GraphQL Tutorial Beginner – Learn GraphQL in NodeJS / ExpressJS

If you are interested in learning GraphQL, this tutorial is a great starting point for beginners. We will guide you through the necessary steps to set up GraphQL in a NodeJS/ExpressJS environment.

What is GraphQL?

GraphQL is a query language for APIs and a runtime for executing those queries with the existing data. It provides a more efficient and flexible alternative to traditional RESTful APIs. With GraphQL, you can precisely request the data you need, reducing unnecessary round-trips to the server.

Setting up NodeJS and ExpressJS

Before diving into GraphQL, you need to have NodeJS and ExpressJS installed on your computer. If you haven’t installed them yet, follow these steps:

1. Visit the official NodeJS website (https://nodejs.org) and download the latest stable version for your operating system.
2. Once the installation is complete, open your terminal or command prompt and run the command node -v to verify that NodeJS has been successfully installed.
3. Next, you need to install ExpressJS. Run the command npm install express to install Express globally on your system.
4. Use the command express --version to confirm that ExpressJS has been installed.

Install necessary packages

Now that you have NodeJS and ExpressJS set up, you need to install the required packages for GraphQL integration. Run the following command in your terminal:

npm install express-graphql graphql

Creating a GraphQL server

In your project folder, create a new file called server.js. This will be the entry point for your GraphQL server.

Copy the following code into server.js:


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

app.listen(4000);
console.log('GraphQL server running at http://localhost:4000/graphql');


Save the file and open your terminal. Navigate to the project folder and run the command:

node server.js

Congratulations! You just created your first GraphQL server using NodeJS and ExpressJS.

Testing the GraphQL API

Open your web browser and visit http://localhost:4000/graphql. You will see the GraphiQL interface, which allows you to interact with the GraphQL API.

On the left side, you will find a JSON editor where you can write GraphQL queries. Try executing the following query:


query {
hello
}


Click on the “Play” button or press Ctrl + Enter to execute the query. On the right side, you will see the response:


{
"data": {
"hello": "Hello, GraphQL!"
}
}


Congratulations! You have successfully executed your first GraphQL query.

Conclusion

In this tutorial, you learned how to set up GraphQL in a NodeJS/ExpressJS environment. You created a basic GraphQL server and tested it using the GraphiQL interface. Now you have a solid foundation to explore further and build more complex GraphQL APIs.

Continue experimenting with GraphQL and discover its powerful features for creating efficient and flexible APIs.