Hi there again!

I am still confused about association mapping in nHibernate and cant get a special case fixed :-(

In my Domainmodel i got a class Customer and Employee. So Customer is holding a Hashtable of employeeComments. There are no Properties defined. There are instead some public methods to get and set the hashtable.

public class User
{
private Hashtable employeeComments;
....
public string GetEmployeeComments( Employee emp)
{
if( employeeComments == null )
{
return null;
}
else
{
return (string) employeeComments[emp];
}
}

public void SetEmployeeComments( Employee emp, string comments)
{
if( employeeComments == null )
{
employeeComments = new Hashtable();
}
else
{
//the old value has to be removed first,
//if there is no value contained for empl, then it is a no-op
employeeComments.Remove( emp );
}
employeeComments[emp] = comments;
}
.....
}

I played around with some mappings, but it didnt work out.
I thought i should use something like:

<class name="NHTest.Customer, NHTest" table="Customer">
<id name="Id" column="Id" type="Int32">
<generator class="hilo" />
</id>
<properties..../>

<set name="employeeComments" access="field" table="Comments" cascade="all-delete-orphan">
<key column="CustId"/>
<many-to-many class="NHTest.Employee, NHTest" column="EmployeeId"/>
</set>
<many-to-one class="NHTest.Adress, NHTest"....


And the creationcode of some objects:

Adress ad = new Adress(..)...
Employee emp = new Employee("Lei", "Kathi", System.DateTime.Now);
//session.Save(emp);
Customer cust = new Customer();
cust.Name = "Bla";
cust.Surname ="Chup";
cust.CustomerNr=1001;
cust.Adress=ad;
cust.SetEmployeeComments(emp, "Lazy Dog");
session.Save(cust);

At session.Save(cust) i got an exception:

An unhandled exception of type 'NHibernate.ADOException' occurred in nhibernate.dll

Additional information: Could not save object


Still i would need an element of something like <element="comments" type="String" in the set. How could i implement this. A mix of value and entities inside an set isnt allowed? I think i got somethin fundamentally wrong and i am really confused now. Any help would be really great!

Thx

the newbie Chris

I believe the <map> collection mapping is for a IDictionary (Hashtable) collection, but I've never used it. You probably need to check the Hibernate (Java) documentation, as it's not well documented for NHibernate (yet).

You should use a ternary association map like the examples here. Since you only have one comment per employee per customer then using composite elements shouldn't be necessary.

Thx for this link again! Now i will check the HibernateDoc first!

Finally i´ve got a kind of "workaround"...

I´ve added an empty Set().


and this mapping:


Regards

Chris