Hibernate version:1.2.0.GA

Hi I'm mapping manually(Smart code wouldn't work with my old Oracle database)... and this is a mapping question.
I have chosen a "table per concrete class" strategy, to map to a List, as suggested in chapter 8 in the documentation.

So I have this List in a class -IntermediateTrack:

and I have 3 subobjects implementing my RailwayObject class. I have mapped and tested the subobject, they work fine. But how do I fill my list with random railway objects... I can't quiet capture the idea from the chapter. How do I use the thing?

Do I have to map the base class -RailwayObject, even though it has no table?

I have three tables, which all have a Foreign key containing an ID from one other table. The foreign key column are named the same in all 3 tables -"IntermediateTrackId".

Mapping document for IntermediateTrack:


<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="BDK.TIB.ObjectModel" namespace="BDK.TIB.ObjectModel">
<class name="BDK.TIB.ObjectModel.IntermediateTrack, BDK.TIB.ObjectModel" table="INTERMEDIATETRACK" lazy="false">
<id name="ID" column="ID">
<generator class="sequence">
<param name="sequence">SEQTIB</param>
</generator>
</id>
<many-to-one name="DepartureSectionStation" class="BDK.TIB.ObjectModel.SectionStation, BDK.TIB.ObjectModel" column="DEPARTURESTATIONID" />
<many-to-one name="DestinationSectionStation" class="BDK.TIB.ObjectModel.SectionStation, BDK.TIB.ObjectModel" column="DESTINATIONSTATIONID" />
<set name="RailwayObjects">
<key column="INTERMEDIATETRACKID" />
<many-to-many class="BDK.TIB.ObjectModel.RailwayObject, BDK.TIB.ObjectModel" />
</set>
</class>
</hibernate-mapping>



I hope u don't mind -I didn't care to make question more general, by changing my objects to cats and mice :D
Hope you guys can help me?
Sorry about my english...

Still need help...

Changed the list type to:



And tried the following, but any are not accepted...

Change your collection type to IList<IRailwayObject> and the mapping type to <bag>.



<set> should be used if you want to use the Iesi.Collections set. <bag> is the IList<T> equivalent in .NET.
<map> is an IDictionary<K,V> equivalent.

Hope this helps...
Mike

Hi Mike.

Thank you for your answer, had given up on this forum...

Yes I normally use the bag and IList method, when I map a collection of objects... but was desperate, so I have tested a lot of options... So I'm actually back to the IList... -as u suggest...

But the problem is if I do as you describe, I'm referening to an abstract class Railwayobject, which is a base class with no table bound to it... So it has no mapping file like the subclasses...
-(The table-per-concrete-class stragey), So if I try your method I get the message:


Should I map the abstract class???
Please help I'm about to give up on NHibernate...

[/code]

*edit*
Sorry, I didn't realize at first that you were using the table-per-concrete class strategy. Referring again to Hibernate in Action, it warns that using this mapping strategy makes it difficult to represent polymorphic associations, because you can't map a foreign key relationship to the table of the abstract superclass. Chapter 6 of the book gives an example of using the <any> element, though if it's not too late, I would highly recommend moving to a table-per-class strategy unless something is preventing you from doing so.

If you haven't picked up the Hibernate in Action book, I would recommend doing so before giving up. It's an invaluable reference.

Jeff is right on with this...I'm afraid I glossed over your choice of the table-per-concrete-class strategy. See here
http://www.hibernate.org/hib_docs/nhibernate/1.2/reference/en/html_single/#inheritance-limitations

Is this db schema something you can't control (legacy)? If you can, then I'd recommend choosing a different strategy to simplify things and open up the query options/association options for your model.