void Load_Lable()
{
MyDb db = new MyDb();
SqlCommand command = new SqlCommand("select * from std ", db.getConnection);
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataTable table = new DataTable();
adapter.Fill(table);
int siso = table.Rows.Count;
lbSiso.Text = ("Tổng số học sinh:" + siso);
SqlCommand command1 = new SqlCommand("select * from std where gender=@Gender", db.getConnection);
command1.Parameters.Add("@Gender", SqlDbType.VarChar).Value = "Female ";
SqlDataAdapter adapter1 = new SqlDataAdapter(command1);
DataTable table1 = new DataTable();
adapter1.Fill(table1);
int sisonu = table1.Rows.Count;
double nu = (sisonu * 100) / siso;
lbNu.Text = ("Nu:" + Math.Round(nu, 2));
double nam = 100 - nu;
lbNam.Text = ("Nam: " + Math.Round(nam, 2));
}