JPA:如何读取实体的特定字段？

String jpql = "SELECT e.name, e.age FROM Entity e";
List<Object[]> results = entityManager.createQuery(jpql).getResultList();
for (Object[] result : results) {
    String name = (String) result[0];
    int age = (int) result[1];
    // 对结果进行处理
}

String sql = "SELECT name, age FROM entity_table";
List<Object[]> results = entityManager.createNativeQuery(sql).getResultList();
for (Object[] result : results) {
    String name = (String) result[0];
    int age = (int) result[1];
    // 对结果进行处理
}

public interface EntityProjection {
    String getName();
    int getAge();
}

@Repository
public interface EntityRepository extends JpaRepository<Entity, Long> {
    @Query("SELECT e.name AS name, e.age AS age FROM Entity e")
    List<EntityProjection> findNameAndAge();
}

List<EntityProjection> results = entityRepository.findNameAndAge();
for (EntityProjection result : results) {
    String name = result.getName();
    int age = result.getAge();
    // 对结果进行处理
}