Schema-first development in GraphQL - Mini Project: Build & Apply

Build a Simple GraphQL Schema with Schema-First Development

📖 Scenario: You are creating a small GraphQL API for a bookstore. The API will allow clients to query books and authors.

🎯 Goal: Build a GraphQL schema using schema-first development. Define types for Book and Author, and a query type to fetch books and authors.

📋 What You'll Learn

Define a Book type with fields id (ID!), title (String!), and authorId (ID!)

Define an Author type with fields id (ID!) and name (String!)

Create a Query type with fields books and authors returning lists of Book and Author respectively

Use schema-first approach: write the schema definition first

💡 Why This Matters

🌍 Real World

GraphQL schema-first development is used to design APIs clearly before coding resolvers, improving collaboration and planning.

💼 Career

Many companies use GraphQL for APIs; knowing schema-first helps you design scalable and maintainable APIs.

1

Define the Book type

Write the GraphQL type definition for Book with fields id of type ID!, title of type String!, and authorId of type ID!.

GraphQL

# Write the type definition for Book here

Need a hint?

Use type Book { ... } and specify each field with its type and exclamation mark for required fields.

2

Define the Author type

Add the GraphQL type definition for Author with fields id of type ID! and name of type String!. Keep the Book type from step 1.

GraphQL

type Book {
  id: ID!
  title: String!
  authorId: ID!
}

# Write the type definition for Author here

Need a hint?

Define Author similarly to Book, with required id and name fields.

3

Define the Query type

Add a Query type with two fields: books returning a list of Book (use [Book!]!) and authors returning a list of Author (use [Author!]!). Keep the previous type definitions.

GraphQL

type Book {
  id: ID!
  title: String!
  authorId: ID!
}

type Author {
  id: ID!
  name: String!
}

# Write the Query type here

Need a hint?

Use square brackets to indicate lists and exclamation marks to mark non-nullable lists and items.

4

Complete the schema with all types

Ensure the schema includes the Book, Author, and Query types exactly as defined in previous steps. This completes the schema-first development for the bookstore API.

GraphQL

type Book {
  id: ID!
  title: String!
  authorId: ID!
}

type Author {
  id: ID!
  name: String!
}

type Query {
  books: [Book!]!
  authors: [Author!]!
}

# Finalize the schema here if needed

Need a hint?

Review all type definitions to confirm completeness and correctness.