[英]CascadeType problem in One to Many Relation
I have two classes which have a Unidirectional One to Many relation with each other. 我有两个类,它们之间具有单向一对多关系。
public class Offer{
...
@OneToMany(cascade=CascadeType.ALL)
@JoinTable(name = "Offer_Fields",
joinColumns =
@JoinColumn(name = "OFFER_ID"),
inverseJoinColumns =
@JoinColumn(name = "FIELDMAPPER_ID"))
private Set<FieldMapper> fields = new HashSet<FieldMapper>();
}
@Entity
@Table(name = "FieldMapper")
public class FieldMapper implements Serializable {
@Id
@Column(name = "FIELDMAPPER_ID")
@GeneratedValue
private int id;
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name = "multilingual_field_fk")
private MultiLingual field;
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name = "multilingual_value_fk")
private MultiLingual value;
}
I want to store an Offer with a set of FieldMapper to database. 我想将具有一组FieldMapper的商品存储到数据库中。 When I Use CascadeType.ALL in my OneToMany, I got this error:
当我在OneToMany中使用CascadeType.ALL时,出现此错误:
org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
and when I change CascadeType to something else I got this error: 当我将CascadeType更改为其他内容时,出现此错误:
org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.RCSTT.library.FieldMapper
and here is where I save Offer : 这是我保存Offer的地方:
public void insert(Offer offer) throws SQLException {
Session session = HibernateUtil.getSession();
Transaction tx = session.beginTransaction();
session.save(offer);
tx.commit();
session.close();
}
and I don't use session in somewhere else. 而且我不在其他地方使用会话。
in tx.commit();
在
tx.commit();
line throws explained exceptions. 行抛出解释了异常。
Thanks for your help. 谢谢你的帮助。
The first exception leads me to believe that this is not a problem with your mapping/entities but with how the object lifecycle or Hibernate session is handled. 第一个例外使我相信这不是您的映射/实体的问题,而是对象生命周期或Hibernate会话的处理方式。
Are the FieldMappers that you're trying to save already persistent (in another session)? 您要保存的FieldMappers是否已经永久保存(在另一个会话中)? You might need to detach those first.
您可能需要先分离它们。
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