# Replace H2 with a real database for testing


<!-- Source: https://github.com/testcontainers/tc-guide-replace-h2-with-real-database-for-testing -->

In this guide, you will learn how to:

- Understand the drawbacks of using H2 in-memory databases for testing
- Replace H2 with a real PostgreSQL database using the Testcontainers special JDBC URL
- Use the Testcontainers JUnit 5 extension for more control over the container
- Test both Spring Data JPA and JdbcTemplate-based repositories

## Prerequisites

- Java 17+
- Maven or Gradle
- A Docker environment supported by Testcontainers

> [!NOTE]
> If you're new to Testcontainers, visit the
> [Testcontainers overview](https://testcontainers.com/getting-started/) to learn more about
> Testcontainers and the benefits of using it.