Suppose we have a relation instance R(A,B,C) as following:
RA B C
----------------------------------
1 2 3
4 5 6
7 8 9
Which is the result of the query:
SELECT SUM(B) FROM R WHERE C > 10
a. 0
b. NULL
c. 3
d. 10
Answer: B
Suppose we have a relation instance R(A,B,C) as following:
A B C
----------------------------------
1 2 3
4 5 6
7 8 9
Which is the result of the query:
SELECT SUM(B) FROM R WHERE C > 10
a. 0
b. NULL
c. 3
d. 10
Answer: B