Question

How do i aggregate(using linq) the value of one column of a Dataset where the other column is the same.

For example, my columns are

Row1  Row2  

2     3  
4     5  
6     7  
2     2  
6     4  
7     4  
2     4

I need something like this

Row1 Row2  

2    9  
4    5  
6    11  
7    4

edit: the values in “Row2” are the number of “Row1”. so the values of (for example: 2) have to be aggregated into a new datatable where is only a single entry for (2).
I’m sorry if the question is vague.

Answer 1

You can use LINQ to aggregate rows and copy the results to a new table:

DataTable source = // whatever
DataTable dest = source.Clone();

var aggregate = source
    .AsEnumerable()
    .GroupBy(row => row.Field<int>("Row1"))
    .Select(grp => new { Row1 = grp.Key, Row2 = grp.Select(r => r.Field<int>("Row2")).Sum() });

foreach(var row in aggregate)
{
    dest.Rows.Add(new object[] { row.Row1, row.Row2 });
}