Can you give me an example of how can I query on dataset? Counts and SUMS are to be derived from the Dataset.

Try this:

private void ComputeBySalesSalesID(DataSet myDataSet){

    // Presumes a DataTable named "Orders" that has a column named "Total."

    DataTable myTable;

    myTable = myDataSet.Tables["Orders"];

    // Declare an object variable.

    object objSum;

    objSum = myTable.Compute("Sum(Total)", "EmpID = 5");

 }



private void CountBySalesQuantity(DataSet myDataSet){

    // Presumes a DataTable named "Orders" that has a column named "Quantity."

    DataTable myTable;

    myTable = myDataSet.Tables["Orders"];

    // Declare an object variable.

    object objSum;

    objSum = myTable.Compute("Count(Quantity)", "EmpID = 5");

 }