
                name: {type: GraphQLString},
                email: {type: GraphQLString},
                password: {type: GraphQLString}
            },
            async resolve(parent, args){
                const existingUser =  await User.findOne({email: args.email})
                if (!existingUser){
                    const error = new Error("User already exists");
                }

                const encryptedPassword =  await bcrypt.hash(args.password, 12)

                let user = new User({
                    name: args.name,
                    email: args.email,
                    password: encryptedPassword
                })

                const createdUser =  user.save();
                return createdUser
            }
        }



    }
})


module.exports = new GraphQLSchema({
    query: UserQuery,
    mutation: UserMutation,
})

我还在一个名为UserType、AuthType、MealType、NutritionType和WorkoutType的文件中定义了schema.js

const graphql = require("graphql")
const Workout = require("../models/Workout.js")
const User = require("../models/User.js")
const Meal = require("../models/Meal")

const {GraphQLObjectType, GraphQLID, GraphQLString, GraphQLSchema, GraphQLInt, GraphQLList} = graphql;

//describes what attributes and its types, a User has in each query
const UserType = new GraphQLObjectType({
    name: "User",
    fields: () => ({
        id: {type: GraphQLID},
        name: {type: GraphQLString},
        email: {type: GraphQLString},
        password: {type: GraphQLString},
        workouts: {
            type: new GraphQLList(WorkoutType),
            resolve(parent, args){
                //returns all the workouts created by a user
                return Workout.findById({userId: parent.id})
            }
        },
        meals: {
            type: new GraphQLList(MealType),
            resolve(parent, args){
                //returns all the meals created by a user
                return Meal.findById({userId: parent.id})
            }
        }

    })
})

const NutritionType = new GraphQLObjectType({
    name: "Nutrition",
    fields: () => ({
        carbohydrates: {type: GraphQLInt},
        fats: {type: GraphQLInt},
        proteins: {type: GraphQLInt}
    })
})



const WorkoutType = new GraphQLObjectType({
    name: "Workout",
    fields: () => ({
        id: {type: GraphQLID},
        name: {type: GraphQLString},
        reps: {type: GraphQLInt},
        burnedCalories: {type: GraphQLInt},
        sets: {type: GraphQLInt},
        user: {
            type: UserType,
            resolve(parent, args){
                //returns the user from the database that created the workout instance
                return User.findById(parent.userId)

            }
        }

    })
})




const AuthType = new GraphQLObjectType({
    name: "Authentication",
    fields: () => ({
        token: {type: GraphQLString},
        userId: {type: GraphQLString}
    })
})



const MealType = new GraphQLObjectType({
    name: "Meal",
    fields: () => ({
        id: {type: GraphQLID},
        calories: {type: GraphQLInt},
        servings: {type: GraphQLInt},
        nutrition: {type: NutritionType},
        user: {
            type: UserType,
            resolve(parent, args){
                //returns the user from the database that created the meal instance
                return User.findById(parent.userId)
            }
        }

    })
})




module.exports = {
    AuthType,
    WorkoutType,
    UserType,
    MealType,
    NutritionType
}

我怀疑我所得到的错误是由于来自graphql工具的mergeSchema对象，也许它不能正确地合并GraphQLSchema类型？我不确定。任何帮助都是非常感谢的！

node.js

express

graphql

javascript

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回答 1

Stack Overflow用户

发布于 2020-02-16 09:11:52

mergeSchemas打算与模式拼接一起使用。它不应该仅仅用于模块化您的单个模式，这正是您在这里要做的。

您应该只创建单个GraphQLSchema对象，为查询根类型创建单个GraphQLObjectType，为突变根类型创建单个GraphQLObjectType。如果希望将特定类型的字段(如Mutation类型)分散到多个模块中，则应该导出--仅是这些字段--，而不是整个类型或模式。

module.exports = {
  queries: {
    workout: { ... },
    workouts: { ... },
  },
  mutations: {
    addWorkout: { ... },
  },
}

无论您在什么文件中创建模式，都可以从多个模块导入这些字段，并将它们组合成一个单独的模式。

const query = new GraphQLObjectType({
  name: 'Query',
  fields: () => ({
    ...require('moduleA').queries,
    ...require('moduleB').queries,
    ...require('moduleC').queries,
  }),
})
const mutation = new GraphQLObjectType({ ... })
const schema = new GraphQLSchema({ query, mutation })