NULL Predicate

The NULL Predicate determines if a column in a selected row is defined or not.

Note: It is illegal to say Column_Reference = NULL.

Syntax

Column_Reference IS [ NOT ] NULL

Element

Column_Reference

Specifies the column name (alias).

Example

The following example retrieves rows consisting of the FileName and DocAuthor for all files under the virtual root /contracts where DocAuthor is defined.

SELECT FileName, DocAuthor FROM SCOPE('"/contracts"') WHERE DocAuthor IS NOT NULL