LINQ in Action - LINQ Book & News

Visual Studio Orcas March 2007 CTP

Microsoft has just released a new Orcas preview.

This new version is supposed to include almost all the functionality from the LINQ May 2006 CTP and more.
LINQ features in this version include:

  • VB 9.0: Query Expressions (Basic querying, filtering, and ordering support); Object Initializers; Extension Methods; Local Variable Type Inference; Anonymous Types; XML literals; XML properties; New Line and Expression IntelliSense
  • C# 3.0: Query Expressions; Object and Collection Initializers; Extension Methods; Local Variable Type Inference; Anonymous Types; Lambdas bound to Delegates and Expression trees; Complete design-time support (Intellisense, Formatting, Colorization)
  • LINQ to ADO.NET (LINQ to SQL, LINQ to DataSets, LINQ to Entities):
    • LINQ to SQL has enhanced the functionality from the May 2006 LINQ CTP. You can find it in System.Data.Linq namespace in System.Data.Linq.dll. New in this release is that DataContext provides optimized modes for read-only use and serialization . Also new is that DataShape streamlines eager loading capabilities and adds the ability to set queries on relationships
    • LINQ To SQL Designer: Methods can be created from stored procedures and functions within the designer; Better handling of database schemas; Improved inheritance support in the designer.
    • LINQ to SQL designer integration in websites and web applications
  • LINQ to XML:
    • System.Xml Bridge Classes added – There is a set of extension methods allowing XPath / XSLT to be used over LINQ to XML trees, allow XSLT transformations to produce an LINQ to XML tree, and to validate an XElement tree against an XML Schema.
    • Event Model - This allows LINQ to XML trees to be efficiently synchronized with a GUI, e.g. a Windows Presentation Foundation application
    • Class hierarchy changes - XObject class added, XStreamingElement class (temporarily) removed
    • Various understandability / usability improvements – There have been a number of relatively minor changes done in response to internal reviews, usability studies, and external feedback to make the API more clean and consistent.
  • LINQ to Objects: This API is defined in the System.Linq namespaces inside System.Core.dll.

Of course there are also many features not related to LINQ. See the links below to learn more. 

The Orcas March 2007 CTP is available as a Virtual PC image or as a standard self-extracting install. Get ready to swallow more than 6GB of download!

Published Wednesday, February 28, 2007 8:59 PM by Fabrice Marguerie



Derek said:

Wow, 150x the download size of the May LINQ CTP, and "almost all the functionality" ... hmm.

February 28, 2007 12:27 PM

Dominick said:

MS should really think about providing it on a DVD(s). There is no way I'll ever be able to DL that from my office.

February 28, 2007 1:09 PM

Fabrice Marguerie said:

The difference with the May CTP is that this is the complete Visual Studio product, not just extensions for LINQ support like was the case with the May CTP.

However, I agree that this is a huge download!

February 28, 2007 1:38 PM

Linq in Action News said:

After several months of work, the project reaches a new milestone. Steve and I have the pleasure to announce

March 5, 2007 3:38 AM

Fabrice's weblog said:

After several months of work, the project reaches a new milestone. Steve and I have the pleasure to announce

March 5, 2007 3:41 AM

x said:

On the Microsoft download page for the March CTP ( it says "Download the files most appropriate for you." - How do I know what is included in which file? Can anybody tell me where I can find out?

March 7, 2007 5:31 AM

Fabrice Marguerie said:

x, in fact you need to download all the files. The first one is an executable that will extract its content and the content of all the other files as well.

Refer to the instructions on the same page:


To install, follow these instructions in the exact order shown

  1. Download the seven files to a location on the local drive

  2. Double-click the VSMar2007CTP_VSTS_7PartsTotal.part1.exe which will open up the WinRAR package

  3. Choose a destination for the file extraction (C:\VSMarchCTP)

  4. Click Install

  5. When it has completed extracting the packages, go to C:\VSMarchCTP and double-click setup.exe to start the Visual Studio March CTP install


March 7, 2007 5:42 AM

Fine NN said:

I need the virtual inheritance capability, the LINQ inheritance right now does not let me to modify the code generated. I need to add vitual functions in the base class...Is the book support that? If no then please point  me to the right direction


April 16, 2007 12:37 PM

Jim Wooley said:

Fine, I'm not sure that the designers support virtual inheritance. I'm sure Sqlmetal does not. I will have to research the graphical designer to check it out more as it has more support for inheritance. Failing that, you can manually code them yourself either with attributes or XML. I recently posted about inheritance with LINQ at If you want, we can discuss this further in the book's forum at

April 18, 2007 2:12 PM
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