How to use Linq with Castle ActiveRecord

Question

I am playing around with Castle ActiveRecord and noticed that the download included the file, Castle.ActiveRecord.Linq.dll. I haven't found any documentation for using Linq with ActiveRecord, only some old blog posts.

What is the usage pattern? Is Castle.ActiveRecord.Linq ready for production use?

Answer 1

Yes, Castle.ActiveRecord.Linq is production ready. It's included in the latest ActiveRecord release. The actual Linq provider is implemented in NHibernate.Linq.dll, the ActiveRecord Linq dll is a thin pass-through layer. There are basically two ways to use it:

1. Make your entities inherit from ActiveRecordLinqBase<T>, then to query:

   var blogs = (from b in Blog.Queryable select b).ToList();
   

2. Use ActiveRecordLinq.AsQueryable<T>, e.g.:

   var blogs = (from b in ActiveRecordLinq.AsQueryable<Blog>() select b).ToList();
   

Look at the tests for some sample code.

UPDATE: as of ActiveRecord 3.0 beta, Linq is integrated into Castle.ActiveRecord.dll, and NHibernate.Linq.dll is no more (integrated into NHibernate.dll as of NHibernate 3)