JPA NamedQueries與PK實體

我已經使用Netbeans生成實體類。我的類有一個複合主鍵，所以Netbeans爲我生成了一個額外的PK實體類。我希望在Entity類中使用NamedQuery，但由於傳遞給名爲查詢的參數是嵌入在PK類中的，因此NamedQuery調用失敗，查詢看起來不完整。JPA NamedQueries與PK實體

任何人都可以提供一個例子，我的代碼應該看起來像使用NamedQuery它有一個組合PK（@EmbeddedId關聯）嗎？下面失敗：

門面類（部分）：

@Stateless 
public class EMyEntityFacade extends AbstractFacade<EMyEntity> { 

public EMyEntityFacade() { 
    super(EMyEntity.class); 
} 

//does not work 
/* 
private Query queryByComp1Id(int comp1Id) { 
    Query query = this.getEntityManager().createNamedQuery("EMyEntity.findByComp1Id"); 
    query.setParameter("comp1Id", comp1Id); 
    return query; 
} 
*/ 

//any nearer? 
private Query queryByComp1d(int comp1Id) { 
    EMyEntityPK eMyEntityPK = new EMyEntityPK(); 

    Query query = this.getEntityManager().createNamedQuery("EMyEntity.findByComp1Id"); 

    eMyEntityPK.setComp1Id(comp1Id); 

    //how do I pass the eMyEntityPK through to the Entity so the query is well formed? 
    //??? 

    return query; 
} 

public List<EMyEntity> findByComp1Id(int comp1Id) { 
    Query query = queryByComp1Id(comp1Id); 
    return query.getResultList(); 
}

實體類（部分）：

@Entity 
@Table(name = "my_entity") 
@NamedQueries({ 
    @NamedQuery(name = "EMyEntity.findByComp1Id", 
    query = "SELECT e FROM EMyEntity e WHERE e.eMyEntityPK.comp1Id = :comp1Id"),...)}) 

public class EMyEntity implements Serializable { 
    private static final long serialVersionUID = 1L; 
    @EmbeddedId 
    protected EMyEntityPK eMyEntityPK; 
    @Basic(optional = false) 
    @Column(name = "inherit_from_parent") 
    ... 
    ... 
}

PK類（部分）：

@Embeddable 
public class EMyEntityPK implements Serializable { 
    @Basic(optional = false) 
    @Column(name = "comp1_id") 
    private int comp1Id; 
    @Basic(optional = false) 
    @Column(name = "comp2_id") 
    private int comp2Id; 
    ... 
    ... 
}

來源

2011-01-20 JPC

什麼是錯誤？ – Bozho 2011-01-20 18:50:55

顯示異常和堆棧跟蹤 – Bozho 2011-01-21 13:27:29

你應該通過誰代表主鍵的對象，而不僅僅是它的一個字段。如果您需要查詢部分pk，請在where子句中引用它：where pk.fld=

來源

2011-01-20 17:33:25 Bozho

JPA NamedQueries與PK實體

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