CIS3530 Assignment1 Solution

Learning Goals
By the end of this assignment, you should:
1. Have a good understanding of the relational model
2. Be able to read and understand a given relational schema and its structure
3. Have mastered the techniques for writing relational algebra (RA) queries and basic SQL queries
Submission Instructions
- You must use the same notation of Relational Algebra that we have used in class and in the slides (∏, ∞, ÷,σ,×,∩,U, - , ∞left ..)
- Each question has its own submission instruction. Please read them carefully and submit accordingly.
Later in the course, towards weeks 5 and 6, you will learn about designing and developing your own schema, given a set of requirements. For this assignment, a relational schema is provided to you for each question.
Schema for Questions 1 and 2: Relations
• Student (sID, firstName, lastName, email, cgpa)
A tuple in this relation represents a student – a student is identified by their sID. Other information stored about a student is their firstName, lastName, email address and their cgpa. An example student tuple is <0411111, 'Fay', 'Simpson', 'fsimpson@uoguelph.ca', 1.4>
• Course (cNum, name, dept, credit)
A tuple in this relation represents a course. Note that a course is identified by its number and the department to which it belongs. An example course tuple is <3530, 'Intro to Databases', 'CIS', 3>
• Took (sid, oid, grade)
A tuple in this relation stores a student’s grade in a course offering. An example tuple of took is < 0991326, 1, 79>
Integrity Constraints
• Primary Key of relation o Student is sID o Course is (cNum, dept) o Offering is oID o Took is (sID, oID)
• Foreign Key o Offering has a foreign key (cNum, dept) that references relation Course o Took has 2 foreign keys
§ Foreign key (sID) references relation Student
§ Foreign key (oID) references relation Offering
Write relational algebra expressions to answer the following. Expected results for the given instance are shown for your convenience. Submit a file called A1Q1_lastname_firstname.txt that includes all the RA queries for questions 1a to f (other file extensions such as docx or rtf will also be allowed).
Tip: once you compile and run your RA query on the RelaX editor, copy and paste it onto Word (or notepad or textEdit).
a. Find all offerings of 3530 Expected Output:



c. Find all courses offered by Ritu Expected Output:

Expected Output:

e. Find all students who do not take course CIS3530.
Expected Output:

f. Find students who take all ‘HIS’ courses offered Expected Output:

g. Find all courses that have the same number but are offered by different departments.
Expected Output:

h. Write a query that displays all courses and the term and year they are offered, if offered. The courses that are not offered must display NULL values for term and year.
i. Develop a query for this database, write its description / question in English (as given in questions 1a to 1h), give its solution and expected output. The query must involve at least 2 tables and at least 3 operators. You will be marked based on its originality and the operators used.
There are 12 queries to write for this question (a-l). Submit a file called
A1Q2_lastname_firstname.sql that includes all the SQL queries for questions 1a to f. a-h. Write SQL queries for question 1a-h.
i. Find all students who have taken CIS3530 multiple times.
Expected Output:


k. Write a query to update table OFFERING such that course 3530 is always offered by ‘Harry’.
l. Write a query that deletes all courses taught by ‘Ritu’.
Schema for Question 3
Relations
Males (name)
A tuple in this relation stores names of all males in this database.
Females (name)
A tuple in this relation stores names of all females in this database.
parent_of (parent, child)
A tuple in this relation stores names of all parents in this database and their children. For example, if ‘David’ has 2 kids, ‘Paul’ and ‘Sue’, then this relation will consist of 2 tuples:
<’David’, ‘Paul’> and <’David’, ‘Sue’> married_to (husband, wife)
A tuple in this relation stores names of husband and their wife. An example tuple is <’John’, ‘Sue’>
Note that there are no foreign key constraints defined in this database. Primary keys are shown as underlined.
Write SQL Queries for the following. Submit a file called A1Q3_lastname_firstname.sql that includes all the SQL queries for questions 1a to f.
a. all_grand_parents

Expected Output: Grand Parents
---------------
Jeff
David
John
Sue
(4 rows)

b. sister_of
Expected Output: sister | name -----------+-------
Angela | John Sue | Paul
Mary | Simon
(3 rows)
c. aunty_or_uncle_of Expected Output:
Aunt Or Uncle | name
-------------------+------- Angela | Mary
Angela | Simon
John | Beth
Paul | Mary
Paul | Simon
Simon | Bill
(6 rows)

d. neice_of
Expected Output:
Aunt Or Uncle | niece
---------------+------- John | Beth
Paul | Mary
Angela | Mary
(3 rows)
e. cousin_of
f. daughter_in_law_of