Fall Semester 2002

1. Director is an independent entity, and the features (attributes) are listed.
2. Notice that one attribute could be NULL (as in the case of the sample practical).
3. Movie is an independent entity with the listed attributes.
4. Movies and Directors are related. Additional attributes are listed for the Movies.
5. Among these attributes there's also an indication repeating groups could be used.
6. With the repeating groups one could relate Movies and Directors.
7. Actors are just another entity. Some attributes are listed.
8. Movies are related to Actors too. How do we do that?
9. (Of course the answer is that we use repeating groups for each MovieNum).
10. At each stage we need to normalize and merge tables.
11. Some user vies are going to be redundant. See User View 6 on Page 191.
12. Still, one needs to verify all User Views, and carefully mark them as implemented.

• Director
• Movie
• Actor
• Movie-Actor

Note that

• there's always only one Director per Movie, but
• seldom only one (or less) actor(s) per Movie.

(Also: these are only ideas, your design may vary).

Problem 2. With this problem (regarding memberships) we approach entity subtypes.

1. Entity subtypes are described on pages 208 and following.
2. There's really nothing extra special about them.
3. Then there are also some attributes of members, which are listed.
4. But other than that the rest is simply vanilla.
5. (That means lacking pizzazz and/or basically plain, ordinary).
6. So there's another entity, call it DVD, with some attributes...
7. ... and that's about it.

To summarize, one might have to add two tables:

• Member, and
• Tape (or DVD)

Please indicate with care all the FK's.