Menyimpan Data ke Database SQl di Netbeans

Langsung aja ya bro..

private void tmblSimpanActionPerformed(java.awt.event.ActionEvent evt) {                                          
// TODO add your handling code here:
String notrans,petugas,tanggal,kodebrg, namabrg, harga,qty,total,subtotal,bayar,kembali;
notrans=txtNotrans.getText(); petugas=txtPetugas.getText(); tanggal=txtTanggal.getText();
kodebrg=txtKodebrg.getText(); namabrg=txtNamabrg.getText(); harga=txtHarga.getText();
qty=txtQty.getText(); total=txtTotal.getText(); subtotal=txtSubtotal.getText();
bayar=txtBayar.getText(); kembali=txtKembali.getText();
String sql="insert into transaksi values('"+notrans+"','"+petugas+"','"+tanggal+"','"+kodebrg+"','"+namabrg+"',"
        + "'"+harga+"','"+qty+"','"+total+"','"+subtotal+"','"+bayar+"','"+kembali+"');";
try {
st = conn.createStatement();
st.execute(sql);
JOptionPane.showMessageDialog(null,"Data berhasil di simpan");
kosongkan();
}catch (SQLException e) {
System.out.println("Penyimpanan Gagal "+e);
return;
}
}

public void kosongkan(){
    txtKodebrg.setText("");
    txtNamabrg.setText("");
    txtHarga.setText("");
    txtQty.setText("");
    txtTotal.setText("");
    txtSubtotal.setText("");
    txtBayar.setText("");
    txtKembali.setText("");
    txtKodebrg.requestFocus();
}