Hi,

I have an method that tries to update a hibernate mapped object. The object that I am trying to update is a Product object which has a many-to-many relationship with the supplier objects.

1. public ProductDataObject updateProduct(ASObject asProduct) {
2. Product product = (Product) new ASTranslator().fromActionScript(asProduct);
3. return (ProductDataObject) new ProductDAO().makePersistent(product).getDataObject();
4. }

On line 2. the product object is fully populated except for the "supplier" field which is a Set of Supplier objects. The "supplier" field is null at this stage. When I try to save this Product object on line 3 there is a query executed that deletes the existing supplier relationship. Other than trying to select the supplier collection from the database is there another way that I can stop this relationship deletion from happening?

Is there a way to tell hibernate to only delete collections when I specify it? I essentially only want hibernate to update relationships when the code tells it to. (or the mapping files tell it to).

Any pointers would be appreciated.

Thanks

Jordan

[b]Hibernate version:3.05

[b]Name and version of the database you are using:MySQL

[b]The generated SQL (show_sql=true):

Can you include your mapping files.

Thanks for the reply. Here are two mapping files which specify the many-to-many relationship between a Product and an Outlet. In my original post I should have said Outlet and not Supplier. It's the same problem though.

It seems that if I set the collections to 'null' then I get the deletion. If I set them to the populated collections then it is ok.

I suspect that I must be missing an attribute on one of the mappings. Again, any help would be most appreciated.

Thanks again

Jordan

////////////////////////////
Product mapping file
///////////////////////////

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="uk.co.caley.vo.Product"
table="PRODUCT"
dynamic-update="true"
dynamic-insert="true"
select-before-update="true"
>

<id
name="id"
column="ID"
type="java.lang.Long"
length="10"
>
<generator class="native">
<!--
To add non XDoclet generator parameters, create a file named
hibernate-generator-params-Product.xml
containing the additional parameters and place it in your merge dir.
-->
</generator>
</id>

<property
name="productName"
type="java.lang.String"
update="true"
insert="true"
>
<column
name="PRODUCT_NAME"
length="250"
not-null="true"
unique="false"
sql-type="VARCHAR (250)"
/>
</property>

<set
name="discounts"
lazy="true"
inverse="false"
cascade="delete-orphan"
sort="unsorted"
order-by="DATE_ADDED"
>

<key
column="PRODUCT_ID"
>
</key>

<one-to-many
class="uk.co.caley.vo.Discount"
/>

</set>

<set
name="outlets"
table="PRODUCT_OUTLET"
lazy="true"
inverse="true"
cascade="none"
sort="unsorted"
>

<key
column="PRODUCT_ID"
>
</key>

<many-to-many
class="uk.co.caley.vo.Outlet"
column="OUTLET_ID"
outer-join="auto"
/>

</set>

</class>

</hibernate-mapping>


////////////////////////////
Outlet mapping file
///////////////////////////

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="uk.co.caley.vo.Outlet"
table="OUTLET"
dynamic-update="true"
dynamic-insert="true"
select-before-update="true"
>

<id
name="id"
column="ID"
type="java.lang.Long"
length="10"
>
<generator class="native">
<!--
To add non XDoclet generator parameters, create a file named
hibernate-generator-params-Outlet.xml
containing the additional parameters and place it in your merge dir.
-->
</generator>
</id>

<property
name="outletName"
type="java.lang.String"
update="true"
insert="true"
>
<column
name="OUTLET_NAME"
length="250"
not-null="true"
unique="false"
sql-type="VARCHAR (250)"
/>
</property>

<set
name="discounts"
lazy="true"
inverse="true"
cascade="delete-orphan"
sort="unsorted"
>

<key
column="OUTLET_ID"
>
</key>

<one-to-many
class="uk.co.caley.vo.Discount"
/>

</set>

<set
name="products"
table="PRODUCT_OUTLET"
lazy="true"
inverse="false"
cascade="none"
sort="unsorted"
>

<key
column="OUTLET_ID"
>
</key>

<many-to-many
class="uk.co.caley.vo.Product"
column="PRODUCT_ID"
outer-join="auto"
/>

</set>

</class>

</hibernate-mapping>