Category Archives: LINQ

Efficient querying with LINQ, AutoMapper and Future queries

Even after all these years, I’m still a big fan of ORMs. One common complaint over the years is people using ORMs use the tool identically for both reads and writes. With writes, I want tracked entities, managed relationships, cascades … Continue reading 

Also posted in AutoMapper, EntityFramework | 33 Comments

Thinking Linq

I’ve been comfortable using LINQ for what seems like a long time. I’m noticing that I’ve been implementing some of the lesser used functions a bit more as of late, but I’m not sure exactly when they’re appropriate. Take the … Continue reading 

Also posted in TDD | 7 Comments

Queue is Always Empty Using yield return

I ran into an issue in a C# application the other day. Thankfully I figured out what was going wrong right away, but it could have turned into a big headache potentially.

Also posted in Tools | Leave a comment

Autoprojecting LINQ queries

Something I’ve been looking at adding to AutoMapper was the idea of doing automatic query projection in the Select query projection in LINQ statements.  One downside of AutoMapper is that projection from domain objects still forces the entire domain object … Continue reading 

Also posted in AutoMapper, C# | 29 Comments

What is Projection?

I think there’s great benefit in not only knowing how to design your code to use common patterns but also to be able to speak about them clearly and concisely to others. If I mention that the problem sounds like … Continue reading 

Also posted in Agile | Leave a comment

Implementing Domain Queries

My current Repository interface looks something like this: public interface IRepository { T FindOne<T>(int id); T FindBy<T>(Expression<Func<T, bool>> expression); IEnumerable<T> FindAllBy<T>(Expression<Func<T, bool>> expression); IEnumerable<T> FindAll<T>(); T FindOneBy<T>(Expression<Func<T, bool>> expression); void Save<T>(T target); void Update<T>(T target); void SaveOrUpdate<T>(T target); void Delete<T>(T … Continue reading 

Also posted in Agile | Leave a comment

Selecting Static Results with Dynamic LINQ

Dynamic LINQ (DLINQ) is a LINQ extension provided in the VS 2008 Samples. Scott Guthrie provides a good overview here: Dynamic LINQ (Part 1: Using the LINQ Dynamic Query Library), but the executive summary is that it implements certain query … Continue reading 

Also posted in TeamBuild, VSTS | Leave a comment

LINQ query operators and null lists

One of my pet peeves with the LINQ extension methods is their inability to handle null source lists.  For example, this will throw an ArgumentNullException: [Test] public void Should_handle_nulls() { List<int> ints = null; ints.Any(num => num < 0).ShouldBeFalse(); } … Continue reading 


More missing LINQ operators

Continuing an old post on missing LINQ operators, the wonders of extension methods allow us as developers to fill potential holes in LINQ operators.  Whether it’s a Zip method (now included in .NET 4.0), or better methods for IComparer-based operators, … Continue reading 


Hacking LINQ Expressions: Join With Comparer

In this installment of my Hacking LINQ series we’ll take a look at providing an IEqualityComparer for use in a LINQ join clause. The Problem Many of the Standard Query Operators require comparing sequence elements and the default query providers … Continue reading 

Also posted in C# | 3 Comments