/313-frameworks-spring-db-migrations-flyway

name: 313-frameworks-spring-db-migrations-flyway
description: Use when you need to add or review Flyway database migrations in a Spring Boot application — Maven dependencies, db/migration scripts, spring.flyway.* configuration, baseline and validation, and alignment with JDBC or Spring Data JDBC. This should trigger for requests such as Add or review Flyway migrations in a Spring Boot project; Configure spring.flyway or db/migration layout; Add versioned Flyway SQL migrations for Spring Boot; Review Spring Boot database migration ordering; Fix repeatable Flyway migrations in a Spring project. Part of Plinth Toolkit
license: Apache-2.0
metadata:
  author: Juan Antonio Breña Moral
  version: 0.18.0

Spring — Database migrations (Flyway)

Apply Flyway migration guidelines for Spring Boot.

**What is covered in this Skill?**

• flyway-core and database-specific Flyway modules (e.g. PostgreSQL) with Spring Boot BOM
• Versioned SQL under `src/main/resources/db/migration` (`V{version}__{description}.sql`)
• `spring.flyway.*` properties: locations, baseline-on-migrate, validate-on-migrate
• Optional Java migrations (`BaseJavaMigration`) for data backfills
• Forward-only discipline: do not rewrite applied migrations in shared environments
• Parallel Change as the safe expand, migrate, contract workflow for breaking or data-sensitive schema changes
• Coordination with `@311-frameworks-spring-jdbc` and `@312-frameworks-spring-data-jdbc`

**Scope:** Apply recommendations based on the reference rules and good/bad examples.

Constraints

Before applying Flyway or SQL changes, ensure the project compiles. After improvements, run full verification.

• **MANDATORY**: Run `./mvnw compile` or `mvn compile` before applying any change
• **SAFETY**: If compilation fails, stop immediately
• **VERIFY**: Run `./mvnw clean verify` or `mvn clean verify` after applying improvements
• **BEFORE APPLYING**: Read the reference for detailed rules and good/bad patterns
• **BREAKING CHANGE REVIEW**: Before recommending or applying a migration, assess whether it can break deployed application versions, dependent services, reports, jobs, or production data interpretation; if yes, require explicit human review before proceeding
• **EDGE CASE**: If the user goal is ambiguous, stop and ask a clarifying question before editing files or running project-wide commands
• **EDGE CASE**: If required context, files, credentials, or tools are missing, report the blocker explicitly and ask whether to proceed with setup or fallback guidance
• **EDGE CASE**: If requested changes conflict with project constraints or safety boundaries, explain the conflict and ask for user confirmation on the preferred trade-off

When to use this skill

• Add or review Flyway migrations in a Spring Boot project
• Configure spring.flyway or db/migration layout
• Add versioned Flyway SQL migrations for Spring Boot
• Review Spring Boot database migration ordering
• Fix repeatable Flyway migrations in a Spring project

Workflow

1. **Read references and assess project context**

Read `references/313-frameworks-spring-db-migrations-flyway.md`, `references/313-frameworks-spring-db-migrations-flyway-antipatterns.md`, and `references/313-frameworks-spring-db-migrations-flyway-parallel-change.md`, then inspect the current project setup before proposing changes.

2. **Gather scope and decide target improvements**

Identify requested outcomes, constraints, and the minimum safe set of changes to apply.

3. **Apply framework-aligned changes**

Implement or refactor configuration/code following the reference patterns and project conventions. Use Parallel Change (expand, migrate, contract) as the safe default for breaking or data-sensitive schema changes.

4. **Run verification and report results**

Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.

Reference

For detailed guidance, examples, and constraints, see:

• [references/313-frameworks-spring-db-migrations-flyway.md](references/313-frameworks-spring-db-migrations-flyway.md)
• [references/313-frameworks-spring-db-migrations-flyway-antipatterns.md](references/313-frameworks-spring-db-migrations-flyway-antipatterns.md)
• [references/313-frameworks-spring-db-migrations-flyway-parallel-change.md](references/313-frameworks-spring-db-migrations-flyway-parallel-change.md)