Flyway

motivation

Flyway aims to streamline the database migration process, making it faster and less error-prone for development teams. It integrates perfectly with with CI/CD pipelines.

• Safe and reliable deployments: Flyway ensures that database schema changes are applied in the correct order across all environments (development, testing, production). This reduces the risk of errors and unexpected behavior.
• Safety checks: Flyway verifies if the scripts have already been applied to the database before running them again. This prevents accidental re-runs that could cause issues.
• Rollback support: If a migration causes problems, Flyway allows you to easily rollback to a previous state.

alternatives

• Liquibase: Like flyway but uses xml for configuration
• manual execution of sql scripts

basics

1. Write migration scripts
2. Execute flyway commands

write migration scripts

• Flyway uses versioned filenames to ensure migrations are applied in the correct order. Typically: V<version number>__<description>.sql (e.g. V001__create_users_table.sql).
• Inside the script file, write your SQL statements that modify the database schema. This could include creating tables, adding columns, or altering existing structures.

execute flyway commands

• migrate: This command instructs Flyway to scan for new or pending migrations and apply them to your database.
• info: This command displays information about the current state of Flyway, such as which migrations have been applied and the Flyway version.
• baseline: This command is typically used for initial setup. It helps Flyway create the internal tracking table in your database to manage the migration history.
• clean: This command removes applied migrations from your database, essentially rolling back all changes. Use with caution!