Solutions approach

With the advent of ORM technologies like ADO.NET Entity Framework (EF) and NHibernate, writing an application which targets multiple database offerings has become easier. The authors believe that ADO.NET EF works in tandem with the Visual Studio environment and its tools, and would be difficult to deal with in a book meant for pattern oriented software development. For people from the Java world, who are accustomed to the Hibernate library, NHibernate flattens the learning curve. Despite its dwindling usage and popularity (reasons unknown) amidst .NET professionals, the authors feel that NHibernate is a viable option to write enterprise grade applications in. In this book, for the sake of simplicity, we will be using the ADO.NET programming model to isolate the database specificities.

The ADO.NET library is based on the following set of interfaces defined in the System.Data assembly from Microsoft:

Interface	Definition
IDbConnection	Interface for managing database...