Data source integration in GraphQL - Mini Project: Build & Apply

GraphQL Data Source Integration

📖 Scenario: You are building a simple GraphQL API for a bookstore. The data about books is stored in a list of dictionaries. You want to connect this data source to your GraphQL schema so clients can query book information.

🎯 Goal: Create a GraphQL schema that integrates a data source of books and allows querying the list of books with their titles and authors.

📋 What You'll Learn

Create a list called books with three books, each having id, title, and author fields.

Define a GraphQL type Book with fields id, title, and author.

Create a query type Query with a field books that returns the list of books.

Connect the books field resolver to return the books data source.

💡 Why This Matters

🌍 Real World

GraphQL APIs often need to connect to data sources like databases or in-memory lists to serve client queries.

💼 Career

Understanding how to integrate data sources with GraphQL is essential for backend developers building APIs.

1

Create the data source list

Create a list called books with these exact entries: {"id": "1", "title": "The Great Gatsby", "author": "F. Scott Fitzgerald"}, {"id": "2", "title": "1984", "author": "George Orwell"}, and {"id": "3", "title": "To Kill a Mockingbird", "author": "Harper Lee"}.

GraphQL

# Create the books data source list
# Your code here

Hint

Use a Python list of dictionaries to store the book data exactly as shown.

2

Define the GraphQL Book type

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

GraphQL

books = [
    {"id": "1", "title": "The Great Gatsby", "author": "F. Scott Fitzgerald"},
    {"id": "2", "title": "1984", "author": "George Orwell"},
    {"id": "3", "title": "To Kill a Mockingbird", "author": "Harper Lee"}
]

# Define the GraphQL Book type
# Your code here

Hint

Use GraphQL SDL syntax to define the Book type with the required fields and types.

3

Add the Query type with books field

Add a GraphQL Query type with a field books that returns a list of Book objects, using the syntax books: [Book!]!.

GraphQL

books = [
    {"id": "1", "title": "The Great Gatsby", "author": "F. Scott Fitzgerald"},
    {"id": "2", "title": "1984", "author": "George Orwell"},
    {"id": "3", "title": "To Kill a Mockingbird", "author": "Harper Lee"}
]

type_defs = """
type Book {
  id: ID!
  title: String!
  author: String!
}

# Add the Query type with books field
# Your code here
"""

Hint

Extend the GraphQL schema by adding a Query type with a books field that returns a non-null list of non-null Book objects.

4

Connect the books field resolver

Create a resolver dictionary called resolvers with a Query key. Inside Query, add a books function that returns the books list.

GraphQL

books = [
    {"id": "1", "title": "The Great Gatsby", "author": "F. Scott Fitzgerald"},
    {"id": "2", "title": "1984", "author": "George Orwell"},
    {"id": "3", "title": "To Kill a Mockingbird", "author": "Harper Lee"}
]

type_defs = """
type Book {
  id: ID!
  title: String!
  author: String!
}

type Query {
  books: [Book!]!
}
"""

# Create resolvers dictionary with Query.books returning books list
# Your code here

Hint

Define a resolvers dictionary with a Query key. The books resolver should be a function returning the books list.