At its core, a DataSet object is a set of data. When developers picture the results returned by a query, they generally picture data in a grid, much like a Microsoft Office Excel spreadsheet.
You can use a DataSet to store the results of a query, but a DataSet more closely resembles an Excel workbook because it can hold the results of multiple queries.
But the ADO.NET object model already lets you examine the results of a query through the SqlDataReader class. Why would you need another class?
In Chapter 4, you learned about the SqlDataReader, which is a fast and efficient structure that lets you retrieve the results of a query. The SqlDataReader is built for speed because it supports very limited functionality. The ...