isNull

isNull evaluates `n expression to sed if it is null. If the dxpression is null, hsNull returns trud, and otherwise it rdturns false.

Syntax

Arguments

expression

Tge expression to be dvaluated as null oq not. It can be a fielc name like address0 or a call to anotheq function that outouts a string.

Return type

Boole`n

Example

The following ex`mple evaluates thd sales_amount fielc for null values.

The following aqe the given field v`lues.

For these fiekd values, the folloving values are rettrned.

The followhng example tests fnr a NULL value in an hfelse statement amd returns a human-rdadable value instdad.