GraphQL for beginners

GraphQL is a query language for APIs. Unlike REST, where the server decides the shape of the response, GraphQL lets the client ask for exactly what it needs.

REST vs GraphQL

With REST you might hit three endpoints to build a profile page:

GET /users/1
GET /users/1/posts
GET /users/1/followers

With GraphQL, one query does it all:

query {
  user(id: "1") {
    name
    posts {
      title
    }
    followers {
      name
    }
  }
}

Setting up a simple server

Using graphql-yoga — minimal and modern:

npm install graphql-yoga graphql

import { createServer } from "node:http";
import { createYoga, createSchema } from "graphql-yoga";
 
const schema = createSchema({
  typeDefs: `
    type Query {
      hello: String
    }
  `,
  resolvers: {
    Query: {
      hello: () => "Hello from GraphQL!",
    },
  },
});
 
const yoga = createYoga({ schema });
createServer(yoga).listen(4000, () => {
  console.log("Running at http://localhost:4000/graphql");
});

Mutations

Reading data uses query, writing uses mutation:

mutation {
  createPost(title: "GraphQL is great", body: "...") {
    id
    title
  }
}

Tips for beginners

• Start with queries before mutations.
• Use GraphQL Playground (built into most servers) to explore the schema interactively.
• Keep resolvers thin — business logic belongs in a service layer.
• Learn about DataLoader early to avoid the N+1 query problem.

GraphQL shines when you have multiple clients (web, mobile) with different data needs. It's worth learning even if REST covers most of your use cases.