Question

I made a query that requests a random row from database using ID. But I have a little problem. I want it to show a message if it exists or it doesn’t exist. For example my database like that:

ID – ingilizce – turkce
1 – hello – merhaba
4 – hi – selam

As you see, the second and third record don’t exist. I generate a random number between 1 and 4 and I get the row that belongs to ID. So, when it generates a number like 2 or 3, it will generate a new random number.
My code is here:

public void kelimeUret() {

SQLiteDatabase db = kelimeler.getReadableDatabase();

rastgele = new Random();

Cursor kayit = db.rawQuery("SELECT count(*) FROM kelimeler", null);

kayit.moveToFirst();

int max = Integer.parseInt(kayit.getString(0));
int min = 1;

int rastgeleKayit = rastgele.nextInt(max - min + 1) + min;

Cursor kayit3 = db.rawQuery("SELECT * FROM kelimeler WHERE id=" + rastgeleKayit, null);
kayit3.moveToFirst();
int kayitSayisi = kayit3.getCount();

if (kayitSayisi<1) {

    //Toast.makeText(getApplicationContext(), "bu kayıt yok", Toast.LENGTH_SHORT).show();
    //kelimeUret();

    // I COULDN'T DO HERE !

} else {

    Cursor kayit2 = db.rawQuery("SELECT ingilizce FROM kelimeler WHERE id=" + rastgeleKayit, null);

    kayit2.moveToFirst();

    String sonuc = kayit2.getString(0);

    olusturulanKelime = sonuc;

    kelime = (TextView) findViewById(R.id.kelime);
    kelime.setText(sonuc);

}

Thanks for your responds…

Answer 1

Cursor kayit3 = db.rawQuery("SELECT * FROM kelimeler WHERE id=" + rastgeleKayit, null);
kayit3.moveToFirst();

kayit3.getCount(); will return the number of records returned by the query. If there are no records, then it does not exist. If it returns more than 1 record, then the record exist.

Hope this helps