In an earlier post , I discussed implementation of custom query operators that combine existing built-in operators. In StreamInsight 1.2 , we have made some changes to simplify implementation of custom operators. In the running example from the previous...

A few weeks ago, Torsten Grabs – a colleague on the StreamInsight team and accomplished violist – came to me with a potential bug. He was seeing an ADO.NET SqlClient exception when running a StreamInsight query: “ There is already an open DataReader associated...

A colleague was asking how to construct a particular LINQ “operator macro” today. Basically, he was finding it inconvenient to repeat boilerplate for particular operator patterns in his code, but was struggling to inline expression snippets into LINQ...

Over the past few weeks, I’ve spent time building a handful of applications using the new sequence integration APIs in StreamInsight 1.1. I think StreamInsight veterans will be pleasantly surprised at the seamlessness of the experience! If you’re new...

Embedding a StreamInsight server instance in your application is easy: using (var server = Server.Create("Default")) { … } But there’s a hitch. What does“Default” mean? If you’ve spent time with the StreamInsight...

Over the past couple of weeks, a handful of people have asked for help dynamically creating StreamInsight queries. I usually scrawl some boxes and arrows on the whiteboard and say “you could try something like this…” My hand-waving...

The EF Extensions sample has been updated for Visual Studio 2010. It’s available for download here . Nothing new in this release… some features have actually been removed because they’re no longer needed in .NET 4.0. The EF proper now includes an ObjectSet<TEntity>...

I talked a little bit about patterns using InvocationExpression in a previous post (you might want to review the post for some context). It turns out my advice wasn’t that easy to implement… Fortunately, the EFExtensions helper library now includes an...

A user of the EFExtensions library asked me how to retrieve a set of ‘categories’ and their related ‘products’ through a single stored procedure call. I made some changes to the sample application to illustrate this pattern, but I thought I should also...

The EFExtensions helper library has a few updates: - CreateCommand now respects the CommandTimeout property on ObjectContext . A user of the library reported this bug to me a while ago, and I’m finally getting around to fixing it. - One tricky...

A beta of Visual Studio 2008 SP1 was released on Monday and the ADO.NET Entity Framework (EF) is now in the box! You can download and install the Beta here . The EF Extensions library has been updated to work with the beta and includes several public...

Someone asked a great question on the ADO.NET Entity Framework forums yesterday: how do I compose predicates in LINQ to Entities? I’ll give three answers to the question. Answer 1: Chaining query operators Basically, you have some query and you...

This week at DevConnections in Orlando, I gave a “deep-dive” talk on LINQ. I wanted to give people a feel for what's possible with the new language features and core APIs in .NET 3.5. I spent most of the talk discussing a single example: take an ADO.NET...

The ADO.NET Entity Framework (EF) allows you to map stored procedures to functions that return typed results in the conceptual model. However, when stored procedures results don't match the patterns supported by the EF, reading and tracking results is...