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';