Android Studio SQL Veri Çekmek

public class DatabaseAccess {
    private SQLiteOpenHelper openHelper;
    private SQLiteDatabase database;
    private static DatabaseAccess instance;
    String yazar_id;
    String asd;
    List<String> a = new ArrayList<>();

    /**
     * Private constructor to aboid object creation from outside classes.
     *
     * @param context
     */
    private DatabaseAccess(Context context) {
        this.openHelper = new DatabaseOpenHelper(context);
    }

    /**
     * Return a singleton instance of DatabaseAccess.
     *
     * @param context the Context
     * @return the instance of DabaseAccess
     */
    public static DatabaseAccess getInstance(Context context) {
        if (instance == null) {
            instance = new DatabaseAccess(context);
        }
        return instance;
    }

    /**
     * Open the database connection.
     */
    public void open() {
        this.database = openHelper.getWritableDatabase();
    }

    /**
     * Close the database connection.
     */
    public void close() {
        if (database != null) {
            this.database.close();
        }
    }




    /**
     * Read all quotes from the database.
     *
     * @return a List of quotes
     */
    public List<String> getyazarlar() {
        List<String> list = new ArrayList<>();
        Cursor cursor = database.rawQuery("SELECT yazar_adi,id FROM yazarlar ORDER BY RANDOM()  ", null);
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            list.add(cursor.getString(0));
            a.add(cursor.getString(1));
            cursor.moveToNext();
            vericek();
        }

        cursor.close();
        return list;
    }

    public List<List> getYazarlar(){
        List<List> liste = new ArrayList<>();
        List<String> list = new ArrayList<>();
        List<String> id = new ArrayList<>();
        Cursor cursor = database.rawQuery("SELECT yazar_adi,id FROM yazarlar ORDER BY RANDOM()  ", null);
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            list.add(cursor.getString(0));
            id.add(cursor.getString(1));
            cursor.moveToNext();
            vericek();
        }

        liste.add(list);
        liste.add(id);

        return liste;

    }



    public List<String> vericek(){
         List <String> a = this.a;

        return a;
    }

    public String getKitap() {
        Cursor cr=  database.rawQuery("SELECT kitap_adi,yazar_id FROM kitaplar ORDER BY RANDOM() LIMIT 1  ",null);
        String sum= "";
        for(cr.moveToFirst();!cr.isAfterLast();cr.moveToNext()){
            sum = cr.getString(cr.getColumnIndex("kitap_adi"));
            yazar_id = cr.getString(cr.getColumnIndex("yazar_id"));


        }
        cr.close();
        return sum;
    }

    public String getyazarid() {

        String yazarid = this.yazar_id;
        return yazarid;
    }

public class MainActivity extends AppCompatActivity {


    TextView textView;
    TextView dogru;
    TextView yanlis;

    int yanlis_sayac = 0;
    int dogru_sayac = 0;



    Button A;
    Button B;
    Button C;
    Button karistir;
    String gelenVeri;
    int sayac = 0;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);



        this.textView = (TextView) findViewById(R.id.textView);



        this.A = findViewById(R.id.cevapA);
        this.B = findViewById(R.id.cevapB);
        this.C = findViewById(R.id.cevapC);
        this.yanlis = findViewById(R.id.yanlis);
        this.dogru = findViewById(R.id.dogru);
        this.karistir = findViewById(R.id.karistir);


        DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);

        databaseAccess.open();


        //List<String> quotes = databaseAccess.getyazarlar();
        //List<String> quotes2 = databaseAccess.vericek();
        List<List> deneme = databaseAccess.getYazarlar();

        /*
        //ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, quotes);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, deneme.get(1));
        ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, deneme.get(0));

*/


        this.A.setText((String) deneme.get(0).get(0));
        this.A.setTag((String) deneme.get(1).get(0));
        this.B.setText((String) deneme.get(0).get(1));
        this.B.setTag((String) deneme.get(1).get(1));
        this.C.setText((String) deneme.get(0).get(2));
        this.C.setTag((String) deneme.get(1).get(2));
        this.dogru.setText(String.valueOf(dogru_sayac));
        this.yanlis.setText(String.valueOf(yanlis_sayac));
/*
        this.listView.setAdapter(adapter);
        this.listView2.setAdapter(adapter2);

*/

        String gelenKitap = databaseAccess.getKitap();
        String gelenyazarid =databaseAccess.getyazarid();
        String asd =databaseAccess.deneme();
        this.karistir.setText("GEÇ");
        //textView22.setText(asd);
        textView.setText(gelenKitap);
        textView.setTag(gelenyazarid);
        databaseAccess.close();


        A.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if(A.getTag().equals(textView.getTag())){

                    A.setBackgroundColor(Color.GREEN);
                    dogru_sayac++;
                }

                else{
                    A.setBackgroundColor(Color.RED);
                    yanlis_sayac++;
                }

                reload();


            }
        });

        B.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if(B.getTag().equals(textView.getTag())){

                    dogru_sayac++;
                    B.setBackgroundColor(Color.GREEN);

                }

                else{
                    B.setBackgroundColor(Color.RED);
                    yanlis_sayac++;
                }

                reload();

            }
        });

        C.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if(C.getTag().equals(textView.getTag())){
                    C.setBackgroundColor(Color.GREEN);
                    dogru_sayac++;

                }

                else{
                    C.setBackgroundColor(Color.RED);
                    yanlis_sayac++;
                }

                reload();

            }
        });



        karistir.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                reload();

            }
        });


    }

    public void reload() {
        Intent intent = getIntent();
        overridePendingTransition(0, 0);
        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        finish();
        overridePendingTransition(0, 0);
        startActivity(intent);





    }


}