This repository is an example application for the Spring Boot framework that employs the Netflix DGS framework to expose a GraphQL API and that interacts with a PostgreSQL DBMS via Spring Data JPA.

It shows the following features:

• Datafetchers
• Mutations
• DataLoader to prevent the N+1 problem
• Lombok for model classes
• Spring Data JPA

There are other examples of using the DGS framework as well:

• Java DGS Framework example
• Kotlin DGS Framework example
• Federation examples (with Apollo Gateway)

This example is built around three main types: Agencies, Agents, and Properties. Each real estate agency has an ID, a name, a tax code, and is associated with N agents and N properties. A real estate agent has a UUID, a full name and is associated with only one agency. Each property has an ID, a name, a type (enumeration), coordinates, a purchase date and is associated with only one real estate agency. A property can be created, updated or deleted using a mutation.

The schema file is located in the following path.

/src/main/resources/schema/schema.graphql

The example requires Java 17 and PostgreSQL 14.

Create a PostgreSQL database, using the database name, username, and password contained in application.yml.

Run the application in an IDE using its main class or using Gradle:

./gradlew bootRun

Interact with the application using GraphiQL on http://localhost:8081/graphiql.