Entity Class Inheritance
So far, in all my LINQ to SQL discussion, there has been a single entity class mapped to a single table for any table that has an entity class mapped to it. Thus, the mapping between entity classes and tables has been one-to-one so far.
The example used in this section creates a data model containing Square and Rectangle classes. Geometrically speaking, a square is a rectangle, but a rectangle is not necessarily a square. However, in the data model created for this example, the reverse relationship is true. This class model defines a rectangle to be derived from a square. Therefore, a rectangle is a square, but a square ...