NHibernate mapping System.Type

4
votes

When I map an entity that has a property of type System.Type, I know that NHibernate maps this to DbType.String, holding Assembly Qualified Name, and I can see that in the table, the type column holds values like "TarkusSoftware.Abstract.ITask, TarkusSoftware.Abstract, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null".

What does this mean for long-term development, what will happen when we eventually change the assembly version for example to 2.0.0.0? I figure NHibernate will fail to hydrate the object, since it won't be able to find the type with its assembly qualified name. In this case, how should one proceed to mapping System.Type to ensure future compatibility? Thanks :)

1
nhibernate

1 Answers

3
votes

That is probably correct. You can implement your own IUserType to be more in control.

I just checked NH source, you are right. It only uses the type and assembly name, ignoring version, etc. If interested, check the code in: TypeNameParser.Parse()