Matt Warren, who has been one of the lead developers on many aspects of LINQ, recently posted two very interesting stories describing The Origins of LINQ to SQL, and IQueryable's Deep Dark Secret.  In his first post on the Origins of LINQ to SQL, Matt talks about some of the previous dead projects, such as ObjectSpaces and WinFS, that influenced LINQ to SQL.  I found it interesting to hear about how LINQ to SQL came to be, and some of the internal politics that had to be overcome to make it a reality.  In his second post, IQueryable's Deep Dark Secret, Matt talks about how a call from Don Box eventually led to what is now at the core of LINQ, IQueryable.

I'm going to document the things I run into as I transition from the May 2006 CTP of LINQ to the full March 2007 CTP of Orcas. Tonight after sorting out my data source issue I ran into a compile error with my Visual Basic code samples that are using XML Axis properties. The error is "XML Axis properties do not support late binding". Hopefully I'll be able to post back here shortly with an answer to why I'm getting this....

UPDATE:  Thanks to a comment from Avner I figured out that this is due to a regression in the capability of VB9 to infer types.  Previously things worked swimmingly with the following code:

    Dim rss = XElement.Load("rss.xml")
    Dim items = rss...<item>

With the March CTP the type of "rss" needs to be explicitly defined like so:

    Dim rss As XElement = XElement.Load("rss.xml")
    Dim items = rss...<item>

I like the old way better :)

Yesterday I mentioned I was having some trouble adding a Data Source in Orcas. I'm happy to report that following the instructions in the Orcas March CTP on Vista Database Connections Problem Solved post resolved my issue. Once I commented out the SQL Server CE Data Provider in the machine.config everything was back to normal.

I had a jolly good fun time tonight updating my code samples to the March CTP of Orcas.  Well, actually, I'm not quite finished as of yet because of the wonderful error in the title of this post.  It appears VS.NET Orcas doesn't want to let me recreate my data connection for my database that I'm using for some LINQ to SQL examples. Woot!  Hopefully I'll figure out what the dealy is shortly because I've got chapters I need to finish. :)