Cascading persist and existing object
- by user322061
Hello,
I am working with JPA and I would like to persist an object (Action) composed of an object (Domain).
There is the Action class code:
@Entity(name="action")
@Table(name="action")
public class Action {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="num")
private int num;
@OneToOne(cascade= { CascadeType.PERSIST, CascadeType.MERGE,
CascadeType.REFRESH })
@JoinColumn(name="domain_num")
private Domain domain;
@Column(name="name")
private String name;
@Column(name="description")
private String description;
public Action() {
}
public Action(Domain domain, String name, String description) {
super();
this.domain=domain;
this.name=name;
this.description=description;
}
public int getNum() {
return num;
}
public Domain getDomain() {
return domain;
}
public String getName() {
return name;
}
public String getDescription() {
return description;
}
}
When I persist an action with a new Domain, it works. Action and Domain are persisted. But if I try to persist an Action with an existing Domain, I get this error:
javax.persistence.EntityExistsException:
Exception Description: Cannot persist detached object [isd.pacepersistence.common.Domain@1716286]. Class> isd.pacepersistence.common.Domain Primary Key> [8]
How can I persist my Action and automatically persist a Domain if it does not exist? If it exists, how can I just persist the Action and link it with the existing Domain.
Best Regards,
FF
