java如何在hibernate实体中使用瞬态字段作为映射的键？

Question

我需要有一个项目的映射，但我需要设置“键”的项目是暂时的，hibernate无法将其设置为“键”。我怎么做

@Entity
@AssociationOverrides({
        @AssociationOverride(name = "rela.city", 
                         joinColumns = @JoinColumn(name = "cityId")),
        @AssociationOverride(name = "rela.person", 
                         joinColumns = @JoinColumn(name = "id")),
        @AssociationOverride(name = "rela.social", 
                         joinColumns = @JoinColumn(name = "code")) })
public class Person implements java.io.Serializable {
    @EmbeddedId
    private RelationshipId rela = new RelationshipId();

    @Transient
    public String getCode(){
         return rela.getSocial().geCode();
    }
    ....
}

@Entity
public class City implements java.io.Serializable {
    @OneToMany(fetch = FetchType.LAZY, 
               mappedBy = "rela.city", cascade = CascadeType.ALL)
    @MapKey(name = "code")
    Map<String, Person> People = new HashMap<>();
    ....
}

正如您所看到的，我想使代码成为映射的键，但它不起作用，因为代码是瞬态的