Draw the ERD
The following tables and attributes exist in a relational database:
Table:Attributes:
ProfessorProfessor #, name, office
StudentStudent #, name, street address, city, state, professor #
CourseCourse #, name, # credits
SectionCRN, days, time, professor #, Course #
Student-Section Student #, CRN, grade
Draw the ERD
The Busy B Company wants to store data about its employees’ skills. Each employee possesses one or more specific skills. In addition, several employees may have the same skill. The following facts need to be included in the database:
Employee name
Skill number
Skill name
Employee number
Date hired
Date of birth
Date skill acquired
Create a data model for the following scenario.
A charter company owns boats that are used to chart trips to islands. Each trip lasts between 2 and 5 hours and consists of one boat with one captain visiting one island. The company has created a computer system to track the boats it owns, including each boat’s ID number, name, and seating capacity. The company also tracks information about the various islands, such as the island names and populations.
Every time a boat is chartered, it is important to know the date and time that the boat is to depart and the number of people planning to take the trip. The company also keeps information about each captain, such as Social Security number, name, and birth date. Captains are not permanently assigned to a boat, rather they are randomly assigned as need arises. When the time for the trip comes, the company wants to keep track of the actual number of people taking the trip, in case it is different from the planned count.
Create a data model for the following scenario.
The year is 1996. You have been asked to design a database for the Atlanta Committee for the Olympic Games (ACOG). They want to develop a system that will be able to maintain information about the Summer Olympics. You have interviewed some of the members of ACOG and this is what you have been able to find out about what they want the system to do:
First, they are interested in keeping track of the events that are going to be held (e.g., 100 yard dash, marathon, parallel bar competition, vault, etc.). For each event they want to know the date and time that the event will take place, as well as the venue (location name) of the event. For example, they would want to know that the 100 yard dash is on August 1, 1996 at 10am on the Olympic Stadium. For simplicity sake, assume that each event takes place at only one time in only one place. For each venue they also want to keep information about the number of seats that it has (i.e. seating capacity) and the street address where it’s located. Each venue will likely host multiple events during the Olympics.
They also want to know the names, height, and weight of all the athletes who are participating in the games. They need to know the country that the athlete is from and the size of the population of that country (for statistical reporting purposes). There will be multiple athletes from each country and they would not keep track of a country if it does not have any athletes participating. They also must also be able to keep track of which athletes are participating in which events. It is, of course, possible for an athlete to participate in more than one event.
Finally, when an athlete participates in an event they receive a score and ACOG would like to store the score so they can track the performance of each athlete in each event. Eventually they want to be able to keep track of which athletes received which medals, including the color of the medal, but for now you can assume that the process of storing information about medals is outside the scope of the system.