ADO RDS Programming with ASP

Dino Esposito

The Wrox logo states that all Wrox books are written "programmer to programmer." Professional ADO RDS Programming with ASP, by Matt Brown, Charles Crawford Caison Jr., Peter DeBetta, John Papa, and Eric Wilson, is an excellent example of such a policy. It's practical, full of solutions, and code heavy. Even when discussing theoretical aspects, Professional ADO RDS maintains a practical style and never loses contact with the programming reality. Active Data Objects (ADO), and its web counterpart Remote Data Services (RDS), are hands-on subjects that leave little room for philosophical speculation. It's a subject that developers want covered in detail, sprinkled with workarounds and tips and, of course, without further ado!

ADO 2.0 represents a turning point in database programming for at least two reasons: It attempts to unify DAO and RDO (two of the most used object models for data access) and it introduces OLE DB in place of ODBC as the key technology for universal data access. Both points represent a source of errors and headaches for developers. And since most programmers do their data retrieval and update via the Web and ASP, this book is quite timely.

There are a number of completely new features with ADO 2.x (2.1 is available now and 2.5 is coming soon). In particular, the recordset--the basic element that renders a table of records--can be disconnected from a database, defined at run time without being linked to a database, locally persistent, and even hierarchical nesting child recordsets.

The book is logically divided into three parts: ADO, RDS, and a set of chapters examining the pitfalls of using ADO with an Oracle database server. ASP is relevant since all the samples provided are ASP pages.

The first chapter provides a quick overview of the ADO object model in relation to other data access technologies. Then, various objects that form ADO are examined in detail, from the Connection object to Command, and finally Recordset. The most interesting and insightful part of the book revolves around the characteristics of the new recordset: disconnected, custom, and persistent. An entire chapter is dedicated to data shaping, the theory behind hierarchical recordsets.

From Chapters 10 to 13, the main actor becomes RDS. The presentation is done progressively: First, the various objects that form RDS with their functionality and potential are discussed. Then, the authors show how Dynamic HTML can make effective use of RDS and how to arrange client pages for such a component.

To this point, Professional ADO RDS Programming with ASP assumes Internet Explorer 4 or higher as the browser to view ASP pages and SQL Server as the preferred database. For a triumphal end, the authors discuss what they call "The Oracle Factor." Oracle, they believe, is and will be an important player in database technology. Sooner or later, you'll be required to work against it. If you do it through the ADO interface, you will probably find the few tricks and possible pitfalls explained really useful. The book also includes a long series of appendices dedicated to reference tables about ADO, RDS, database schemas, available OLE DB providers, and more.
— Electronic Review of Books