IS NOT NULL in Oracle SQL PLSQL

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

Example 1:
Syntax to use IS NOT NULL in IF statement is:

IF literal_name IS NOT NULL THEN
<business_logic>
END IF;

Here if the literal_name does not have NULL value then the IF condition will evaluate to TRUE, then the “THEN” section of the code will get executed.

Example 2:

Using IS NOT 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 NOT NULL, then we can achieve the same as:

SELECT *
FROM employee
WHERE commission IS NOT NULL;

We will get the following results:

Employee_ID	Employee_Name	Salary	Department	Commission
102	Emp B	IT	20000	20
103	Emp C	IT	28000	20
104	Emp D	Support	30000	5
105	Emp E	Sales	32000	10
106	Emp F	Sales	20000	5

Here we can see that we have successfully retrieved records having NOT NULL commission using IS NOT NULL in Oracle SQL PLSQL SELECT statement.