Similar SQLite toString() functions yielding different results?

I have a SQLite table initialised as such. It is a single row implementation.

public void onCreate(SQLiteDatabase db) {
    String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
            COLUMN_ID + " INTEGER PRIMARY KEY DEFAULT 1, " +
            COLUMN_PRODUCTNAME + " TEXT ," +
            COLUMN_DATE + " TEXT " +
            ");";
    db.execSQL(query);
}

I update the row this way.

public void updateRow(int id, Products product){
    ContentValues values = new ContentValues();

    values.put(COLUMN_ID, id);
    values.put(COLUMN_PRODUCTNAME, product.get_productname());
    values.put(COLUMN_DATE, getDateTime());

    SQLiteDatabase db = getWritableDatabase();
    db.replace(TABLE_PRODUCTS, null, values);
    db.close();
}

Initially, I did not have COLUMN_DATE. I tacked it on after the original was working correctly. When I want to check that things work, I toast a String to the screen. And this works great with COLUMN_PRODUCTNAME, here's the function to do this.

public String prodToString(){
    String dbString = "";
    SQLiteDatabase db = getWritableDatabase();
    String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";
    Cursor c = db.rawQuery(query, null);
    c.moveToFirst();
    dbString = c.getString(c.getColumnIndex(COLUMN_PRODUCTNAME));
    db.close();
    return dbString;
}

But when I copypasted the exact same function above under name dateToString(), only changing COLUMN_PRODUCTNAME to COLUMN_DATE and call said function, I get the error:

Failed to read row 0, column -1 from a CursorWindow which has 1 rows, 2 columns.

java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. 

Make sure the Cursor is initialized correctly before accessing data from it.

I doubt it has anything to do with the getDateTime() function, because I can output that fine. Whether I put it into the table correctly is still unclear to me, but it looks to be ok in that sense. I'm not sure what's going wrong. Can anyone see it?