one-to-many,bidirectionnal : could not save object

xavan · **Joined:** Tue Nov 15, 2005 2:14 am **Posts:** 7

I received a could not save object exception and the InnerException is :
Unable to cast object of type 'System.Collections.ArrayList' to type 'Iesi.Collections.ISet'

Summary of the two classes :

Code:

public class Product
{
      private int id;
      private String name;
      private ArrayList releases; //I also try an ISet but with the same class cast exception
                
                // + properties
}


public class ProductRelease
{
      private int id;
      private String name;
      private DateTime released;
      private Product product;
}

So a product can have more than one release.

The mapping files :

Code:

<?xml version="1.0"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
   <class name="sgub.ProductRelease, sgub" table="productrelease">
      <id name="Id" column="id" > 
         <generator class="native" /> 
      </id> 
      <property name="Name" column= "name" type="String" length="45" /> 
      <property name="Released" column= "productreleased" type="Date" /> 
      <many-to-one name="Product" column="productid" not-null="true" />
      
   </class>

</hibernate-mapping>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
   <class name="sgub.Product, sgub" table="product">
      <id name="Id" column="id" > 
         <generator class="native" /> 
      </id> 
      <property name="Name" column= "name" type="String" length="45"/> 
      <set name="Releases" inverse="true">
         <key column="id" />
         <one-to-many class="sgub.ProductRelease, sgub" />
      </set>
      
   </class>
</hibernate-mapping>

And the way I save the objects

Code:

Product nutella=new Product();
nutella.Name="Nutella";

ProductRelease alpha=new ProductRelease();
alpha.Name="alpha";
alpha.Released=DateTime.Now;
      
nutella.Releases.Add(alpha);
alpha.Product=nutella;

session =factory.OpenSession();
transaction = session.BeginTransaction();
session.Save(nutella);
session.Flush();
transaction.Commit();

Guest · **Posted:** Mon Dec 12, 2005 12:34 pm

OK I replace ArrayList by ISet but now my program save only the Product object and not the ProductReleases objects :-(

Why?

xavan · **Joined:** Tue Nov 15, 2005 2:14 am **Posts:** 7

Ok I call the save method on all the objects:

Code:

session.Save(nutella);
session.Save(alpha);
session.Save(beta);

Is it an expected behavior? :?:

heyvenki · **Posted:** Mon Dec 12, 2005 1:31 pm

With the given hbm, yes this is the expected behaviour.

If you want to save the children when saving the parent, then use the cascade attribute in your parent definition. Just for saving and updating alone, use "save-update". In case u want to have this behaviour for save, update and delete, use cascade="all".