Install GraphQL in Node.js

Step 1: Check Node.js and npm

node -v && npm -v

Step 2: Create a project folder

mkdir graphql-example
cd graphql-example

Step 3: Start a Node.js project

npm init -y

Step 4: Install GraphQL

npm install graphql

For a web server with GraphQL, add Express and a handler. The old express-graphql package is no longer maintained. A good current choice is graphql-http:

npm install graphql express graphql-http

Step 5: Write a basic GraphQL query

Create a file graphqlFile.js:

var { graphql, buildSchema } = require("graphql");

var customSchema = buildSchema(`
  type Query {
    greeting: String
  }
`);

var root = {
  greeting: () => "Hello from GraphQL!",
};

graphql({ schema: customSchema, source: "{ greeting }", rootValue: root })
  .then((response) => console.log(JSON.stringify(response)));

• The schema describes the data you can ask for. Here there is one field, greeting.
• The root has the functions that give the data (resolvers).
• graphql(...) runs a query against the schema.

Step 6: Run it

node graphqlFile.js

You should see {"data":{"greeting":"Hello from GraphQL!"}}.

A small web server

const express = require("express");
const { createHandler } = require("graphql-http/lib/use/express");
const { buildSchema } = require("graphql");

const schema = buildSchema(`type Query { greeting: String }`);
const root = { greeting: () => "Hello from GraphQL!" };

const app = express();
app.all("/graphql", createHandler({ schema, rootValue: root }));
app.listen(4000);
console.log("Running at http://localhost:4000/graphql");

Quick recap

• npm init -y and npm install graphql.
• Define a schema and resolvers.
• Run queries with graphql() or serve them with Express.