INF2603 Assignment 5 (COMPLETE ANSWERS) 2025 (865742) - DUE 5 September 2025; 100% TRUSTED Complete, trusted solutions and explanations. Ensure your success with us....

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INF2603 Assignment 5
(COMPLETE ANSWERS)
2025 - DUE 5 September
2025
NO PLAGIARISM

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,Exam (elaborations)
INF2603 Assignment 5 (COMPLETE
ANSWERS) 2025 - DUE 5 September 2025
Course
 Databases I (INF2603)
 Institution
 University Of South Africa (Unisa)

INF2603 Assignment 5 (COMPLETE ANSWERS) 2025 (865742) - DUE 5
September 2025; 100% TRUSTED Complete, trusted solutions and
explanations. Ensure your success with us....




Section A: Normalization & Database Design
1. Without using ChatGPT and examples from the book, provide an example to emphasize
your case. Describe the situations when a 3rd NF relation is in BCNF and when it is not.
(4)
2. Why is a table whose primary key consists of a single attribute automatically in 2NF
when it is in 1NF? (2)
3. Explain what is a disjoint subtype? And give an example. (4)
4. What is a strong (or identifying) relationship? (2)
5. Describe and illustrate using an example the process of attribute inheritance. (4)




Section B: SQL Concepts & Constraints
6. What is the difference between a column constraint and a table constraint? (4)
7. What three join types are included in the OUTER JOIN classification? (6)
8. What is metadata? (2)
9. Explain what is physical independence in data models? (2)




Section C: SQL Queries (Employee Table)
10. Write SQL code to display the employees’ names, year of birth, and the bonus for each
employee. Sort the results by the employee_id. (5)

Table 5.1 Example:

, Employee_ID EmployeeNames_BirthYears Dept_ID Bonus
Bontle Nxumalo (1982) 2305 —
Mpho Nkomo (1989) 2405 R24,000
Mahlako Nkomo (1984) 6605 —
Tshepi Phahlane (1986) 2305 R53,000

11. Write the SQL code to delete the row for the employee who was paid R24,000 bonus. (2)




Section D: SQL Queries (Student Table)
12. Write the SQL code that will create the STUDENT table below. This table is a subset of
the UNISA student registration database. (Note: DEPT_CODE is a FK to
DEPARTMENT). (5)

Table 5.2 STUDENT attributes:

 StudentID {PK}
 DEPT_CODE {FK}
 STUD_Gender
 STUD_fname
 STUD_lname
 STUD_INITIAL
 STUD_EMAIL

13. Because you are a registered student at UNISA and you have classmates who are your
friends, please write SQL code to enter your own correct information and also the
information of another student into the STUDENT table (2 records). (4)
14. Write a SQL code to change your email address from your myLife email address to a
Gmail address. (4)
15. Write a SQL code to delete the STUDENT table from the database. (2)




Section E: ERD and Modelling
16. Using the following transport business rules, draw the appropriate ERD using UML
notation for a unique e-hailing taxi service in Mpumalanga. Include all appropriate
entities, relationships, and multiplicities:

 One driver can be assigned to multiple taxis over time, but each taxi has only one driver
at a time.
 Each customer can have multiple rides, and the e-hailing services offer sharing options.
 One taxi can be used for multiple rides.