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Quick Start

Early Development

This library is in early development and should not be used in production environments yet.

This guide will help you get Flyway migrations running in your R2DBC application in just a few minutes.

Step 1: Enable Migrations

Add this minimal configuration to your application.yml:

flyway-r2dbc:
  enabled: true

That's it! The library will automatically use your R2DBC configuration for migrations.

Step 2: Create Your First Migration

Create a directory for your SQL migrations:

mkdir -p src/main/resources/db/migration

Add your first migration file V1__create_users_table.sql:

-- src/main/resources/db/migration/V1__create_users_table.sql
CREATE TABLE users (
    id BIGSERIAL PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    email VARCHAR(255) NOT NULL UNIQUE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_users_email ON users(email);

Step 3: Run Your Application

Start your application normally:

./gradlew run

You'll see migration logs during startup:

INFO  us.charliek.flyway.FlywayR2dbcMigrator - Starting Flyway migrations...
INFO  org.flywaydb.core.internal.command.DbMigrate - Current version of schema "public": << Empty Schema >>
INFO  org.flywaydb.core.internal.command.DbMigrate - Migrating schema "public" to version "1 - create users table"
INFO  us.charliek.flyway.FlywayR2dbcMigrator - Flyway migrations completed successfully

Step 4: Add More Migrations

As your application evolves, add new migrations with incrementing version numbers:

-- V2__add_user_profile.sql
CREATE TABLE user_profiles (
    user_id BIGINT PRIMARY KEY REFERENCES users(id),
    bio TEXT,
    avatar_url VARCHAR(500),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- V3__add_posts_table.sql
CREATE TABLE posts (
    id BIGSERIAL PRIMARY KEY,
    user_id BIGINT NOT NULL REFERENCES users(id),
    title VARCHAR(200) NOT NULL,
    content TEXT,
    published_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_posts_user_id ON posts(user_id);
CREATE INDEX idx_posts_published_at ON posts(published_at);

Complete Example

Here's a complete Micronaut application configuration:

# application.yml
micronaut:
  application:
    name: myapp

r2dbc:
  datasources:
    default:
      url: "r2dbc:postgresql://localhost:5432/myapp"
      username: "${DB_USERNAME:postgres}"
      password: "${DB_PASSWORD:password}"
      initial-size: 5
      max-size: 20

flyway-r2dbc:
  enabled: true
  baseline-on-migrate: true  # Useful for existing databases

Troubleshooting

Migration Not Running?

Check that: 1. flyway-r2dbc.enabled is set to true 2. Your migration files are in src/main/resources/db/migration/ 3. Migration files follow the naming pattern: V{version}__{description}.sql

Connection Issues?

The library will log detailed error messages. Common issues: - Database not running - Incorrect credentials - Network connectivity

Need More Control?

See the Configuration Guide for advanced options like: - Custom migration locations - Placeholders - Baseline configuration - Direct JDBC configuration

Next Steps