@ConstructorResult的情况下将@SqlResultSetMapping放在哪里 [英] Where to place @SqlResultSetMapping in case of @ConstructorResult

问题描述

我正在尝试使用jpa的EntityManager的createNativeQuery方法映射非实体pojo.通过使用这样的东西

I'm trying to map a non-entity pojo with the createNativeQuery method of entityManager of jpa. By using something like this

@SqlResultSetMapping(name="ResultMapping", 
classes={
@ConstructorResult(
     targetClass=Employee.class,
       columns={
          @ColumnResult(name="empID", type=Long.class),
          @ColumnResult(name="empName", type=String.class),
          }
   )
}
)
public class Loader{
 private EntityManager em;

 public void load(){

   Query query = em.createNativeQuery("select empID, empName from employee",  "ResultMapping");
   List<Employee> = query.getResultList();
 }

}

public class Employee{

 private long empID;
 private String empName;
 public Employee(long empid, String empname)
 {
     this.empID = empid;
     this.empName = empname;
 }
}

我收到unknown SqlResultSetMapping ResultMapping错误 我应该将SqlResultSetMapping放在哪里，以便EntityManager能够识别它?

I getting unknown SqlResultSetMapping ResultMapping error Where I am supposed to put SqlResultSetMapping so that the entityManager will able to recognize it?

推荐答案

我应该将SqlResultSetMapping放在哪里，以便EntityManager能够识别它?

Where I am supposed to put SqlResultSetMapping so that the entityManager will able to recognize it?

据我所见，它与持久性提供程序有所不同:

As far as I can see it varies from a persistence provider:

• EclipseLink :将其放在类路径中的任何类上

• Hibernate :将其放在任何带@Entity注释的类中；实际上，当我将其放在其他位置时，我能够重现该错误:

• EclipseLink: put it at any class in the classpath

• Hibernate: put it at any class annotated with @Entity; in fact I am able to reproduce the error when I put it elsewhere:

org.hibernate.MappingException: Unknown SqlResultSetMapping [ResultMapping]

在EclipseLink 2.5.2，Hibernate 4.3.8.Final上进行了测试

Tested with EclipseLink 2.5.2, Hibernate 4.3.8.Final

通常，为了使您的应用程序可跨JPA提供程序移植，最好将SqlResultSetMapping放在任何实体类中.

In general to make your application portable across JPA providers it would be the best to put SqlResultSetMapping at any entity class.

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