Java Hibernate:与InheritanceType.Single_表中的子类的关系

MyObject有两个子类：SubObject 1和SubObject 2。现在我又有了一个实体：OtherClass。OtherClass与子对象1之间存在1:1关系，OtherClass与子对象2之间存在1:n关系

MyObject:

@Entity
@Table( name = "MYOBJECT" )
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn( name = "OBJ_TYP", discriminatorType = DiscriminatorType.STRING )
public abstract class MyObject{

     @Id
     @Column( name = "OBJ_ID")
     private Long id;

     ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB1" )
public class SubObject1 extends MyObject{
    @OneToOne(mappedBy="subObject1")
    private OtherClass otherClass;
    ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB2" )
public class SubObject2 extends MyObject{

    @OneToMany(mappedBy="subObject2")
    private Set<OtherClass> otherClassList;  
    ...
}

@Entity
@Table( name = "OTHER")
public class OtherClass{

    @OneToOne
    @JoinColumn(name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable=true)
    private SubObject1 subObject1;

    @ManyToOne
    @JoinColumn( name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable = true)
    private SubObject2 subObject2;

}

子对象1:

@Entity
@Table( name = "MYOBJECT" )
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn( name = "OBJ_TYP", discriminatorType = DiscriminatorType.STRING )
public abstract class MyObject{

     @Id
     @Column( name = "OBJ_ID")
     private Long id;

     ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB1" )
public class SubObject1 extends MyObject{
    @OneToOne(mappedBy="subObject1")
    private OtherClass otherClass;
    ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB2" )
public class SubObject2 extends MyObject{

    @OneToMany(mappedBy="subObject2")
    private Set<OtherClass> otherClassList;  
    ...
}

@Entity
@Table( name = "OTHER")
public class OtherClass{

    @OneToOne
    @JoinColumn(name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable=true)
    private SubObject1 subObject1;

    @ManyToOne
    @JoinColumn( name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable = true)
    private SubObject2 subObject2;

}

子对象2:

@Entity
@Table( name = "MYOBJECT" )
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn( name = "OBJ_TYP", discriminatorType = DiscriminatorType.STRING )
public abstract class MyObject{

     @Id
     @Column( name = "OBJ_ID")
     private Long id;

     ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB1" )
public class SubObject1 extends MyObject{
    @OneToOne(mappedBy="subObject1")
    private OtherClass otherClass;
    ...
}

@Entity
@Table( name = "MYOBJECT" )
@DiscriminatorValue( value = "SUB2" )
public class SubObject2 extends MyObject{

    @OneToMany(mappedBy="subObject2")
    private Set<OtherClass> otherClassList;  
    ...
}

@Entity
@Table( name = "OTHER")
public class OtherClass{

    @OneToOne
    @JoinColumn(name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable=true)
    private SubObject1 subObject1;

    @ManyToOne
    @JoinColumn( name = "OTHER_OBJ_ID", referencedColumn = "OBJ_ID", nullable = true)
    private SubObject2 subObject2;

}

现在，当我有一个hql查询时，如：

FROM OtherClass c LEFT JOIN FETCH c.subObject1 LEFT JOIN FETCH c.subObject2

我得到：

java.lang.RuntimeException: org.hibernate.MappingException: Repeated column in mapping for entity: ...OtherClass column: OTHER_OBJ_ID (should be mapped with insert="false" update="false")

我知道“其他对象ID”列重复出现。但是为什么我不能那样做呢？我认为hibernate可以找出应该存在哪种类型的实体，因为声明了鉴别器值。我真的不想在另一个表中添加列。是否可以在不添加新列并分离obj1和obj2的情况下执行此操作

---

请帮帮我

您别无选择，只能在映射中使用不同的列，或者使用一个单一的MyObject集合，让Java代码或HQL获取您要查找的子类。

AFAIK，不，这是不可能的。假设我初始化bith subObject1和subObject2，那么在unique列中Hibernate stre将是什么？应用程序的上下文不允许这两种情况。所以这永远不会发生。但是Hibernate不知道上下文。它将一个关联映射到一列，仅此而已。是否可以告诉hibernate其中至少有一个始终为空？我可以更改java模型，但如果可能的话，我不想更改数据库。不，我不这么认为。