Sum the amount if id is duplicate

I have one data table/ excel in which there are lots of columns, first column is id and one of the columns is Amount, and that amount is filled with values. I want to sum up the amount of the rows whose ID are duplicate , and in result data table all non duplicate rows also should be there

[id ] ---- [sum] ---- [rest of coulums with ffilled values…
1 ---- 10----
2 ---- 20----
3 ---- 30----
4 ---- 40—
1 -----20—
1 – – 20—
2 ---- 10—


id ---- sum ---- rest of coulmns with filled values
1 ---- 50
2 ---- 30
3 ---- 30
4 ---- 40

I want a linq query

we wold recommend to recheck the above requirement part

dictLK | Dictionary (Of String, Int32) =

(From d in YourDataTable.AsEnumerable
Group d by k=d("id").toString.Trim into grp=Group
Let cn = grp.Sum(Function (g) CInt(g("sum").toString.Trim))
Select t = Tuple.Create(k,cn)).ToDictionary(Function (t) t.Item1, Function (t) t.Item2)


Please try this

Use build datatable and create a datatbe with two columns if type string

Newdt = dt.AsEnumerable.GroupBy(function(x) x("id").ToString).Select(function(x) New {x.key,x.Sum(function(y) cdbl(y("sum").ToString).ToString}).CopyToDataTable


yes PPR non duplicate rows should also be there along with duplicate(single)

it is showing Type name expected error and type or with expected


Pleaze try adding with after new keyword new with {…


when grouping we do sum up all group members. But you are listing the need of additiona columns

here is not specified a rule for fetching the values e.g. first group member, last …

I didnot understand @ppr

tried but not working

did you request an output datatable with more than 2 cols?

Hi @adishjain ,

Step 1: Assign dtResults = dt.clone

Step 2: Assign dtResults = (From row In Dt.AsEnumerable
Group row By col1=row(0).ToString.Trim Into grp = Group
Select dtResults.Rows.Add({col1, grp.Sum(Function (x) CInt(x(1).toString.Trim))})).CopyToDataTable

This will work even unique value exists in the datatable.

If this works. Please provide as solution


hello darshan, my column index in not fix, can you please make it by ID and SUM name so that if my index changes the it can process data by column names

Sure @adishjain

Step 1: Assign dtResults = dt.clone

Step 2: Assign dtResults = (From row In Dt.AsEnumerable
Group row By col1=row(“ID”).ToString.Trim Into grp = Group
Select dtResults.Rows.Add({col1, grp.Sum(Function (x) CInt(x(“Sum”).toString.Trim))})).CopyToDataTable

That’s it.



Have corrected it

dt.AsEnumerable.GroupBy(function(x) x(“id”).ToString).Select(function(g) dt.Clone.LoadDataRow({g.Key,g.Sum(Function(r) CDBL(r(“B”).ToString)).ToString},False)).CopyToDataTable

or use as following

( From row In dt.AsEnumerable
	Group row By k=row("id").ToString.Trim
	Into grp=Group
	Let cs = grp.Sum(Function(x) CDbl(x("Sum").ToString))
	Select dt2.Rows.Add({k, cs.ToString})


it is giving result but rest of all data is getting removed from data table means only two columns have data and rest of columns come empty


I have given it as per the structure you have show …if there are more column add those details in {k, cs.ToString} like grp.First()("ColumnName").ToString in the same order you need


we adressed this for requirement clearing by:


Hi @adishjain

Try this-

var query = from row in originalDataTable.AsEnumerable()
group row by row.Field(“id”) into grp
select new
id = grp.Key,
sum = grp.Sum(r => r.Field(“Amount”))

DataTable resultDataTable = new DataTable();
resultDataTable.Columns.Add(“id”, typeof(int));
resultDataTable.Columns.Add(“sum”, typeof(int));

foreach (var item in query)
resultDataTable.Rows.Add(, item.sum);

var nonDuplicateRows = originalDataTable.AsEnumerable()
.GroupBy(row => row.Field(“id”))
.Where(grp => grp.Count() == 1)
.Select(grp => grp.First());

foreach (var row in nonDuplicateRows)
DataRow newRow = resultDataTable.Rows.Add();
foreach (DataColumn column in originalDataTable.Columns)
newRow[column.ColumnName] = row[column.ColumnName];


Hey I have another solution,

Save to= variable (as DataTable) | Value to save =

vDt.AsEnumerable() _
.GroupBy(Function(x) x(“id”).ToString) _
.Select(Function(g) vDt.Clone().LoadDataRow({g.Key, g.Sum(Function(r) CDbl(r(“sum”).ToString)).ToString}, False)) _

So you have to insert a for each row of the Data Table with this assign.

Here is an example:

Results of this table:

Greetings :slight_smile: