NULL Predicate

The NULL predicate indicates whether the document has a value for the indicated column. The NULL predicate syntax follows:

…WHERE <column> IS [NOT] NULL

The optional NOT keyword negates the result. The column can be a regular or delimited identifier.

Important To test whether a column has the NULL value, you must use the NULL predicate. It is not legal to use the NULL value in a comparison predicate. "WHERE column IS NULL" is the proper method. "WHERE column = NULL" is not allowed.

Example

The following example returns documents that have no related documents.

…WHERE "urn:schemas-microsoft-com:publishing:RelatedDocument" IS NULL

Full-Text Predicates

LIKE Predicate

Literal Value Comparison

MATCHES Predicate

Multi-valued (ARRAY) Comparisons