jpa-spring-data-kotlin-mapper

Kotlin JPA entities fail lazy loading when generated as data classes or without explicit nullability, breaking Hibernate proxy initialization. Use non-data class entities with explicit fetch plans to ensure safe lazy loading and avoid runtime exceptions.

Map bidirectional relationships in Spring Data JPA by applying EntityGraph, JOIN FETCH, and projections to optimize fetch plans. This prevents N+1 queries by explicitly fetching required associations during repository queries.

Kotlin data classes are not suitable for Hibernate entity mapping. You must use non-data class entities to support Hibernate proxy creation, ensure lazy loading safety, and maintain correct identity strategies across persistence contexts.

Separate persistence models and transport DTOs by mapping Kotlin entities as non-data classes and keeping DTOs independent. This ensures explicit nullability for Hibernate compatibility and isolates database concerns from API transport layers.

Optimize batch operations and indexing in Spring Data JPA by defining explicit fetch strategies, applying EntityGraph, and using JOIN FETCH in repository queries. This resolves N+1 risks and improves performance across typical CRUD operations.

Explicit nullability and identity strategies are required for Kotlin JPA mappings whenever using Hibernate lazy loading or bidirectional relationships. They ensure proxy compatibility, prevent mapping errors, and maintain consistent entity state.