ISNULL function

Syntax

ISNULL (variable)

Description

Use the ISNULL function to test whether a variable is the null value. If variable is the null value, 1 (true) is returned, otherwise 0 (false) is returned. This is the only way to test for the null value since the null value is not equal to any value, including itself.

Example

X = @NULL
Y = @NULL.STR
PRINT ISNULL(X), ISNULL(Y)

This is the program output:

1   0