I know the use of drag-and-drop and DataSource Controls in web applications make a lot of people cringe, but there are plenty of web applications where the use of DataSource Controls ( SqlDataSource, LinqDataSource, and EntityDataSource ) make good sense and can bring some much enjoyed rapid application development / productivity to your ASP.NET Website Development.
In the new Visual Studio 2008 SP1, you can find the wonderful EntityDataSource in your ASP.NET Data Controls Section of your toolbox. Just like the LinqDataSource works with LINQ To SQL, the EntityDataSource is intended to work with your ADO.NET Entity Data Model ( ADO.NET Entity Framework ).
ADO.NET Entity Data Model
Adding an ADO.NET Entity Data Model to your ASP.NET Web Application is as simple as it gets. Just choose “Add Item...“ from your ASP.NET Web Application and pick the ADO.NET Entity Data Model. I won't show all the steps as it is pretty easy, but here I am adding a new ADO.NET Entity Data Model to my web application and calling it Northwind as I will be connecting it to the Northwind Database.
This invokes the ADO.NET Entity Data Model Wizard that will ask you for your connection string and then ask you what assets you want to include in the model. Here I just pick all the Northwind Database Tables:
Configuring the EntityDataSource
Once you get your Northwind ADO.NET Entity Data Model saved in your project, you can then configure the EntityDataSource to use the new model to provide CRUD operations to a GridView, ListView or any other control that accepts a DataSource Control. Just like the LinqDataSource, the very simplest thing you can do is just choose an EntitySet in the ADO.NET Entity Data Model as your datasource. Note I said EntitySet and not Table. The ADO.NET Entity Data Model is a conceptual view of your data ( in this case from a database ) and does not have to be a 1:1 mapping of your database. Here I am choosing to bind to the Categories EntitySet:
I will go ahead and bind to all the properties as well as enable inserts, updates, and deletes and save the EntityDataSource Configuration.
EntityDataSource and GridView
Let's go ahead and wire the EntityDataSource to a GridView Control. Choose the EntityDataSource as the GridView's DataSource and go ahead and enable paging, sorting, editing, deleting, etc. just to see how much functionality you are getting by using the EntityDataSource.
Run the example and enjoy the benefits of the EntityDataSource in your RAD ASP.NET Web Application:
Conclusion
The new EntityDataSource is very cool just like its kissing cousin, the LinqDataSource. The EntityDataSource allowed us to provide full CRUD operations against the Categories EntitySet in our ADO.NET Entity Data Model. Take this a step further with ASP.NET Dynamic Data to provide scaffolding in your ASP.NET Web Applications for a complete database-driven application with very little coding. When using such tools be careful to make sure the savings in the initial development doesn't translate to exponential costs when trying to maintain and develop new features in the future.
Hope this helps,
Dave