kotlin-backend-jpa-entity-mapping

Kotlin data classes generate equals and hashCode using all properties, which conflicts with Hibernate entity proxies and lazy loading. Use a regular class with explicit ID-based equality to prevent broken equality checks and ORM trapping issues.

LazyInitializationException and N+1 queries in Spring Data JPA require safe fetch strategies and proper entity relationship mapping. Apply modern Kotlin JPA best practices by adjusting fetch plans and diagnosing lazy-loading pitfalls in your persistence layer.

Identity and uniqueness constraints in Kotlin JPA entities are best implemented using explicit ID-based equality and practical rules for uniqueness. This ensures correct entity design and identity management across typical ORM traps in production code.

Define a Kotlin JPA entity as a regular class annotated with @Entity, ensuring an ID-based equals and hashCode implementation. Separate persistence models from DTOs and apply entity-design rules in your Spring Data JPA setup.

Yes, you can use Kotlin data classes for DTOs while keeping regular classes for JPA entities. Separating persistence models from DTOs prevents Kotlin-specific persistence bugs and maintains clean entity design in Spring Data projects.

You should not use data classes for Hibernate entity mapping in Kotlin when dealing with lazy-loaded relationships or complex equality checks. Data classes include all properties in equals and hashCode, breaking ORM proxy behavior and causing entity identity issues.