Extract a unique list of items from System.Data.DataTable

 

results is a datatable containing some rows. I want a list of strings of distinct values extracted from the column MyColumn:

List<string> columns = (from row in results.AsEnumerable()

                       select row.Field<string>("MyColumn")).Distinct().ToList<string>();

If the list<string> already contains duplicate values, use a hashset to get them out:

List<string> allColumns = new List<string>();

//add a buncha items to this list. //Then get out the unique values:

var unique_items = new HashSet<string>(allColumns);