# Dept. of Computer & Information Sciences

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Dept. of Computer & Information Sciences
Riyadh Philanthropic Society For Science Prince Sultan College For Woman Dept. of Computer & Information Sciences CS 340 Introduction to Database Systems (Chapter 6 Tutorial)

Exercise 1 Given the Following database schema:
Specify the following queries in: Relation algebra Tuple relational calculus Domain relational calculus Only for a, b, c, f, i, j Chapter 6 Tutorial 1

Exercise 1 - a Retrieve the names of all employees in department 5 who work more than 10 hours per week on the ‘Product x’ project. Relational Algebra: PROJ_X  PNAME = ‘Product x’ (PROJECT) EMP_WORK_  HOURS>10 (PROJ_X PNUMBER=PNO WORKS_ON) EMP_DEPT_  DNO=5 (EMPLOYEE SSN=ESSN EMP_WORK_10) RESULT p FNAME, LNAME (EMP_DEPT_5) Chapter 6 Tutorial 2

Exercise 1 - a Tuple relational calculus:
{e.FNAME, e.LNAME | EMPLOYEE(e) AND e.DNO=5 AND (p) (w) (PROJECT(p) AND WORKS_ON(w) AND p.PNAME=‘Product x’ AND w.HOURS>10 AND e.SSN=w.ESSN AND p.PNUMBER= w.PNO)} Domain relational calculus: {qs | (z) (a) (b) (e) (f) (g) (EMPLOYEE(qrstuvwxyz) AND PROJECT(abcd) AND WORKS_ON(efg) AND z=5 AND a=‘Product x’ AND g>10 AND t=e AND b=f)} Chapter 6 Tutorial 3

Exercise 1 - b List the names of all employees who have a dependent with the same first name as themselves. Relational Algebra: EMP (EMPLOYEE SSN=ESSN AND FNAME=DEPENDENT_NAME DEPENDENT) RESULT p FNAME, LNAME (EMP) Chapter 6 Tutorial 4

Exercise 1 - b Tuple relational calculus:
{e.FNAME, e.LNAME | EMPLOYEE(e) AND (d) (DEPENDENT(d) AND e.SSN=d.ESSN AND e.FNAME=d.DEPENDENT_NAME)} Domain relational calculus: {qs | (t) (a) (b) (EMPLOYEE(qrstuvwxyz) AND DEPENDENT(abcde) AND t=a AND q=b)} Chapter 6 Tutorial 5

Exercise 1 - c Find the names of all employees who are directly supervised by ‘Franklin Wong’. Relational Algebra: Domain relational calculus: Tuple relational calculus: Chapter 6 Tutorial 6

Exercise 1 - d For each project, list the project name and the total hours per week (by all employees) spent on that project. Relational Algebra: Chapter 6 Tutorial 8

Exercise 1 - e Retrieve the names of all employees who work on every project. Relational Algebra: Chapter 6 Tutorial 9

Exercise 1 - f Retrieve the names of all employees who do not work on any project. Relational Algebra: Domain relational calculus: Tuple relational calculus: Chapter 6 Tutorial 10

Exercise 1 - g For each department, retrieve the department name and the average salary of all employees working in that department. Relational Algebra: Chapter 6 Tutorial 12

Exercise 1 - h Retrieve the average salary of all female employees.
Relational Algebra: Chapter 6 Tutorial 13

Exercise 1 - i Find the names and addresses of all employees who work on at least one project located in Houston but whose department has no location in Houston. Relational Algebra: Domain relational calculus: Tuple relational calculus: Chapter 6 Tutorial 14

Exercise 1 - j List the last names of all department managers who have no dependents. Relational Algebra: Domain relational calculus: Tuple relational calculus: Chapter 6 Tutorial 16