I have a Data Form Web Part (DFWP) in SP2010 and need to filter one of the columns ("Department") on a value using the querystring. How do you do this?
Open the web part page that contains the web part in question.
In the web part parameters in Sharepoint Designer, you create a new query string parameter. Then you filter the web part so that your desired column is filtered by that parameter. Then you pass in the desired value in the query string and you should get the desired results.