Hello,
I would like to build an web application where the entity relationship looks
like as follow:
User 1 -> * Possibility * -> 1 Country
1 -> 1 Profile * -> 1 Country
............ *initialization and persistence*
User.getPossibilities().add(Possibility);Possibility.setCountry(Country);
User.setProfile(Profile);Profile.setCountry(Country);
em.persist(User);
............ *I got this error below*
WARNING: Exception:Detected attempt to establish CPossibility(no-id-yet) as
the
parent of CUser(46)/CProfile(47)/CCountry(48) but the entity identified by
CUser
(46)/CProfile(47)/CCountry(48) is already a child of
CUser(46)/CProfile(47). A
parent cannot be established or changed once an object has been persisted.
Does this concept goes against the GAE datastore hierarchy ?
There are many situation when we have to share the same locations among the
individual object.
What is the real solution on this issue ?
Thanks in advance.
cscsaba
*PS:Implementation of the entities*
....................................... CUser
@Entity
public class CUser {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="USER_ID")
private Key Id;
private String email;
@OneToMany(cascade = CascadeType.ALL)
private List<CPossibility> Possibilities = new
ArrayList<CPossibility>();
@OneToOne(fetch = FetchType.LAZY,cascade = CascadeType.ALL)
private CProfile Profile;
....................................... CPossibility
@Entity
public class CPossibility {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="POSSIBILITY_ID")
private Key id;
private String name;
@ManyToOne(fetch = FetchType.LAZY,cascade = CascadeType.ALL)
private CCountry country;
....................................... CProfile
@Entity
public class CProfile {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
private String phone;
@ManyToOne(fetch = FetchType.LAZY,cascade = CascadeType.ALL)
private CCountry country;
....................................... CCountry
@Entity
public class CCountry {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
private String name;
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