.Net 3.5 had some nice tricks in it. LINQ-to-XML was one of them. With the new "X"-types, you can make working with XML really easy. VB.Net 9 takes it one step further, and lets you write XML in your code without strings. "Hey Rich, that’s old news," I hear you say. "And who’s interested in [...]

Have you wondered if and when you should use the new LINQ features in .Net 3.5? Like, where should I put a new extension method? Should I use Func<T> or a custom delegate? How do I best implement a mix-in (extension methods on an interface)? Well, Mircea Trofin has just published a new draft of [...]

I just read a fantastic quote about LINQ from the book Pro LINQ: Language Integrated Query in C# 2008 by Joseph C. Rattz, Jr.: I prefer to think of LINQ as a data iteration engine, but perhaps Microsoft didn’t want a technology named DIE. I think they already built the technology for such a product, [...]

Yesterday I thought I’d learn about the LinqDataSource in ASP.Net 3.5, and got an interesting surprise. The new LinqDataSource can also be used with a LINQ-to-SQL model to perform updates. You simply add the DataSource to your page, set the table name, and set EnableUpdate to true. Then, using a standard DataControl, you can make [...]

When learning LINQ-to-SQL, it’s not immediately obvious how to do an update. Querying is easy, and there are methods for inserting and deleting. Updating usually occurs by modifying an object already known to the DataContext and then calling SubmitChanges on the context. var product = (from p in dataContext.Products where p.ProductID == 1 select p).Single(); [...]

Quick tip: If you want to see the SQL generated by LINQ to SQL for a query or command, simply set the Log property of your generated DataContext class to an instance of a TextReader. If this is your code: using System; using System.Linq; using System.Data.Linq; namespace LINQtoSQLConsole { class Program { static void Main(string[] [...]

When you started using LINQ, did you think it looked like SQL? I did. The more I learned LINQ, the more I realized it wasn’t anything like SQL. Take grouping, for example. Because LINQ has a group by statement, and it looks like SQL, I assumed that the syntax for grouping in LINQ would be [...]

Last week I had to prepare a small presentation for a new LINQ workshop. For my research, I browsed through the MSDN documentation on LINQ where I came across a reference to "LINQ to DataSets". I couldn’t find any more information about it though, and so LINQ to DataSets got a small mention in my [...]

I am really getting into LINQ now! I think it’s fantastic. I recently wanted to develop a quick drop-down list in ASP.Net which allows a user to select a time of day from a list. The times are 15 minutes apart, so the list would look like this: … 08:00 08:15 08:30 08:45 09:00 … [...]

When using LINQ, you need to be careful to use the right kind of Lambda expression. “What, there is more than one kind?”, I hear you gasp. There sure is! And if you aren’t careful, you’ll get a nice little message at runtime to tell you: “System.Object DynamicInvoke(System.Object[])’ has no supported translation to SQL.” What [...]