Выпадающий список в ячейках DataGridView

 
        MySqlConnection myConnection = new MySqlConnection();
        MySqlDataAdapter DateAdapter;
        DataSet myDataSet = new DataSet();
 
public void UpdateTable()
        {
           
            myConnection.ConnectionString = "Database=test;Data Source=localhost;User Id=root;Password=123";
            myConnection.Open();
            DateAdapter = new MySqlDataAdapter("SELECT journal.Id,journal.Date,journal.defect,subdivision.name,journal.mark,journal.iduser "+
                                                                        "FROM journal LEFT OUTER JOIN subdivision ON journal.idsubdivision = subdivision.Id", myConnection);
            DateAdapter.Fill(myDataSet);
            if (myDataSet.Tables.Count > 0)
             dataGridView1.DataSource = myDataSet.Tables[0];
             DataGridViewComboBoxColumn comboboxColumn;
             DataGridViewComboBoxColumn column = new DataGridViewComboBoxColumn();
             comboboxColumn = column;
             SetAlternateChoicesUsingDataSource(comboboxColumn);
             dataGridView1.Columns.Insert(3, comboboxColumn);
      myConnection.Close();
 
private void SetAlternateChoicesUsingDataSource(DataGridViewComboBoxColumn comboboxColumn)
        {
            {
                comboboxColumn.DataSource = RetrieveAlternativeTitles();
                comboboxColumn.ValueMember = ColumnName.Subdivision.ToString();
                comboboxColumn.DisplayMember = comboboxColumn.ValueMember;
            }
        }
 
        private DataTable RetrieveAlternativeTitles()
        {
            return Subdivision("SELECT subdivision.name FROM subdivision");
        }
 
        private DataTable Subdivision(string sqlCommand)
        {
 
            MySqlCommand command = new MySqlCommand(sqlCommand, myConnection);
            MySqlDataAdapter adapter = new MySqlDataAdapter();
            adapter.SelectCommand = command;
 
            DataTable table = new DataTable();
            table.Locale = System.Globalization.CultureInfo.InvariantCulture;
            adapter.Fill(table);
 
            return table;
        }

            ds = new DataSet();
            db_connection = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=books.accdb");
            db_connection.Open();
 
            adapter_Books = new OleDbDataAdapter(new OleDbCommand("SELECT * FROM Books ORDER BY bNumber", db_connection));
            var cb_adapter_Books = new OleDbCommandBuilder(adapter_Books);
 
            adapter_Series = new OleDbDataAdapter(new OleDbCommand("SELECT * FROM Series ORDER BY sName", db_connection));
            var cb_Series = new OleDbCommandBuilder(adapter_Series);
 
            adapter_Books.Fill(ds, "Books"); // прочитать books
            adapter_Series.Fill(ds, "Series"); // прочитать series
 
            db_connection.Close();
 
            ds.Tables["Series"].Columns["sName"].Unique = true;
 
            // Установка связи таблиц Books.bSeries = Series.sNumber
            ds.Relations.Add(new DataRelation("rlSeriesBooks", ds.Tables["Series"].Columns["sNumber"], ds.Tables["Books"].Columns["bSeries"]));
 
            dataGridView1.DataSource = ds.Tables["Books"]; // Books - в DataGrid
 
            dataGridView1.Columns["bSeries"].Visible = false; // скрыть колонку с идентификатором
 
            var cbx_Series = new DataGridViewComboBoxColumn(); // добавить новую колонку
            cbx_Series.Name = "Серия";
            cbx_Series.DataSource = ds.Tables["Series"];
            cbx_Series.DisplayMember = "sName"; // Отображать из Series
            cbx_Series.ValueMember = "sNumber";
            cbx_Series.DataPropertyName = "bSeries"; // Для связи с Books
            cbx_Series.MaxDropDownItems = 10;
            cbx_Series.FlatStyle = FlatStyle.Flat;
            dataGridView1.Columns.Insert(5, cbx_Series);
            dataGridView1.Columns[5].Width = 200;

private OleDbConnection db_connection;
        private DataSet ds;
        private OleDbDataAdapter adapter_Books;
        private OleDbDataAdapter adapter_Series;