我有一个bean结构,如下所示。我面临的问题是在试图保留XBean时,我能够保存所有数据(即xName,pBean,qBean,rBean,kBeans在存储中都是可见的),但是没有Y_BEAN的条目。JPA ManyToOne字段没有储存
我对JPA注释非常新,所以不太确定我所做的是否正确。这个想法是有XBean的多个条目(即列表)与一个YBean实例
XBean也将举行一个YBean的实例作为其父,所以当我检索XBean时,我应该得到所有的数据。 @ManyToOne
注释有什么问题吗?
@Entity
@Table (name = "X_BEAN")
public class XBean implements XInterface {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
private String xName;
@OneToOne(cascade=CascadeType.ALL)
private PBean pBean;
@ManyToOne
@JoinColumn(name="y_id")
private YBean yBean;
@OneToOne(cascade=CascadeType.ALL)
private qBean qBean;
@OneToOne(cascade=CascadeType.ALL)
private RBean rBean;
@OneToMany (mappedBy="xBean", cascade=CascadeType.ALL)
private List<KBean> kBeans;
// getter setters for each are below ...
}
和YBean的结构如下图所示
@Entity
@Table (name = "Y_BEAN")
public class YBean implements XInterface {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
@OneToOne(cascade=CascadeType.ALL)
private ZBean zName;
@OneToOne(cascade=CascadeType.ALL)
private PBean pBean;
@OneToOne(cascade=CascadeType.ALL)
private RBean rBean;
@OneToMany (mappedBy="yBean", cascade=CascadeType.ALL)
private List<XBean> xBeans;
// getter setter for each are below ...
}
我使用谷歌App Engine的存储
这里'Key'的类型是什么? – erencan 2014-10-08 19:00:57
'Key'是'com.google.appengine.api.datastore.Key'。我正在使用谷歌App Engine的存储 – S4beR 2014-10-08 19:02:46