IsNull

Description

Reports whether the value of a column or expression is null.

Syntax

IsNull ( any )

Argument

Description

any

A column or expression that you want to test to determine whether its value is null


Return value

Boolean. Returns true if any is null and false if it is not.

Usage

Use IsNull to test whether a user-entered value or a value retrieved from the database is null.

Examples

This expression returns true if either a or b is null:

IsNull(a + b)

This expression returns true if the value in the salary column is null:

IsNull(salary)

This expression returns true if the value the user has entered is null:

IsNull(GetText())

See also

Example 1: counting null values in a column

Example 4: displaying all data when a column allows nulls