Hello every one. In my application i've the following mapping for a one-to-many relationship between 2 tables.
<hibernate-mapping package="com.mccalv.dbObject">

<class name="Contenuti" table="contenuti">
<id name="idcontenuti" column="idContenuti" type="integer">
<generator class="native"/>
</id>

<property name="titolo" column="titolo" type="string" not-null="true" />
<property name="idautore" column="idAutore" type="integer" not-null="true" />
<property name="dataimmissione" column="dataImmissione" type="timestamp" not-null="true" />
<property name="datapubblicazione" column="dataPubblicazione" type="timestamp" not-null="true" />
<property name="approvato" column="approvato" type="integer" not-null="true" />
<property name="datariferimento" column="dataRiferimento" type="timestamp" not-null="true" />
<property name="idschede" column="idSchede" type="integer" not-null="true" />
<property name="idcategoria" column="idCategoria" type="integer" not-null="true" />
<set name="contenuticampi" cascade="all" order-by="ordine ASC">
<key column="idContenuti"></key>
<one-to-many class="Contenuticampi"></one-to-many>
</set>

</class>
</hibernate-mapping>
And..

hibernate-mapping package="com.mccalv.dbObject">

<class name="Contenuticampi" table="contenuticampi">
<id name="idcontenuticampi" column="idContenutiCampi" type="integer">
<generator class="native"/>
</id>

<property name="nomecampo" column="nomeCampo" type="string" />
<property name="value" column="value" type="string" />


<property name="ordine" column="ordine" type="integer" not-null="true" />
</class>

</hibernate-mapping>
Every works fine for INSERT AND DELETE.
When i update a Contenuti Hibernate writes the data twice, first time with the rigth association and second time with the foreign key as "null".
The code i use for update is the following.
java.util.Date date=new java.util.Date();
contenuti.setTitolo(manageContenutiForm.getTitolo());
contenuti.setIdautore(Integer.parseInt(""+request.getSession().getAttribute("idutenti")));
contenuti.setIdcategoria(manageContenutiForm.getIdcategoria());
contenuti.setIdschede(manageContenutiForm.getIdschede());
contenuti.setDataimmissione(date);
contenuti.setDatapubblicazione(date);


contenuti.setDatariferimento(date);

contenuti.setApprovato(0);
int fieldNumber= Integer.parseInt(""+request.getParameter("len"));
String field = null;
String name=null;

Set contentFields= new HashSet();

if (request.getParameter("len")!=null){
for (int i=1;i<=fieldNumber;i++){

field =request.getParameter("field"+i);
name= request.getParameter("field"+i+"[name]");

Contenuticampi contenuticampi=new Contenuticampi();
contenuticampi.setNomecampo(name);
contenuticampi.setOrdine(i);
contenuticampi.setValue(field);
}
contenuti.setContenuticampi(contentFields);
}



try{

s.update(contenuti);
....

Hello My Friend:

After read your code, i saw a point that is the reason which cause you that problem.

If you see your code:

[code] Contenuticampi contenuticampi=new Contenuticampi()[/code]
contenuticampi.setNomecampo(name);
contenuticampi.setOrdine(i);
contenuticampi.setValue(field);

You are instancing a "new" Object without its original Id. So, when you want to update it, it`s natural say you "id is null...", and so on.

I suggest you obtain the ID for that Object, then you can execute update job.

request for comments.

Neketsu Shonen[/code][/quote]