Update mutation pattern in GraphQL - Mini Project: Build & Apply

Create a GraphQL Update Mutation

📖 Scenario: You are building a simple GraphQL API for a bookstore. You want to allow users to update the details of a book, such as its title and author.

🎯 Goal: Build a GraphQL updateBook mutation that updates a book's id, title, and author fields.

📋 What You'll Learn

Create a GraphQL input type called UpdateBookInput with fields id, title, and author.

Define a mutation called updateBook that takes an input argument of type UpdateBookInput.

The mutation should return the updated book's id, title, and author.

Use the exact names UpdateBookInput, updateBook, and input in your code.

💡 Why This Matters

🌍 Real World

GraphQL update mutations are used in APIs to allow clients to modify existing data records safely and clearly.

💼 Career

Understanding how to write update mutations is essential for backend developers working with GraphQL APIs in real-world applications.

1

Define the UpdateBookInput input type

Create a GraphQL input type called UpdateBookInput with the fields id of type ID!, title of type String, and author of type String.

GraphQL

# Define the UpdateBookInput input type
# Your code here

Need a hint?

Use the input keyword to define an input type with the specified fields.

2

Add the updateBook mutation field

Add a mutation field called updateBook that takes an argument named input of type UpdateBookInput!.

GraphQL

input UpdateBookInput {
  id: ID!
  title: String
  author: String
}

# Add the updateBook mutation field below
# Your code here

Need a hint?

Define a Mutation type and add the updateBook field with the correct argument.

3

Define the Book type

Define a GraphQL type called Book with fields id of type ID!, title of type String, and author of type String.

GraphQL

input UpdateBookInput {
  id: ID!
  title: String
  author: String
}

type Mutation {
  updateBook(input: UpdateBookInput!): Book
}

# Define the Book type below
# Your code here

Need a hint?

Use the type keyword to define the Book type with the specified fields.

4

Complete the update mutation schema

Ensure the full schema includes the UpdateBookInput input type, the Book type, and the Mutation type with the updateBook mutation returning a Book.

GraphQL

input UpdateBookInput {
  id: ID!
  title: String
  author: String
}

type Mutation {
  updateBook(input: UpdateBookInput!): Book
}

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

# Finalize the schema if needed
# Your code here

Need a hint?

Review your schema to confirm all parts are included and correctly linked.