Hibernate / Hibernate 7 Basics Interview Questions
What is JPQL vs HQL in Hibernate 7?
JPQL is the standardised query language from Jakarta Persistence. HQL is a strict superset with additional Hibernate-specific features.
| Aspect | JPQL | HQL |
|---|---|---|
| Specification | Jakarta Persistence 3.2 standard | Hibernate superset of JPQL |
| Portability | Works with any JPA provider | Hibernate-specific |
| Functions | Standard functions | All JPQL + regexp, ilike, array, JSON, XML (Hibernate 7) |
| Set operations | UNION/INTERSECT/EXCEPT (JP 3.2) | Same as JPQL + more |
// JPQL (standard): EntityManager em = emf.createEntityManager(); List<Product> p = em .createQuery("SELECT p FROM Product p WHERE p.price < :max", Product.class) .setParameter("max", new BigDecimal("100")) .getResultList(); // HQL shorthand (Hibernate-specific): List<Product> p2 = session .createQuery("FROM Product WHERE price < :max", Product.class) .setParameter("max", new BigDecimal("100")) .getResultList(); // HQL-only: regexp List<Product> re = session .createQuery("FROM Product WHERE name regexp :pat", Product.class) .setParameter("pat", "^(Laptop|Phone)").getResultList(); // UNION (supported in both JPQL 3.2 and HQL): List<Object[]> combined = session.createQuery( "SELECT p.id, p.name FROM Product p WHERE p.category = :cat " + "UNION " + "SELECT s.id, s.name FROM Service s WHERE s.category = :cat", Object[].class).setParameter("cat", "tech").getResultList();
What is the relationship between HQL and JPQL?
What set operations did Hibernate 6/7 add to HQL?
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