1. IS6125 Database Analysis and Design Lecture 8: Practice with ERDs
Rob Gleasure

2. From IS6125 Winter Exam 2015
Draw an Enhanced Coarse Granular Design-Specific Entity-Relationship Diagram using Chen’s notation based on the following narrative: A publisher employs both authors and editors. For authors, data need to be stored for their name, address, and one or more s. For editors, data need to be stored for their name, employee number, and salary. Some editors are senior editors, in which case their start date in that role will be recorded, as well as possibly an end date. Other editors are associate editors, in which case a domain of interest will be noted. A list of paired editors must also be provided, which provides all data relating to these editors, plus total editor-related salary overheads for that pair. Data also need to be stored for different books, including the book’s unique ISBN, the title, and a list price. Books are mostly horror (in which case they are assigned a violence rating from 1-5), non-fiction (in which case they are assigned a period and possibly a related historic event), or teen fiction (in which case they are assigned an age recommendation of ‘early teens’ or ‘mid-to-late teens’). Books may also be available second hand, in which case a reduced price will be stored. Books are associated with at least one author and at least one editor.

3. One possible solution

4. From IS6125 Winter Exam 2014
Draw an Enhanced Entity-Relationship (EER) Diagram* using Chen’s notation:
A company is comprised of many branches. Each branch employs numerous managers across a range of functions but managers only work for one branch. Managers are involved in just one function in a branch, including marketing and sales, product development, and human resources. Data that needs to be stored for all managers, regardless of branch, include their employee number, name, qualifications, date of birth, phone number, age, and internal awards.
Managers working in marketing and sales also need to have data stored for their dedicated clients, current sales quota, previous sales quota for the same quarter the previous year, and the proportion of sales they have brokered that have later broken down (or ‘breakdown ratio’). Managers working in product development also need to have data stored for each project currently under development, patents registered, and technical qualifications. Managers working in human resources also need to have data stored for the languages they speak, initiatives pioneered, and any reports logged.
Note that some managers will be working in a branch on a long-term basis, in which case data will also need to be stored regarding their pension details and dependents. Other managers will be working in a branch as a sponsored exchange with a sister company, in which case the duration and objectives of the exchange will be noted, as well as the relationship to the sister company.

5. One possible solution