thjanssen

em.createNamedQuery(“selectAuthors”).getResultList();

thjanssen

Session s = (Session) em.getDelegate();
		Query q = s.createQuery("SELECT a FROM Author a WHERE id = :id");
		q.setParameter("id", 1L);
		q.setCacheable(true);
log.info(q.uniqueResult());

thjanssen

@SqlResultSetMapping(
        name = "AuthorMapping",
        entities = @EntityResult(
                entityClass = Author.class,
                fields = {
                    @FieldResult(name = "id", column = "authorId"),
                    @FieldResult(name = "firstName", column = "firstName"),
                    @FieldResult(name = "lastName", column = "lastName"),
                    @FieldResult(name = "version", column = "version")}))

thjanssen

@Entity
@Immutable
public class BookView {
	
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	@Column(name = "id", updatable = false, nullable = false)
	private Long id;
	@Version
	@Column(name = "version")

thjanssen

EntityManager em = emf.createEntityManager();
em.getTransaction().begin();

Author a = em.createQuery("SELECT a FROM Author a JOIN FETCH a.books WHERE a.id = 1", Author.class).getSingleResult();

em.getTransaction().commit();
em.close();
	
log.info(a.getFirstName()+" "+a.getLastName()+" wrote "+a.getBooks().size()+" books.");

thjanssen

05:22:13,930 DEBUG [org.hibernate.SQL] – 
select authors0_.bookId as bookId1_2_0_, 
    authors0_.authorId as authorId2_2_0_, 
    author1_.id as id1_0_1_, 
    author1_.firstName as firstNam2_0_1_, 
    author1_.lastName as lastName3_0_1_, 
    author1_.version as version4_0_1_ 
from BookAuthor authors0_ inner join Author author1_ 
    on authors0_.authorId=author1_.id 
where authors0_.bookId=? 

thjanssen

PersonEntity p = em.find(PersonEntity.class, 1L);

log.info("Detach PersonEntity");
em.flush();
em.detach(p);

em.createNativeQuery("UPDATE person p SET firstname = firstname || '-changed'").executeUpdate();

p = em.find(PersonEntity.class, 1L);

thjanssen

Book b = (Book) em.createNativeQuery("SELECT * FROM book b WHERE id = 1", Book.class).getSingleResult();

thjanssen

@Entity
@Table(name = "purchaseOrder")
public class Order implements Serializable {
  
  @OneToMany(mappedBy = "order", fetch = FetchType.EAGER)
  private Set<OrderItem> items = new HashSet<OrderItem>();
  
  ...
  
}

thjanssen

@Entity
public class Author {

	@Id
	@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "author_generator")
	@SequenceGenerator(name="author_generator", sequenceName = "author_seq")
	@Column(name = "id", updatable = false, nullable = false)
	private Long id;
	
	...