I binded data to a combobox using a dataset.

companycb.DisplayMember = "company";
            companycb.ValueMember = "visitorVisitID";
            companycb.DataSource = ds.Tables["tblVisitorVisit"];

I need to remove the duplicate values from the combobox. Is there any other way instead of doing it using an SQL Distinct query?

You could store them in an array, and use the "distinct()" method.

I'm not sure if there's a more direct way to do it. Perhaps someone else here might know.

commented: thanks for the idea +1

Look at this code, it removes the duplications:

public partial class Form1 : Form
    {
        DataSet ds;
        public Form1()
        {
            InitializeComponent();
            CreatingDS();            
        }

        private void CreatingDS()
        {
            ds = new DataSet();
            DataTable table = new DataTable("MyTable");
            table.Columns.Add("id", typeof(int));
            table.Columns.Add("name", typeof(string));

            string[] names = { "A", "B", "C", "A", "B" };
            DataRow dr;
            for (int i = 0; i < names.Length; i++)
            {
                dr = table.NewRow();
                dr["id"] = i + 1;
                dr["name"] = names[i];
                table.Rows.Add(dr);
            }
            ds.Tables.Add(table);
            table = RemoveDuplicateRows(table, "name");

            comboBox1.DataSource = ds.Tables["MyTable"];
            comboBox1.DisplayMember = "name";
            comboBox1.ValueMember = "id";
        }

        public DataTable RemoveDuplicateRows(DataTable dTable, string colName)
        {
            Hashtable hTable = new Hashtable();
            ArrayList duplicateList = new ArrayList();

            foreach (DataRow drow in dTable.Rows)
            {
                if (hTable.Contains(drow[colName]))
                    duplicateList.Add(drow);
                else
                    hTable.Add(drow[colName], string.Empty);
            }

            foreach (DataRow dRow in duplicateList)
                dTable.Rows.Remove(dRow);

            return dTable;
        }
    }

hope it helps,
Mitja

commented: thanks for combobox removal of dups! +1