Multi Table mapped on one class in NHibernate

Question

Hi,

we use an external Database where we cant edit table designs only add own tables to extend the core tables.

So I need map two tables on one class, i try this:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
               assembly="DaVinci"
               namespace="DaVinci.Domain">
<class name="Vorgang" table="VORGANGSKOPF">
<id name="Id" column="ID">
<generator class="native" />
</id>
<property name="Vorgangsnummer" column="VORGANG" />
...
<join table="OWN_VORGANG_WAEHRUNG" optional="true">
      <key column="VOR_ID" property-ref="Vorgangsnummer" />
      <property name="WaehrungVK_Internet" column="WAEHRUNG" />
      <property name="WaehrungsKursVK_Internet" column="KURS" />
      <property name="Preis_Internet" column="BETRAG_EURO" />
      <property name="PreisFremdWaehrung_Internet" column="BETRAG_FREMD" />
  </join>
...

After testing i know now that "property-ref" for joins dosn't work. Bugreport here

Does anyone know an other way to map two tables on one class?

Answer 1

I have the same problem. I climb all over internet, but found only way to join one column from other table to current table - http://ayende.com/Blog/archive/2006/12/26/LocalizingNHibernateContextualParameters.aspx. Also I have some idea to join two tables using fetch="join" attribute (stackoverflow.com/questions/1543382/fetchjoin-to-tables-to-one-class-nhibernate), but I fail with it. Please anyone reply to this post!

Answer 2

(I'm struggling a little with the table and column names here.)

Could you use a joined subclass for this? Even if the tables don't follow the logical relationship, if there's a 1-to-1 database relationship between the two tables, then you'd get what you want by ignoring the parent, and doing all your operations on the subclass.