DataAdapter nie aktualizuje danych do bazy danych

Witam. Napisałem kody, który aktualizuje pewne dane w bazie danych:

// Create a connection to the file datafile.sdf in the program folder
                string dbfile = new System.IO.FileInfo(System.Reflection.Assembly.GetExecutingAssembly().Location).DirectoryName + "\\Database1.sdf";
                SqlCeConnection connection = new SqlCeConnection("datasource=" + dbfile);

                SqlCeDataAdapter adapter = new SqlCeDataAdapter("select * from Zamowienia", connection);
                DataSet data = new DataSet();

                adapter.Fill(data);

                data.Tables[0].Rows.Add((data.Tables[0].Rows.Count + 1).ToString(), index.ToString(), dataGridView1.Rows[dataGridView1.SelectedCells[0].RowIndex].Cells[0].Value.ToString(), DateTime.Now);

                SqlCeCommandBuilder builder = new SqlCeCommandBuilder(adapter);
                
                adapter.Update(data);
                data.AcceptChanges();
                adapter = new SqlCeDataAdapter("select * from Samochody where Id_samochodu=" + dataGridView1.Rows[dataGridView1.SelectedCells[0].RowIndex].Cells[0].Value.ToString(), connection);
                data = new DataSet();

                adapter.Fill(data);

                data.Tables[0].Rows[0].ItemArray[7] = 1;

                builder = new SqlCeCommandBuilder(adapter);
                
                adapter.Update(data);
data.AcceptChanges();
                adapter = new SqlCeDataAdapter("select * from Zlecenia where Id_zlecenia=" + (index + 1).ToString(), connection);
                data = new DataSet();

                adapter.Fill(data);

                data.Tables[0].Rows[0].ItemArray[7] = 7;


                builder = new SqlCeCommandBuilder(adapter);
                
                adapter.Update(data);
data.AcceptChanges();
                connection.Close();

Szukałem wielu rozwiązań, jest to wynik moich kombinacji, niestety żadna z nich nie pomogła :/. Bardzo proszę o pomoc i pozdrawiam :).

Uprościłem kod:

            string dbfile = new System.IO.FileInfo(System.Reflection.Assembly.GetExecutingAssembly().Location).DirectoryName + "\\Database1.sdf";
            SqlCeConnection connection = new SqlCeConnection("datasource=" + dbfile);

            SqlCeDataAdapter adapter = new SqlCeDataAdapter("select * from Samochody", connection);
            DataSet data = new DataSet();
            
            adapter.Fill(data);
            
            data.Tables[0].Rows[0]["Id_samochodu"] = 13443;
            data.AcceptChanges();
            SqlCeCommandBuilder sql = new SqlCeCommandBuilder(adapter);
            
            adapter.Update(data);

            connection.Close();