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

Syntax

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

Parameters

Remarks

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 of the expressions can be compared. When found, the database server compares the expressions and then returns the result (the first non-NULL expression) 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 );