Boolean Predicate (bool_predicate)

Use

Boolean values ( BOOLEAN) are compared in a Boolean predicate ( bool_predicate).

Structure

				
<bool_predicate>::=
  <column_spec> [IS [NOT] TRUE | IS [NOT] FALSE]

Explanation

If only one column specification ( column_spec) is specified, the syntax is identical to <column_spec> IS TRUE. The column specification must always denote a column with the data type BOOLEAN.

The following rules apply to the result of a Boolean predicate:

Column Value	IS TRUE	IS NOT TRUE	IS FALSE	IS NOT FALSE
False	False	True	True	False
Undefined	Undefined	Undefined	Undefined	Undefined
True	True	False	False	True