>>>>>Assume I have a datatable in a dataset with columns called ItemName and Quantity. Due to changes by the customer, there will now be multiple rows with the same ItemName and a Quantity of 1. The app used to have one row for the item and the total quantity.
>>>>>
>>>>>How do I combine the DT so that there is again one row with the total quantity?
>>>>
>>>>Do you want to save the totalled datatable to the backend? If so will this just be a one-off (tidy up) operation ?
>>>>Or do you just need the totalled version to work with temporarily in the app ?
>>>
>>>Temporarily. It wont be sent to the DB.
>>
>>Something like:

var v = from x in dataTable.AsEnumerable()
>>                    group x by x.Field<string>("ItemName") into g
>>                    select new
>>                    {
>>                        ItemName = g.Key,
>>                        Quantity = g.Sum(x => x.Field<int>("Quantity"))
>>                    };
>>
>>//The above might be enough to work with?
>>//If not then this would get it into a revised DataTable - but there's probably something better....
>>
>>            List<DataRow> al = new List<DataRow>();
>>
>>            foreach (var x in v)
>>            {
>>                DataRow dr = dataTable.NewRow();
>>                dr["ItemName"] = x.ItemName;
>>                dr["Quantity"] = x.Quantity;
>>                al.Add(dr);
>>            }
>>            dataTable.Rows.Clear();
>>            foreach (DataRow dr in al)
>>            {
>>                dataTable.Rows.Add(dr);
>>            }

>
>Hey Viv,
>
>I implemented this code, and while is does merge the rows, the only columns with data in them are Part_Number (Sorry, it's not called ItemName ) and Quantity. I tried this:
>
>

>
>private void CombineDuplicateRows()
>{
>    DataTable table = csCOSApp.ActiveProject.dsDataStore.Tables[0];
>
>    var v = from x in table.AsEnumerable()
>            group x by x.Field<string>("Part_Number") into g
>            select new
>            {
>                Part_Number = g.Key,
>                Quantity = g.Sum(x => x.Field<int>("Quantity")),
>                RowId = x.RowId,
>                ProjectId = x.ProjectId,
>                ProductId = x.ProductId,
>                Product_Series = x.Product_Series,
>                Product_Number = x.Product_Number,
>                Product_Name = x.Product_Name,
>                Product_Description = x.Product_Description,
>                PartId = x.PartId,
>                Part_Description = x.Part_Description,
>                New_Part_Number = x.New_Part_Number,
>                Keyword = x.Keyword,
>                Category = x.Category,
>                TribalNumber = x.TribalNumber,
>                WhseQty1 = x.WhseQty1,
>                WhseQty2 = x.WhseQty2,
>                PartPrice = x.PartPrice,
>                PartRatio = x.PartRatio
>            };
>
>    List<DataRow> al = new List<DataRow>();
>
>    foreach (var x in v)
>    {
>        DataRow dr = table.NewRow();
>        dr["Part_Number"] = x.Part_Number;
>        dr["Quantity"] = x.Quantity;
>        al.Add(dr);
>    }
>
>    table.Rows.Clear();
>    foreach (DataRow dr in al)
>    {
>        table.Rows.Add(dr);
>    }
>}
>

>
>but it doesn't know what 'x' is in the anonymous type. My Linq is not too good here. Could use some help.

Hi,
'v' is an instance of IGrouping < string,DataRow > so you could reach in to the first row of the group:

var v = from x in dataTable.AsEnumerable()
                    group x by x.Field<string>("Part_Number") into g
                    select new
                    {
                        Part_Number = g.Key,
                        Quantity = g.Sum(x => x.Field<int>("Quantity")),
                        ProjectId = ((DataRow)g.First())["ProjectId"],
                        ProductId = ((DataRow)g.First())["ProductId"]
                        //Etc
                     };

I've a feeling there's a better way but I guess this works....