Double Your Data Power: Spring Boot Dual Database Guide

Connecting to multiple databases in a Spring Boot app is often needed in big projects. Whether you’re handling different modules, separating read and write tasks, or linking up with old systems, Spring Boot makes it simple. This guide will show you how to easily set up and connect to two different databases in Spring Boot.

Step-by-Step Guide

1. Add Dependencies

First, ensure that you have the necessary dependencies in your pom.xml for the databases you intend to use. For this example, we will connect to both MySQL and PostgreSQL.

2. Configure Properties

Next, define properties for each data source in your application.properties or application.yml.

3. Define Configuration Classes

Create configuration classes for each data source. Each configuration class should define the data source, entity manager factory, and transaction manager for its respective database.

Primary Data Source Configuration (MySQL)

Secondary Data Source Configuration (PostgreSQL)

4. Define Repositories and Entities

Separate your repositories and entities into different packages for each data source. This ensures that each entity is managed by the correct entity manager factory.

Primary Repository and Entity (MySQL)

Secondary Repository and Entity (PostgreSQL)

Conclusion

By following these steps, you can configure Spring Boot to communicate with two different databases seamlessly. This setup ensures that each data source has its own configuration, transaction management, and repository setup, allowing for a clean and maintainable codebase.

This approach is highly flexible and can be extended to include more than two databases if needed. Always ensure that your database configurations are optimized for the specific use case to maintain performance and reliability.