使用c＃.net减去gridview的最后两行

Question

I have a gridview on my page I am binding data from table (Mysql database) to it. Also gridview has AutoGenerateColumns property to 'true'. Now the gridview have all the columns autogenerated and I have last 2 rows named 'Total' & 'HeadCount'. I want to subtract 'HeadCount' from 'Total'. And add new row 'Final Total' to the grid. How can I do this? Should I do it database side? If so How? Should I do it application c# code side? If so How? Please help me out if anyone has an answer for this. Thanks..!

Code:

ds=getAllStudents();
gridStuds.DataSource=ds;
gridStuds.DataBind();

Answer 1

do it as code below

DataColumn totalColumn = new DataColumn();
totalColumn.ColumnName = "FinalTotal";
totalColumn.DataType = typeof (int);
totalColumn.DefaultValue = 0;
dtSourceTable.Columns.Add(totalColumn);

foreach (DataRow row in dtSourceTable.Rows)
{
    row["FinalTotal"] = Convert.ToInt32
       (row["HeadCount"]) - Convert.ToInt32(row["Total"]);
}