C# DataGridViewBindingToDataSet

// 11 http://csharp.net-informations.com/datagridview/csharp-datagridview-sql-server.htm

private void button1_Click(object sender, EventArgs e)
        {

            //this.dataGridView1.Refresh();

            // DataGridView dg1 = new DataGridView();
            // dg1.DataSource = src1;

            // Update Data in src1

            // string connectionString = "Data Source=.;Initial Catalog=pubs;Integrated Security=True";
            string sql = "SELECT * FROM Users";
            // OleDbConnection connection = new SqlConnection(connectionString);
            OleDbDataAdapter dataadapter = new OleDbDataAdapter(sql, connection);
            DataSet ds = new DataSet();
            connection.Open();
            dataadapter.Fill(ds, "users_table");
            connection.Close();
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = "users_table";


            // dataGridView1.DataSource = null;
            // dataGridView1.DataSource = src1;
            // dataGridView1.Refresh();
        }