Republished with Permission - Original Article

LINQ (language integrated query) is one of the new features provided with VS 2008 and .NET 3.5.  LINQ makes the concept of querying data a first class programming concept in .NET, and enables you to efficiently express queries in your programming language of choice.

One of the benefits of LINQ is that it enables you to write type-safe queries in VB and C#.  This means you get compile-time checking of your LINQ queries, and full intellisense and refactoring support over your code:

Figure 1

While writing type-safe queries is great for most scenarios, there are cases where you want the flexibility to dynamically construct queries on the fly.  For example: you might want to provide business intelligence UI within your application that allows an end-user business analyst to use drop-downs to build and express their own custom queries/views on top of data. 

Traditionally these types of dynamic query scenarios are often handled by concatenating strings together to construct dynamic SQL queries.  Recently a few people have sent me mail asking how to handle these types of scenarios using LINQ.  The below post describes how you can use a Dynamic Query Library provided by the LINQ team to dynamically construct LINQ queries.