Help needed with JPA please...

[paulmkeogh]

Hi,

I have written a test that writes a record to the database twice. Everything is the same except for one element of the entity ID which I have defined as;

    @TableGenerator(name="CDR_GEN")
    @GeneratedValue(strategy=GenerationType.TABLE, generator="CDR_GEN")
    @Column(name="id", nullable=false)
    @NotNull
    public long getId() {
        return this.id;
    }
   
    public void setId(long id) {
        this.id = id;
    }

I thought this is enough to uniquely construct the entity ID but I get;

org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

When there is only one record, the ID is generated and makes it to the database just fine.

So, clearly the generated ID is not making it into the session - googling suggests I can wrap a TX around every DB write or call flush() but I was wondering if theres an alternative ? Or am I way off in this approach ?

Thanks,

[qwertywin]

    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO
    public long getId() {
        return this.id;
    }
         public void setId(long id) {
        this.id = id;
    }

should work

[chawax]

I used TABLE generation type too and it works fine for me. One difference I see is that you didn't add @javax.persistence.Id annotation to your getId() method. Maybe you should try this ;)

[paulmkeogh]

Thanks for the replies but I think the issue is a bit more complex.

@Id in this case is in fact part of a composite primary key.

And, according to this post on the Hibernate forum, you cannot use @GeneratedValue in an EmbeddedId class (the composite primary key).

See http://forums.hibernate.org/viewtopic.php?p=2393944&sid=57b20ef2c7de6f6bcba632130987bc22

So I guess its back to java.util.random and rolling my own IDs :-(