Reference no: EM132195730

Topic - Entity Relationship Modelling

Review Questions

1. Identify issues in the Crow's Foot notations used in the following ERD.

2. Lucidchart - this product is a browser based diagramming tool; it is able to draw a wide range of different diagrams, including ER Diagrams. As a University student you are entitled to a free Lucidchart account. You can sign up for the free account using your university email address. When your account is created and an invitation email sent to your FedUni student account (check Spam if the message is not in your inBox). Click on the link in your Lucidchart welcome email and you will be able to make use of the software. As a first step you should look at the provided tutorials, in particular "Entity Relationship Diagrams".

To prepare conceptual models (ERDs), you may use Lucidchart or any other drawing package.

3. Given a scenario represented by the following entities, where customers place orders for products:

CUSTOMER - customer number, name, address, phone number
ORDER - order number, order date, customer number and for each product ordered the quantity ordered and the total line price
PRODUCT - product number, product description and product unit price

This ERD only shows the primary keys of each of the entities, sometimes an ERD is drawn such that it will show all the non-primary key attributes for the model. In such a complete ERD you must not show or label foreign keys, the use of foreign keys indicates that you are looking at a logical model where a choice has been made to use a relational database, rather than a conceptual model.

Replicate the above diagram in your preferred diagramming software package. Once you have done that, add all the non-primary key attributes listed in the scenario above.

In this case, if you were to add the foreign keys to the respective entities, can you see any problems moving from a conceptual model to a logical/relational model? What would you need to do to fix the problem?

4. Using the above diagram and the business rules below, create an Entity Relationship Diagram using Crow's Foot notations.
o Include:
• all appropriate connectivities,
• all cardinalities and
• at least the minimum number of attributes required to implement the model

o Business Rules:
• A department employs many employees, but each employee is employed by one department.
• Some employees, known as "rovers," are not assigned to any department.
• A division operates many departments, but each department is operated by one division
• An employee may be assigned to many projects, and a project may have many employees assigned to it.
• A project must have at least one employee assigned to it.
• One of the employees manages each department, and each department is managed by one employee
• One of the employees runs each division, and each division is run by one employee.

5. Design an ER diagram for a car insurance company whose customers own one or more cars each. Each car has associated with it zero to many number of recorded accidents.

6. Acme Pty Ltd is made up of a number of departments that manage none or more projects. Each project is made up of none or more team members.
Each team member belongs to one department. Each team member belongs to zero to one project.
One of the team members supervise the other team members on the project.

Portfolio Questions

7. Given the following business rules, create an ER diagram for each of the specified relationships:
- A company operates four departments
- Each department employs staff
- Each staff may work for one or more departments
- A staff may be supervised by another staff member
- Each department has one manager. Identify the entities and the attributes

8. Design an ER diagram for an university registrar including the following entities:
- Courses, including course number, title, credits, syllabus, and prerequisites;
- Course offerings, including course number, year and teaching period, instructors, timings and classroom
- Students, including student-id, name, and program; and
- Instructors, including identification number, name, department, and title.
- Furthermore, the enrolment of students in courses and grades awarded to students in each course they are enrolled in, must be appropriately modelled.
Document all assumptions that you have made

Prepare an Entity Relationship Diagram (ERD) showing all primary and non-primary key attributes for the following description of a Property Rental System:

- Properties are rented by tenants. Each tenant is assigned a unique number by the Agency. Data held about tenants include family name, given name, property rented, contact address - street, city, state, postcode & telephone number. A tenant may rent more than one property and many tenants may rent parts of the same property (eg. a large shopping complex).
- Properties are owned by owners. Each property is assigned a unique building number. The agency only recognises a single owner for any of the properties it handles. The owner, address, and value are recorded for each property. In addition the lease period and bond are recorded for each property or sub property rented. An owner may own several properties.
- Properties are subject to damage and the agency records all instance of damage to its properties - property, date, type of damage and repair cost are recorded. Repair costs are charged directly to tenants
- Normal property maintenance is also noted - property, date, type of maintenance and cost are recorded. Maintenance costs are charged to the property owner.
- Tenants pay accounts to the Agency - these consist of weekly rental payments, bond payments (for new properties) and damage bills. The date of payment, tenant, property, type of account (Rental, Bond, Damage) and amount are recorded.

Attachment:- LAB 2 bigdata and analytics.rar