Question

I have a DataTable in C# with two columns

State    Region
A        1
A        2
B        3
B        4

What I want to achieve is

State    Region
A        1,2
B        3,4

Is this possible in C# with a single LINQ query?

I am not good in LINQ and also don’t want to loop through table to achieve that.

Answer 1

var result = dataTable.AsEnumerable()
            .GroupBy(row => row.Field<string>("State"))
            .Select(g =>
                {
                    var row = dataTable.NewRow();
                    row.ItemArray = new object[]
                    {
                        g.Key, 
                        string.Join(",", 
                                  g.Select(r => r.Field<string>("Region")))
                    };

                    return row;
                }).CopyToDataTable();