Hello,

This is the first time i'm using orm instead of typed dataset.
I decided to use nhibernate v 2.0 to handle my data entities.

The topic is a bit long but the question is pretty simple.

I'm programming application for insurance office.
* Framework - C# .net 3.5
* Database - MSSQL 2005
* Architecture - Client-Server (using wcf)

My question relates "Value tables" (aka "lookup tables"). Assuming i have a "Person Entity" with "Status".

Database ERD (Partial)

Table Person
ID | Bigint
FirstName | nvarchar(50)
StatusID | int

Table PersonStatus
ID | int
Value | nvarchar(20)

In my previous applications, I usually seperated between two actions:
Editing Action
For editing purpose I used to extract the 'StatusID' value for the 'Person' entity (and not 'Status' entity).
In the UI layer - I'm using combobox from which the user select the relevent status.

Viewing Action
For viewing purpose i used to extract the 'Status Value' for the 'Person' entity using join sql.
In the UI layer - i only display the value. This way the sql handles the extraction of the relenet value and not the UI layer.

finally, my question:
I understand how to use nhibernate for the 'Editing Action' (using the 'table per subclass' strategy and extract the actual id value).

How to perform the 'Viewing Action'? i don't want to extract 'Status' entity for each 'Person' entity only the actual value as simple type.

What is considered as best practice in this situation.

Many thanks for the help.
Eran Sakal.

Hi Eran,
I think that the good practice for "lookup tables" (such as Status table),
is to create static table (without Entity) or to create text files
that will handle all "lookup tables".
To create an Entity for those static data will be an "Overhead" to your application.

BR,

maybe i'm missing something but why not use

<many-to-one name="PersonStatus" class="FullClassName, AssemblyName" column="StatusID"/>

and make sure that you have a class called PersonStatus
that has both id (int) and value (string)

that way you can get either value or the name by using

objPerson.Status.ID or objPerson.Status.Name

hopefully that helps..

That seems like a sound way to go, raanan.raz, for the Person class, but how would you be able to populate a drop-down of PersonStatuses?

I'm facing the same problem. There seems to be no support for top-level collections that aren't contained or referenced by class entitites.

I'm using spring so here is an example.. but it's the same for the basic
hibernate
return HibernateTemplate.LoadAll(typeof(PersonStatus));
will return a IList with all the PersonStatuses inside..

now all that is left is to bind it to a control..

hope that helps