nhibernate: how to map two tables to a single non-persistent class?

Question

I have two similar tables:

Table1:

[ id ] | [ name ]

Table2:

[ id ] | [ name ]

and I need to read/write data using only one class:

public class TwinTable
{
   public virtual int Id { get; set; }
   public virtual string Name1 { get; set; }
   public virtual string Name2 { get; set; }
}

Plus one of the tables may or may not have an entity with the specified Id, and both tables may or may not have entities, so Name1 can be null and Name2 can be null and both of them can be null.

I can not change the structure of the DB, and it's not a good thing if i have to add something to it.

Hope for your help!

Answer 1

One solution is to map Table1 to a class, and then map Table2 as a joined-subclass of Table1. The joined subclass will then be like your TwinTable as you described above:

<class name="Class1" table="Table1" >
  <id name="Id" column="id">
    <generator class="identity" />
  </id>
  <property name="Name1" column="name" not-null="true" />
</class>

<joined-subclass name="Class2" table="Table2">
  <key column="Id" />
  <property name="Name2" column="name" not-null="true" />
</joined-subclass>