Working with Query Extender control

Many ASP.NET websites allow users to filter data presented to them on the basis of certain conditions. A general approach used in such cases is to re-construct the database query again and again for each such filter parameter. Though this works well as far as end user requirements are concerned, it can make your code a bit tricky and cumbersome to manage. This is because you need to manipulate the WHERE parameters of the data source control under consideration (LINQ Data Source for example) in your source code. That is where the Query Extender control comes handy. The ASP.NET Query Extender server control allows you to filter data retrieved from a data source without changing the underlying query. It does so using a declarative syntax without any need to programmatically manipulate query parameters. This article explores the Query Extender control with the help of several examples.

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