本文介绍了使用组合键加入实体的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有2个带有复合键的旧版数据库实体，其中之一具有带@EmbeddedId注释的复合键.
I have 2 entities for legacy db with composite keys, one of them has a composite key with @EmbeddedId annotation.
// first entity
@Entity
public class Product {
@Id
private Integer productId;
// lookup table contains code-description pairs
@OneToOne
private ProductDefects defects;
//getters and setters and other code omitted
}
// lookup entity
@Entity
public class ProductDefects {
@EmbededId
private ProductDefectsPK id;
//getters and setters and other code omitted
}
//composite key
@Embedable
public class ProductDefectsPk{
private Integer realId;
private String category;
}
我应该如何定义@OneToOne关系以进行连接，如以下示例所示:
How should I define the @OneToOne relation to join as in the following example:
select p.Id, pd.description
from Product p
inner join p.defects pd
推荐答案
我发现@MapsId注释在我的情况下有帮助 http://download.oracle.com/javaee/6/api/javax/persistence/MapsId.html
I figure out that @MapsId annotation helps in my case http://download.oracle.com/javaee/6/api/javax/persistence/MapsId.html
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