IFNULL Function [Miscellaneous]

Returns the first nonnull expression, or NULL.

If the first expression is the NULL value, then the value of the second expression is returned. If the first expression is not NULL, the value of the third expression is returned. If the first expression is not NULL and there is no third expression, then the NULL value is returned.

Syntax

IFNULL ( expression1, expression2 [ , expression3 ] )

Parameters

Parameters
Parameter	Description
expression1	The expression to be evaluated. Its value determines whether `expression2` or `expression3` is returned.
expression2	The return value if `expression1` is NULL
expression3	The return value if `expression1` is not NULL.

Returns

The data type returned depends on the data type of expression-2 and expression-3.

Examples

The following statement returns the value -66:

SELECT IFNULL( NULL, -66 ) FROM iq_dummy

The following statement returns NULL, because the first expression is not NULL and there is no third expression:

SELECT IFNULL( -66, -66 ) FROM iq_dummy

Standards and compatibility

SQL—Transact-SQL extension to ISO/ANSI SQL grammar.
Sybase—Not supported by Adaptive Server Enterprise.