MS Entity Framework VS NHibernate and its derived contribs (FluentNHibernate, Linq for NHibernate)

Question

I just read this article about the Entity Framework 4 (actually version 2).

Entity Framework seems to offer a huge improvement over its first release. Thus, I have never ever used EF in any project, since I think EF is not mature enough in comparison to NHibernate.

NHibernate and its current contributions of FluentNHibernate and Linq for NHibernate by Ayende Rahien

My feeling is that Microsoft is solely trying to gain terrain it has lost in favor of NHibernate when the 2nd version of NHibernate came out. Nevertheless, my concerns are the followings (not in particular order):

• Will EF4 tend to be less XML-verbose?
• Will EF4 be compatible with underlying datastores other than just SQL Server?
• What are the greatest benefits of going with EF4 instead of FluentNHibernate or NHibernate itself?

NHibernate is a great tool, I guess everyone agrees. Due to its predecessor Hibernate, we may easily find documentions and tutorials and sample applications to get acquainted with it. This is not the case for FluentNHibernate. Particularly as per the project I'm working on right now which demands that I investigate further about NHibernate and its options (FluentNHibernate for instance) in order to document the rules of usage and the best practices of NHibernate and FluentNHibernate technology. Thus, being handcuffed with VB.NET, being a C-Style developer, I can't find some syntax equivalencies in VB.NET for the examples provided, though I made my way so far.

I do believe that NHibernate is a best choice, but as a software consultant, I can't (don't want to) miss important technology changes, improvements and evolution.

Despite the bad comments I read about EF1, EF4 seems to be very promising. What you all think about both NHibernate and Entity Framework avenues? As for me, I am becoming puzzled with all that readings. I need you to bring back my head out of the water.

Thanks to you all!

Answer 1

I know almost nothing about EF, but a quick skim of the links provided leads me to believe that EF has no equivilent to Fluent NHibernate's Automapping functionality.

Edit: Some of the commenters pointed me to links indicating there is some automapping in EF, but it's not really clear if it's as powerful as FNH (for example, being able to automap collections of other objects).

Personally, I love being able to design POCOs in an OO manner, and letting the tool handle all the busy work of mapping to a relational database.

FNH still has the most powerful automapping capability, as far as I know.

Go to Fluent NHibernate Automapping for more info.