Select a Random row in realm table

问题

I want to select a random row from the realm table. Something like -

SELECT * FROM table ORDER BY RANDOM() LIMIT 1;

回答1:

Something like this would do, yes?

Random random = new Random();
RealmResults<YourTable> list = realm.where(YourTable.class).findAll();
YourTable yourTable = list.get(random.nextInt(list.size()));

回答2:

Depends on what you want to do:

Do you want to get a random row from a table? Or A (random) row from a random table?

I guess you mean the former: If you have an id in your table, you could just:

SELECT * FROM table b WHERE id = FLOOR(RAND() * (3 - 0 + 1)) + 0

You should place a min and max here like so:

FLOOR(RAND() * (<max> - <min> + 1)) + <min>

(as found here)

回答3:

String query =String.format("SELECT * FROM realm ORDER BY %d LIMIT 1", random());
databaseHelper = new DatabaseHelper(this);
        database = databaseHelper.getWritableDatabase();
Cursor cursor = database.execSQL(query);

It works assuming that you have a class DatabaseHelper which extends SQLiteOpenHelper

来源：https://stackoverflow.com/questions/33827910/select-a-random-row-in-realm-table