Integrating GraphQL with a database is essential for building dynamic and real-time applications. In this chapter, we will learn how to connect our GraphQL API to a database, using an ORM (Object-Relational Mapping) to simplify operations. We will use MongoDB as the database along with Mongoose, a popular ORM library for Node.js.

Installing Dependencies

First, we will install the necessary dependencies:

bash

Configuring Mongoose

Create a db.js file to set up the connection to the MongoDB database:

javascript

Defining Mongoose Schemas

Now, let's define data models using Mongoose. We will create two models: Book and Author.

Author Model

Create a models/Author.js file:

javascript

Book Model

Create a models/Book.js file:

javascript

Updating Resolvers to Use Mongoose

Update the resolvers to use the Mongoose models for read and write operations.

Resolvers in resolvers.js

javascript

Server Configuration

Update server.js to include the database connection:

javascript

Testing the Integration

Once the server and resolvers are configured, we can test the queries and mutations:

Create an Author

graphql

Create a Book

graphql

Get All Books

graphql

Summary

In this chapter, we learned how to integrate GraphQL with a database using MongoDB and Mongoose. We saw how to configure the database connection, define data models, and update the resolvers to use these models. These skills enable you to build dynamic and real-time GraphQL APIs.

[Placeholder: Diagram showing how resolvers interact with Mongoose models and the MongoDB database]

In the next chapter, we will explore how to handle authentication and authorization in GraphQL.