I finally broke down and tried out the ASP.NET Dynamic Data recently and was pleasantly surprised. Dynamic Data sites can be automatically built from either a LINQ ot SQL model or an Entity Framework Entity Data Model.

A dynamic data site leverages predefined page templates and controls combined with the appropriate data source control (LinqDataSource or EntityDataSource).

I have already used EntityDataSource for building RAD websites with Entity Framework but when it comes to dealing with relationships between entities, there's plenty of extra work to do. When you want to provide master/detail data, you will need to do some wiring up directly in the markup. More importantly, if you want to be able to edit reference data, such as a selecting a product in an order detail, there's lots of extra work that you need to do to make this happen.

That is the place where the Dynamic Data really stood out for me. It automatically detects where the relationships exist based on the model and implements the necessary user interface and databinding to make that work.

That's just display mode. What I really liked was that in edit mode, the dropdown lists were there with the approriate data.

I was really astonished that it had chosen the product name to display but quickly figured out that it was using the first string field it could find.

The default site that I get from the template out of the box gets me a very good part of the way to what I would want my final site to be. THere is still tweaking necessary but most of it is formatting. There is so much cusotmization that you can do to the templates that it is important to keep in mind that this is not an "automated website" tool but one that will get you a huge head start when you are doing RAD development with ASP.NET.

So if you are building web sites with LINQ to SQL or ENtity Framework today, I would definitely spend some time taking a look at this tool if you haven't yet. (www.asp.net/dynamicdata) And keep in mind that there are big changes coming to Dynamic Data in ASP.NET 4.0.