如何在JPQL或HQL中仅检索实体的某些字段？JPQL或HQL中的ResultSet等价物是什么？

SELECT e.firstName, e.lastName FROM Employee e

EntityManager em = ...; // 获取EntityManager实例
TypedQuery<Object[]> query = em.createQuery("SELECT e.firstName, e.lastName FROM Employee e", Object[].class);
List<Object[]> results = query.getResultList();
for (Object[] result : results) {
    String firstName = (String) result[0];
    String lastName = (String) result[1];
    // 处理每个结果
}