This step of the VIDEO TUTORIAL will show on how to create business logic layer (BLL) classes that include ProductsBLL, CategoryBLL, EmployeesBLL and SuppliersBLL. In addition, the tutorial will also introduce the users on how to add methods to these business logic layer classes and conclude by introducting System.ComponentModel, DataObjectMethodAttribute, DataObjectMethodType, input parameters to these business class methods with Nullable types. For detailed information and source code for this step, please refer to the original article.

This step of the VIDEO TUTORIAL will show the user on how to access the BLL classes from the DAL. This tutorial will conclude by demonstrating the display of a GridView in an .aspx page that utilizes a method from business logic layer for the data display. For detailed information and source code for this step, please refer to the original article.

This step of the VIDEO TUTORIAL will demonstrate field level validation for the property values of business objects. The field level validation is implemented by creating a columnChanging event handler for the ProductsDataTable class. For detailed information and source code for this step, please refer to the original article.