ALTER TABLE bands_genres DROP CONSTRAINT IF EXISTS band_genre_uniqkey;
ALTER TABLE bands_genres DROP CONSTRAINT bands_genres_band_id_fkey;

ALTER TABLE bands_genres RENAME TO genre_players;
ALTER TABLE genre_players RENAME COLUMN band_id TO player_id;
ALTER TABLE genre_players ADD COLUMN player_type VARCHAR(128);

ALTER TABLE genre_players ADD CONSTRAINT genre_player_uniqkey UNIQUE (player_id, player_type, genre_id);

UPDATE genre_players SET player_type = 'JamRuby::Band';
