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Question 1 Create an ER diagram for each of the following descriptions: a. Each company operates four departments, and each department belongs to one company. b. Each department in part (a) employs one or more employees, and each employee works for one department. c. Each of the employees in part (b) may or may not have one or more dependants, and each dependant belongs to one employee. d. Each employee in part (c) may or may not have an employment history. e. Represent all the ER diagrams described in (a), (b), (c), and (d) as a single ER diagram. Question 2 You are required to create a conceptual data model of the data requirements for a company that specializes in IT training. The Company has 30 instructors and can handle up to 100 trainees per training session. The Company offers five advanced technology courses, each of which is taught by a teaching team of two or more instructors. Each instructor is assigned to a maximum of two teaching teams or may be assigned to do research. Each trainee undertakes one advanced technology course per training session. a. Identify the main entity types for the company. b. Identify the main relationship types and specify the multiplicity for each relationship. c. Using your answers for (a) and (b), draw a single ER diagram to represent the data requirements for the company. Question 3 Read the following case study, which describes the data requirements for a video rental company. The video rental company has several branches throughout the USA. The data held on each branch is the branch address made up of street, city, state, and zip code, and the telephone number. Each branch is given a branch number, which is unique throughout the company. Each branch is allocated staff, which includes a Manager. The Manager is responsible for the day-to-day running of a given branch. The data held on a member of staff is his or her name, position, and salary. Each member of staff is given a staff number, which is unique throughout the company. Each branch has a stock of videos. The data held on a video is the catalog number, video number, title, category, daily rental, cost, status, and the names of the main actors, and the director. The catalog number uniquely identifies each video. However, in most cases, there are several copies of each video at a branch, and the individual copies are identified using the video number. A video is given a category such as Action, Adult, Children, Drama, Horror, or Sci-Fi. The status indicates whether a specific copy of a video is available for rent. Before

hiring a video from the company, a customer must first register as a member of a local branch. The data held on a member is the first and last name, address, and the date that the member registered at a branch. Each member is given a member number, which is unique throughout all branches of the company. Once registered, a member is free to rent videos, up to maximum of ten at any one time. The data held on each video rented is the rental number, the full name and number of the member, the video number, title, and daily rental, and the dates the video is rented out and date returned. The rental number is unique throughout the company a. Identify the main entity types of the video rental company. b. Identify the main relationship types between the entity types described in (a) and represent each relationship as an ER diagram. c. Identify attributes and associate them with entity or relationship types. Represent each attribute in the ER diagrams created in (b). d. Determine candidate and primary key attributes for each (strong) entity type. e. Using your answers (a) to (e) attempt to represent the data requirements of the video rental company as a single ER diagram. Question 4 a. Given the following business rules, create the appropriate ERD using UML notation. A football team has at least 11 players and may have up to 40 players. b. Each player may or may not play one or more games. c. A minimum of 11 players and a maximum of 14 players may participate in one game. d. A player may or may not score one or more goals. e. Each game may have zero or more goals. Question 5 The Hudson Engineering Group (HEG) has contacted you to create a conceptual model whose application will meet the expected database requirements for the company's training program. The HEG administrator gives you the description (see below) of the training group's operating environment. (Hint: Some of the following sentences identify the volume of data rather than cardinalities. Can you tell which ones?) The HEG has 12 instructors and can handle up to 30 trainees per class. HEG offers five "advanced technology" courses, each of which may generate several classes. If a class has fewer than 10 trainees, it will be canceled. Therefore, it is possible for a course not to generate any classes. Each class is taught by one instructor. Each instructor may teach up to two classes or may be assigned to do research only. Each trainee may take up to two classes per year. Given that information, create an ERD using UML notation.

Question 6 A store in Thohoyandou decides to go High Tech. You are asked to design a database for the store. After brainstorming with the store managers, you come up with the following specification: The store has multiple departments, identified by their names. Each dept may have many employees but (at most) one of them is the dept manager. Employees are identified by their names. We also need to record their salaries. Each employee works in exactly one department Managers are employees as well, each with a salary higher than all other employees in the department he manages. The store sells various items identified by item ID's. Exactly one department carries each item, while each department may carry many items. For each item, we also need to keep a short description and its quantity in stock. The store deals with a number of suppliers identified by their names. We need to record their addresses. Each supplier supplies an item at a particular price. A supplier may supply any number of items, and each item must be supplied by at least 3 suppliers (probably different prices). The store receives orders identified by order ID's. Each order has a date, a shipping address, and may include different quantities of multiple items. 1 (a) Draw an ER diagram for the database identifying: i) all entities ii) all relationships the primary key for each entity (including weak entities) and each relationship; (b) Convert the ER design into a relationship scheme. For each relation state: i) the name of the relation ii) the names of attributes iii) the primary key iv) the foreign key Question 7 A university registrar's office maintains data about the following entities: courses, including number, title, credits, syllabus, and prerequisites; course offerings, including course number, year, semester, section number, instructor(s), timings, and classroom; students, including student-id, name, and program; instructors, including identification number, name, department, and title. Further, the enrolment of students in courses and grades awarded to students in each course they are enrolled for must be appropriately modelled. Construct an E-R diagram for the registrar's office. Document all assumptions that you make about the mapping constraints.