GraphQL入门3(Mutation)

创建一个新的支持Mutation的Schema.

var GraphQLSchema = require('graphql').GraphQLSchema;

var GraphQLObjectType = require('graphql').GraphQLObjectType;

var GraphQLString = require('graphql').GraphQLString;

var GraphQLList = require('graphql').GraphQLList;

var buildSchema  = require('graphql').buildSchema;

var fetch = require('node-fetch');

require("babel-polyfill");

// Construct a schema, using GraphQL schema language

var schema = buildSchema(

'    input MessageInput {'

+ '        content: String'

+ '        author: String'

+ '    }'

+ ''

+ '    type Message {'

+ '        id: ID !'

+ '        content: String'

+ '        author: String'

+ '    }'

+ ''

+ '    type Query {'

+ '        getMessage(id: ID!): Message'

+ '    }'

+ ''

+ '    type Mutation {'

+ '         createMessage(input: MessageInput): Message'

+ '         updateMessage(id: ID!, input: MessageInput): Message'

+ '    }'

);

// If Message had any complex fields, we'd put them on this object.

class Message {

constructor(id, {content, author}) {

this.id = id;

this.content = content;

this.author = author;

}

}

// Maps username to content

var fakeDatabase = {};

var root = {

getMessage: function ( { id }) {

if (!fakeDatabase[id]) {

throw new Error('no message exists with id ' + id);

}

return new Message(id, fakeDatabase[id]);

},

createMessage: function ({input}) {

// Create a random id for our "database".

var id = require('crypto').randomBytes(10).toString('hex');

fakeDatabase[id] = input;

return new Message(id, input);

},

updateMessage: function ({id, input}) {

if (!fakeDatabase[id]) {

throw new Error('no message exists with id ' + id);

}

// This replaces all old data, but some apps might want partial update.

fakeDatabase[id] = input;

return new Message(id, input);

}

};

module.exports.Schema = schema;

module.exports.Root = root;

创建一个新的router来使用这个Schema:

var express = require('express');

var graphQLHTTP = require('express-graphql');

var schema = require('../schemas/Schema2').Schema;

var root = require('../schemas/Schema2').Root;

var router = express.Router();

router.use(graphQLHTTP({

schema: schema,

rootValue: root,

graphiql : true

}));

module.exports = router;

客户端的测试代码如下:

app.js:

//Mutation

var Test7 = require('./Test7');

Test7.Execute();

Test7.js

//Test7: Mutation

var gRequest = require('graphql-request').request;

var util = require('util');

exports.Execute = function () {

var query = 'mutation CreateMessage($input: MessageInput) {'

+ '  createMessage(input: $input) {'

+ '    id,'

+ '    author,'

+ '    content'

+ '  }'

+ '}' ;

var varibles1 =

{

"input":

{

"author": "Tom",

"content": "this is my message"

}

};

//gRequest('http://localhost:1337/graphql/graphql', query).then(function (data) { console.log(data) });

gRequest('http://localhost:1337/graphql2/graphql', query, varibles1).then(function (data) {

console.log(util.inspect(data, { showHidden: false, depth: null }))

});

};

执行结果如下:

{ createMessage:

{ id: '48ed1228a3b390909365',

author: 'Tom',

content: 'this is my message' } }

示例来自: https://graphql.org/graphql-js/mutations-and-input-types/