how to use IS NULL in oracle plsql

In Oracle SQL / PLSQL IS NULL is used to check whether the value of a literal is NULL or not.

Example 1:
Syntax to use IS NULL in IF statement is:
IF literal_name IS NULL THEN
<business_logic>
END IF;

Here if the literal_name has NULL value then the IF condition will evaluate to TRUE, then the “THEN” section of the code will get executed.

Example 2:

Using IS NULL is Oracle SQL / PLSQL SELECT statement:

Suppose we have a table named ‘employee’ as shown below:

Employee_ID	Employee_Name	Salary	Department	Commission
101	Emp A	10000	Sales
102	Emp B	20000	IT	20
103	Emp C	28000	IT	20
104	Emp D	30000	Support	5
105	Emp E	32000	Sales	10
106	Emp F	20000	Sales	5
107	Emp G	12000	Sales
108	Emp H	12000	Support

Suppose we want to see the records having commission as NULL, then we can achieve the same as:

SELECT *
FROM employee
WHERE commission IS NULL;

We will get the following results:

Employee_ID	Employee_Name	Salary	Department	Commission
101	Emp A	10000	Sales
107	Emp G	12000	Sales
108	Emp H	12000	Support

Here we can see that we have successfully retrieved records having NULL commission using IS NULL in Oracle SQL PLSQL SELECT statement.