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CBSE CLASS XII

5. (a) What do you understand by the terms Candidate Key and Cardinality of a relation in relational database ?

(b) Consider the following tables WORKERS and DESIG. Write SQL commands for the
statements (i) to (iv) and give outputs for SQL queries (v) to (viii) : 6
WORKERS
W_ID FIRSTNAME LASTNAME ADDRESS CITY
102 Sam Tones 33 Elm St. Paris
105 Sarah Ackerman 440 U.S. 110 New York
144 Manila Sengupta 24 Friends Street New Delhi
210 George Smith 83 First Street Howard
255 Mary Jones 842 Vine Ave. Losantiville
300 Robert Samuel 9 Fifth Cross Washington
335 Henry Williams 12 Moore Street Boston
403 Ronny Lee 121 Harrison St. New York
451 Pat Thompson 11 Red Road Paris
DESIG
W_ID SALARY BENEFITS DESIGNATION
102 75000 15000 Manager
105 85000 25000 Director
144 70000 15000 Manager
210 75000 12500 Manager
255 50000 12000 Clerk
300 45000 10000 Clerk
335 40000 10000 Clerk
400 32000 7500 Salesman
451 28000 7500 Salesman
(i) To display W_ID, Firstname, Address and City of all employees living in New York from the table WORKERS.
(ii) To display the content of WORKERS table in ascending order of LASTNAME.
(iii) To display the Firstname, Lastname, and Total Salary of all Clerks from the tables WORKERS and DESIG, where Total Salary is calculated as Salary + Benefits.
(iv) To display the Minimum salary among Managers and Clerks from the table DESIG.
(v) SELECT FIRSTNAME, SALARY
FROM WORKERS, DESIG
WHERE DESIGNATION = ‘Manager’ AND
WORKERS.W_ID=DESIG.W_ID;
(vi) SELECT COUNT(DISTINCT DESIGNATION) FROM DESIG;
(vii) SELECT DESIGNATION, SUM(SALARY) FROM DESIG GROUP BY DESIGNATION HAVING COUNT(*)<3;
(viii) SELECT SUM(BENEFITS) FROM WORKERS WHERE DESIGNATION = ‘Salesman’;

6. (a) State and verify Absorption law in Boolean Algebra. 2

(b) Write the equivalent Boolean expression for the following Logic Circuit : 2

(c) Write the POS form of a Boolean Function F, which is represented by the following
truth table : 1
X Y Z F
0 0 0 1
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 1
1 1 0 0
1 1 1 0

(d) Reduce the following Boolean expression using K - Map :F (A, B, C, D) = Ó (0, 1, 2, 3, 4, 5, 10, 11, 15)

Paper By Mr. Ravi Kiran
Email Id : [email protected]