SQLiteDatabases and Cursors

Question

I was wondering if anyone could give me a brief overview of Android Cursors. A few specific questions:

1 - I have a method that returns a cursor after a database query:

    public static Cursor getVehicles()
{
    SQLiteDatabase db = vehicleData.getReadableDatabase();
    Cursor cursor = db.query(TABLE_NAME, GET_VEHICLES_FROM_CLAUSE, null, null, null, null, ORDER_BY);

    return cursor;
}

To housekeeping, I tried db.close () immediately before the return statement. However, this resulted in the returned cursor containing no rows. Why is this?

2 - What is the difference between closing the cursor and closing the database?

3 - Do I need to close the cursor if it is a local variable, or can I leave it to the garbage collector for cleaning?

4 - My database is small and is used only by my application - can I just open it?

Answer 1

1) - , , . / ( → ). , , → .

2) , → , ( ), . , ( ).

3) . - GC , .

4) , , .