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IS [NOT] NULL (Transact-SQL)

Determines whether a specified expression is NULL.

Topic link iconTransact-SQL Syntax Conventions

Syntax

expression IS [ NOT ] NULL

Arguments

  • NOT
    Specifies that the Boolean result be negated. The predicate reverses its return values, returning TRUE if the value is not NULL, and FALSE if the value is NULL.

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.

Result Types

Boolean

Examples

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.

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

See Also

Reference

CASE (Transact-SQL)
CREATE PROCEDURE (Transact-SQL)
CREATE TABLE (Transact-SQL)
Data Types (Transact-SQL)
Expressions (Transact-SQL)
INSERT (Transact-SQL)
LIKE (Transact-SQL)
Operators (Transact-SQL)
Logical Operators (Transact-SQL)
SELECT (Transact-SQL)
sp_help (Transact-SQL)
UPDATE (Transact-SQL)
WHERE (Transact-SQL)

Other Resources

Null Values

Help and Information

Getting SQL Server 2005 Assistance