Exercises for E-R Modeling I (Lecture 2)
The following questions were adapted from Rob, P. & Coronel, C. (1997) Database Systems: Design, Implementation, and Management. Cambridge, MA: Course Technology. This book is on reserve at the FIMS library. I recommend that you read pages 226-233 and work through the example on pages 255-256. Make sure you fully understand the examples and resultant ER diagrams before proceeding with the following questions.
1. Use the following business rules to write all appropriate connectivities and cardinalities in an E-R diagram:
2. The Hudson Engineering Group (HEG) has contacted you to create a conceptual model whose application will meet the expected database requirements for its training program. The HEG administrator gives you the following description of the training group's operating environment:
The HEG has twelve instructors and can handle up to thirty trainees per class. HEG offers five "advanced technology" courses, each of which may generate several classes. If a class has fewer than ten trainees in it, it will be canceled. It is, therefore, possible for a course not to generate any classes during a session. Each class is taught by one instructor. Each instructor may teach up to two classes or may be assigned to do research. Each trainee may take up to two classes per session.
Given this information, do the following:
3. Given the following business rules, create the appropriate E-R diagram for each of the specified relationships:
4. The Jonesburgh County Basketball Conference (JCBC) is an amateur basketball association. Each city in the county has one team that represents it. Each team has a maximum of twelve players and a minimum of nine players. Each team also has up to three coaches (offensive, defensive, and PT coaches.) Each team plays two games (home and visitor) against each of the other teams during the season. Given these conditions, do the following:
5. Create an ER Model for the following: