Database Exercise: Book Authors

Refer back to the library book exercise in the preceding section if necessary. Remember that we couldn't include authors in the CatalogEntry class because there might be more than one author for each book.

In a real (old-fashioned) library catalog, there was an additional card for each author of a book. (Author and title cards were contained in different sets of card drawers.)

Design a class diagram that shows the catalog entry plus authors, the attributes of each class, and the association between the classes.

Describe each class in English.

Draw the class diagram.

Describe each association in English (both directions).

Draw the relation scheme.

Your first version of this model might not have included a way to identify which author should be listed first, second, and so on. In real life, authors are very sensitive about this. Revise your model if necessary to accommodate this requirement.

The solution to this exercise will be discussed in class

Exercise: Book Authors

Refer back to the library book exercise in the preceding section if necessary. Remember that we couldn't include authors in the CatalogEntry class because there might be more than one author for each book.

In a real (old-fashioned) library catalog, there was an additional card for each author of a book. (Author and title cards were contained in different sets of card drawers.)

Design a class diagram that shows the catalog entry plus authors, the attributes of each class, and the association between the classes.

Describe each class in English.

Draw the class diagram.

Describe each association in English (both directions).

Draw the relation scheme.

Your first version of this model might not have included a way to identify which author should be listed first, second, and so on. In real life, authors are very sensitive about this. Revise your model if necessary to accommodate this requirement.

library book exercise from preceding section:

Exercise: library books You are building a very simplified beginning of the database for a library. The library, of course, owns (physical) books that are stored on shelves and checked out by customers. Each of these books is represented by a catalog entry (now in the computer, but think of an old-fashioned card file as a model of this). Assume that there is only one "title" card for each book in the catalog, but there can be many physical copies of that book on the shelves. Call the title card class a "CatalogEntry" and the physical book class a "Bookonshelf." You might think of the book's publisher as a simple attribute of the catalog entry-but in fact, the library will probably want to know more than just the publisher's name (for example, the phone number where they can contact a sales representative) Describe each class in English. Draw the class diagram Describe each association in English (both directions) Draw the relation scheme. The solution to this exercise will be discussed in class or online at a later date