Spring data JPA：在结果元组中找不到别名！执行自定义查询时出错

我正在尝试使用 mysql 数据库执行自定义查询@Queryspring data jpa 的注解。

该表是

+------------+---------------+------+-----+---------+-------+
| Field      | Type          | Null | Key | Default | Extra |
+------------+---------------+------+-----+---------+-------+
| id         | decimal(10,0) | NO   | PRI | NULL    |       |
| first_name | varchar(20)   | YES  |     | NULL    |       |
| last_name  | varchar(20)   | YES  |     | NULL    |       |
+------------+---------------+------+-----+---------+-------+

mysql 中的查询是

select last_name,count(last_name) as count from person group by last_name;

在 Spring data jpa 中实现这一点。我正在使用这个逻辑，

1. 创建另一个类CountPerson包含两个变量，last_name and count
2. 使用@Query编写查询，该方法返回对象列表CountPerson class.

spring data jpa 中的查询是

@Query("select p.lastName,count(p.lastName) as count from Person p group by p.lastName")

当代码编译并且网络服务器启动正常时，当我尝试运行相关方法时，我得到

There was an unexpected error (type=Internal Server Error, status=500).
No aliases found in result tuple! Make sure your query defines aliases!; nested exception is java.lang.IllegalStateException: No aliases found in result tuple! Make sure your query defines aliases!

搜索此错误显示spring data jpa：在结果元组中找不到别名！确保您的查询定义了别名这表明这是一个已修复的错误。所以我想我的问题是不同的

代码是

人物类

//imports

@Entity
@Table(name = "person")
public class Person{

    @Id
    Long id;
    String firstName;
    String lastName;

    private Person(){}
    //constructor
}

人员存储库类

//imports
@Transactional
public interface PersonRepository extends CrudRepository<Person,Long>{

    @Query("select p.lastName,count(p.lastName) as count from Person p group by p.lastName")
    public List<CountPerson> countbylastname();
}

控制器类

@Controller
public class PersonController{

    @Autowired
    PersonRepository repository;

    @RequestMapping("/count")
    @ResponseBody
    public List<CountPerson> countbylastname(){
        return repository.countbylastname();
    }
}

计数 Person 类

public class CountPerson{
    String lastName;
    int count;

    protected CountPerson(){}

    public CountPerson(String lastName,int count){
        this.lastName = lastName;
        this.count = count;
    }
}

快到了...（心里想，所以我希望它是完美的）您需要创建一个新的 CountPerson(...)

select new com.mypackage.CountPerson(p.last_name, count(p.last_name)) from person p ... 

JpaRepository只能轻松返回Person对象，但您可以自己在HQL中创建对象。