休眠如何保存ManyToOne

Question

我有两个实体Equipement和Company，如下所示：

public class Equipement{
  String type ;
  Company company ;
  @ManyToOne(cascade = CascadeType.ALL)
  public Company getCompany(){
    return this.company ;
  }
}
public class Company{
  // fields getters setters ..
}

每个Equipement都是从Company购买的，我需要创建Company，然后将其注入Equipement

Session session = SessionFactory.openSession() ;
Transaction tx = session.beginTransaction() ;
Equipement equipement = new Equipement() ;
Company company = new company() ;
equipement.setCompany(company) ;
session.save(equipement) ;
tx.commit() ;
session.close() ;

这给了我一个例外

TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: org.marsamaroc.mmapp.domain.Company

Answer 1

尝试

public class Company 
{
    @OneToMany(cascade = CascadeType.ALL)
    public Set<Equipement> getEquipements() { ... }
}

和

...
Session session = SessionFactory.openSession() ;
Transaction tx = session.beginTransaction() ;
Equipement equipement = new Equipement() ;
Company company = new company() ;
equipement.setCompany(company) ;
// Save should cascade (i.e. "equipment" should be saved too).
session.save(company) ;
tx.commit() ;
session.close() ;
...

顺便说一句，在英语中，它是"设备"，没有额外的"e"（如果你在乎的话！）。