Returns the first non-NULL expression from a list. This function is identical to the COALESCE function.

Syntax

ISNULL( expression, expression [, ...] )

Parameters

Returns

The return type for this function depends on the expressions specified. That is, when the database server evaluates the function, it first searches for a data type in which all the expressions can be compared. When found, the database server compares the expressions and then returns the result in the type used for the comparison. If the database server cannot find a common comparison type, an error is returned.

See also

• COALESCE function [Miscellaneous]

Standards and compatibility

Example

The following statement returns the value -66.

SELECT ISNULL( NULL ,-66, 55, 45, NULL, 16 );