• To develop a conceptual data model diagram
• To perform logical design (optional)
In this assignment, you need to perform the following tasks for the given case study:
• Draw an Entity Relationship (ER) diagram
• Perform logical design (optional)
• Create 3NF Relations (optional)
Case Study: QRentals database system
QRentals (QR) is an Australian-owned business located in a large city that specializes in car hire service. The management of QR has approached you to build a relational database that will be used as the most critical backend software component in their enterprise management system so that the relevant business data will be recorded appropriately and further information query will be processed efficiently. The proposed database system requires efficiently to track all QR’s vehicles, customers, employees and relevant rental activities. Consider the following user requirements carefully and design a database conceptual schema (i.e. E-R model) to support such an application.
The company owns a large number of cars for hire. These cars are usually parked in a number of locations (belonging to QR’s property) in the city-wide, each location at a distinct address. Each car has a unique registration number which can used as an identifier. The car’s make and model, manufactured year, as well as the number of seats must be recorded. All cars in this case study hypothetically fall into a number of categories such as minivan, SUV, sedan, ute, luxury limos, etc. The daily hire rate of a vehicle is dependent on its category; for example the daily price of an ordinary sedan is approximately $35 while hiring a minivan may need paying up to $70 per day. In addition, each car has been commercially insured. The related insurance details are required to store in the database, which include the policy number, amount of premium, insurer name, policy start date and expiry date.
The system also needs to handle two different kinds of people: QR’s employees and customers. An employee, whose main duty is to process booking request from customers, is identified by a unique identification number, and has a name consisting of first name and last name. Other data on employees need to record are their birthdate, phone, skill level, annual salary and the working location
which normally is located at where the QR cars have been parked. For each customer, in addition to an identification number assigned, it is necessary to record his/her full name, license number, address, and phone number. In addition, the customers are generally categorized into two distinct types: individual and corporate. For an individual customer, whether the customer has a personal life insurance or not is recorded. For a corporate customer, the organization name, Australian Business Number (ABN) and whether the business travel special deal is applicable or not are recorded.
To rent a car from QR, the customer must contact the company by a phone call. An employee of QR will make a booking through the phone. QR often also stores details of some customers who have made enquiries through phone calls but have not made actual booking due to availability issue or a factor of price. The database keeps their details on record so that QR may follow up with them at a later stage particularly in promotional activities. For each booking, a reservation number will be created automatically. A brief description of reservation, the required category of car and the booking date will be recorded. Then the customer will go to a particular location to pick up the car at the scheduled start date (there is no concern what time to pick up it). After the rental activity ends, the customer returns the car to a location (the so called drop off location) which may be different from the pickup location. The database must keep track of relevant rental details such as pick up/drop off location, start date, end date as well as the cost in the system. Finally, the database also stores an image for each vehicle so that the prospective customers can conveniently view them online before their hiring.
In this assignment, you need to create an Entity Relationship (ER) diagram relevant to the above case study and optionally perform logical design to produce appropriate 3NF Relations.
The attributes for various entities have not been purposely described in the case study so that the students are encouraged to further research and list the pertinent attributes in addition to the required identifier for each and every entity in their ERD.
1 Draw an appropriate ER diagram
Use the symbols as prescribed in your unit-textbook to draw the ER diagram (ERD) for the above case study.
Your ERD must
• show all necessary entities, attributes and relationships
• show identifiers/identifying attributes as necessary
• show multi-valued attributes, if any
• show participation and cardinality
• show associative entities, if appropriate
• show weak entities, if any
• use the notation described in the set text
• use consistent and appropriate naming for entities and attributes as specified in the
unit text book
Some business rules or other aspects of the case study may not be clear to you when you read the case study. If this is the case, then you should either approach your lecturer or tutor for clarification, or you may simply make an assumption and then develop your ERD accordingly. For example, the case study might not mention all relevant participation information (also called minimum cardinalities). If so, you may make an assumption about what the minimum cardinalities might reasonably be, and then show them in your ERD accordingly. You should justify each assumption in terms of the business, for example: in the case study regarding the E-R model for customers placing an order it is assumed that each customer must have at least one order because it is assumed that the business does not record customer details until the customer places an order. To get yourself started, ask yourself, ‘If I were running this business, what things I need to keep a list of?’ Write those things down. For each thing, what information would you need to record about it? How can it be identified? The answers to these questions will help you to develop your ERD.
2 Assumptions and Business rules
Provide assumptions and business rules relevant to your ERD.
3 Create Logical Design (Optional):
If you would like to perform this optional component of this assignment, you can map your Entity Relationship diagram (ERD) into relations and make sure that all the relations are in 3NF. Provide all the relations in the following format (for example):
Customer (CustomerId, CustomerName, Street, Suburb, State, PostCode, Email)
Invoice (InvoiceNumber, InvoiceDate, Total, CustomerId)
foreign key (CustomerId) references Customer(CustomerId)
How and what to submit:
You must make an electronic submission for this assignment using the appropriate assignment submission link in the unit web site.
You should submit a Microsoft Word document containing:
• A copy of your ERD.
• A list of business rules and assumptions including their justifications.
• 3NF Relations – optional.
Your document should contain appropriate identifying information (your student number, name, unit number, etc.) and should contain appropriate headings for each section. Note: We recommend you to use Microsoft Visio to draw the E-R diagram and then copy & paste it to the Word document.
• You must work individually on this assignment.
• The model solution to this assignment will be released approximately TWO (2) weeks after the due date.
• Assignments that are submitted after the release of the model solution will receive zero marks.
• You must state in your assignment (at the end under the heading Acknowledgements is a good place) all materials and sources you used. This may be as simple as ‘This assignment was completed using only the COIT20247 unit materials’ to mention that you have used only the items provided by the unit COIT20247.
• Before submitting your assignment, review the marking criteria that are available in the assignment specification. Ensure that all the criteria are addressed in your submission.
• After submitting your assignment, please verify that your submission was successful, i.e. download your submitted files to ensure that they are correct.
• Penalty related to late submission and plagiarism is handled as per the university policies.