Bind Data to DatagridCombobox

ds = new DataSet();
da = new SqlDataAdapter("select * from holiday", con);
da.Fill(ds, "holiday");
DataTable tab = ds.Tables[0];
MessageBox.Show(ds.Tables[0].Rows.Count.ToString());
int i = 0;

foreach (DataRow row in tab.Rows)
{
    dataGridView1.Rows.Add();
    
    //MessageBox.Show(row[0].ToString());
    dataGridView1[0, 1].Value=row[0].ToString();
    dataGridView1[1, i].Value = row[1].ToString();
    dataGridView1[2,i].Value = row[2].ToString();
    i++;
}