Using Linq to GroupBy and Sum datatable

Question

Hi, I have a Datatable like this:

Id             Amount 1        Amount 2        Amount 3  
1              2               2               2  
12         


        

Answer 1

You can GroupBy first, then project the groups to DataRows, then create the DataTable using CopyToDataTable extension:

var newDt = dt.AsEnumerable()
              .GroupBy(r => r.Field("Id"))
              .Select(g =>
              {
                  var row = dt.NewRow();

                  row["Id"] = g.Key;
                  row["Amount 1"] = g.Sum(r => r.Field("Amount 1"));
                  row["Amount 2"] = g.Sum(r => r.Field("Amount 2"));
                  row["Amount 3"] = g.Sum(r => r.Field("Amount 3"));

                  return row;
              }).CopyToDataTable();