How do I use SELECT GROUP BY in DataTable.Select(Expression)?

Question

I try to remove the duplicate rows by select a first row from every group. For Example

PK     Col1     Col2
1        A        B
2        A        B
3                 


        

Answer 1

dt = dt.AsEnumerable().GroupBy(r => r.Field("ID")).Select(g => g.First()).CopyToDataTable();