Martin Fowler is a brand name for lucid ("UML distilled"), maturity enhancing ("Refactoring" for the practical side and the great "Analysis Patterns" for the modeling side) top notch books for software professionals. This book even has on its front cover a label telling us it is a "Martin Fowler Signature Book". This book was a disappointment. In the introduction Fowler claims much less. This book should be merely "useful". It is much better than that. It is good.
So what is the problem? The title is misleading. It is about patterns, but not really about enterprise applications. I am not in the subject of enterprise applications. I never ever have touched a program like SAP or a language like COBOL. But I encountered nearly every problem addressed in the patterns. Even the money class has corresponding problems in other fields: a Voltage has both a value and a unit. Also having complaints about the fact that 3 times 33% are less than 100% are always common.
What is this book about? It is basically about problems you have in moderately big applications. How do you connect a relational database with its structure and transactionality to a system, especially an object-oriented system (but not only)? And how do you connect to the user interface, especially a web interface. Also it contains a lot of useful small patterns at the end. As you can see: a lot of valuable stuff for many people. Yes and you get the deep judgments and fine humor of Martin Fowler too.
What is the main problem? This book is not really suited for actual reading. It contains an introductory part of a hundred and a reference part of four hundred pages. The introduction part is annoying to read. It is at the same time too simple (Some knowledge of relational databases should be a requirement for this book, and much more...) and too difficult (An extremely lot of forward references to patterns described later in this book). Also a lot of stuff is in the most trivial sense repeated within a few pages distance only. And it is repeated down to the wording of the individual sentences.
The reference part is a lot better. It gets better to read the further along you already read. The number of forward references gets less along the way. I liked especially the last part about base patterns. As their name already says they should have been much more to the beginning of the book.
This book contains an excellent book within it, just waiting to be "refactored" out of this collection of valuable thoughts. I firmly believe that Martin Fowler is well suited to do this refactoring job. I do sincerely hope that he does it for the next edition of the book. Most of the work is already invested and the result would be very valuable for many people. It is possible to write excellent and readable books about patterns as for example Buschmann et al in "Pattern Oriented Software Architecture" showed.