Question

Hibernate创建空的＆＃34; ID＆＃34;代码中的列，如本文所述。

如何调整它以不创建＆＃34; ID＆＃34;列（＆＃34; ID＆＃34;是创建列的确切名称）或者这不能更改？

    @Entity
    @Table(name = "CATEGORY_RELATIONS")
    public class CategoryRelations implements Serializable {
    private CategoryRelationsPrimaryKey id;
    @Id
    @Column(name = "CATEGORY_RELATIONS_CATEGORY_ID")
    private String categoryId;
    @Id
    @Column(name = "CATEGORY_RELATIONS_PARENT_ID")
    private String parentId;
    //getters and setters
    @Entity
    @IdClass(CategoryRelationsPrimaryKey.class)
    public class CategoryRelationsPrimaryKey implements Serializable {
        protected long categoryId;
        protected long parentId;
        //euqals, hashCode
    }
}

Answer 1

1）@IdClass应该站在实体，而不是复合id类;

2）如果您已按@Id标记了ID属性，则不需要单独的id属性：

@Entity
@Table(name = "CATEGORY_RELATIONS")
@IdClass(CategoryRelationsPrimaryKey.class)
public class CategoryRelations implements Serializable {

    @Id
    @Column(name = "CATEGORY_RELATIONS_CATEGORY_ID")
    private String categoryId;

    @Id
    @Column(name = "CATEGORY_RELATIONS_PARENT_ID")
    private String parentId;

    //...

}

public class CategoryRelationsPrimaryKey implements Serializable {
    protected String categoryId;
    protected String parentId;
    // ...
}

如果您需要一些名为id的属性，请将其设为transient以避免映射到数据库表列。

在Hibernate中删除复合键的冗余列

1 个答案: