One of the powerful features of Crystal Reports is the great amount of flexibility you have as a report developer in grouping your data.  Once you can group your data you can sum, count, average, perform standard deviation, variance, and a host of other operations on your data.  Grouping data in a SQL statement can be problematic because you can only include the fields you're grouping on in your select statement.  Crystal Reports does not have this limitation. 

Crystal also has a feature for hierarchy grouping for situations where you have nested groups and you don't know how many levels of grouping there are.  This article will show you how to create a report with simple grouping and summation fields and will also create a report using the hierarchy grouping feature. 

Before you begin you will need to have installed Visual Studio 2010. Crystal Reports is no longer distributed with Visual Studio and is available as a separate download. You can download Crystal Reports here. You also will need to download the AdventureWorks sample database from here.  Once you've installed the database you need to create a SQL Login that the application can use to connect to the database. My sample code expects a SQL Login to be called "aspalliance" and the password should be set to "aspalliance". The sample code for this application can be downloaded here.