Question

How to insert the database access column in combobox, on button click?it has 1 column

Answer 1

Try this:

create a private method that get msaccess data and bind to a datatable:

private DataTable BindData()
        {
            using (var conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\YOURDB.mdb; PersSecurity Info=False;")) /your connectionsting
            {
                using (var dAd = new OleDbDataAdapter("select ID,column1 from Table ", conn)) //select query from your DB
                {

                    var dSet = new DataTable();
                    try
                    {
                        conn.Open();

                        dAd.Fill(dSet);

                        return dSet;

                    }
                    catch
                    {
                        throw;
                    }
                    finally
                    {
                        if (conn.State == ConnectionState.Open) conn.Close();
                    }
                }
            }
        }

Then on your button click Add

        var dt = BindData();
        cmbBox.DataSource = dt;
        cmbBox.DisplayMember = "column1"; //Display Table Column on your DB
        cmbBox.ValueMember = "ID";

See also:

The C# Station ADO.NET Tutorial

Regards