CREATE TABLE song_likes (
  user_id    INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  song_id    INTEGER NOT NULL REFERENCES songs(id) ON DELETE CASCADE,
  created_at TEXT NOT NULL DEFAULT (datetime('now')),
  PRIMARY KEY (user_id, song_id)
);
CREATE TABLE song_favorites (
  user_id    INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  song_id    INTEGER NOT NULL REFERENCES songs(id) ON DELETE CASCADE,
  created_at TEXT NOT NULL DEFAULT (datetime('now')),
  PRIMARY KEY (user_id, song_id)
);
CREATE TABLE playlist_likes (
  user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  playlist_id INTEGER NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
  created_at  TEXT NOT NULL DEFAULT (datetime('now')),
  PRIMARY KEY (user_id, playlist_id)
);
CREATE TABLE playlist_favorites (
  user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  playlist_id INTEGER NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
  created_at  TEXT NOT NULL DEFAULT (datetime('now')),
  PRIMARY KEY (user_id, playlist_id)
);