book

LINQ For Dummies®

Name: LINQ For Dummies®
Author: John Paul Mueller
ISBN: 9780470277942

by John Paul Mueller

August 2008

Beginner to intermediate

364 pages

8h 35m

English

For Dummies

Read now

Unlock full access

Copyright
About the Author
Author's Acknowledgments
Introduction
About This BookConventions Used in This BookWhat You Should ReadWhat You Don't Have to ReadFoolish AssumptionsHow This Book Is OrganizedPart I: An Overview of LINQPart II: Using Standard LINQ to TechnologiesPart III: Extending LINQ to New HorizonsPart IV: The Part of TensThe accompanying Web siteIcons Used in This BookWhere to Go from Here
I. An Overview of LINQ
1. Getting to Know LINQ
1.1. Considering LINQ1.1.1. Understanding the task that LINQ performs1.1.2. Contemplating why you need LINQ1.1.3. Defining the LINQ design goals1.1.4. Understanding the LINQ requirements1.2. Using LINQ in the Real World1.3. Understanding Declarative Programming1.4. An Overview of the LINQ Namespaces1.4.1. System.Linq namespace1.4.2. System.Linq.Expressions namespace1.4.3. System.Data.Linq namespace1.4.4. System.Data.Linq.Mapping namespace1.4.5. System.Data.SqlClient namespace1.4.6. System.Data.SqlClient.Implementation namespace1.4.7. System.Xml.Linq namespace
2. Creating Simple LINQ Queries
2.1. Defining the LINQ Keywords2.1.1. Working with from2.1.2. Working with where2.1.3. Working with orderby2.1.4. Working with join2.1.5. Working with let2.2. Creating a Simple from Query2.2.1. Understanding the simple query application code2.2.2. Using the debugger to see the simple query in action2.3. Filtering a Query2.4. Grouping Queries2.5. Creating Queries from Multiple Sources2.5.1. Understanding the multiple-source application code2.5.2. Working with the alternative multiple-source example2.5.3. Using calculated values in multiple-source queries2.6. Working with the Standard Query Operators2.7. Mapping Keywords to Methods
3. Considering the .NET Language Extensions
3.1. An Overview of the Language Extensions3.2. Working with Lambda Expressions3.3. Understanding the Role of the IEnumerable and IEnumerable <T> Interfaces3.4. Understanding Object Initializers3.5. Understanding Collection Initializers3.6. Working with Extension Methods3.7. Working with Partial Methods3.8. An Overview of Expression Trees3.9. Working with Query Expressions
4. Working with LINQ in Visual Basic .NET
4.1. Understanding the Visual Basic Differences4.2. Creating the Simple Visual Basic Example4.2.1. Working with From4.2.1.1. Understanding the code4.2.1.2. Using the debugger to see the code execute4.2.2. Working with Where4.2.3. Working with Order By4.2.4. Working with Join4.2.5. Working with Let4.3. Using the Additional Visual Basic Keywords4.3.1. Working with Aggregate4.3.2. Working with Distinct4.3.3. Working with Skip4.3.4. Working with Take4.4. Working with Lambda Functions in Visual Basic

5. Working with LINQ in Visual Studio 2005
5.1. Obtaining LINQ Support for Visual Studio 20055.2. Installing LINQ Support5.3. Creating the Simple Visual Studio 2005 Project5.3.1. Defining the project5.3.2. Working with from5.3.2.1. Understanding the code5.3.2.2. Using the debugger5.3.3. Working with join5.3.4. Working with where5.3.5. Working with orderby5.3.6. Working with let
II. Using Standard LINQ to Technologies
6. LINQ to Object
6.1. Considering the Use of Objects with LINQ6.2. Creating the Simple Object Query Example6.3. Understanding the Role of Deferred Operators6.4. Creating the Deferred Operator Examples6.4.1. Working with Concat6.4.2. Working with AsEnumerable, AsQueryable, Cast, and OfType6.4.3. Working with OfType and Where6.4.4. Working with DefaultIfEmpty, Empty, Range, and Repeat6.4.5. Working with GroupBy and ToLookup6.4.6. Working with GroupJoin and Join6.4.7. Working with Skip, SkipWhile, Take, and TakeWhile6.4.8. Working with Select and SelectMany6.4.9. Working with Distinct, Except, Intersect, and Union6.4.10. Working with OrderBy, OrderByDescending, Reverse, ThenBy, and ThenByDescending6.5. Understanding the Role of Nondeferred Operators6.6. Creating the Nondeferred Operator Examples6.6.1. Working with Aggregate, Average, Count, LongCount, Max, Min, and Sum6.6.2. Working with ToArray, ToDictionary, ToList, and ToLookup6.6.3. Working with ElementAt, ElementAtOr Default, First, FirstOrDefault, Last, LastOrDefault, Single, and SingleOrDefault6.6.4. Working with SequenceEqual6.6.5. Working with All, Any, and Contains
7. LINQ to DataSet
7.1. Considering the Use of DataSets with LINQ7.2. Creating the Simple DataSet Example7.2.1. Defining the test tables7.2.2. Outputting the results7.2.3. Exploring the connection7.3. Understanding the LINQ to DataSet Operators7.4. Creating the Filtered Output Example7.4.1. Creating a simple display7.4.2. Modifying the filtered output7.4.3. Using the CopyToDataTable operator7.4.4. Working with typed DataSets7.4.4.1. Defining the DataSet7.4.4.2. Working with the typed DataSet7.5. Working with Multiple DataSet Tables
8. LINQ to SQL Server
8.1. Considering the Use of SQL Server with LINQ8.2. Obtaining and Installing the Northwind Database8.2.1. Downloading the database8.2.2. Installing the database8.2.3. Testing the Visual Studio connection8.2.4. Generating the Northwind entity classes and XML mapping files8.3. Creating the Simple SQL Server Query Example8.3.1. Overcoming the Visual Studio 2008 connectivity issues8.3.2. Defining the project8.3.3. Adding the code8.3.4. Viewing the debugger output8.4. Using Object Relational Designer8.5. Understanding the LINQ to SQL Server Operators
9. LINQ to XML
9.1. Considering the Use of XML with LINQ9.2. Working with the LINQ to XML API9.3. Understanding the LINQ to XML Operators9.3.1. Working with XDeclaration, XElement, and XDocument9.3.2. Working with XNamespace9.3.3. Working with XProcessingInstruction9.3.4. Working with XAttribute9.3.5. Working with XComment and XText9.3.6. Working with XCData9.3.7. Working with XDocumentType9.3.8. Working with XNodeDocumentOrderComparer9.3.9. Working with XNodeEqualityComparer9.3.10. Working with Remove9.3.11. Working with XName9.4. Creating the Simple XML File Example9.4.1. Creating the project9.4.2. Building an XML document9.4.3. Saving an XML document9.4.4. Loading an XML document
III. Extending LINQ to New Horizons
10. Using LINQ with Office 2007
10.1. Understanding the Office Document Structure10.2. Understanding LINQ Interaction with Office10.3. Obtaining the Required Library10.4. Creating the Office 2007 Document Example10.4.1. Creating the project10.4.2. Understanding the custom properties10.4.3. Reading document properties10.4.4. Writing document properties
11. Advanced LINQ to SQL Server
11.1. Considering SQL Server Issues11.1.1. Understanding concurrency problems11.1.1.1. Understanding the problem and its resolution11.1.1.2. Seeing concurrency checks and resolution in action11.1.1.3. Defining alternatives to ResolveAll()11.1.1.4. Using entity class attributes to modify concurrency detection11.1.2. Overcoming performance issues11.1.2.1. Using Column attributes11.1.2.2. Relying on standard database performance tricks11.1.2.3. Performing database updates only as needed11.1.2.4. Using eager loading11.2. Creating the Database Modification Example11.2.1. Performing an insert11.2.2. Performing an update11.2.3. Performing a delete11.3. Using Concurrency Checks and Resolving Errors11.3.1. Resolving conflicts at the object level11.3.2. Resolving conflicts at the member level
12. LINQ to Active Directory
12.1. Working with Specific Active Directory Objects12.2. Defining Active Directory Variables12.3. Obtaining the LINQ to Active Directory Provider12.4. Creating the Simple Active Directory Query Example12.4.1. Performing the project setup12.4.2. Defining an Active Directory object class12.4.3. Creating a root node pointer12.4.4. Reading user information12.4.5. Writing user information12.5. Understanding the Limitations of Active Directory Interaction12.5.1. Some LINQ methods aren't implemented12.5.2. Defining the need for LDAP patience
13. Other LINQ to Strategies
13.1. Understanding the Qualifications for a LINQ to Solution13.2. Accessing COM+ Using LINQ13.2.1. COM+ accessed as a Web service13.2.2. COM+ accessed using interop functionality13.3. Creating the Resource Description Format (RDF) Files Example13.3.1. A quick overview of RDF13.3.2. A quick overview of SPARQL13.3.3. Starting the project13.3.4. Configuring the project13.3.4.1. Defining the client project13.3.4.2. Defining the host project13.3.5. Creating the host application13.3.6. Creating the application class definition13.3.7. Reading RDF files13.4. Creating the MySQL Example13.4.1. Getting the MySQL ADO.NET connector13.4.2. Compiling the DbLinq.DLL and DbLinq.MySQL.DLL files13.4.3. Configuring the database13.4.4. Defining the MySQL project13.4.5. Developing the query code
IV. The Part of Tens
14. Ten Ways to Improve LINQ Development
14.1. Using LINQ Tools to Simplify Coding14.1.1. Getting the VLinq add-in application14.1.2. Creating a VLinq query14.1.3. Using a VLinq query in an application14.2. Using LINQ to Create Self Documenting Code14.3. Analyzing Code Patterns14.4. Querying a Code Snippet Database14.5. Locating Other Development Resources14.6. Using LINQ to Query Data Formats14.7. Finding Usage Trends14.8. Developing a LINQ Library14.9. Sharing LINQ Queries with Others14.10. Analyzing Compiler and IDE Output
15. Ten Ways to Reduce Application Support Costs
15.1. Creating Self-Modifying Queries15.2. Using LINQ to Create Reports15.3. Addressing User Search Needs15.4. Creating User-Friendly Mashups15.5. Making Help More Accessible15.6. Organizing and Querying Support Requests and Responses15.7. Developing Fast Searches from Multiple Sources15.8. Helping Users Locate Existing Resources15.9. Performing Support Task Automation15.10. Improving Application and System Management
16. Ten LINQ Resources
16.1. Starting with the Microsoft Developer Network16.2. Getting Tips from the Microsoft Blogs16.3. Finding Help in Third-Party Web Sites16.4. Finding Help in Third-Party Newsletters and Blogs16.5. Using Other Sources for LINQ to Objects Projects16.6. Using Other Sources for LINQ to SQL Server Projects16.7. Using Other Sources for LINQ to XML Projects16.8. Considering Other LINQ to Sources Projects16.9. Getting Help with Visual Basic Projects16.10. Getting Help with C# Projects

Overview

If you’ve asked yourself “Why can’t I develop database and XML queries in a language I already know?”, then Language INtegrated Query, or LINQ, is for you. LINQ For Dummies introduces you to LINQ and the .NET Framework technologies, so you can use LINQ to query any object, any data set, any kind of XML, and SQL Server—no questions asked.

This plain-English guide gives you a thorough overview of LINQ, from understanding the tasks it performs to making LINQ work with both Visual Basic and Visual Studio 2005. It explains the four LINQ providers in the .NET Framework, the easiest ways to go about accessing data, and how to write more efficient applications with less code using LINQ. There’s also clear guidance on combining third-party providers with LINQ to create even more powerful apps. With this single, comprehensive guide, you’ll discover how to:

Use one query language with all Microsoft languages

Examine .NET language extensions and work with extension methods, partial methods, lambda expressions, and query expressions

LINQ to DataSet operators, SQL server operations, XML API, or Active Directory

Deal with databases — download and install the Northwind database, generate Northwind entity classes, and create the Northwind XML mapping file

Create the partial class example, the partial method example, and the database modification example

Use objects with LINQ

Query databases in Visual Basic and C#

As an added bonus, you can visit the companion Web site for LINQ examples in C# and Visual Basic. With LINQ For Dummies, you’ll link up with LINQ in no time and see how you can query almost anything!

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.

Julian F.

Head of Cybersecurity

I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.

Addison B.

Field Engineer

I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.

Amir M.

Data Platform Tech Lead

I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.

Mark W.

Embedded Software Engineer

Publisher Resources

ISBN: 9780470277942Purchase book

Cloud Computing

Data Engineering

Data Science

AI & ML

Programming Languages

Software Architecture

IT/Ops

Security

Design

Business

Soft Skills