Pro WPF and Silverlight MVVM: Effective Application Development with Model-View-ViewModel

Chapter 8. Data Access Layer

Silverlightand some WPF applications do not use offline storage for persisting data. Instead, they use a relational database to store the object data in a structured format. Rather than employing serialization, applications that use a relational database for storage will have a dedicated Data Access Layer (DAL) that serves to insulate the model from additional responsibility while allowing clients to load and save the model state.

There are four typical operations that the DAL should provide for each object in the model: create, read, update, and delete (often given the unfortunate acronym CRUD). These operations correspond to inserting new records in the database, retrieving records from the database, editing existing ...