How Spring talks to databases
Before writing repositories and entity classes, it helps to understand what's happening in the layers below. Spring Boot makes database access feel effortless, but there's a real stack underneath. Knowing it saves you when things go wrong, and they will.
Reverse engineering JPA entities
Generate JPA entity classes at build time directly from an existing SQL schema instead of writing them by hand.
JPA repository usage
Wire JPA entities into the hexagonal architecture so the app can query the database, convert results to domain models, and handle the not found case cleanly.
Database setup
Replace the embedded H2 with PostgreSQL 17 and use Flyway to manage schema migrations for your Spring Boot applications.
Query paginated results
Add pagination to the /films endpoint so clients can request pages of results instead of loading everything at once.
Completing the CRUD
Implement create, update, and delete operations for the Film resource following hexagonal architecture and handling the not-found case.