Consider a relational database containing the following schemas.
The primary key of each table is indicated by underlying the constituent fields.
SELECT s.sno, s.sname
FROM Suppliers s, Catalogue c
WHERE s.sno = c.sno AND
Cost > (SELECT AVG (cost)
FROM Catalogue
WHERE pno = ‘P4’
GROUP BY pno);
The number of rows returned by the above SQL query is
A
4
B
5
C
2
D
0
2
GATE CSE 2018
MCQ (Single Correct Answer)
+1
-0.3
Consider the following two tables and four queries in SQL.
Book (isbn, bname), Stock (isbn, copies)
Query 1:
SELECT B.isbn, S.copies
FROM Book B INNER JOIN Stock S
ON B.isbn = S.isbn;
Query 2:
SELECT B.isbn, S.copies
FROM Book B LEFT OUTER JOIN Stock S
ON B.isbn = S.isbn;
Query 3:
SELECT B.isbn, S.copies
FROM Book B RIGHT OUTER JOIN Stock S
ON B.isbn = S.isbn;
Query 4:
SELECT B.isbn, S.copies
FROM Book B FULL OUTER JOIN Stock S
ON B.isbn = S.isbn;
Which one of the queries above is certain to have an output that is a superset of the outputs
of the other three queries?
A
Query 1
B
Query 2
C
Query 3
D
Query 4
3
GATE CSE 2015 Set 1
MCQ (Single Correct Answer)
+1
-0.3
SELECT operation in SQL is equivalent to
A
the selection operation in relational algebra
B
the selection operation in relational algebra, except that SELECT in SQL retains duplicates
C
the projection operation in relational algebra
D
the projection operation in relational algebra, except that SELECT in SQL retains duplicates
4
GATE CSE 2015 Set 3
MCQ (Single Correct Answer)
+1
-0.3
Consider the following relation
$$\,\,\,\,\,\,\,\,$$ Cinema(theater, address, capacity)
Which of the following options will be needed at the end of the $$SQL$$ query
$$\,\,\,\,\,\,\,\,$$ SELECT $$P1.$$address
$$\,\,\,\,\,\,\,\,$$ FROM Cinema $$P1$$
such that it always finds the addresses of theaters with maximum capacity?
A
WHERE $$P1$$.capacity >= All (select $$P2$$.capacity from Cinema $$P2$$)
B
WHERE $$P1$$.capacity >= Any (select $$P2$$.capacity from Cinema $$P2$$)
C
WHERE $$P1$$.capacity > All (select max($$P2$$.capacity) from Cinema $$P2$$)
D
WHERE $$P1$$.capacity > Any (select max($$P2$$.capacity) from Cinema $$P2$$)