private function cleanupRelation()
{
$sql = 'DELETE FROM `*PREFIX*music_album_artists` ' . 'WHERE `album_id` NOT IN (SELECT `id` FROM `*PREFIX*music_albums`) ' . 'OR `artist_id` NOT IN (SELECT `id` FROM `*PREFIX*music_artists`)';
$this->db->prepareQuery($sql)->execute();
$sql = 'DELETE FROM `*PREFIX*music_playlist_tracks` ' . 'WHERE `track_id` NOT IN (SELECT `id` FROM `*PREFIX*music_tracks`)';
$this->db->prepareQuery($sql)->execute();
}
