var objectTable = new DataTable();
objectTable.Columns.Add("resource_name", typeof(string));
objectTable.Columns.Add("day_date", typeof(DateTime));
objectTable.Columns.Add("actual_hrs", typeof(decimal));
objectTable.Rows.Add(1, DateTime.Today, 1);
objectTable.Rows.Add(2, DateTime.Today, 2);
var newSort = from row in objectTable.AsEnumerable()
where row.Field<string>("resource_name") == "1"
orderby row.Field<string>("resource_name") descending
group row by new { ID = row.Field<string>("resource_name"), time1 = row.Field<DateTime>("day_date") } into grp
select new
{
resource_name1 = grp.Key.ID,
day_date1 = grp.Key.time1,
Sum = grp.Sum(r => r.Field<Decimal>("actual_hrs"))
};
//newSort.Dump();
foreach (var array in newSort)
{
// newDataTable.Rows.Add(array);
}