Hibernate ORM and Jakarta Persistence

Problem -> anti-pattern -> fix library for entity mapping and querying. Framework-neutral: it covers EntityManager/Session behavior, JPQL/HQL, and mapping annotations. If the project uses Spring Boot and the java-springboot and spring-boot-testing skills are installed, use them for Spring Data repositories, transaction wiring, and @DataJpaTest; for Panache and reactive persistence see the Quarkus skills. Integration tests against a real database: java-testcontainers.

First: detect the stack

1. Read pom.xml/build.gradle (or the dependency tree) for hibernate-core and the persistence API: jakarta.persistence (Hibernate 6+/Jakarta EE 9+) vs javax.persistence (Hibernate 5, see javax-to-jakarta-migration).
2. Note the Hibernate major version; behavior differs (see references/tooling-and-versions.md). Hibernate 6.0-6.1 implement Jakarta Persistence 3.0, 6.2+ implement 3.1, 7.x implements 3.2, and Hibernate 7 needs Java 17+.
3. Note the database and whether the schema is managed by Flyway/Liquibase.
4. Turn on SQL logging and statistics in a test (see references/tooling-and-versions.md) before "optimizing" anything: measure statement counts.

Quick decision table