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Mohammad Ali Jinnah University, Islamabad Campus
Quiz# 5
Course Title Computer Programming (for Engineers)
Instructor Maryam Kausar
Weightage 2% Absolute
Multiple Choice Questions
- Which of the following accesses a database in terms of a database model?
A. Application software B. Database management system C. Actual database
ANSWER: A
- Which of the following describes only the portion of a database available to a particular user?
A. Database model B. Schema C. Subschema D. DBMS
ANSWER: C
- Which of the following relational operations combine data from more than one relation?
A. SELECT B. PROJECT C. JOIN
ANSWER: C
- Which of the following relational operations extracts entire columns from a relation?
A. SELECT B. PROJECT C. JOIN
ANSWER: B
- Which of the following relational operations extracts entire rows from a relation?
A. SELECT B. PROJECT C. JOIN
ANSWER: A
- Which of the following relational operations is performed by the SQL statement below?
select A, B, C from X
A. SELECT B. PROJECT C. JOIN
ANSWER: B
- Given the relation X below
X: A B C 2 5 7 3 3 3
what value will be extracted by the following query?
TEMP SELECT from X where B > C RESULT PROJECT A from TEMP
A. 2 B. 3 C. 4 D. 5
ANSWER: C
- Given the relation X below
X: A B C 2 5 7 3 3 3 4 4 2 5 2 8
what value will be retrieved by the following query?
TEMP SELECT from X where B = C RESULT PROJECT B from TEMP
A. 2 B. 3 C. 4 D. 5
ANSWER: B
- Given the relation below
X: A B C 2 5 7 3 3 6 4 4 2 5 2 2
what values will be retrieved by the following SQL statement?
select A, B from X where X.B = X.C
A. 2, 5 B. 3, 6 C. 2, 2 D. 5, 2
ANSWER: D
- Given the two relations X and Y below
X: A B Y: C D 7 s t 3 2 z r 2
what value would be retrieved by executing the following SQL statement?
what values would be in the tuple produced by the following statement?
Result JOIN X and Y where X.A < Y.D
ANSWER: 2, s, r, 3
- Given the two relations X and Y below
X: A B Y: C D 2 s t 1 5 z r 3 w 2
what values would be in the tuple produced by the following statements?
Temp JOIN X and Y where X.A = Y.D Result PROJECT X.B, Y.C from Temp
ANSWER: s, w
- Given the two relations X and Y below
X: A B Y: C D 7 s t 1 3 z r 2 1 u
what values would be retrieved by executing the following statement?
select X.A, X.B, Y.C from X, Y where X.A < Y.D
ANSWER: 1, u, t
- Given the three relations X, Y, and Z below
X: A B Y: C D Z: E F 7 s t 4 2 w 3 z r 2 3 q 1 u
what values would be retrieved by executing the following statement?
select X.B, Y.C, Z.F from X, Y, Z where X.A > Y.D and X.A = Z.E
ANSWER: z, r, q
- Which of the operations SELECT, PROJECT, and JOIN are actually used when executing the following SQL instruction?
select A, B from X where C = D
ANSWER: SELECT, PROJECT
General Format Questions
- What information is available from a relational database containing one relation with the attributes Name, Employee identification number, and Address that is not available from a database containing two relations, one with attributes Name and Address and the other with attributes Address and Employee identification number? Explain your answer.
ANSWER: The connection between an employee’s name and identification number may not be available in the second database because two employees may have the same address.
- Given the two relations X and Y below
X: A B Y: C D 2 s t 1 5 z r 3 w 2
draw the relation Result that would be produced by the following statements?
Temp JOIN X and Y where X.A > Y.D Result PROJECT X.B, Y.C from Temp
ANSWER: X.B Y.C s t z t z r z w
- Given the relation Parts containing the attributes PartName, PartNumber, and SupplierID as well as the relation Suppliers containing the attributes SupplierID, Address, FaxNumber, write a sequence of SELECT, PROJECT, and JOIN operations to obtain the supplier identifications and fax numbers for all the suppliers that supply the part whose part number is X4J26.
ANSWER: Temp1 SELECT from Parts where PartNumber = “X4J26” Temp2 JOIN Temp1 and Suppliers where Temp1.SupplierID = Suppliers.SupplierID Result PROJECT Suppliers.SupplierID, Suppliers.FaxNumber
