Basics of GraphQL Syntax

Introduction

GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. It allows clients to request only the data they need, making it more efficient than traditional REST APIs.

This lesson will cover the basics of GraphQL syntax, focusing on queries, mutations, and subscriptions.

Queries

Queries in GraphQL are used to fetch data. The basic syntax for a query is as follows:

{
  user(id: "1") {
    name
    email
  }
}
            

In this example, we are querying for a user with the ID "1" and asking for their name and email.

Mutations

Mutations are used to modify server-side data. The syntax for a mutation looks like this:

mutation {
  createUser(input: { name: "John Doe", email: "john@example.com" }) {
    id
    name
  }
}
            

This mutation creates a new user and returns the user's ID and name.

Subscriptions

Subscriptions are used to get real-time updates from the server. The syntax for a subscription is similar to that of a query:

subscription {
  userUpdated {
    id
    name
    email
  }
}
            

This subscription listens for updates to user data and returns the updated fields.

Best Practices

• Use descriptive names for your queries and mutations.
• Keep queries and mutations simple and focused.
• Utilize fragments to avoid duplication in queries.
• Implement error handling and validation for mutations.

FAQ