I've been meaning to play around with Microsoft's new ADO.NET Data Service stuff (formerly known as "Astoria") for some time now, but couldn't find the time until today. When I last blogged about it, the technology was still in a Community Technology Preview. Since then, however, it has matured, is now packaged with the ASP.NET 3.5 Extensions CTP, and will undoubtedly be included in a future service pack or release of the .Net Framework. Until then, though, you have to walk a difficult road to get it installed and working as, like a lot of Microsoft's "unofficial/unsupported side projects", it isn't just a single install to get it up and running. It's, rather, a series of installs followed by obscure IIS configuration changes followed by pulling your hair out followed by (finally) some ADO.Net bliss.

Here are the steps to get your development machine setup to work on ADO.Net Data Services. These instructions apply to a 64-bit Windows XP SP2 installation. The steps may vary for other versions of Windows, but I'm pretty sure that most of them will apply in most cases.

• First of all, Visual Studio 2008 is a prerequisite for developing ADO.Net Data Services. You can use any version, including Visual Web Developer Express.
• Next you need to download and install the ASP.Net 3.5 Extensions CTP. If you're on a 64-bit operating system, you may have to manually copy the System.Data.Entity and System.Data.Entity.Design .dlls from your GAC to your .Net v3.5 directory (I had to). A bit more detail:
  • For some reason, these two dlls don't seem to install correctly when you run the ASP.Net 3.5 Extensions CTP installer. To solve this:
    • Click "Start>Run" and then paste the paths below into the "Open:" dialog and hit enter:
      • C:\Windows\assembly\GAC_MSIL\System.Data.Entity\3.5.0.0__b77a5c561934e089
      • C:\Windows\assembly\GAC_MSIL\System.Data.Entity.Design\3.5.0.0__b77a5c561934e089
    • From each of the now open directories, drag and drop the single .dll into the following directory: C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5.
• Next you need to download and install the XML Editor QFE and the ADO.Net Entity Framework Tools Dec 07 CTP, in order.
• And now you should be ready to develop ADO.Net Data Services! There's a great walkthrough available on the ASP.Net 3.5 "Quick Starts" site.

After you've created your data service on your local dev machine, you're probably going to want to deploy it to a dev server, right? Well, I did. And, of course, I ran into another issue that required quite a bit of Googling and cursing to solve. After deploying the application and pointing a Virtual Directory at it, I received the following error message when browsing to the .svc in Internet Explorer:

"A name was started with an invalid character. Error processing resource"

Well, what is this? I found lots of others asking that very same question, and finally stumbled onto a solution in the MSDN forums. I'll outline the steps here, as much for my own sanity if I run into this problem again on another server as to help others. These steps apply for IIS 6. If you're on IIS 7, here's a quick tip: make sure that you make the directory an application and not just a Virtual Directory...

• First of all, make sure that you have the ASP.Net 3.5 Extensions CTP installed on the server. This should be obvious, I know, but it wouldn't be the first time...
• Next, you'll need to manually add a script mapping for the .svc extension to your application's properties in IIS Manager:
  • Open IIS Manager.
  • Right-click on your application and choose "Properties".
  • On the "Virtual Directory" tab, click on the "Configuration..." button.
  • On the "Mappings" tab, make sure that .svc isn't already present in the "Application extensions" section. If it isn't, click on the "Add..." button.
  • Click on the "Browse..." button and browse to and select C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll.
  • Back on the "Add/Edit Application Extension Mapping" dialog, type ".svc" in the "Extension:" textbox and click "OK".
  • Click "OK" two more times to get out of the application properties.

Theoretically none of this should be necessary, as IIS's script mappings are supposed to be updated whenever a new version of the .Net Framework is installed on the machine. However, I found that this didn't happen in my case (I was, again, doing this on 64-bit machine (Windows Server 2003), so maybe it is another funky 64-bit thing). I also found that running ServiceModelReg.exe, which is supposed to WCF-enable IIS, didn't work either.

So after you do all of this (and I honestly hope that you had a much easier time than I did) you're good to go.

I'll post about my actual development experience with ADO.Net Data Services in a separate post. But I'll put in this teaser: You can do some really cool stuff with these extensions!