1 创建项目

使用以下命令创建项目

cd graphql-with-nodejs
npm init -y

npm install express
npm install express-graphql graphql

在项目里新建server.js

const express = require('express');
const { graphqlHTTP } = require('express-graphql');
const { buildSchema } = require('graphql');

// 定义 GraphQL schema
const schema = buildSchema(`
   type Account {
      name : String
      age: Int
      sex : String
      department : String
   }

   type Query {
        hello: String
        age: Int
        account: Account
   }
`);

// 定义 resolver
const root = {
    hello: () => 'hello world',
    age: () => 21,
    account: () => ({
        name: '张三',
        age: 18,
        sex: 'male',
        department: '销售'
    })
 };

// 创建 Express 服务器
const app = express();
app.use('/graphql', graphqlHTTP({
   schema: schema,
   rootValue: root,
   graphiql: true // 启用 GraphiQL 方便测试
}));

// 监听端口
app.listen(5000, () => {
   console.log('🚀 Server running at http://localhost:5000/graphql');
});

启动项目

node .\server.js

访问 http://localhost:5000/graphql

在页面中输入查询参数

{
   hello
   age
   account {
    name
    age
    sex
    department
  }
}

2 参数类型和传递

新建文件 baseType.js

const express = require('express');
const { graphqlHTTP } = require('express-graphql');
const { buildSchema } = require('graphql');

// 定义 GraphQL schema
const schema = buildSchema(`
     type Query {
          getClassMates(classNo: Int!): [String]
     }
`);

// 定义 resolver
const obj = {
    "31": ["张三", "李四", "王五"],  // 数字改为字符串
    "61": ["张三2", "李四2", "王五2"]
};

const root = {
    getClassMates: (args) => {
       return obj[args.classNo.toString()] || []; // 确保 classNo 转成字符串匹配键名
    }
};

// 创建 Express 服务器
const app = express();

app.use('/graphql', graphqlHTTP({
   schema: schema,
   rootValue: root,
   graphiql: true // 启用 GraphiQL 方便测试
}));

// 监听端口
app.listen(5000, () => {
   console.log('Server running at http://localhost:5000/graphql');
});

启动项目

node .\baseType.js

在页面中输入查询参数

{
   getClassMates(classNo: 31)
}

参考页面

https://www.infoq.cn/article/i5jmm54_awrrzcem1vgh