Как очистить DataGridView

    public partial class Form1 : Form
    {
        DbConnection con;
        DbCommand Select;
        DbDataAdapter adapter;
        public Form1()
        {
            InitializeComponent();
            adapter = new OleDbDataAdapter();
            try
            {
                con = new OleDbConnection("Provider = Microsoft.ACE.OLEDB.12.0; Data Source = ./TelBase.accdb");
                Select = new OleDbCommand();
                Select.Connection = con;
                Select.CommandText = "SELECT Tb0AllData.Id AS ID,Tb1SecondName.SecondName AS SecondName,Tb2Name.Name AS Name,Tb3Father.Father AS Father,Tb4Street.Street AS Street,Tb5House.House AS House,Tb6Flat.Flat AS Flat,Tb0AllData.Telephone AS Telephone,Tb7Postcode.Postcode AS Postcode FROM Tb0AllData,Tb1SecondName,Tb2Name,Tb3Father, Tb4Street,Tb5House,Tb6Flat,Tb7Postcode WHERE Tb0AllData.SecondName=Tb1SecondName.ID AND Tb0AllData.Name=Tb2Name.ID AND Tb0AllData.Father=Tb3Father.ID AND Tb0AllData.Street=Tb4Street.ID AND Tb0AllData.House=Tb5House.ID AND Tb0AllData.Flat=Tb6Flat.ID AND Tb0AllData.Postcode=Tb7Postcode.ID";
                adapter.SelectCommand = Select;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
            }
            dataSet1.Clear();
            adapter.Fill(dataSet1);
            dataGridView1.DataSource = dataSet1.Tables[0];
        }
        private void Search_Click(object sender, EventArgs e)
        {
            Select.CommandText = "SELECT Tb3Father.Father AS Father,Tb4Street.Street AS Street,Tb5House.House AS House,Tb6Flat.Flat AS Flat,Tb0AllData.Telephone AS Telephone,Tb7Postcode.Postcode AS Postcode FROM Tb0AllData,Tb1SecondName,Tb2Name,Tb3Father, Tb4Street,Tb5House,Tb6Flat,Tb7Postcode WHERE Tb0AllData.SecondName=Tb1SecondName.ID AND Tb0AllData.Name=Tb2Name.ID AND Tb0AllData.Father=Tb3Father.ID AND Tb0AllData.Street=Tb4Street.ID AND Tb0AllData.House=Tb5House.ID AND Tb0AllData.Flat=Tb6Flat.ID AND Tb0AllData.Postcode=Tb7Postcode.ID";
            //dataGridView1.Rows.Clear();
            dataSet1.Clear();
            adapter.Fill(dataSet1);
            dataGridView1.DataSource = dataSet1.Tables[0];
        }
    }

dataGridView1.DataSource = null;