3. Draw the ER diagram for the following mini-world:
Music companies keep data about each MUSICIAN, such as the name (which is
unique), birthplace, birthdate, and the music genre.
In addition, the pieces of MUSIC produced by the MUSICIAN is stored. For each
piece of MUSIC, the production year, the unique title, the genre (e.g., Pop, Rock, Jazz,
Blues), and production cost is stored.
Companies also keep data about each ALBUM which typically contains several pieces
of MUSIC. Each ALBUM is identified by a unique name.
Finally, music companies keep data about each CLIENT, including a unique client id,
name, address, and the MUSICIAN and ALBUM that the client tends to like.
4. Draw an EER diagram for a DVD rental COMPANY where people can borrow movie
DVDs. The data requirements are summarized as follows:
• The COMPANY has a unique name and manages several OFFICES each of which
with an address and a unique number. Each office can be either a MAIN OFFICE or
a BRANCH OFFICE.
• Each DVD is described by a unique code number, a title and a producer. A DVD has
COPY and the COMPANY may own one or more than one COPY of a DVD. The price
that was paid for each COPY is recorded.
• A BORROWER who has a unique ID, can borrow a COPY of a DVD.
