Neil,

>Which should I use when creating a DataSet in my busuness objects? DataSet or mmDataSet? And... can anyone tell me why in the sample application the method GetOrdersByCustomerID creates a dataview in the following manner?

Whether you realize it or not, when you call GetDataSet it automatically creates an instance of mmDataSet for you (although it returns it as a standard .NET DataSet). The question is whether you decide to cast the return value to mmDataSet. As it stands now, the only real reason for doing this is if you want to use its extended DataView capabilities. Check out the MM .NET Dev Guide Help topic "Working with DataViews" to see how this works.

Regards,