Designing Databases with CodeFluent Entities: Inheritance

CodeFluent Entities tries to reduce the impedance mismatch between relational worlds and object-oriented worlds as much as possible and a good example of this I guess is how CodeFluent Entities supports inheritance across layers of your application.

Using CodeFluent Entities, an entity hierarchy defined in your model will be translated following the Table-Per-Type pattern in the persistence layer, when, in the generated business object model, this will be a regular class inheritance.

For instance, say we have the following hierarchy:

Here’s the result in the database:

Furthermore, data access methods will be modified accordingly to load the objects as expected in .NET. For instance, here’s the “Load” stored procedure that is automatically generated for the DiscountProduct entity:

CREATE PROCEDURE [dbo].[DiscountProduct_Load]
(
@Id [uniqueidentifier]
)
AS
SET NOCOUNT ON
SELECT DISTINCT [DiscountProduct].*, Product].* 
  FROM [DiscountProduct]
   INNER JOIN [Product] ON ([DiscountProduct].[Product_Id] = [Product].[Product_Id])
  WHERE ([DiscountProduct].[Product_Id] = @Id)

RETURN

Cheers,

Carl Anderson