If you want to update the record in the database that is associated with the selected datagridviewrow:
public void btnUpdate_Click(object sender, EventArgs e)
DataGridViewRow selectedRow = dataGridView1.SelectedRows;
string result = createUpdateSQLStatement(selectedRow);
If you want to update the datagridview, then just call for your Bind method again, and you may want to include a dataGridView1.Refresh(); in your Bind method.