Use node.js to quickly build a GraphQL development environment to output hello world

1. You have to make sure that node.js has been installed

Open cmd input to see if it has been installed

node -v

2. Initialize the node.js environment

node init

3. Installation

Related documentation  GraphQL The easiest way is to use Express (a popular web application framework on Node.js)

npm install express express-graphql graphql --save

4. Create a new server.js and copy the code into it

var express = require('express');
//注意有个小坑,使用var定义会报错，这里需要修改成const
//var graphqlHTTP = require('express-graphql');
const { graphqlHTTP } = require('express-graphql');
var { buildSchema } = require('graphql');

// 使用 GraphQL Schema Language 创建一个 schema
var schema = buildSchema(`
  type Query {
    hello: String
  }
`);

// root 提供所有 API 入口端点相应的解析器函数
var root = {
  hello: () => {
    return 'Hello world!';
  },
};

var app = express();
app.use('/graphql', graphqlHTTP({
  schema: schema,
  rootValue: root,
  graphiql: true,
}));
app.listen(4000);
console.log('Running a GraphQL API server at http://localhost:4000/graphql');

5. Run

node server.js

6. Visit in the browser and you're done

http://localhost:4000/graphql