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对于实施例其他ID,我有A级与级联到B:休眠级联从另一个数据库
public class A{
private String id;
private Set<B> bs = new HashSet<B>(0);
@Id
@GenericGenerator(name = "seq_id", strategy = generators.SequenceIdGenerator")
@GeneratedValue(generator = "seq_id")
@COLUMN(name="id" unique = true, nullable = false, length = 28)
public void getId(){
return this.id;
}
@OneToMany(fetch = FetchType.LAZY, mappedBy = "A")
@Cascade({CascadeType.SAVE_UPDATE, CascadeType.DELETE, CascadeType.PERSIST})
public void getBs(){
return bs;
}
}
和我有B,其具有它自己的ID和从A
public class B
String id;
String aId;
A a;
@Id
@GenericGenerator(name = "seq_id", strategy = "generators.SequenceIdGenerator")
@GeneratedValue(generator = "seq_id")
@Column(name = "ID", unique = true, nullable = false, length = 28)
public String getId() {
return this.id;
}
@Column(name = "A_ID", nullable = false, length = 28)
public String getAId() {
return aId;
}
public void setAId(String aId) {
this.aId = aId;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "A_ID", nullable = false, insertable = false, updatable = false)
@MapsId("aId")
public Admission getAdmission() {
return this.admission;
}
public void setAdmission(Admission admission) {
this.admission = admission;
}
包含ID的列
如何在保存A时自动分配aId?我想要设置一个ID,但是我总是得到一个错误,说A_ID不能设置为空。
谢谢!