public void SetDataContextComboBoxSelected(MainWindow mainWindow)
        {
            Parameter parameterWindow;
            string    param;

            int choose = mainWindow.comboBox.SelectedIndex;

            using (var context = new BiuroPodrozyEntities())
            {
                switch (choose)
                {
                case 0:
                    mainWindow.viewModel.TableName    = ColumnNames.klienci;
                    mainWindow.viewModel.TableContent = context.Klienci.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 1:
                    mainWindow.viewModel.TableName    = ColumnNames.uczestnicy;
                    mainWindow.viewModel.TableContent = context.Uczestnicy.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 2:
                    mainWindow.viewModel.TableName    = ColumnNames.zamowienia;
                    mainWindow.viewModel.TableContent = context.Zamówienia.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 3:
                    mainWindow.viewModel.TableName    = ColumnNames.wycieczki;
                    mainWindow.viewModel.TableContent = context.Wycieczki.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 4:
                    mainWindow.viewModel.TableName    = ColumnNames.hotele;
                    mainWindow.viewModel.TableContent = context.Hotele.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 5:
                    mainWindow.viewModel.TableName    = ColumnNames.rezydenci;
                    mainWindow.viewModel.TableContent = context.Rezydenci.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 6:
                    mainWindow.viewModel.TableName    = ColumnNames.uslugi;
                    mainWindow.viewModel.TableContent = context.Usługi.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 7:
                    mainWindow.viewModel.TableName    = ColumnNames.atrakcje;
                    mainWindow.viewModel.TableContent = context.Atrakcje.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 8:
                    mainWindow.viewModel.TableContent = context.vRezydenciPodrozy.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 9:
                    mainWindow.viewModel.TableContent = context.vIlośćWycieczek
                                                        .GroupBy(info => info.Kraj)
                                                        .Select(group => new
                    {
                        Metric = group.Key,
                        Count  = group.Count()
                    })
                                                        .OrderBy(x => x.Metric)
                                                        .ToList();
                    mainWindow.TextBox1.Text = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                              = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                          = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                      = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 10:
                    mainWindow.viewModel.TableContent = context.vTrwajaceWycieczki.ToList();
                    mainWindow.TextBox1.Text          = mainWindow.TextBox2.Text = mainWindow.TextBox3.Text
                                                                                       = mainWindow.TextBox4.Text = mainWindow.TextBox5.Text = mainWindow.TextBox6.Text
                                                                                                                                                   = mainWindow.TextBox7.Text = mainWindow.TextBox8.Text = mainWindow.TextBox9.Text
                                                                                                                                                                                                               = mainWindow.TextBox10.Text = mainWindow.TextBox11.Text = "";
                    mainWindow.DataContext = mainWindow.viewModel;
                    break;

                case 11:
                    parameterWindow = new Parameter("Rodzaj atrakcji");
                    parameterWindow.ShowDialog();
                    param = parameterWindow.parameter;

                    if (!string.IsNullOrWhiteSpace(param))
                    {
                        mainWindow.viewModel.TableContent = context.WycieczkiPoRodzajuAtrakcji(param).ToList();
                        mainWindow.DataContext            = mainWindow.viewModel;
                    }
                    break;

                case 12:
                    parameterWindow = new Parameter("Id wycieczki");
                    parameterWindow.ShowDialog();
                    param = parameterWindow.parameter;

                    if (!string.IsNullOrWhiteSpace(param))
                    {
                        mainWindow.viewModel.TableContent = context.UczestnicyWycieczki(int.Parse(param)).ToList();
                        mainWindow.DataContext            = mainWindow.viewModel;
                    }
                    break;

                case 13:
                    parameterWindow = new Parameter("Cena");
                    parameterWindow.ShowDialog();
                    param = parameterWindow.parameter;
                    if (!string.IsNullOrWhiteSpace(param))
                    {
                        mainWindow.viewModel.TableContent = context.WycieczkiDoCeny(decimal.Parse(param)).ToList();
                        mainWindow.DataContext            = mainWindow.viewModel;
                    }
                    break;

                case 14:
                    parameterWindow = new Parameter("Kraj");
                    parameterWindow.ShowDialog();
                    param = parameterWindow.parameter;

                    if (!string.IsNullOrWhiteSpace(param))
                    {
                        mainWindow.viewModel.TableContent = context.WycieczkiDoKraju(param).ToList();
                        mainWindow.DataContext            = mainWindow.viewModel;
                    }
                    break;

                default:
                    break;
                }
            }
        }