You must submit two separate copies (one Word file and one PDF file) using the A

You must submit two separate copies (one Word file and one PDF file) using the Assignment Template on Blackboard via the allocated folder. These files must not be in compressed format.
It is your responsibility to check and make sure that you have uploaded both the correct files.
Zero mark will be given if you try to bypass the SafeAssign (e.g. misspell words, remove spaces between words, hide characters, use different character sets, convert text into image or languages other than English or any kind of manipulation).
Email submission will not be accepted.
You are advised to make your work clear and well-presented. This includes filling your information on the cover page.
You must use this template, failing which will result in zero mark.
You MUST show all your work, and text must not be converted into an image, unless specified otherwise by the question.
Late submission will result in ZERO mark.
The work should be your own, copying from students or other resources will result in ZERO mark.
Use Times New Roman font for all your answers.
2 Marks
Learning Outcome(3):
Create Entity-Relationship model, Relational model, and write SQL queries.

Question One
Based on your understanding of specialization and generalization constraints, use your own words to define and discuss the two primary constraints: Disjointness Constraint and Completeness Constraint.
Answer:
2 Marks
Learning Outcome(3):
Create Entity-Relationship model, Relational model, and write SQL queries.
Question Two
Show the schema mapping of the following Payment EER schema diagram, using Option 8A: Multiple relations-Superclass and subclasses.
Answer:

2 Marks
Learning Outcome(3):
Create Entity-Relationship model, Relational model, and write SQL queries.
Question Three
SQL constraints are used to specify rules for the data in a table. From what has been studied, what is the benefit of using constraints in DB. Also, explain three common SQL constraints.
2 Marks
Learning Outcome(3):
Create Entity-Relationship model, Relational model, and write SQL queries.
Question Four
Using the relational algebra operations, write the following queries on the COMPANY relational database schema shown in the figure below.
(a)Retrieve the address of employees in department 2 who work less than 5 hours per week on the ‘ProductX’ project.
(b)Retrieve the names and salary of employees who work on every project.

Answer