Boolean Predicate (bool_predicate) 

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

Syntax

<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