Download Retrieve the names of employees who work on every project

Exercise 2
Relational Calculus
Database System-dww
6 Relations of Company
Database System-dww
Find the first and last names of all employees whose salary is
above $50,000
Rel Algebra 
FNAME,LNAME(SALARY>‘50000’ (EMPLOYEES))
Tuple Rel Calculus 
{t.FNAME,t.LNAME|EMPLOYEE(x) AND t.SALARY>‘50000’))
Domain Rel Calculus 
{ac|(Ǝi) EMPLOYEE(abcdefghijkl) AND i>‘50000’))
SQL 
select FNAME, LNAME
from EMPLOYEES
where SALARY>‘50000’
Database System-dww
Exercises
(a) Retrieve the names of employees in
department 5 who work more than 10 hours
per week on the 'ProductX' project.
(b) List the names of employees who have a
dependent with the same first name as
themselves.
(c) Find the names of employees that are
directly supervised by 'Franklin Wong'.
(e) Retrieve the names of employees who
work on every project.
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Exercises
(f) Retrieve the names of employees who do
not work on any project.
(i) Find the names and addresses of
employees who work on at least one project
located in Houston but whose department
has no location in Houston.
(j)List the last names of department managers
who have no dependents.
Database System-dww
Retrieve the names of employees in department 5 who work more than
10 hours per week on the 'ProductX' project
Graphical approach can be used to help the logical and prosedural
approach
Example of above query, the graphical approach: clue from query the
relations that (may) work on the query are in the red text
P
Pnumber=Pno
Pname=‘ProductX’
ProductX
W
ESSN=SSN
Hours > 10
Fname, Lname (?)
Dno = 5
> 10
WORKS_ON_ProductX (Rel.A)
(PNAME=‘ProductX’(PROJECT)
E
5
PNUMBER=PNO(WORKS_ON))
EMPLOYEE_DEPT5_WORKS_MORE_10_onProductX (Rel.B)
((EMPLOYEE) SSN=ESSN( HOURS>10(Rel.A)))
RESULT  FNAME,LNAME(DNO=‘5’ (Rel.B))
Database System-dww
Retrieve the names of employees in department 5 who work more than
10 hours per week on the 'ProductX' project
P
Pnumber=Pno
Pname=‘ProductX’
ProductX
W
ESSN=SSN
Hours > 10
> 10
E
Fname, Lname (?)
Dno = 5
5
{ e.LNAME, e.FNAME | EMPLOYEE(e) AND e.DNO=5 AND (Ǝp)(Ǝw)
(WORKS_ON(w) AND PROJECT(p) AND e.SSN=w.ESSN AND
w.PNO=p.PNUMBER AND p.PNAME='ProductX' AND w.HOURS>10 ) }
{ qs | EMPLOYEE(qrstuvwxyz) AND z=5 AND (Ǝa) (Ǝb) (Ǝe)
(Ǝf) (Ǝg) ( WORKS_ON(efg) AND PROJECT(abcd)
AND t=e AND f=b AND a='ProductX' AND g>10 ) }
Database System-dww
List the names of employees who have a
dependent with the same first name as
themselves.
Dp
Depend_name=Fname
ESSN=SSN
E
Fname, Lname (?)
RESULT  FNAME,LNAME(DEPENDENT
(ESSN,DEPEND_NAME)=(SSN,FNAME)(EMPLOYEE))
{ e.LNAME, e.FNAME | EMPLOYEE(e) AND (Ǝd) ( DEPENDENT(d)
AND e.SSN=d.ESSN AND e.FNAME=d.DEPENDENT_NAME ) }
{ qs | (Ǝt) (Ǝa) (Ǝb) ( EMPLOYEE(qrstuvwxyz) AND
DEPENDENT(abcde) AND a=t AND b=q ) }
Database System-dww
Find the names of employees that are
directly supervised by 'Franklin Wong'.
E_SSN_FRANKLIN_WONG(Rel.A)
( SSN( FNAME=‘FRANKLIN’ LNAME=‘WONG’(EMPLOYEE)))
E_SUPERVISED_BY_FRANKLIN_WONG (Result)
( FNAME, LNAMES(EMPLOYEE) SUPERSSN=SSN(Rel.A))
{ e.LNAME, e.FNAME | EMPLOYEE(e) AND (Ǝs) ( EMPLOYEE(s) AND
s.FNAME='Franklin' AND s.LNAME='Wong' AND e.SUPERSSN=s.SSN ) }
{ qs | (Ǝy) (Ǝa) (Ǝc) (Ǝd) ( EMPLOYEE(qrstuvwxyz)
AND EMPLOYEE(abcdefghij) AND a='Franklin' AND c='Wong' AND y=d ) }
Database System-dww
Retrieve the names of employees who
work on every project
ALL_EMPLOYEE(SSN, PNO)(Rel.A) ( SSN, PNO(WORKS_ON))
ALL_PROJECT(PNO)(Rel.B) ( PNO(PROJECT))
E_ALL_PROJECT ( Rel.A÷Rel.B)
RESULT ( FNAME, LNAME (E_ALL_PROJECT * EMPLOYEE))
{ e.LNAME, e.FNAME | EMPLOYEE(e) AND (Ѵp) ( NOT(PROJECT(p))
OR (Ǝw) (WORKS_ON(w) AND p.PNUMBER=w.PNO AND w.ESSN=e.SSN ) ) }
{ qs | (Ǝt) ( EMPLOYEE(qrstuvwxyz) AND (Ѵb) (
NOT(PROJECT(abcd)) OR (Ǝe) (Ǝf) (WORKS_ON(efg) AND e=t AND f=b) ) }
Database System-dww
Retrieve the names of employees who
do not work on any project
ALL_EMPLOYEE(SSN)(Rel.A) ( SSN(EMPLOYEE))
ALL_EMPLOYEE_WORKING(SSN)(Rel.B) ( ESSN(WORKS_ON))
E_NOT_WORKING ( Rel.A - Rel.B)
RESULT ( FNAME, LNAME (
(EMPLOYEE) SSN=ESSN(E_NOT_WORKING))
{ e.LNAME, e.FNAME | EMPLOYEE(e) AND NOT(Ǝw) ( WORKS_ON(w)
AND w.ESSN=e.SSN ) }
{ qs | (Ǝt) ( EMPLOYEE(qrstuvwxyz) AND NOT(Ǝa)
(WORKS_ON(abc) AND a=t ))}
Database System-dww
Find the names and addresses of employees who work on at least one
project located in Houston but whose department has no location in
Houston
{ e.LNAME, e.FNAME, e.ADDRESS | EMPLOYEE(e) AND (Ǝp) (Ǝw)
(WORKS_ON(w) AND PROJECT(p) AND e.SSN=w.ESSN AND
w.PNO=p.PNUMBER AND p.PLOCATION='Houston'
AND NOT(Ǝl) ( DEPT_LOCATIONS(l) AND
e.DNO=l.DNUMBER AND l.DLOCATION='Houston' ) ) }
{ qsv | (Ǝt) (Ǝz) ( EMPLOYEE(qrstuvwxyz) AND (Ǝb)
(Ǝc) (Ǝe) (Ǝf) ( WORKS_ON(efg)
AND PROJECT(abcd) AND t=e AND f=b AND c='Houston' AND
NOT(Ǝh) NOT(Ǝi) ( DEPT_LOCATIONS(hi)
AND z=h AND i='Houston’ ) ) }
Database System-dww
List the last names of department
managers who have no dependents
D_MNG_SSN(Rel.A)( SSN(DEPARTMENT)
E_WITH_DEPENDENT(Rel.A)( SSN(DPENDENT)
MNGR_NO_DEPENDENT(Rel.A – Rel.B)
RESULT( LNAME(EMPLOYEE * MNGR_NO_DEPENDENT))
{ e.LNAME | EMPLOYEE(e) AND (Ǝd) ( DEPARTMENT(d) AND
e.SSN=d.MGRSSN AND
NOT(Ǝx) (DEPENDENT(x) AND e.SSN=x.ESSN) ) }
{ s | (Ǝt) ( EMPLOYEE(qrstuvwxyz) AND (Ǝc) ( DEPARTMENT(abcd)
AND t=c AND NOT(Ǝe) (DEPENDENT(efghi) AND e=t) ) }
Database System-dww