Entity Framework vs. nHibernate for Performance, Learning Curve overall features

Question

I know this has been asked several times and I have read all the posts as well but they all are very old. And considering there have been advancements in versions and releases, I am hoping there might be fresh views.

We are building a new application on ASP.NET MVC and need to finalize on an ORM tool. We have never used ORM before and have pretty much boiled down to two - nHibernate & Entity Framework.

I really need some advice from someone who has used both these tools and can recommend based on experience. There are three points that I am focusing on to finalize -

1. Performance
2. Learning Curve
3. Overall Capability

Your advice will be highly appreciated.

Best Regards,

Answer 1

EF doesn't have a lot of providers for other databases. EF doesn't have a big community behind it.

NHibernate has community. NHibernate has database providers. NHibernate is a lot more configurable, probably simpler.

I use NHibernate, I've learned it. I checked EF and didn't see anything that would want me to switch.

Answer 2

I would use Nhibernate. I would pickup Sharp Architecture as a great framework that wraps NHibernate, ASP.NET MVC and a bunch of other open-source tools into a coherent whole that will give you a solid architectural foundation.

Nhibernate is more mature than EF4. It is well supported by the community. As long as you are willing to get your hands dirty from time to time, you will like it. It's support for LINQ is currently a little weak but it is rapidly getting better. The learning curve is not bad, but things like session management can be a little confusing at first. One of the reasons I like Sharp Architecture is they have all the NHibernate stuff you will need in place and plenty of guidance on how to use it properly in an ASP.NET MVC project.

EF4 has the MS stamp of approval. It is pretty good now but still behind NHibernate. It is a perfectly good choice and you will find lots of docs from MS, MS support and eventually more developers that are familiar with the ins and outs. I should also mention that the Sharp Architecture folks are adding support for EF4 to their overall framework. They will still support NHibernate, but you will be able to use EF4 if you like.

Answer 3

I think it takes more time to learn NHibernate.

EF provides graphical designer, unfortunately NHibernate doesn't have a generic designer. BTW it's not a problem. If you design in domain-driven (DDD) manner, you will design your entities first and you don't care about database structure (as you used to), NHibernate will handle that for you.

EF 4 got closer to NHibernate. I wouldn't start working with EF 3.5, it lacks a lot of features.

If you think NHibernate is too complicated at first sight, you can start with frameworks built on top of NHibernate. ActiveRecords and Sharp Architect are good examples.

AFAIR EF 3.5 supported only SQL Server 2000. It couldn't handle the new data types from SQL Server 2005. I have no information on EF 4 but I suppose it support these improvements.

If you use NHibernate in real word applications, you have to build an infrastructure. E.g. I implemented the Unit of Work and Repository patterns to be able to write tests and create layers in my application. You have to expect the same using EF. Detaching and attaching entities in EF 3.5 was not an easy thing, I had to write tricky extension methods to mark fields dirty and so on. I hope they solved it in EF 4. There is no such problem with NHibernate.

You don't have to write HQL queries in NHibernate, you can use the LINQ provider. I think it's very important. :)

All in all NHibernate is a mature product with good community and commercial support. EF is young but strongly supported by Microsoft. Oh, and EF is a Microsoft-only thing while you can port your NHibernate knowledge to Java as well. It this counts for you.