Most complete ORM with LINQ support?

Question

I'm looking for an ORM that offers complete or near-complete LINQ support.

LINQ to SQL
- Supports about everything inside of LINQ (.Contains, Math.Log, etc)
- Cannot eager load relationship properties without creating a new datacontext

ADO.NET Entity Framework
- Terrible LINQ support (lots of missing features).
- Great mapping features - Can eager load on demand with .Include methods on an ObjectQuery<>

LightSpeed
- Great LINQ support missing some features (.Contains within a Where)
- Some of the SQL generated is very inefficient.

None of these seem to fit just perfectly, I honestly wish I could take bits and pieces from each. I personally really like ADO.NET EF except the features it is missing make it just frustrating to use.

I know some people praise NHibernate up and down and I'm not knocking it but I spent today trying it out and it's ok but it's LINQ support is not that great.

Answer 1

Try DataObjects.NET. I'm one of the DO developers. And my latest activity within that project is to implement LINQ for DataObjects. So I could describe it briefly:

• Supports almost all LINQ methods except Last/LastOrDefault/Aggregate/Reverse/TakeWhile/SkipWhile etc. and methods that has .NET specific arguments - such as IComparer (nobody supports them).
• Almost all string and Math methods supported (and you have ability to write your own function mappings!).
• Complex scenarios with GroupBy\SelectMany\Contains\Single\etc. in subqueries and correlated subqueries are supported.

We have about 1000 tests of LINQ implementation and 99% of them are passed. So I can say that current implementation is close to EF. Some methods do not work with EF, some with our framework. Check this brief description http://www.x-tensive.com/Products/DO/.

Answer 2

Llblgen seems to have pretty good linq support. Frans has a whole series of blogs posts on his development of it http://weblogs.asp.net/fbouma/archive/2007/09/11/developing-linq-to-llblgen-pro-day-0.aspx