GraphQL Schema Basics

1. Introduction

GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. The schema is a core component of GraphQL, defining the structure of your API.

2. What is a Schema?

A schema defines the types and their relationships in a GraphQL API. It serves as a contract between the client and server, specifying how clients can access the data.

3. Schema Types

GraphQL schemas consist of several types:

• Object Types
• Query Types
• Mutation Types
• Input Types
• Scalar Types
• Enum Types

4. Defining Types

To define an object type in GraphQL, you use the following syntax:

type User {
    id: ID!
    name: String!
    email: String!
}
            

In this example, we've defined a User type with three fields: id, name, and email.

5. Queries and Mutations

Queries are used to fetch data, while mutations are used to modify data. Here’s how to define both:

type Query {
    user(id: ID!): User
}

type Mutation {
    createUser(name: String!, email: String!): User
}
            

6. Best Practices

• Use descriptive names for types and fields.
• Keep your schema simple and focused.
• Document your schema effectively.
• Version your schema as your API evolves.

7. FAQ