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Transformation Language Reference

10.5.1
- 10.5.6
- 10.5.4
- 10.5
- 10.4.0
- 10.2.2 Service Pack 1
- 10.2.2
- 10.2.1

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ISNULL

Returns whether a value is NULL. ISNULL evaluates an empty string as FALSE.

To test for empty strings, use LENGTH.

Syntax

ISNULL( value )

The following table describes the argument for this command:

Argument	Required/ Optional	Description
value	Required	Any datatype except Binary. Passes the rows you want to evaluate. You can enter any valid transformation expression.

Return Value

TRUE (1) if the value is NULL.

FALSE (0) if the value is not NULL.

Example

The following example checks for null values in the items table:

ISNULL( ITEM_NAME )

ITEM_NAME	RETURN VALUE
Flashlight	0 (FALSE)
NULL	1 (TRUE)
Regulator system	0 (FALSE)
''	0 (FALSE) Empty string is not NULL

ISNULL and Complex Data Types

You can use ISNULL to check whether an array or a struct has a null value.

The following expressions check for the null values in the following complex data types:

Complex Data Type	Input Value	RETURN VALUE
NULL_array = NULL	ISNULL(NULL_array)	1 (TRUE)
NULL_struct = NULL	ISNULL(NULL_struct)	1 (TRUE)
num_array = [1, 2, 3]	ISNULL(num_array)	0 (FALSE)
num_array = [1, NULL, 3]	ISNULL(num_array)	0 (FALSE)
num_struct{ number: int rank: int }	ISNULL(num_struct)	0 (FALSE)

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Table of Contents

Transformation Language Reference

Transformation Language Reference

ISNULL

ISNULL

Syntax

Return Value

Example

ISNULL and Complex Data Types