NHibernate in Action [Paperback]

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Given that NHibernate 1.2 takes advantage of features present only up to .Net 2.0, the book also reads like a somewhat outdated book: for example, how to integrate with .Net's DataSet technology (something that Microsoft is starting to move away from in favor of newer technologies) is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.