JPA加入复合键的一部分

Question

我尝试使用JPA

连接两个表

第一个表与实体ReportTripSingle相关联 第二个表与实体TripData相关联 使用复合密钥（实体TripDataPK）

描述第二个表的主键

实体TripDataPK

@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;

}

实体TripData

public class TripData implements java.io.Serializable {

    @EmbeddedId
    private TripDataPK tripDataPK;

    // some properties ...

}

实体ReportTripSingle

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，我想加入ReportTripSingle和TripData

它不起作用：（

这是堆栈跟踪：

  

引起：org.hibernate.AnnotationException：   referencedColumnNames（FTP_ID）of   com.nexo.susan.be.model.ReportTripSingle.tripData引用   com.nexo.susan.be.model.TripData未映射到单个属性   org.hibernate.cfg.BinderHelper.createSyntheticPropertyReference（BinderHelper.java:336）     在   org.hibernate.cfg.ToOneFkSecondPass.doSecondPass（ToOneFkSecondPass.java:116）     在   org.hibernate.cfg.Configuration.processEndOfQueue（Configuration.java:1522）     在   org.hibernate.cfg.Configuration.processFkSecondPassInOrder（Configuration.java:1443）     在   org.hibernate.cfg.Configuration.secondPassCompile（Configuration.java:1346）     在   org.hibernate.cfg.Configuration.buildSessionFactory（Configuration.java:1737）

确实TripData没有映射到单个属性，但我想加入FTP_ID

问候。

Answer 1

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

如果有人有兴趣，这是我的实施：

实体ReportTripSingle

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

一个更好的选择是在{Joincolumn中使用修饰符insertable = false和updatable = false，如https://dwuysan.wordpress.com/2012/02/22/joincolumn-is-part-of-the-composite-primary-keys

所述

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;

}