复合密钥部分的JPA连接

Question

我尝试用JPA连接两个表

第一个表与实体ReportTripSing相关联第二个表与实体TripData相关联第二个表的主键用复合键（实体TripDataPK）描述

@Embeddable
public class TripDataPK implements Serializable {


    public TripDataPK() {
    }

    @Column(name = "FTP_ID", nullable = false)
    private long ftpId;

    @Column(name = "FTP_BATCH_ID", nullable = false)
    private long ftpBatchId;

    @Column(name = "FTP_DAY", nullable = false)
    private long ftpDay;

}

public class TripData implements java.io.Serializable {

    @EmbeddedId
    private TripDataPK tripDataPK;

    // some properties ...

}

public class ReportTripSingle implements java.io.Serializable {


    @Id
    @Column(name = "TRE_ID", precision = 10, scale = 0)
    private long id;

    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name = "TRE_FTP_ID", referencedColumnName = "FTP_ID")
    private TripData   tripData;


}

如您所见，我想将ReportTripSingle与TripData结合起来

它不起作用：(

这是堆栈跟踪：

原因：组织。冬眠AnnotationException：com的referencedColumnNames（FTP\U ID）。nexo公司。苏珊。是模型ReportTripSingle。tripData引用com。nexo公司。苏珊。是模型TripData未映射到组织中的单个属性。冬眠cfg公司。活页夹帮助器。在org上创建SyntheticPropertyReference（BinderHelper.java:336）。冬眠cfg公司。ToOneFkSecondPass。doSecondPass（toonefksecondapass.java:116）位于org。冬眠cfg公司。配置位于组织的processEndOfQueue（Configuration.java:1522）。冬眠cfg公司。配置在org上处理FKSecondPassinOrder（Configuration.java:1443）。冬眠cfg公司。配置位于org的secondPassCompile（Configuration.java:1346）。冬眠cfg公司。配置buildSessionFactory（配置：1737）

实际上，TripData没有映射到单个属性，但我想加入FTP\U ID

当做

Answer 1

我无法加入复合键的一部分。为了解决这个问题，我修改了与实体ReportTripSingle关联的表，添加了ftpBatchId和ftpDay作为外键

如果有人感兴趣，以下是我的实现：

实体报告TripSingle

public class ReportTripSingle implements java.io.Serializable {

@Id
@Column(name = "TRE_ID", precision = 10, scale = 0)
private long id;

@Column(name = "TRE_FTP_ID", length = 15, nullable = false, precision = 10, scale = 0, insertable = false, updatable = false)
private long tripDataId;

@Column(name = "TRE_BATCH_ID", nullable = false, insertable = false, updatable = false)
private long tripBatchId;

@Column(name = "TRE_FTP_DEP_DAY", nullable = false,insertable = false, updatable = false)
private long tripDay;

@ManyToOne(fetch = FetchType.EAGER)
@JoinColumns({
        @JoinColumn(name = "TRE_FTP_ID", referencedColumnName = "FTP_ID"),
        @JoinColumn(name = "TRE_BATCH_ID", referencedColumnName = "FTP_BATCH_ID"),
        @JoinColumn(name = "TRE_FTP_DEP_DAY", referencedColumnName = "FTP_DAY")

})
private TripData tripData;
}

Answer 2

更好的选择是在@Joincolumn中使用修饰符insertable=false和updateable=false，如中所述：https://dwuysan.wordpress.com/2012/02/22/joincolumn-is-part-of-the-composite-primary-keys

public class ReportTripSingle implements java.io.Serializable {


    @Id
    @Column(name = "TRE_ID", precision = 10, scale = 0)
    private long id;

    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name = "TRE_FTP_ID", referencedColumnName = "FTP_ID", **insertable = false, updatable = false**)
    private TripData   tripData;

}