SQL Server ISNULL() Function Example

Important Points About SQL Server ISNULL Function

Let’s look at some examples of the ISNULL function in SQL Server. Learning the ISNULL function with examples will help in understanding the concept better.

Example 1

Using the ISNULL() function and getting the output.

SELECT ISNULL('gfg', 'Geeks');

Output :

gfg

Here, the expression is returned as the given value is not NULL.

Example 2

Using ISNULL() function and getting the output.

SELECT ISNULL(NULL, 'Geeks');

Output :

Geeks

Here, the expression is NULL so, the specified value is returned as output.

Example 3

Using ISNULL() function and getting the output using a variable.

DECLARE @exp VARCHAR(50);
SET @exp = 'w3wiki';
SELECT ISNULL(@exp, 150);

Output :

w3wiki

Example 4

Using ISNULL() function and getting the output using variables.

DECLARE @exp VARCHAR(50);
DECLARE @val VARCHAR(50);
SET @exp = NULL;
SET @val = 'GFG';
SELECT ISNULL(@exp, @val);

Output :

GFG