How to Configure Spring Boot and PostgreSQL Using application.yml

June 01, 2025

When you're building a Spring Boot application, connecting to a PostgreSQL database is one of the most common and important steps. Whether you're running the app locally during development or deploying it to a live production server, managing your configuration cleanly is essential.
A great way to organize your database settings is by using the application.yml file. With Spring Boot’s built-in profile support, you can maintain different configurations for development (dev) and production (prod) environments in the same file.
In this article, you'll learn how to:

Configure PostgreSQL for Spring Boot using application.yml
Set up dev and prod environments using Spring profiles
Include the PostgreSQL dependency in your project

Let’s walk through it step-by-step.

1. Add PostgreSQL Dependency

Before configuring anything, make sure your project includes the PostgreSQL driver.
If you're using Maven, add this to your pom.xml:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.6.0</version> <!-- Use the latest stable version -->
</dependency>

If you're using Gradle, add this to your build.gradle:

implementation 'org.postgresql:postgresql:42.6.0'

This dependency allows Spring Boot to connect to your PostgreSQL database.

2. Structure of `application.yml` with Profiles

Spring Boot allows you to define different sections within application.yml for specific environments by using profiles.
Here’s the basic structure:

spring:
  profiles:
    active: dev

Then, you can separate the dev and prod configurations using ---:

# Development configuration
spring:
  profiles: dev
  # dev settings here

---

# Production configuration
spring:
  profiles: prod
  # prod settings here

Let’s fill in the details.

3. Configure PostgreSQL for Development

Here’s an example configuration for local development:

spring:
  profiles: dev

  datasource:
    url: jdbc:postgresql://localhost:5432/devdb
    username: postgres
    password: postgres
    driver-class-name: org.postgresql.Driver

  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
    database-platform: org.hibernate.dialect.PostgreSQLDialect

What each line means:

url: connection string to your local PostgreSQL database
ddl-auto: update: automatically updates your database schema (handy in dev)
show-sql: true: prints SQL statements in the console for debugging

4. Configure PostgreSQL for Production

For production, you’ll want tighter control over the schema and no logging of SQL. It’s also best to use environment variables to keep credentials secure.

spring:
  profiles: prod

  datasource:
    url: ${DB_URL}
    username: ${DB_USERNAME}
    password: ${DB_PASSWORD}
    driver-class-name: org.postgresql.Driver

  jpa:
    hibernate:
      ddl-auto: validate
    show-sql: false
    database-platform: org.hibernate.dialect.PostgreSQLDialect

Best practices:

Use ddl-auto: validate or none in production to avoid accidental schema changes.
Hide credentials using environment variables (DB_URL, DB_USERNAME, DB_PASSWORD).
Make sure environment variables are configured in your server or deployment system.

5. Complete Example of `application.yml`

Here’s how your final application.yml might look:

spring:
  profiles:
    active: dev

---

spring:
  profiles: dev

  datasource:
    url: jdbc:postgresql://localhost:5432/devdb
    username: postgres
    password: postgres
    driver-class-name: org.postgresql.Driver

  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
    database-platform: org.hibernate.dialect.PostgreSQLDialect

---

spring:
  profiles: prod

  datasource:
    url: ${DB_URL}
    username: ${DB_USERNAME}
    password: ${DB_PASSWORD}
    driver-class-name: org.postgresql.Driver

  jpa:
    hibernate:
      ddl-auto: validate
    show-sql: false
    database-platform: org.hibernate.dialect.PostgreSQLDialect

This setup allows your app to automatically use the correct configuration based on the active profile.

6. Switching Between Dev and Prod

You can change the active profile in several ways:

Option 1: In `application.yml`

spring:
  profiles:
    active: prod

Option 2: Command line

java -jar app.jar --spring.profiles.active=prod

Option 3: Environment variable

export SPRING_PROFILES_ACTIVE=prod

This flexibility lets you deploy the same codebase across different environments without making code changes.

Best Practices Summary

Use Spring profiles to separate dev and prod logic
Keep your credentials secure in production by using environment variables
Use ddl-auto: update in development, but never in production
Always test your production configuration before deploying live
Use clear, consistent naming for databases in each environment