@Entity
public class NewEntity implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Embedded
    private NewEntityEE neee = new NewEntityEE();
}

@Embeddable
public class NewEntityEE implements Serializable {

    @OneToOne(cascade = {CascadeType.PERSIST}, orphanRemoval = true)
    @JoinColumn(nullable = false)
    private NewEntity3 ne3 = new NewEntity3();
}

@Entity
public class NewEntity3 implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
}

@Stateless
public class NewEJB {
    @PersistenceContext
    private EntityManager em;

    public NewEntity create(){
        NewEntity ne = new NewEntity();
        em.persist(ne);
        return ne;
    }
}

 UPDATE SEQUENCE SET SEQ_COUNT = SEQ_COUNT + ? WHERE SEQ_NAME = ?
	bind => [50, SEQ_GEN]
 SELECT SEQ_COUNT FROM SEQUENCE WHERE SEQ_NAME = ?
	bind => [SEQ_GEN]
 INSERT INTO NEWENTITY (ID, NE3_ID) VALUES (?, ?)
	bind => [1, 2]
 VALUES(1)
 Local Exception Stack: 
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: ...