Customer Reviews

NHibernate in Action

5 star:		(9)
4 star:		(3)
3 star:		(2)
2 star:		(0)
1 star:		(1)

 

 

Most of the text in this book is copied from Hibernate in Action, a best-seller in 2004, except some C#2005 example code for an old NHibernate release - NHibernate 1.2, the equivalent dotNET version of Java Hibernate 2.1 covered by Hibernate in Action.

The current NHibernate release is 2.0, which had been released for six months before this book was published.

And the revised edition of Hibernate in Action, Java Persistence with Hibernate (covering Hibernate 3.2), was published in November 2006, two years and three months before this book.

More than a year after the release of NHibernate 1.2, a .Net port of the highly successful and popular Java Object-Relational Mapping (ORM) tool mirroring the feature sets of Hibernate 2 and 3, a book providing dedicated coverage of the tool for .Net developers finally gets published! Like the Hibernate In Action book it is based on, this book is divided into three parts: Discovering ORM With NHibernate (Chapters 1-2), NHibernate Deep Dive (Chapters 3-7), and NHibernate in the Real World (Chapters 8-10). Developers unfamiliar with ORM and Hibernate will find the first two parts of the book very useful. Those chapters are very well-written, easy to follow, and provide sufficiently deep technical details. Developers looking for guidance on what to look out for when building NHibernate applications would benefit from discussions on how to handle session management, security, and performance / scalability concerns. Data binding (to web- and windows-forms) strategies are also discussed, but in my opinion, only to a limited extent. Given that NHibernate 1.2 takes advantage of features present only up to .Net 2.0, the book also reads like a somewhat outdated book: for example, how to integrate with .Net's DataSet technology (something that Microsoft is starting to move away from in favor of newer technologies) is discussed, but there is no discussion of potential problem integrating with the newer data binding mechanisms used in Windows Presentation Foundation (WPF). Also, even though NHibernate 2 has been released since September 2008, nothing about it made it into the book.

I'd argue that this book may be more appropriately naming something along the lines of "ORM in Action (with a focus on NHibernate)" because it is not only a bible for understanding and using NHibernate, but for ORM concepts in general! The authors skillfully intertwine detailed and insightful discussion of general database, ORM, and enterprise development concepts with the nitty-gritty implementation details of NHibernate, all in an easy-to-read manner. Beginning with a tour of many of the various ORM (and ORM-ish) solutions available to .NET developers and ending with a few chapters dedicated to discussing best practices of enterprise application development, this is a very well-rounded book that is easily digested by developers of pretty much any skill level. I knew only high-level details about NHibernate and had a few mis-guided attempts at implementing it by myself prior to reading this book, but now I feel incredibly confident that I will be able to create plenty of NHibernate-driven applications with ease. Another great benefit is the comfort I get from knowing that when I hit any more snafus in the future, it is obviously that this book will be there as a solid reference to help get me through.

The cons? Yeah, I agree with many of the other comments/reviews when they say that it'd be nice if the book discussed NHibernate 2 & .NET 3.x functionality (like LINQ-to-NHibernate), but I think those expectations are somewhat unrealistic. Because of its open source nature, NHibernate is a living organism with stark contrast to a published book. Due to this contrast, I am more interested in a text that can explain the fundamental concepts than an incredibly in-depth (and quickly obsolete!) explanation of the technical implementation of those concepts.

When it comes down to it, this is a great book that delivers on its promises and provides a comprehensive look at NHibernate in Action and how you can get it working for you. I'm just gonna come right out and say it - this is the NHibernate Bible.

Like everyone else, NHiberate 2 out long after this book was finally published. Book would be great if it mentioned or covered anything about Nhiberate 2... but maybe the next book...

Hibernate has been around in the Java world for a while now, and this NHibernate reference does a great job of documenting its arrival into the .Net world, explaining the concepts, showing the mapping process and providing good examples of mechanisms and mapping processes required.

A necessary read for all wanting to understand and implement a simple data access mapping layer in the .Net world.

I've gotten started using NHibernate thanks to this book. It provides an introduction to the tool and describes the problem it solves, then dives into making it work for you. The coverage starts off easy, but gets detailed, dense, and deep in short order. I'm now comfortable enough with the tool to start using it, and will refer back to the book frequently.

It's unfortunate the book was written for NHibernate 1.2, and published after NHibernate 2.0 was released, but I've gathered that it is still quite relevant as it covers foundational concepts that aren't likely to change. I'm fine by that, as I'm still new, and the book has provided an important foundation.

I bought this book because I took over an existing NHibernate project and I needed to get up to speed quickly on some of the underlying concepts. Although I'm an experienced .NET develoer, I needed help both with NHibernate and ORM generally since I had never used an ORM approach before. I think this book helped on both fronts. To be sure, NHibernate is a complex solution and it's not that easy to work with, but this book does provide a good foundation.

The other thing I really liked about this book is that the authors stress repeatedly that NHibernate may be too complex for many situations where a simpler approach is warranted. I couldn't agree more and appreciate the authors' honesty here. Too often, I read books on OO design where authors present an overly complicated and bloated approach to software design and act like it should be implemented for most situations.

Finally, I think this book would be very helpful for developers who are deciding whether NHibernate would make sense for their project because I think the authors present its strengths and weaknesses fairly.

Addendum to original review: After using NHibernate for 6 months on a project, I would definitely not recommend it. At the end of the day, it creates more problems than it solves.

I now read about 80% of the book and must agree, that it is not very well organized and definitely not current.

But, the good things first.
I am new to NHibernate and ORMs in general and this book gives a great introduction to the design patterns, inner workings, alternatives and so on.

Sometimes it is hard to follow though.

A lot of things get repeated or are explained out of order, so you loose your train of thought.
A friend of mine lent me "Hibernate in Action (In Action series)" (I was hoping it might be better organized) and I was surprised to find that "NHibernate in Action" is a chapter, for chapter, word for word replica of it.
Just substitute .Net for Java.
(Naturally the NHibernate configuration/mapping chapters are different).

Unfortunately that difference is not too useful because the C# configuration and mapping code/XML is hopelessly outdated (at first I thought they made a mistake on the cover ("Covers Version 1.2"). I assumed they meant version 2.1.
This means of course that there is no mention of Fluent NHibernate, which at the least should replace attribute defined mapping (in the book it is recommended over XML mappings for type safety advantages which Fluent NHibernate brings to the table along with a much more natural mapping approach).

To sum it up, while it is a great book, the adjustments from the Java book to .Net are not of much use today and you might therefore get the Java version which is equally as good.
This will save you about $15 since it goes for $8.50 used right now.

This book does a fantastic job of showing the ins and outs of ORM with NHibernate while giving guidance on best practices in data mapping. Good Stuff.

If you work with NHibernate, are hesitating between several ORM, or are simply curious about how NHibernate works, this book is absolutely necessary.

Indeed, a recurring problem, I believe, with NHibernate, is the difficulty of finding a clear and comprehensive reference... what is now the case with this book.
It reviews not only the configuration and use of the NHibernate framework, but the authors also address the design choices that were made, and an introduction to concepts of architecture.
All this, without dogmatism, without imposing their vision of development, and emphasizing that NHibernate is not a silver bullet.

We will first see a definition of Object/relational mapping, and issues the ORMs seek to solve, then we will see how to configure NHibernate, to map the subject entities, transactions, the caching options, while following the construction of an auction application.

In conclusion, an excellent book, the only drawback (explaining the rating of 4 / 5), is that the book targets the 1.2 version of NHibernate, while version 2.0 was released on August 23. Incompatibilities are few, but it is a pity they are not mentioned in the book. Despite the discrepancy between the two versions, the book remains an investment in my opinion, mandatory for any team working with NHibernate, and for all developers interested in how an ORM works.