Error: hibernate using Bag semantic with Set ?

lsbarbosa · **Joined:** Fri Mar 03, 2006 3:47 pm **Posts:** 6

Hello,

I'm trying to avoid bag semantic with the property perfis in this Entity.

According to the documentation, I should change the type from List to Set :

Code:

@Entity
@Table(name = "PB_USUARIO")
@SequenceGenerator(name="SEQ_USUARIO", sequenceName="PB_USUARIO_SEQ") 
public class Usuario  implements java.io.Serializable {

   private Set<Perfil> perfis;
...

    @ManyToMany
    @JoinTable(
        name="PB_USUARIO_PERFIL"
        ,joinColumns={@JoinColumn(name="codusr")}
        ,inverseJoinColumns={@JoinColumn(name="codpfl")}
    )
    public Set<Perfil> getPerfis() {
        return perfis;
    }
    public void setPerfis(Set<Perfil> perfis) {
       this.perfis = perfis; 
    }

}

But hibernate still deletes my records inside PB_USUARIO_PERFIL :

Hibernate: delete from PB_USUARIO_PERFIL where codusr=?
Hibernate: insert into PB_USUARIO_PERFIL (codusr, codpfl) values (?, ?)
Hibernate: insert into PB_USUARIO_PERFIL (codusr, codpfl) values (?, ?)
Hibernate: insert into PB_USUARIO_PERFIL (codusr, codpfl) values (?, ?)

Then I tried to change it to List again, but using de @IndexColumn + @OrderBy

Code:

@Entity
@Table(name = "PB_USUARIO")
@SequenceGenerator(name="SEQ_USUARIO", sequenceName="PB_USUARIO_SEQ") 
public class Usuario  implements java.io.Serializable {

    private Set<Perfil> perfis;
...

    @ManyToMany
    @JoinTable(
        name="PB_USUARIO_PERFIL"
        ,joinColumns={@JoinColumn(name="codusr")}
        ,inverseJoinColumns={@JoinColumn(name="codpfl")}
    )
    @IndexColumn(name="codusr")
    @OrderBy("codusr")
    public List<Perfil> getPerfis() {
        return perfis;
    }
    public void setPerfis(List<Perfil> perfis) {
       this.perfis = perfis; 
    }

}

But the SessionFactory thrown an exception when I tried to run configure()

Code:

           sessionFactory = new AnnotationConfiguration().configure("br/com/brti/si/sistemas/hibernate/hibernate.cfg.xml").buildSessionFactory();

I'm using
<mapping class="XXX">
for mapping all the Entitys, wo any special property.

[10/03/2006 20:22:35] 10 - SEVERE - br.com.brti.si.L : Initial SessionFactory creation failed.org.hibernate.MappingException: Repeated column in mapping for collection: br.com.brti.si.sistemas.hibernate.Usuario.perfis column: codusr
[10/03/2006 20:22:35] 10 - SEVERE - br.com.brti.si.L : Erro na inicialização do publicador : null
java.lang.ExceptionInInitializerError
at br.com.brti.si.sistemas.hibernate.HibernateUtil.<clinit>(HibernateUtil.java:29)
at br.com.brti.si.sistemas.publicador.servlets.Inicializador.init(Inicializador.java:32)
at javax.servlet.GenericServlet.init(GenericServlet.java:211)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1105)

If I tried to remove the joinColumns and/or inverseJoinColumns properties from @JoinTable, to avoid "Repeated column in mapping ..." error, hibernate used the wrong columns to do the join (as I expected...)

What should I do to avoid bag sematic???

Thanks in advance,
Leonardo Barbosa

Hibernate version:
3.1 with annotations beta8

emmanuel · **Posted:** Sun Mar 12, 2006 5:13 pm

you cannot mix @IndexColumn and @OrderBy, this does not make sense

lsbarbosa · **Joined:** Fri Mar 03, 2006 3:47 pm **Posts:** 6

emmanuel wrote:

you cannot mix @IndexColumn and @OrderBy, this does not make sense

Thanks for your help.
I didn't quite understood the meaning of @IndexColumn. I used it because the documentation was clear:

So specifically, java.util.List collections wo @OrderBy nor @org.hibernate.annotations.IndexColumn are going to be considered as bags.
http://www.hibernate.org/hib_docs/annotations/reference/en/html_single/#entity-mapping-association-collections

I tried them one at a time: @IndexColumn and @OrderBy, but didn't work too. @indexColumn is the index in the database that hibernate should use? I think I really didin't get this one. (I got @OrderBy, at least :)
I tried to use java.util.Set either, but guess what? Bag semantic again...
I just can't avoid Hibernate deleting my records and inserting everything again.

Am I right about that? Bag semantic will delete everything, and reinsert.
List, Set and Map semantics will insert and delete only the modified fields. Aint that right?

As I couldn't avoid delete, and I have a method that have access only to some items from the Bean List, and I needed to update the list, I created a workarround.

FYI, I created a method that: gets the list from the Bean, get a map from the servlet, remove the items from the Bean-list that are NULL in the servlet-map (key exists AND value are null), insert the items from the servlet-map that doesn't existis in the Bean-list, and let the items in the Bean-list, that doesn't existis in the Servlet-map's keys, unchanged.

It seams to work (after I changed the relationship in the Bean to FetchType.EAGER).

If anybody knows how tell hibernate to do this (or anything similar), please let me know.

Thanks,
Leonardo Barbosa

emmanuel · **Posted:** Tue Mar 14, 2006 8:29 am

I do not reproduce this behavior for Sets, there should be something wrong somewhere