LINQ Unleashed: for C# (Unleashed)

Foreword by Darryl Hogan, Architect Evangelist, Microsoft CorporationMicrosoft's highly anticipated LINQ query technology makes it easy to retrieve any information programmatically from any data source, no matter where it comes from or how it's stored. Using LINQ, developers can query objects, relational databases, XML documents, and ADO.NET datasets - and do it all directly from C# 3.0, leveraging the powerful capabilities of LINQ.This is a definitive guide to getting real-world results with LINQ, using C# 3.0 and Visual Studio 2008. In LINQ Unleashed, Microsoft MVP Paul Kimmel covers every facet of LINQ programming, showing how LINQ can help you dramatically improve your productivity and build more reliable, maintainable applications.Kimmel begins by reviewing the state-of-the-art C# programming techniques LINQ uses, including anonymous types, partial methods, and Lambda expressions. Next, using realistic examples and easy-to-adapt sample code, he details the most powerful new LINQ techniques for accessing objects, databases, and XML. You'll gain a deep and practical understanding of how LINQ works "under the hood" - and learn how to do everything from selecting data through integrating XML with other data models. LINQ Unleashed for C# Table of Contents Introduction Conventions Used in This Book Part I: Getting Ready for LINQ 1 Programming with Anonymous Types Understanding Anonymous Types Programming with Anonymous Types Databinding Anonymous Types Testing Anonymous Type Equality Using Anonymous Types with LINQ Queries Introducing Generic Anonymous Methods Summary 2 Using Compound Type Initialization Initializing Objects with Named Types Initializing Anonymous Types Initializing Collections Using Conversion Operators Summary 3 Defining Extension and Partial Methods Extension Methods and Rules of the Road Defining Extension Methods How Extension Methods Support LINQ Implementing a "Talking" String Extension Method Defining Partial Methods Summary 4 yield return: Using .NET's State Machine Generator Understanding How yield return Works Using yield return and yield break Summary 5 Understanding Lambda Expressions and Closures Understanding the Evolution from Function Pointers to Lambda Expressions Writing Basic Lambda Expressions Dynamic Programming with Lambda Expressions Lambda Expressions and Closures Currying Summary 6 Using Standard Query Operators Understanding How LINQ Is Implemented Constructing a LINQ Query Filtering Information Using Quantifiers Partitioning with Skip and Take Using Generation Operations Equality Testing Obtaining Specific Elements from a Sequence Appending Sequences with Concat Summary Part II: LINQ for Objects 7 Sorting and Grouping Queries Sorting Information Grouping Information Summary 8 Using Aggregate Operations Aggregating Averaging Collection Values Counting Elements Finding Minimum and Maximum Elements Summing Query Results Median: Defining a Custom Aggregation Operation Summary 9 Performing Set Operations Finding Distinct Elements Defining Exclusive Sets with Intersect and Except Creating Composite Resultsets with Union Summary 10 Mastering Select and SelectMany Exploring Select Projecting New Types from Multiple Sources Creating a New Sequence from Multiple Sequences with SelectMany Using SelectMany with Indexes Summary 11 Joining Query Results Using Multiple From Clauses Defining Inner Joins Using Custom, or Nonequijoins Implementing Group Join and Left Outer Join Implementing a Cross Join Defining Joins Based on Composite Keys Summary 12 Querying Outlook and Active Directory LINQ to Outlook Querying Active Directory with Straight C# Code LINQ to Active Directory Querying Active Directory with LINQ Summary Part III: LINQ for Data 13 Querying Relational Data with LINQ Defining Table Objects Connecting to Relational Data with DataContext Objects Querying DataSets SqlMetal: Using the Entity Class Generator Tool Using the LINQ to SQL Class Designer Summary 14 Creating Better Entities and Mapping Inheritance and Aggregation Defining Better Entities with Nullable Types Mapping Inheritance Hierarchies for LINQ to SQL Adding EntitySet Classes as Properties Creating Databases with LINQ to SQL Summary 15 Joining Database Tables with LINQ Queries Defining Joins with LINQ to DataSet Defining Joins with LINQ to SQL Querying Views with LINQ Databinding with LINQ to SQL Summary 16 Updating Anonymous Relational Data Adding and Removing Data Calling User-Defined Functions Using Transactions Understanding Conflict Resolution N-Tier Applications and LINQ to SQL Summary 17 Introducing ADO.NET 3.0 and the Entity Framework Understanding the General Nature of the Problem and the Solution Finding Additional Resources Building a Sample Application Using Vanilla ADO.NET Programming Programming with the Entity Framework Doing It All with LINQ Summary Part IV: LINQ for XML 18 Extracting Data from XML Loading XML Documents Querying XML Documents Loading XML from a String Handling Missing Data Using Query Expressions with XML Data Annotating Nodes Summary 19 Comparing LINQ to XML with Other XML Technologies Comparing LINQ to XML with XPath Comparing LINQ to XML Transformations with XSLT Transforming XML Data Using Functional Construction Summary 20 Constructing XML from Non-XML Data Constructing XML from CSV Files Generating Text Files from XML Using XML and Embedded LINQ Expressions (in VB) Summary 21 Emitting XML with the XmlWriter Exploring the XmlWriter, Quickly Using XmlTextWriter to Write an XML File Summary 22 Combining XML with Other Data Models Creating XML from SQL Data Updating SQL Data from XML Summary 23 LINQ to XSD Supports Typed XML Programming Understanding the Basic Design Goals of LINQ to XSD Programming with LINQ to XSD Summary Index A B C D E F G H I J K–L M N O P Q R S T U V W X–Z

Foreword by Darryl Hogan, Architect Evangelist, Microsoft Corporation

Microsoft’s highly anticipated LINQ query technology makes it easy to retrieve any information programmatically from any data source, no matter where it comes from or how it’s stored. Using LINQ, developers can query objects, relational databases,

This is a definitive guide to getting real-world results with LINQ, using C# 3.0 and Visual Studio 2008. In LINQ Unleashed, Microsoft MVP Paul Kimmel covers every facet of LINQ programming, showing how LINQ can help you dramatically improve your productivity and build more reliable, maintainable applications.

Kimmel begins by reviewing the state-of-the-art C# programming techniques LINQ uses, including anonymous types, partial methods, and Lambda expressions. Next, using realistic examples and easy-to-adapt sample code, he details the most powerful new LINQ techniques for accessing objects, databases, and

 

• Build efficient LINQ queries to .NET objects, SQL databases, and

  Utilize anonymous types to reduce design time, coding effort, and debugging time

• Automatically generate .NET state machines with the new yield return construct
• Master LINQ query syntax, operators, extension methods, sorting, grouping, aggregate and set operations, and more
• Make the most of select—and use it in the business layer of your n-tier applications
• Query relational data stored in Microsoft SQL Server
• Use nullable types to eliminate unnecessary database access plumbing code
• Use LINQ with ADO.NET 3.0 and Microsoft’s powerful new Entity Framework
• Extract

  Automatically construct

  Query Active Directory by extendingLINQ

Introduction  1

Part I   Getting Ready for LINQ

1   Programming with Anonymous Types 5

2   Using Compound Type Initialization  29

3   Defining Extension and Partial Methods  61

4   yield return: Using .NET’s State Machine Generator  85

5   Understanding Lambda Expressions and Closures  97

6   Using Standard Query Operators  121

Part II LINQ for Objects

7   Sorting and Grouping Queries 137

8   Using Aggregate Operations 151

9   Performing Set Operations  167

10   Mastering Select and SelectMany  185

11   Joining Query Results  211

12   Querying Outlook and Active Directory  239

Part III   LINQ for Data

13   Querying Relational Data with LINQ 265

14   Creating Better Entities and Mapping Inheritance and Aggregation  289

15   Joining Database Tables with LINQ Queries  309

16   Updating Anonymous Relational Data  349

17   Introducing ADO.NET 3.0 and the Entity Framework  383

Part IV  LINQ for

18   Extracting Data from

19   Comparing LINQ to

20   Constructing

21   Emitting

  463

22   Combining

23   LINQ to XSD Supports Typed

Index

This is the eBook version of the printed book. If the print book includes a CD-ROM, this content is not included within the eBook version.Foreword by Darryl Hogan, Architect Evangelist, Microsoft Corporation Microsoft's highly anticipated LINQ query technology makes it easy to retrieve any information programmatically from any data source, no matter where it comes from or how it's stored. Using LINQ, developers can query objects, relational databases, XML documents, and ADO.NET datasets--and do it all directly from C# 3.0, leveraging the powerful capabilities of LINQ. This is a definitive guide to getting real-world results with LINQ, using C# 3.0 and Visual Studio 2008. In LINQ Unleashed, Microsoft MVP Paul Kimmel covers every facet of LINQ programming, showing how LINQ can help you dramatically improve your productivity and build more reliable, maintainable applications. Kimmel begins by reviewing the state-of-the-art C# programming techniques LINQ uses, including anonymous types, partial methods, and Lambda expressions. Next, using realistic examples and easy-to-adapt sample code, he details the most powerful new LINQ techniques for accessing objects, databases, and XML. You'll gain a deep and practical understanding of how LINQ works “under the hood”--and learn how to do everything from selecting data through integrating XML with other data models. Build efficient LINQ queries to.NET objects, SQL databases, and XML content Utilize anonymous types to reduce design time, coding effort, and debugging time Automatically generate.NET state machines with the new yield return construct Master LINQ query syntax, operators, extension methods, sorting, grouping, aggregate and set operations, and more Make the most of select--and use it in the business layer of your n-tier applications Query relational data stored in Microsoft SQL Server Use nullable types to eliminate unnecessary database access plumbing code Use LINQ with ADO.NET 3.0 and Microsoft's powerful new Entity Framework Extract XML data without the hassles or complexity of XPath Automatically construct XML from CSV files and other non-XML data Query Active Directory by extending LINQ Introduction 1 Part I Getting Ready for LINQ 1 Programming with Anonymous Types 5 2 Using Compound Type Initialization 29 3 Defining Extension and Partial Methods 61 4 yield return: Using.NET's State Machine Generator 85 5 Understanding Lambda Expressions and Closures 97 6 Using Standard Query Operators 121 Part II LINQ for Objects 7 Sorting and Grouping Queries 137 8 Using Aggregate Operations 151 9 Performing Set Operatio "This is a definitive guide to getting real-world results with LINQ, using C# 3.0 and Visual Studio 2008. In LINQ unleashed, Microsoft MVP Paul Kimmel covers every facet of LINQ programming, showing how LINQ can help you dramatically improve your productivity and build more reliable, maintainable applications." "Kimmel begins by reviewing the state-of-the-art C# programming techniques LINQ uses, including anonymous types, partial methods, and Lambda expressions. Next, using realistic examples and easy-to-adapt sample code, he details the most powerful new LINQ techniques for accessing objects, databases, and XML. You'll gain a deep and practical understanding of how LINQ works "under the hood" - and learn how to do everything from selecting data through integrating XML with other data models."--book jacket A thorough overview of LINQ (Language Integrated Query), the most important new feature in Visual Studio 2008, explains how to use LINQ to improve access for .NET developers, furnishes helpful explanations that demonstrate how to use LINQ in applications, and covers such topics as conversion operators, lambda expressions and closures, relational data, and much more. Original. (Intermediate)