private void buttonHapus_Click(object sender, EventArgs e)
 {
     try
     {
         ClassData classData = new ClassData();
         classData.deleteMahasiswa(textBoxNim.Text);
         Clear();
         dataGridMahasiswa.DataSource = classData.getAllData();
         MessageBox.Show("Data successfuly deleted");
     }
     catch (Exception ex)
     {
     }
 }
        private void buttonUpdate_Click(object sender, EventArgs e)
        {
            try
            {
                Mahasiswa mhs = new Mahasiswa();
                mhs.nim      = textBoxNim.Text;
                mhs.nama     = textBoxNama.Text;
                mhs.prodi    = textBoxProdi.Text;
                mhs.angkatan = textBoxAngkatan.Text;

                ClassData classData = new ClassData();
                classData.updateDatabase(mhs);
                MessageBox.Show("Data successfuly updated");
                Clear();
                dataGridMahasiswa.DataSource = classData.getAllData();
            }
            catch
            {
            }
        }