>>>>>>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....

That did it. Thanks. I'm not too worried about design as I'm going to be refactoring this app soon anyhow.