Java 如何使用嵌入式id编写JPQL SELECT？

我正在使用Toplink essentials JPA+GlassFish v3+NetBean 6.9

我有一个具有复合主键的表：

table (machine)
----------------
|PK machineId  |
|PK workId     |
|              |
|______________|

我创建了两个实体类，一个是实体本身，第二个是PK类

public class Machine {
   @EmbeddedId
   protected MachinePK machinePK;

   //getter setters of fields..
}

public class MachinePK {
    @Column(name = "machineId")
    private String machineId;

    @Column(name = "workId")
    private String workId;

}

现在。。如何使用JPQL编写SELECT子句，其中包含WHERE

这是失败的

SELECT m FROM Machine m WHERE m.machineId = 10

根据网页，添加val？不，它也失败了

   SELECT m FROM Machine m WHERE m.machineId.val = 10

在这两种情况下，错误都是：

    Exception Description: Error compiling the query 
[SELECT m FROM Machine m WHERE m.machineId.val = 10], 
line 1, column 30: unknown state or association field 
[MachineId] of class [entity.Machine].

使用Hibernate4.1和JPA2.0进行测试

进行以下更改以正常工作：

类Machine.java

类MachinePK.java

…对于JPQL查询，传递所有列名：

Query query = em.createQuery("SELECT c.machinePK.machineId, c.machinePK.workId, "
                + "FROM Machine c WHERE c.machinePK.machineId=?");
query.setParameter(1, "10");

Collection results = query.getResultList();

Object[] obj = null;
List<MachinePK> objPKList = new ArrayList<MachinePK>();
MachinePK objPK = null;
Iterator it = results.iterator();
while(it.hasNext()){
    obj = (Object[]) it.next();
    objPK = new MachinePK();
    objPK.setMachineId((String)obj[0]);
    objPK.setWorkId((String)obj[1]);
    objPKList.add(objPK);
    System.out.println(objPK.getMachineId());
}

---

如果使用注释，可以使用element=true。

如何将其转换为JPA标准？从机器m中选择m，其中m.machinePK.machineId=：标准如果使用HQL，您也可以从机器m中选择m，其中m.machinePK在：listOfKeys中？在这种情况下，可嵌入类中的字段也是其他用户定义的类，我必须计算该用户定义类中的字段。你知道怎么做吗@QuerySelecte e from electionCompetitor e其中e.primaryKey.Competitor.Competitive ID=？{0}和e.primaryKey.election.elecId=？{1}

public class Machine {
   @EmbeddedId
   protected MachinePK machinePK;

   //getter & setters...
}

@Embeddable
public class MachinePK {
    @Column(name = "machineId")
    private String machineId;

    @Column(name = "workId")
    private String workId;

    //getter & setters...
}

Query query = em.createQuery("SELECT c.machinePK.machineId, c.machinePK.workId, "
                + "FROM Machine c WHERE c.machinePK.machineId=?");
query.setParameter(1, "10");

Collection results = query.getResultList();

Object[] obj = null;
List<MachinePK> objPKList = new ArrayList<MachinePK>();
MachinePK objPK = null;
Iterator it = results.iterator();
while(it.hasNext()){
    obj = (Object[]) it.next();
    objPK = new MachinePK();
    objPK.setMachineId((String)obj[0]);
    objPK.setWorkId((String)obj[1]);
    objPKList.add(objPK);
    System.out.println(objPK.getMachineId());
}