CODEWITHSUNDEEP
javaentity-frameworkjpaentityjpa-2.0
timmornYE
timmornYE

Reputation: 728

Duplicate of Entity

I am not able to get this working and I find no example for my special case. In short words: I have a main entity with relationships. Now I want to make a copy of a sub-entity and link this new sub-entity to the main entity. Best I try to make a short example. I skip the getter and setter methods to make it shorter:

Entity Entry:

@Entity
public class Entry implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToMany(mappedBy = "entry", cascade=CascadeType.ALL)
    private List<EntryData> entriesDataList = new LinkedList<>();

    @OneToOne(cascade=CascadeType.ALL)
    private EntryData entryData;

}

Entity EntryData:

@Entity
public class EntryData implements Serializable{

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String subject;

    @ManyToOne(optional = false)
    private Entry entry;    

    @ManyToMany(mappedBy = "entries", cascade = {CascadeType.ALL} )
    private List<EntryTag> tags = new LinkedList<>();

}

Entity EntryTag:

@Entity
public class EntryTag  implements Serializable{

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(unique=true)
    private String name;

    @ManyToMany() 
    private List<EntryData> entries = new LinkedList<>();        

}

Now I want to do the following:

@Stateless
public class NewEntryData {

    @PersistenceContext
    private EntityManager em;

    public void makeNewEntryData(){
        Entry e = em.find(Entry.class, 10);
        em.detach(e);
        EntryData ed = e.getEntryData();
        ed.setSubject("New Subject");
        ed.setId(null);
        for (Iterator<EntryTag> it = ed.getTags().iterator(); it.hasNext();) {
            it.next().addEntryData(ed);            
        }
        em.merge(e);
    }   
}

What I expected:

A new Entity EntryData is generated which has the same content as the old one which was stored in Entry.entryData, except the new subject. In Entry.entryData a link to the new EntryData is generated. The old EntryData consists in the database as it was.

What I get at em.merge(e):

org.eclipse.persistence.exceptions.ValidationException
Exception Description: The attribute [id] of class [test.EntryData] is mapped to a primary key column in the database. Updates are not allowed.

Can someone help me how to solve this?

Upvotes: 1

Views: 132

Answers (1)

Naveen Kumar Alone
Naveen Kumar Alone

Reputation: 7678

Your column id of test.EntryData class is mapped as primary key, so updates are not allowed in id column

I think you are inserting duplicate value in id column

Upvotes: 1

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