Calvin Sims
Lab Questions 3.2

1.Databases surround us on the web and everyday life. Now that you have a clearer
idea of what database systems do, find two examples of web sites that you believe
are likely to use databases and discuss what kinds of data they might be storing, as
in the example answer.

 Fandango.com uses a database to store information about movies, reviews and availability of tickets 
   for select movies and theatres.

   Edmunds.com uses a database to store information about car prices and values, car reviews, and car that
   are available to buy.

2. Identify relationships. Suppose you are creating a database to help a university
keep track of its course offerings. You might have the following entities in your
database, since they are distinct items in real life that are related to each other in
important ways: course, classroom, professor, and department. In the space
below, draw an ER diagram with a box for each of these four entities and arrows
between the boxes labeled with the relationships they denote.

Department -->  Course -->  Professor -->  Classroom
               '           '              '
         The Course    Professor     Professor will teach
         goes in a     teaches the   the course in a
         certain dept  course.       classroom.
         Ex. English

3.Identify many-to-one relationships. For each of the relationships you diagrammed
above, which ones are many-to-one? Which ones are many-to-many? Indicate
the relationships by writing 1 or 8 at each end of the relationship arrows. If you
are not sure about whether a relationship is one-to-many or many-to-many,
explain why. 

 Department to Course is a one-to-many relationship. Course to Profesor is a one-to-one relationship.
Profesor to Classroom is a one-to-many relationship.

4. Identify entities. Suppose you are creating a database to keep track of a radio
station’s record collection. What are some of the entities your database might
include?

Artist, Title of Album, Year of Release

5.Query results and tables look very similar—like a set of tuples. How are query
results and tables different, however?

 Tables and query results are similar because they present the information provided clearly. 
However; queries are more efficient when directly relating things to one another.