I have the following definitions for the Animal and Dog types. Note that the ID for the object is the AnimalID:
<class name="Animal" table="Animals">
<id name="Id" type="System.Int32" column="AnimalID">
<generator class="identity" />
</id>
<property name="IsBig" column="IsBig" type="System.Bool" not-null="true" />
</class>
<joined-subclass name="Dog" table="Dogs" extends="Animal">
<key column="AnimalID" />
<property name="OwnerID" column="OwnerID" type="System.Int32" non-null="true" />
<property name="IsStrong" column="IsStrong" type="System.Bool" non-null="true" />
</joined-subclass>
Let's say I have the following information in my database:
in table Animals:
AnimalID IsBig
-------- -----
10 True
in table Dogs:
AnimalID OwnerID IsStrong
-------- ------- --------
10 1 True
10 2 False
First, I query for the Dog where OwnerID = 1. In the same session, I query for the Dog where OwnerID = 2. Because of NHibernate's Session cache, the second query returns a Dog object where OwnerID = 1 and IsStrong = True, where it should return a Dog object where OwnerID = 2 and IsStrong = False.
NHibernate automatically caches objects by their ID (primary key) column, so requesting the Dog the second time ends up retrieving an object with the same key. I can solve this problem by calling ISession.Evict() on the object, but that seems like a hack.
Any better suggestions?