我对GraphQL还是很陌生，我之前的问题是关于我遇到的一些参考错误，但我最终解决了该错误，但是现在我遇到了这个错误。似乎无法添加锻炼，因为它无法识别出它是架构中的一个突变字段。
我不断收到
的错误Cannot query field \"addWorkout\" on type \"Mutation\
无论如何，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`)
})
锻炼查询和变异是在我导出的名为executionQueries.js的文件中定义的，您可以看到我在解析程序中定义了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，即使我尝试添加一餐，也会发生此问题，查询和突变是在我已导出的名为DietQueries.js的文件中定义的
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
})
我在创建用户和验证用户方面没有问题，在userQueries.js中定义的查询和突变
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,
})
我还已经在名为schema.js的文件中定义了UserType，AuthType，MealType，NutritionType和WorkoutType。
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
}
我怀疑我得到的错误是由于来自graphql-tools的mergeSchema对象，也许它无法正确合并GraphQLSchema类型？我不确定。任何帮助表示赞赏！
答案 0 :(得分：0)
mergeSchemas与schema stitching一起使用。不应仅将其用于模块化单个架构，这就是您要在此处进行的操作。
您应该只创建一个GraphQLSchema对象，为查询根类型创建一个GraphQLObjectType，为突变根类型创建一个GraphQLObjectType。如果您希望将特定类型的字段（例如Mutation类型的字段分散在多个模块中，则应导出仅这些字段，而不是整个类型或架构。
module.exports = {
queries: {
workout: { ... },
workouts: { ... },
},
mutations: {
addWorkout: { ... },
},
}
无论您在其中创建架构的任何文件，都可以从多个模块导入这些字段，并将它们组合成单个架构。
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 })