java覆盖@CollectionTable

Question

我需要覆盖JPA中的collectiontable？也许有人有主意

 public class nationality{
       @Embedded
       @AttributeOverrides({
              @AttributeOverride(name="language.language", column = @Column(name="code_lang")) })
       private Language language;
    .....

语言课

@Embeddable
public class Language{
  @ElementCollection(fetch = FetchType.Eager)
  @CollectionTable(name="nat", joinColumns = @JoinColumn(name = "id"))
  private Collection<LanguageObj> language;
...
}

这正在工作，但@CollectionTable链接必须发生在National类中。如何做到这一点

类语言必须被从不同表获取数据的其他类重用。 问题是表中已经存在数据，因此无法编辑该表 比如从国家表格中获取数据的国家

public class country{
       @Embedded
       @AttributeOverrides({
              @AttributeOverride(name="language.language", column = @Column(name="code_country")) })
       private Language language;
    .....
}

Answer 1

以下是解决方案
总体思路是：
1.在可嵌入对象注释集合字段中，使用@ElementCollection
2.在实体中，用@CollectionTable注释集合getter。getter应该转发给Embeddeble的getter。对于每个实体，可以在@CollectionTable注释中指定单独的表名

enum DayOfWeek {
    MONDAY,TUESDAY,...
}

@Embeddable
class ScheduleProperties {
    ...
    @ElementCollection
    private List<DayOfWeek> daysOfWeek;
    ...
    public List<DayOfWeek> getDaysOfWeek() {
        return daysOfWeek;
    }
}

@Entity
class SomeEntity {
    ...
    @Embedded
    private ScheduleProperties embd = new ScheduleProperties();
    ...
    @CollectionTable(name="some_entity_days_of_week")
    public List<DayOfWeek> getDaysOfWeek() {
        return embd.getDaysOfWeek();
    }
}

@Entity
class AnotherEntity {
    ...
    @Embedded
    private ScheduleProperties embd = new ScheduleProperties();
    ...
    @CollectionTable(name="another_entity_days_of_week")
    public List<DayOfWeek> getDaysOfWeek() {
        return embd.getDaysOfWeek();
    }
}

Answer 2

像使用@AttributeOverride(s)一样使用@AssociationOverride(s)

@AssociationOverride(name = "language",
                     joinTable = @JoinTable(name = "nat",
                                            joinColumns = @JoinColumn(name = "id")))