Episode 6 – There’s Something About LINQ

This week we're talking about LINQ, what's so special about .NET, the differences IQueryable and IEnumerable, and another round of "Never Have I Ever". Oh, and jokes! Download the episode on iTunes or Stitcher and make sure to send us your feedback! What is LINQ? Language Integrated Query Common interface for working with data Famous for it's fluint style, expressiveness, deferred execution and unconventional syntaxes Great for combining different data sources "Linq enables you to write code that expresses the intent, not the mechanism." @Aaronaught on StackExchange.com "Famous" LINQ Projects Entity Framework Moq Aspectacular LinqToSql LinqToXml LinqToS3 Athena (LinqToFlickr) PLINQ What's so special about .NET Check out our blog post: What's So Special About LINQ? CLR Features Delegates (Func/Action/Predicate) Expression Trees Anonymous Types/Methods Generics C# Features Lambda / Comprehension Syntax/li> Type inference - no string x => x.Trim()! Extension Methods Yield statement IQueryable vs IEnumerable IQueryable implements IEnumerable IQueryable is generally "smarter" than IEnumerable Great post on Code Project Great Answer on StackOverflow It's tough to talk about LINQ intelligently Tough Questions What exactly is deferred execution? Predictability vs Performance "Greedy" methods force enumeration Streaming/Sequences in C# in Depth Yield statement Multiple Enumeration Squigglies in Resharper Syntax - Query vs Lambda Joins are difficult in Lambda From Before Select! You can mix syntax! Are Lambdas / Comprehensions truly equivalent? LINQ Traps LINQ/Entity statements can provide vastly different SQL - Use SQL Profiler Advanced features like NOLOCKS, CTE are tough in LINQ Lazy rendering will bomb if ditch your context before enumerating Don't forget to check for nulls in your collections! Date math in the LINQ statement - set before the LINQ statement () => {} - Isn't "simple" the point? ToList() Creates Copies Never Have I Ever... My lambda expressions are always just a few lines... My lambda expressions are never mixed with Comprehension and vice versa... Now that I have LINQ to SQL, I never have to write use SQL directly again... I've never written my first version as a foreach / for loop only to refactor it as a LINQ / lambda expression Egregious ToList() Abuse Used a List instead of an IEnumerable Multiple enumeration error Egregious casting Written out a for loop only to have Resharper complain that it could be better written as a LINQ expression Fallen in love with a linq method De-anonymize your lambdas (var x = () => Console.WriteLine()) Cursed the lack of "WhereNot" I'm addicted to the ForEach method. There, I said it! Tips / Tricks LinqPad Modular Headphones! Tweetium Additional Resources C# in Depth (author Jon Skeet is awesome btw) LINQ in Action LINQ Fundamentals on Pluralsight LINQ Architechture C# Events, Delegates, and Lambdas Aspectacular

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