通过额外的属性来休眠多对多

Question

我遵循教程mkyong Hibernate - 多对多示例 - 连接表+额外列（注释），以便在我的两个类MachineJob和MachineJobPart之间创建多对多关联。我希望关联的表有额外的列，所以我需要执行以下步骤，

MachineJob表格结构：

CREATE TABLE machine_job
(
  id uuid NOT NULL DEFAULT uuid_generate_v4(),
)

MachineJobPart表格结构：

CREATE TABLE machine_job_part
(
  id uuid NOT NULL DEFAULT uuid_generate_v4(),
  machine_job_id uuid,
  part_id uuid,
  part_cost double precision,
  part_quantity integer,
  total_part_cost double precision,
  CONSTRAINT machine_job_part_pkey PRIMARY KEY (id),
  CONSTRAINT machine_job_part_machine_job_id_fkey FOREIGN KEY (machine_job_id)
      REFERENCES machine_job (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION,
  CONSTRAINT part_tbl_fkey FOREIGN KEY (part_id)
      REFERENCES part (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION
)

我的代码运行正常，但问题是machine_job_id没有保存在machine_job_part表中。

@Entity
@Table(name = "machine_job")
public class MachineJob implements Serializable {

    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid2")
    @Column(name = "id")
    @Type(type = "pg-uuid")
    private UUID id;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.machineJob", cascade=CascadeType.ALL)
    private Set<MachineJobPart> machineJobParts = new HashSet<MachineJobPart>(0);

     @Column(name = "created_date")
    private Date createdDate;

    public UUID getId() {
        return id;
    }

    public void setId(UUID id) {
        this.id = id;
    }

    public void setJobManHoursCost(Double jobManHoursCost) {
        this.jobManHoursCost = jobManHoursCost;
    }

    public Set<MachineJobPart> getMachineJobParts() {
        return machineJobParts;
    }

    public void setMachineJobParts(Set<MachineJobPart> machineJobParts) {
        this.machineJobParts = machineJobParts;
    }

}


@Entity
@Table(name = "machine_job_part")
@AssociationOverrides({
    @AssociationOverride(name = "pk.machineJob",
            joinColumns = @JoinColumn(name = "machine_job_id")),
    @AssociationOverride(name = "pk.part",
            joinColumns = @JoinColumn(name = "part_id"))})
public class MachineJobPart implements Serializable {

    private static final long serialVersionUID = 1L;

    private MachineJobPartId pk = new MachineJobPartId();

    private UUID id;

    private double partCost;

    private Integer partQuantity;

    private Double totalPartCost;

    @EmbeddedId
    public MachineJobPartId getPk() {
        return pk;
    }

    public void setPk(MachineJobPartId pk) {
        this.pk = pk;
    }

    @Column(name = "part_cost")
    public double getPartCost() {
        return partCost;
    }

    public void setPartCost(double partCost) {
        this.partCost = partCost;
    }

    @Transient
    public MachineJob getMachineJob() {
        return getPk().getMachineJob();
    }

    public void setMachineJob(MachineJob machineJob) {
        getPk().getMachineJob();
    }

    @Transient
    public Part getPart() {
        return getPk().getPart();
    }

    public void setPart(Part part) {
        getPk().setPart(part);
    }

    @GeneratedValue(generator = "system-uuid")
    @Column(name = "id", insertable = false, updatable = false)
    public UUID getId() {
        return id;
    }

    public void setId(UUID id) {
        this.id = id;
    }

    @Column(name = "part_quantity")
    public Integer getPartQuantity() {
        return partQuantity;
    }

    public void setPartQuantity(Integer partQuantity) {
        this.partQuantity = partQuantity;
    }

    @Column(name = "total_part_cost")
    public Double getTotalPartCost() {
        return totalPartCost;
    }

    public void setTotalPartCost(Double totalPartCost) {
        this.totalPartCost = totalPartCost;
    }

}

@Embeddable
public class MachineJobPartId implements java.io.Serializable {

    private MachineJob machineJob;

    private Part part;

    @ManyToOne
    public MachineJob getMachineJob() {
        return machineJob;
    }

    public void setMachineJob(MachineJob machineJob) {
        this.machineJob = machineJob;
    }
    @ManyToOne
    public Part getPart() {
        return part;
    }

    public void setPart(Part part) {
        this.part = part;
    }
}