NHibernate 3 with Fluent NHibernate learning curve?

I hear from everywhere that NHibernate 3 learning curve is very huge. It is considered huge from which perspectives ? Do you think that the learning needed depend on the scenario it is used ?

Example: If i just want some application that act on 3 开发者_StackOverflow中文版entities and only looking for basic crud. Is it necessary to understand the whole concept underlying NH ?

Would like to know users experiences with some explanation over your answer to this.

Edit: Do you recommend of using NH over Entity Framework 4 ? (if you tried both)

Thanks.

There is a learning curve for any ORM. Once you've learned one ORM, learning a second ORM goes much faster. In most cases, it doesn't matter (learning speed wise) which ORM you learn first.

Currently, I think you can probably get going faster initially with EF4 than NHibernate, but over the long term I think NHibernate is a superior choice. Those are the main two ORMs worth spending time on at the moment.

Once you understand ORMs, your development speed will be much faster in regards to database access. There are other benefits to ORMs as well, so it's definitely worth taking that learning curve on.

NHibernate indeed does have a leaening curve, but it all depends what your background is...

Is the concept of ORM's familiar to you at all ? Do you have experience working with Entity Framework 4 ?

In order to build a simple application with 3 entities/tables and simple CRUD operations, you don't need to understand the core of NH, but problems will start to come up when you think of expanding the program you are building or the moment you run into bugs or features that you will only find out along the way...

I really suggest using NH, and learning it is always easier on programs with a small db like the one you're probably going to be working on.

I would also suggest diving straight into Fluent NHibernate. It's a way of mapping the entities without using XML at all.

Start out by reading the introduction and the 'first project' page at the Fluent Nhibernate homepage.
You can read alot more about NHibernate and Fluent NHibernate at ayende's blog.

You can learn the NH basics in a single day. And believe me, it will pay off.

I learned EF after NH and can say that if you are going to use automappings, POCO objects etc then learning will be just the same.

NHibernate has NOT a "steep, large, horrendous learning curve".

I learnt NHibernate just reading the (excellent, BTW) manual. It was v1.2 and, believe me, it is much better now than then.