SQL Questions and Answers – SQL Null Functions

This set of SQL Multiple Choice Questions & Answers (MCQs) focuses on “SQL Null Functions”.

1. IS NULL( ) function in SQL server is used to _______
a) Return NULL values
b) Replace NULL values
c) Check NULL values of a table
d) Insert NULL values into a table
View Answer

2. What is the syntax of ISNULL ( ) function used in SQL server?
a)

SELECT column_list, ISNULL (column_name, replace_value)
FROM TABLE_NAME;

b)

SELECT column_list
FROM TABLE_NAME
WHERE ISNULL (column_name, replace_value);

c)

SELECT column_list, ISNULL (replace_value)
FROM TABLE_NAME;

d)

SELECT column_list
FROM TABLE_NAME
WHERE ISNULL (replace_value);

SELECT column_list, ISNULL (column_name, replace_value)
FROM TABLE_NAME;

3. In MySQL ISNULL ( ) function is used to _____
a) Replace the NULL values
b) Insert NULL values into a table
c) Check NULL values in a table
d) Return NULL values
View Answer

4. What is the syntax of ISNULL ( ) function used in MySQL?
a)

SELECT column_list ISNULL(column_name)
FROM TABLE_NAME;

b)

SELECT column_list
FROM TABLE_NAME
ISNULL (column_name);

c)

SELECT column_list ISNULL
FROM TABLE_NAME;

d)

SELECT column_list
FROM TABLE_NAME
WHERE ISNULL (column_name);

SELECT column_list
FROM TABLE_NAME
WHERE ISNULL (column_name);

5. IFNULL ( ) function is available in which of the following environment?
a) MySQL, SQL Server
b) SQL server, Oracle
c) MySQL
d) SQL server
View Answer

6. If the first argument of IFNULL ( ) function is NULL, the function returns the second argument.
a) True
b) False
View Answer

7. What is the syntax of IFNULL ( ) function?
a)

SELECT column_list
FROM TABLE_NAME
WHERE IFNULL (column_name, value_to_replace);

b)

SELECT column_list, IFNULL(column_name, value_to_replace)
FROM TABLE_NAME;

c)

SELECT column_list IFNULL(value_to_replace)
FROM TABLE_NAME;

d)

SELECT column_list
FROM TABLE_NAME
WHERE IFNULL (value_to_replace);

SELECT column_list, IFNULL (column_name, value_to_replace)
FROM TABLE_NAME;

8. COALESCE ( ) function in SQL returns which of the following?
a) All non-NULL expressions among its arguments
b) All NULL expressions among its arguments
c) First NULL expression among its arguments
d) First non-NULL expression among its arguments
View Answer

9. If all the expressions of a COALESCE ( ) function are evaluated to be NULL, then it returns ______
a) Nothing
b) Error
c) Null
d) Some default value
View Answer

10. What is the syntax of COALESCE ( ) function?
a)

SELECT column_list, COALESCE(expressions_list)
FROM TABLE_NAME;

b)

SELECT column_list
FROM TABLE_NAME
WHERE COALESCE (expressions_list);

c)

SELECT column_list, COALESCE(expressions_list, replace_value)
FROM TABLE_NAME;

d)

SELECT column_list
FROM TABLE_NAME
WHERE COALESCE (expressions_list);

SELECT column_list, COALESCE (expressions_list)
FROM TABLE_NAME;

11. NULLIF ( ) function returns _______ if both the arguments of the function are equal.
a) Zero
b) False
c) Null
d) True
View Answer

12. How many arguments are there for NULLIF ( ) function?
a) Zero
b) One
c) Two
d) Any number
View Answer

13. What is the syntax of NULLIF ( ) function?
a)

SELECT column_list
FROM TABLE_NAME
WHERE NULLIF (exp1, exp2);

b)

SELECT column_list, NULLIF (exp1, exp2)
FROM TABLE_NAME;

c)

SELECT column_list, NULLIF (exp1, exp2,exp3)
FROM TABLE_NAME;

d)

SELECT column_list
FROM TABLE_NAME
WHERE NULLIF (exp1);

SELECT column_list, NULLIF (exp1, exp2)
FROM TABLE_NAME;

14. Expressions used in NULLIF ( ) function may or may not be of same data types.
a) True
b) False
View Answer

15. NVL ( ) function is similar to which of the following function(s)?
a) IFNULL ( ) in MySQL, ISNULL ( ) in SQL server
b) IFNULL ( ) in MySQL, COALESCE ( ) in SQL server
c) COALESCE ( ), ISNULL ( ) in SQL server
d) COALESCE ( ), NULLIF ( ) in SQL server
View Answer

Sanfoundry Global Education & Learning Series – SQL.

To practice all areas of SQL, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]