ISNULL Function

Description

The ISNULL function performs a comparison to determine if the result of the expression specified as an argument is NULL. The function returns 1 if it is NULL or 0 otherwise. You can check if a certain value is NULL. This function is working like the ISNULL expression.

Syntax

ISNULL(expression)

• expression: An arithmetic function that has a single-value column, path expression (ex.: tbl_name.col_name), constant value is specified.

Example

--Using ISNULL function to select rows with NULL value

SELECT * FROM condition_tbl WHERE ISNULL(salary);

           id  name                  dept_name                  salary

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            7  'Brown     '          'account'                    NULL