Database-Management-System

Question 23

A table T1 in a relational database has the following rows and columns:

 roll no.	 marks
    1	          10
    2	          20
    3	          30
    4	         Null

The following sequence of SQL statements was successfully executed on table T1.

Update T1 set marks = marks + 5
Select avg(marks) from T1

What is the output of the select statement?

Question 23 Explanation:

Update on null values gives null. Now, avg function ignores null values. So, here avg will be
(15+25+35)/3 = 25

Correct Answer: C

Question 23 Explanation:

Update on null values gives null. Now, avg function ignores null values. So, here avg will be
(15+25+35)/3 = 25