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is-null-transact-sql.md

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title IS NULL (Transact-SQL)
description Determines whether a specified expression is null.
author VanMSFT
ms.author vanto
ms.reviewer randolphwest
ms.date 06/16/2025
ms.service sql
ms.subservice t-sql
ms.topic reference
ms.custom
ignite-2025
f1_keywords
NULL_TSQL
IS_[NOT]_NULL_TSQL
IS_NULL_TSQL
NULL
[NOT]_TSQL
IS
IS_TSQL
IS NULL
IS [NOT] NULL
[NOT]
helpviewer_keywords
verifying nullability
IS NOT NULL clause
null values [SQL Server], verifying
null values [SQL Server], IS [NOT] NULL
IS [NOT] NULL clause
testing nullability
checking nullability
dev_langs
TSQL
monikerRange >=aps-pdw-2016 || =azuresqldb-current || =azure-sqldw-latest || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current || =fabric || =fabric-sqldb

IS NULL (Transact-SQL)

[!INCLUDE sql-asdb-asdbmi-asa-pdw-fabricse-FabricDW-FabricSQLDB]

Determines whether a specified expression is NULL.

:::image type="icon" source="../../includes/media/topic-link-icon.svg" border="false"::: Transact-SQL syntax conventions

Syntax

expression IS [ NOT ] NULL

Arguments

expression

Any valid expression.

  • NOT

    Specifies that the Boolean result is negated. The predicate reverses its return values, returning TRUE if the value isn't NULL, and FALSE if the value is NULL.

Return types

Boolean

Return code values

If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE.

If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE.

Remarks

To determine whether an expression is NULL, use IS NULL or IS NOT NULL instead of comparison operators (such as = or !=). Comparison operators return UNKNOWN when either or both arguments are NULL.

Examples

[!INCLUDE article-uses-adventureworks]

A. Return the name and weight for all products

The following example returns the name and the weight for all products for which either the weight is less than 10 pounds, or the color is unknown, or NULL.

SELECT Name,
       Weight,
       Color
FROM Production.Product
WHERE Weight < 10.00
      OR Color IS NULL
ORDER BY Name;
GO

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

B. Return the full names of all employees with initials

The following example returns the full names of all employees with middle initials.

SELECT FirstName,
       LastName,
       MiddleName
FROM DIMEmployee
WHERE MiddleName IS NOT NULL
ORDER BY LastName DESC;

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