Spring Data JPA for Spring Boot 4

Persistence review

The agent first inspects the entities, repository queries, migrations, transaction boundaries, serialization layer, and existing tests. It preserves the current table and column contract instead of replacing the model with generic templates.

Findings

• The order list loads customer and line data lazily outside a defined fetch plan, producing repeated queries.
• Bidirectional relationships lack clear ownership and helper methods, so both sides can drift out of sync.
• Entity equality depends on generated identifiers before persistence.
• The controller returns entities directly, making lazy loading and JSON serialization part of the API contract.
• The repository test uses mocks and cannot reveal generated SQL or mapping defects.

Deliverables

• Explicit relationship ownership, cascade choices, orphan-removal behavior, and bounded collection access.
• A repository query or entity graph tailored to the list use case without applying eager fetching globally.
• A DTO projection that preserves the endpoint response while keeping persistence entities internal.
• Pagination with deterministic ordering and no collection fetch-join count errors.
• DataJpaTest coverage for mapping constraints, optimistic locking, query counts, pagination, and the selected fetch plan.

Verification

Run the repository tests against the project's supported database profile, inspect the generated SQL for the list query, and compare query counts for one order and a multi-order page. Confirm that migrations remain unchanged unless a schema defect is explicitly identified.