Attracted by the success of Spotify, a group of students want to build their
own music-streaming website called Musicmatic. Being economists, make EER diagram.
A large number of songs will be made available through their website, and the following information on each song needs to be stored: title, year, length, and genre. Also, artist information will be added, including date of birth, name, and a URL to a website (e.g., Wikipedia page) with additional information on the artist. You can assume an artist is uniquely identified by her name, and that a song always belongs to exactly one artist. The Musicmatic students also point out that songs having the same title are possible, and only the combination of song and artist can be assumed to be unique.
The database will also have to store information on the people using Musicmatic. It was decided to only discriminate between two types of users: regular users who will be able to buy music, and business users who will deliver the content (upload the music). The following information is recorded on each user: (unique) ID, name, and address. Business users will also have a tax id number.
The students want to offer a flexible service, and decided business users only can upload individual songs. These songs are classified either as singles or hits, and regular users can directly buy the singles. People can compose a playlist consisting of multiple hits (no singles). An playlist should be uniquely identifiable by an playlist number. The position of each hit in the playlist is stored as a track number in the database.
Finally, a user can be a regular user on some occasions (e.g., when downloading a single or album), and a business user at other times (e.g., when uploading self-made songs to Musicmatic).
Capture as much of the semantics of this situation as you can in an EER diagram!
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