Many people are looking for a clean way to concatenate the values of a column in a .NET DataSet to a string, so here’s a quick code snippet to do just that:

//concatenate first names of persons found
List<String> listNames = new List<string>();

//get names in a list
(DataRow row in dtPersons.Rows)

//concatenate all first names with a comma
concatNames = String.Join(“,” , listNames.ToArray());

In essence, I’m using a Generic List of Strings (List <String>), then a DataSet.ToArray and a String.Join.
Using a constant declaration for the separator, rather than hard-coding it (as above), is always a good practice.

Note: LINQ has some elegant ways to do this too, but I haven’t used any yet.