Updated 6/26/2008

Microsoft had executed so well with Linq but to couter that, it’s now apparent EVEN WITHIN MICROSOFT that what will be shipped in the only ‘real ORM’ sense they might offer will fundamentally be a non-starter (at least as the people who care about ORM are concerned).

Even Microsoft key staff agree. I was shocked to see this:

ADO .NET Entity Framework Vote of No Confidence

The signatories of this letter are unanimous in expressing concern for the welfare of software projects undertaken in the Microsoft customer community that will make use of the forthcoming ADO .NET Entity Framework.
Over the past year, Microsoft and the Entity Framework team have received a tremendous amount of feedback from experts in entity-based applications and software architectures on the .NET platform. While Microsoft’s announcement of its intention to provide framework support for entity architectures was received with enthusiasm, the Entity Framework itself has consistently proved to be cause for significant concern.

And they are right on the money. There is no point is doing things well from a design perspective with ORM using the entity framework as is would counteract any benefit.

I hoped we could have a valid alternative as that could only benefit all of us, but we will not, at least for version 1.0

Long story short?

To do quality ‘large scale enterprise’ software of the type say the Java community for example has been delivering, the use of the Entity Framework would  harm your ability to adapt to change to the point of near uselessness.,

That being said here is my information set of links:

NHibernate – Release Version 1.2.1 GA

with optional Castle ActiveRecord – RC3 (stable and OK for production use in my opinion – wrapper on NHibernate)

NHibernate – Pre Release 2.0.X

SVN Trunk is: https://nhibernate.svn.sourceforge.net/svnroot/nhibernate

Castle ActiveRecord Trunk (evolving with NHIbernate 2.0.X)

Microsoft Linq to Entities – Pre Release

Make sure you understand what Linq is and is not. For example, here is one Microsoft clarification:

Linq to SQL, released with the Visual Studio 2008, is designed to provide strongly-typed LINQ access for rapidly developed applications across the Microsoft SQL Server family of databases. Linq to Entities, to be released in an update to Visual Studio 2008 in the first half of 2008, is designed to provide strongly-typed LINQ access for applications requiring a more flexible Object Relational mapping, across Microsoft SQL Server and third-party databases.Here I only discuss Linq to Entities

In 4/5 options NHIbernate is involved, however I LOVE LINQ and it would be fantastic if today we had a way to FULLY leverage it (we can use it to enumerate data as a full set of course). There is a very compelling effort to provide Linq to NHibernate which I have reviewed extensively, and this just provides more incentive to use a pre-release NHIbernate (not sure if it works on 1.2, will check however).

So the decision is further refined to:

Decision Point: How will you leverage Linq?

Use Linq ‘persistence optimized’ expressions

Linq to Entities – Pre Release using a Provider for your DB

NHIbernate Combined with Evolving Linq to NHIbernate Provider

Linq as Linq to Objects / Non-intelligent provider

Linq to Entities

This is a big unknown for now. Sure Linq is fantastic but this is completely a new area for Microsoft and don’t make the common mistake of thinking Linq = ORM. THEY ARE TOTALLY DIFFERENT however Linq is a nice platform to build ORM on top of (as stated people have done).