Connecting to PostgreSQL

In our previous lesson, we set up a PostgreSQL database using Docker Compose.

Now we'll configure our Spring Boot application to connect to this database.

Database Configuration

Spring Boot uses the application.properties file to manage database connection settings.

Create or open src/main/resources/application.properties and add these properties:

# Database Connection
spring.datasource.url=jdbc:postgresql://localhost:5432/postgres
spring.datasource.username=postgres
spring.datasource.password=changemeinprod!

# JPA Configuration
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

Understanding the Configuration

The database URL follows a specific format that tells Spring how to connect to our PostgreSQL instance.

The spring.jpa.hibernate.ddl-auto=update setting enables Hibernate to automatically update the database schema based on our entity classes.

The show-sql and format_sql properties help during development by logging SQL statements to the console.

Summary

Spring Boot auto-configures most database connection properties
The application.properties file centralizes database configuration
Hibernate's ddl-auto=update mode automatically manages schema changes