In PHP, when should song titles be stored as separate entities from tracks and albums in a database, and when should they be kept together?

In a database, song titles should be stored as separate entities from tracks and albums when they need to be uniquely identified and managed independently. This can be useful when a song appears on multiple albums or when additional metadata specific to the song title needs to be stored. However, song titles can be kept together with tracks and albums in cases where they are always associated with a specific track or album and do not require separate management.

// Example of storing song titles as separate entities from tracks and albums

// Song Titles Table
CREATE TABLE song_titles (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL
);

// Tracks Table
CREATE TABLE tracks (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title_id INT,
    album_id INT,
    duration INT,
    FOREIGN KEY (title_id) REFERENCES song_titles(id),
    FOREIGN KEY (album_id) REFERENCES albums(id)
);

// Albums Table
CREATE TABLE albums (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    release_date DATE
);