JPA 2 "member of"语法不适用于父类(super class)成员

Question

基本上我有一个拒绝工作的命名查询“findServerWithNic”:

@Entity
@Table(name = "vnm_server")
@DiscriminatorValue("S")
@NamedQueries({
    @NamedQuery(
        name="findServerWithNic",
        query="SELECT s FROM Server s, Nic n "+
                "WHERE n.id = :nicId AND n member of s.nics"
    )
})
public class Server extends NetworkedDevice implements Serializable
{...}

nics 没有在 Server 中定义，而是在它的父类(super class) NetworkedDevice 中定义:

@Entity
@Table(name = "vnm_networked_device")
@DiscriminatorColumn(name = "c_device_type", discriminatorType = DiscriminatorType.CHAR)
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class NetworkedDevice extends AbstractIdentifyable implements Serializable
{
    @OneToMany(mappedBy = "connectedHost", cascade = CascadeType.ALL)
    @OrderColumn(name = "c_index")
    protected List<Nic> nics = new ArrayList<Nic>();

    public List<Nic> getNics() {
        return nics;
    }

    public void setNics(List<Nic> nics) {
        this.nics = nics;
    }
}

现在我有一个创建 Nic 实例的测试用例，并将其添加到服务器实例(s.getNics() 包含该实例，我检查过)但是查询的调用

public Server findVirtualServerOfNic(Long nicId) {        
    final Server network = em.createNamedQuery("findServerWithNic", Server.class)
                                .setParameter("nicId", nicId)
                                    .getSingleResult();
    return network;
}

导致 NoResultException

Caused by: javax.persistence.NoResultException: getSingleResult() did not retrieve any entities.
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.throwNoResultException(EJBQueryImpl.java:1246)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getSingleResult(EJBQueryImpl.java:750)
    at com.profitbricks.provisioning.vnm.jpa.impl.VNManagementJPAImpl.findVirtualServerOfNic(VNManagementJPAImpl.java:101)

最初 nics-member 是私有(private)的，但即使将其设置为 protected 也没有用。我们使用 eclipselink 2.2.0-M4 作为我们的 JPA 2-provider。这是 eclipselink 错误还是查询错误？

Answer 1

您是否提交或刷新了交易？如果没有，则数据库可能没有该值(取决于您的刷新模式)，因此您的查询将不会返回任何内容。

启用日志记录并包含 SQL。如果 SQL 正确？

“member of”通常是旧的 JPQL 语法，现在通常使用“join”代替

"SELECT s FROM Server s join s.mics n WHERE n.id = :nicId "