|
Microsoft .NET LINQ Preview (May 2006) is now installed on your machine.
Welcome to the Microsoft
.NET LINQ Preview (May 2006). This is an enhanced version of the LINQ
Preview unveiled at PDC 2005. It contains documentation and samples to let you
see Language-Integrated Query in action, as well as preliminary IDE support
so you can write your own queries.
This release includes a
prototype C# 3.0 compiler, as well as preliminary IDE support for Visual
Studio 2005 and Visual C# 2005 Express.
The following are the
requirements for this preview:
- The prototype C# compiler
and the samples below require one of the following:
- Visual Studio 2005
(required for DLinq designer)
- Visual C# 2005 Express
- Windows XP Service Pack 2,
Windows 2000 Service Pack 4 or Windows Server 2003 or Windows Vista
beta2 with WinFX Runtime beta2 are required. The LINQ Preview has
not been tested on 64-bit operating systems.
- English-language versions of
both Windows and Visual Studio/Visual C#/Visual Basic are recommended.
The LINQ Preview has not been tested on other platforms.
Some samples and
templates have extra requirements:
- To run DLinq samples, you
must have one of the following installed on this machine:
- SQL Server 2005 Express
(included with Visual Studio 2005 or downloadable from http://lab.msdn.microsoft.com/express/sql/default.aspx)
- The following versions of
SQL Server will work, but require some minor code changes to the
samples first (see the Troubleshooting section below for instructions):
- SQL Server 2005
(non-Express)
- SQL Server 2000a
- To use the LINQ WinFX
project template, you must have:
- WinFX Beta 2 SDK installed
LINQ is on the
web! Check out the LINQ Home Page
on MSDN for more information including videos with the designers of LINQ,
latest blog posts and forum where you can share and discuss your experiences
with the LINQ Project.
What’s new?
LINQ:
- IQueryable<T> enables
pluggable query processors.
- ToQueryable provides a way
to get an expression tree from an IEnumerable<T> so that a
pluggable query processor can optimize and execute it
- Expression.Compile enables compilation
of an expression tree for in-memory execution
- Join support has been added:
Join operator provides inner equi-join and a powerful GroupJoin operator
retains the hierarchical structure while providing additional outer-join
like capabilities
- A family of additional
operators: Single, SingleOrDefault, Last, LastOrDefault, ElementAt,
ElementAtOrDefault
C# Language:
- Query expressions now
provide:
- Join syntax for using Join
and GroupJoin
- Let clause for declaring
temporary variables in query expression
- Lambda statement blocks are
enabled in addition to lambda expressions
C# IDE:
- Support for copy-pasting XML
for simplified use of XLinq
DLinq:
- A graphical designer has
been added for generating mapped classes. This designer requires Visual
Studio 2005 Professional Edition or above.
- Inheritance
- Multi-tier entity support
- Enhanced support for stored
procedures and user-defined functions
- Improved concurrency
conflict resolution
- Remote / local EntitySet
- XML mapping file
- Additional .NET functions
XLinq
- Supports annotations, an
extensibility point for user data
- Improved support for XML
mixed content
- Support for streaming output
LINQ over DataSet:
- Adds new LINQ component to
query DataTables – implements the LINQ query pattern including join
- Adds DataSet-specific
operators like DistinctRows, UnionRows for traditional relational set
operations
- Provides ToDataTable()
operator to get a DataTable from a sequence
Miscellaneous:
- Web project template that
allows prototype C# compiler to be used in web projects
- WinForms and ASP.NET
databinding samples
- An expression tree
visualizer for better inspection of expression trees
- A DLinq query visualizer for
better debugging experience
Documents:
- LINQ Project Overview – An explanation of the
motivations behind Language-Integrated Query, and a peek into some of
the new language capabilities that allow for rich type-checked querying
of in-memory data, relational data stores, and XML.
- Standard Query Operators – A description of the
Standard Query Operators, the building blocks that are composed to form
queries.
- Sequence.cs – The implementation of
the Standard Query Operators which demonstrates how they work and
models how you can write your own operators.
- C# 3.0 Specification – The detailed
specifications of the new C# language features that come together to form
the foundation for LINQ.
- DLinq
Overview for C# Developers – An examination of the architecture of DLinq,
which provides type-safe, compiler-checked querying against relational
data stores, such as SQL Server.
- Walkthrough: Using the DLinq Designer – Shows how use the
designer to create DLinq objects and use them for databinding in a
Windows Form.
- XLinq Overview – A look at how to use
XLinq, a new lightweight XML object model that allows for both
language-integrated querying and transformation of XML data.
- XLinq Reference – An in-depth description
of each of the classes within the XLinq object model.
- LINQ
over DataSet – A guide to using standard query operators and additional
operators over DataSet
- Hands on Labs – Self-paced walkthroughs
for each of the major components of LINQ: Standard Query Operators,
DLinq and XLinq, as well as the C# language features that make Language-
Integrated Query possible.
C# Support:
The installer sets up
several LINQ project templates (LINQ Windows Application, LINQ Web Site, LINQ
Console Application, LINQ WinFX Application and LINQ Library) that you can
use to create your own C# 3.0 projects using LINQ.
IDE Support (for Visual Studio 2005/C# 2005 Express):
Project
LINQ relies on several changes to the C# language. C# 3.0 contains new
keywords and syntax that are not considered valid by the Visual Studio 2005
IDE. The result is that editing LINQ-enabled C# code can be difficult:
For example, there is no IntelliSense™ support for the new language features,
errors are incorrectly reported in the output window, and the code editor
underlines valid C# 3.0 code with red squiggles. A modified C# language
service has been created to help alleviate these problems in the IDE, to provide
the new keywords in the completion list, and to provide extension methods in
IntelliSense™.
While
this preliminary IDE support greatly enhances the editing experience when
writing C# 3.0 code in VS 2005, the language service and compiler are still very
much in an alpha phase. In the event of a compiler error, many more
errors may be reported than are actually present. If you see a large
number of errors when building C# 3.0 code, fix the top error in the error
list first and build after each fix.
Follow
these steps to enable LINQ IDE support for Visual Studio 2005 and Visual C#
2005 Express:
- First, verify that you are
running the release version of Visual Studio 2005 or Visual C# 2005
Express. The language service that will be installed only works
with the English version of VS 2005/C# 2005 Express and may cause severe
problems if installed on earlier versions. You can verify your
version by selecting Help\About in Visual Studio 2005.
- Shut down any running
instances of Visual Studio.
- Open the \bin
folder under the LINQ preview installation directory and run “Install C#
IDE Support”.
- Start VS 2005/C# 2005
Express.
Follow
these steps to restore your original VS 2005/C# 2005 Express language
service:
- Shut down any running instances
of Visual Studio.
- Open the \bin
folder under the LINQ preview installation directory and run “Uninstall
C# IDE Support”.
- Start VS 2005/C# 2005
Express.
Visual Basic Support:
If you also have Visual Basic
installed on your machine, the files for preview for Visual Basic are
installed. The readme for Visual Basic can be found here. The preview files for Visual Basic are
not installed if you do not have Visual Basic installed as a part of
Microsoft Visual Studio 2005 or Microsoft Visual Basic Express 2005.
Samples:
Loading samples requires
Visual Studio 2005 or Visual C# 2005. It is recommended that you
install the IDE support above first to improve your experience navigating
through and writing C# 3.0 code.
- SampleQueries – The SampleQueries project
contains hundreds of sample Standard Query Operator, DLinq and XLinq
queries that you can try out and modify to get a feel for the
capabilities of Language-Integrated Query.
- ASP.NET
Databinding – Show a DLinqDataSource that helps you quickly write simple
web applications.
- Expression tree visualizer – Shows how to view an
expression tree generated by a compiler.
- Interactive Query – Dynamically extend DLinq
queries by adding filter, sort, paging expressions.
- LogicProgramming – The LogicProgramming
sample shows how to implement a domain specific language inside of C#
using compiler generated expression trees.
- Reflector – The Reflector sample illustrates
queries over components from System.Reflection and
System.Xml.XLinq. The result is an HTML document outlining the
public APIs for a given assembly, in this case System.Xml.XLinq.dll.
- Rss – The Rss sample uses System.Xml.XLinq
to build a tiny web server that aggregates several RSS feeds.
- WCFLinq – The WCFLinq sample
highlights both the Windows Communication Framework (“Indigo”) and LINQ.
The sample shows using XLinq for the creation and processing of XML
messages and the use of Linq against [DataContract] types.
- WinFormsDataBinding – The WinFormsDataBinding
sample illustrates how the results of DLinq queries can be bound to
WinForms grid for display and updates.
- XLinqIntro – The XLinqIntro sample is
a short introduction to System.Xml.XLinq, building on familiarity with
the XML DOM API.
Forum:
Join
fellow LINQ Preview users for discussions at the LINQ
forum
Bloggers:
A number of Microsoft
bloggers regularly talk about the LINQ Project, so check out their blogs
regularly for the latest tips and tricks! The latest blog entries can be
found on the LINQ
Home Page. Additional information about C# can be found at the Visual C# Developer Center on
MSDN.
Known Issues and Troubleshooting:
A list of
known issues and workarounds where available is on the LINQ home page.
|
