while(cursor.moveToNext()) {
            postHash = cursor.getString(cursor.getColumnIndexOrThrow(KnownPostsContract.KnownPostsEntry.COLUMN_POST_HASH));
            commentHash = cursor.getString(cursor.getColumnIndexOrThrow(KnownPostsContract.KnownPostsEntry.COLUMN_COMMENT_HASH));

            // add the hash to the list