data = new DataTable();
da = new MySqlDataAdapter("SELECT * FROM cds", conn);
cb = new MySqlCommandBuilder(da);
da.Fill(data);
DataGridViewComboBoxCell cbCell = (DataGridViewComboBoxCell)dataGridView1.Rows[0].Cells[1];
foreach (DataRow row in data.Rows)
{
int32TextBox1.AutoCompleteCustomSource.Add(row[1].ToString());
cbCell.Items.Add(row[1].ToString());
}