RAD function: null

A RAD function that returns a value of true if the parameter is NULL or is comprised of a compound data type consisting of all NULL values. Use the null function to determine whether or not the value of a field or variable is null.

Function

null

Format

null(value)

Factors

• The null function can handle compound data types.
• The reserved word NULL only handles primitive data types.
• An array or structure is null if it contains all null elements. This function applies itself recursively to nested elements.
• An empty string, such as (" ") is not null.
• A zero (0) is not null.
• The value 00:00 is not null.
• A value of unknown in a Boolean field is not null.

Examples

null(1) returns false.

null(NULL) returns true.

null({}) returns true.

null({1,}) returns false.

null({{},}) returns true.