MSDN Magazine - March 2008 - (Page 65)

Sponsored Content Based on these three pieces of information, the EntityClient generates both query and update Client Views, similar to SQL views, that map the EntitySets defined within the CSDL to the tables defined as EntitySets within the SSDL. Queries issued by the application are “expanded” by replacing references to EntitySets within the query with the appropriate view, “flattened” into relational terms, and then passed to the underlying relational provider as a Canonical Command Tree. All query evaluation is done on the server, and flattened results returned by the storage provider are assembled into an EntityDataReader capable of representing polymorphic results with nesting and complex-typed properties. installed from http://www.microsoft.com/downloads/ details.aspx?FamilyID=06616212-0356-46A0-8DA2EEBC53A68034. Installing the ADO.NET Entity Framework and Tools The ADO.NET Entity Framework and Entity Designer install as incremental updates on top of the .NET Framework 3.5 that ships as part of Microsoft Visual Studio 2008. To install the ADO.NET Entity Framework and tools after installing Visual Studio 2008: 1) Install The ADO.NET Entity Framework: http://go.microsoft.com/fwlink/?LinkId=104981 2) Install the ADO.NET Entity Framework Tools: http://go.microsoft.com/fwlink/?LinkId=104983 Object Services ObjectServices map Business Objects to the Entity Data Model defined by the CSDL. ObjectServices are logically layered on top of the EntityClient, and leverage the same client views to support a flexible mapping of Business Objects to the underlying relational store. ObjectServices support querying through EntitySQL, or through Language Integrated Query (LINQ); a new innovation in the .NET Framework that supports building strongly typed queries directly within the programming language, providing support for IntelliSense and compile-time checking of queries in addition to strongly typed results. ObjectServices also support identity management and change tracking, so the returned object graph can be directly manipulated in memory with changes subsequently saved back to the database. Creating the Entity Model We’ll start by creating a simple entity model based on the Northwind database. 1. Launch Visual Studio 2008 and select File/New/ Project to create a new Visual C# or Visual Basic project. Select Console Application, give the project an appropriate name and click OK. 2. From the Project Menu, select Add New Item… 3. Select ADO.NET Entity Data Model, give the model an appropriate name, and click OK to launch the Entity Data Model Wizard. 4. With GenerateFromDatabase selected, click Next>. 5. Select a connection to your Northwind database. If the connection does not exist, create it as follows: a. Click on New Connection… b. Select Microsoft SQL Server and click Continue c. In the Server Name editbox, enter .\SQLExpress . d. In the Select or Enter Database Name editbox, enter Northwind. Using the ADO.NET Entity Framework The following section walks through building a simple application against a sample Northwind Traders database. It assumes that Microsoft SQL Server Express Edition, along with the Northwind sample database, are installed. Microsoft SQL Server Express Edition can be installed as part of the Microsoft Visual Studio 2008 setup. The Northwind sample database can be http://www.microsoft.com/downloads/details.aspx?FamilyID=06616212-0356-46A0-8DA2-EEBC53A68034 http://www.microsoft.com/downloads/details.aspx?FamilyID=06616212-0356-46A0-8DA2-EEBC53A68034 http://www.microsoft.com/downloads/details.aspx?FamilyID=06616212-0356-46A0-8DA2-EEBC53A68034 http://go.microsoft.com/fwlink/?LinkId=104981 http://go.microsoft.com/fwlink/?LinkId=104983

Table of Contents Feed for the Digital Edition of MSDN Magazine - March 2008

MSDN Magazine - March 2008 Contents Toolbox CLR Inside Out Data Points Advanced Basics Office Space Introducing ASP.NET MVC Loosen Up CI Server Performance Office Development Test Run Security Briefs Extreme ASP.NET Foundations .NET Matters {End Bracket}

MSDN Magazine - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.