'Android SQLLiteDataBase cursor returning 0 rows

For the life of me, I can't get the cursor to return any data. I've verified that their is data in the database and my insertions are working. The official error is:

CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0

Top level declarations:

private DatabaseHelper DBHelper;
private SQLiteDatabase db;

public DBAdapter(Context ctx) 
{
    this.context = ctx;
    DBHelper = new DatabaseHelper(context);
    this.db = this.DBHelper.getWritableDatabase();
}

My function:

public String getRandomEntry()
    {
    int rand;
    Random random = new Random();
    int numEntries = (int)this.getCount();

    if(numEntries == 0)
        return "ERROR: Database is empty.";
    rand = random.nextInt(numEntries);

    Cursor cursor = DBHelper.getWritableDatabase().rawQuery(
            "SELECT * FROM " + DATABASE_TABLE 
            + " WHERE " + COLUMN_A + " = " + 0, null);

    Log.i("numEntries", Integer.toString(numEntries));
    Log.i("rand", Integer.toString(rand));
    Log.i("cursor", Integer.toString(cursor.getCount()));

    cursor.moveToFirst();
    return cursor.getString(0);
}

I've also tried grabbing the cursor as such:

Cursor cursor = db.rawQuery(
            "SELECT * FROM " + DATABASE_TABLE 
            + " WHERE " + COLUMN_A + " = " + 0, null);

Please give me your thoughts! Thank you!!

javaandroidsqldatabaseandroid-cursor


Solution 1:[1]

Nothing seems random here at all. It appears that you are looking for column_a with a value of 0 every time.

I would assume that column_a has nothing with a value of 0.

Solution 2:[2]

First of all try to query this way:

String args[] = new String[]{"0"};

Cursor cursor = db.rawQuery(
        "SELECT * FROM " + DATABASE_TABLE + " WHERE " + COLUMN_A + " = ?", args);

If this not helps check your db with external tool if you query return rows there.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 nicholas.hauschild
Solution 2 woodshy

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