我有一个Article实体和一个ArticleCode实体 . Aritcle Code有文章伪造密钥,但也有第二和第三主键 .
以下示例是不可能的,因为文章不可序列化 . 有任何想法吗?
谢谢,拉尔夫
@Entity公共类文章{
@Id @GeneratedValue(strategy = GenerationType.TABLE)private Long id;
public Long getId() { return id; }
}
@Entity @IdClass(com.google.gwt.sample.stockwatcher.server.huflattich.ArticleCode.ComposedIdKey.class)public class ArticleCode {
@Id
@OneToOne
private Article article;
@Id
@Column(name="coding_system")
private String codingSystem;
@Id
private String code;
...
public static class ComposedIdKey implements Serializable {
public Article article;
public String codingSystem;
public String code;
public ComposedIdKey () { }
public ComposedIdKey(Article article, String codingSystem, String code) {
this.article = article;
this.codingSystem = codingSystem;
this.code = code;
}
...
}
}
1 回答
哦,在谷歌的BigTable中,不可能有一个以上的主键 .