Event March 2009

Date: 31/03/2009, Nicosia
Members Present: 6
Location: Microsoft Cyprus Office
Presentation: The ADO .NET Entity Framework and LINQ to Entities

Many thanks to the hospitality and support of Microsoft Cyprus, for hosting our user group's event for March 2009.

Data Access; a really interesting topic of computer science. How can data be organized, retrieved, processed; these are some of the "concerns" of Data Access.

The speaker for this event was Artemakis Artemiou, our user group Leader and Microsoft MVP - SQL  Server. His presentation was about the ADO .NET Entity Framework and LINQ to Entities.

In a very interesting session which lasted for 2.5 hours (!) Artemakis introduced to the members of the User Group the ADO .NET Entity Framework. The Entity Framework is built on top of the ADO .NET. The two main components of the Entity Framework are the Entity Data Provider and Object Services. The Entity Data Provider layers over ADO .NET 2.0  Data Providers and exposes the usual ADO .NET Provider model. Though, this Provider's database is the Entity Data Model (EDM); a conceptual schema mapped to the relational model which is used in the target data application.

Using the conceptual schema (EDM) provided by the Entity Data Provider and thus the ADO .NET Entity Framework, offers some really great benefits. Some of them are:

• Abstraction in Data Access
• You just need to know and use the conceptual schema and not the relational model (actual database)
• If the relational model changes, you do not need to change your application's code, you just have to maintain the mappings!
  
• Simplified Representation of Relational Models with the use of new features like:
  
• Inheritance
• Entity Splitting
• Association Sets
  
• Ability to use LINQ to Entities!
• And much more!
  

There are three ways of issuing queries against the Entity Data Model in ADO .NET Entity Framework:

• Entity SQL
• A SQL-like language with extensions
• Text based
  
• Adds object concepts to SQL and expressions for using the EDM features (i.e. entity traversal)
• Only supports SELECT operations
  
• Object Services
• Use eSQL as query language
• Support CUD (Create-Update-Delete) operations
• Object Identity
• Change Tracking
• Column concurrency control
• And much more!
  
• LINQ to Entities
• Supported by Object Services
  
• All the benefits of LINQ
• Compile-time syntax-checking
• Intellisense
• Static Typing
  
• User extensible
  
• All the benefits of EDM
  

The attendees found the session very interesting. Many live demos were performed and some really long and very interesting discussions took place as the ADO .NET Entity Framework and LINQ to entities is a very hot topic! 

Well, after 2.5 hours of a really interesting session, it was time for souvlaki!

For more information on ADO .NET Entity Framework you can visit this link.
For more information on LINQ to Entities you can visit this link.

Many thanks to Microsoft Cyprus for supporting our event.