What ORM should I use for a ASP.Net MVC project?

Question

I am starting a new ASP.Net MVC project and was wondering what is the best Model approach to take.

Most demos recommend LinqToSQL but I know Microsoft are not really en

Answer 1

We're using Fluent + NHibernate here, it works pretty well. Some alternatives that mesh well are SubSonic, Entity Framework, and Linq to SQL. I think straight NHibernate is a bit more cumbersome than it is worth, but is a great underlying layer with Castle ActiveRecord, and with Fluent.

Answer 2

For SubSonic, Rob just release an new MVC template which you can use when starting a new project that bakes a lot of good stuff into a new MVC project including a pre-release of SubSonic 3. Detais are available on Rob Conery's blog.

Answer 3

Castle ActiveRecord works really well for small-to-medium projects based on MVC - I'm using it on a couple of projects at the moment and finding it a very good fit with ASP.NET MVC.

It's an implementation of the active record pattern that uses NHibernate under the hood - in other words, as long as you're happy having one class per database table, it'll do most of the NHibernate configuration for you, leaving you free to write code like:

Customer bob = Customer.Find(/* customer Id goes here */);
bob.FirstName = "Robert";
bob.Save();

Invoice newInvoice = new Invoice();
newInvoice.Products.Add(Product.Find(/* product ID goes here */);
bob.Invoices.Add(newInvoice);
bob.Save();

with very little explicit NHibernate configuration (assuming you have Customer, Invoice and Product tables in your DB, of course)

Because it's NHibernate under the hood, migrating to NHibernate if you need to should be straightforward - you'll already have all the necessary references and libraries. There are a few aspects of NHibernate behaviour that you can't ignore (like session scopes and flushing) - but it's not too hard to work out what's going on with these, and using them in ActiveRecord will give you a head start if/when you need to move to using NHibernate directly.

Answer 4

I use linq2sql and I think it works absolutely great if you use MSSQL as your database (it works on other databases too, but it requires some 3rd party tools). Yes, Microsoft has 'discontinued' its development, but it is mature enough for the average project. I doubt you will run into any walls. If you're starting a big project that you need to support for years to come, then the Entity Framework might be more suitable.

I personally haven't used NHibernate and Subsonic before, but like Craig says, the learning curve of NHibernate is a bit more steep, though it is supposed to be a great framework (everything from what I heard or read).

Answer 5

nHibernate learning curve is higher but worth it. Use Fluent nHibernate to ease the pain a bit. nHibernate is less visual that some ORMs but that is really only an issue when you are beginning and once you have experience with it the lack of visual designer is a benefit IMO.

Answer 6

I worked with a product called netTiers (http://www.nettiers.com/) on a project and that worked very well. It's a CodeSmith script that generates business objects from your database tables, views and stored procedures.