Learn GraphQL

const express = require("express");
const { buildSchema } = require("graphql");
const { graphqlHTTP } = require("express-graphql");
const schema = buildSchema(`
  type Account {
    name: String,
    age: Int,
    sex: String,
    department: String
  }
  type Query {
    hello: String,
    userName: String,
    age: Int,
    account: Account
  }
`);
const root = {
    hello: () => "Hello world!",
    userName: () => "wcd",
    age: () => 25,
    account: () => {
        return {
            name: "wcd",
            age: 25,
            sex: "boy",
            department: "technical division",
        };
    },
};
const app = express();
app.use(
    "/graphql",
    graphqlHTTP({
        schema: schema,
        rootValue: root,
        graphiql: true,
    })
);
app.listen(3000, () => console.log("Now browse to localhost:3000/graphql"));