Reference value check operator

REFS operator allows you to check if the right-side expression value references the left-side table. If this is true, the operator returns TRUE, else — FALSE. For details of table dereferencing see Field Dereferencing.

See also: Logical Expressions

Example:

SELECT
Catalog.Nomenclature.Description,
   Catalog.Nomenclature.UnitOfMeasurements
WHERE
   Catalog.Nomenclature.UnitOfMeasure REFS Catalog.UnitsOfMeasure