Search conditions can be combined using AND, OR, and NOT.
Conditions are combined using AND as follows:
condition1 AND condition2
The combined condition is TRUE if both conditions are TRUE, FALSE if either condition is FALSE, and UNKNOWN otherwise.
Conditions are combined using OR as follows:
condition1 OR condition2
The combined condition is TRUE if either condition is TRUE, FALSE if both conditions are FALSE, and UNKNOWN otherwise.
The syntax for the NOT operator is as follows:
The NOT condition is TRUE if condition is FALSE, FALSE if condition is TRUE, and UNKNOWN if condition is UNKNOWN.
The IS operator provides a means to test a logical value. The syntax for the IS operator is as follows:
expression IS [ NOT ] truth-value
The condition is TRUE if the expression evaluates to the supplied truth-value, which must be one of TRUE, FALSE, UNKNOWN, or NULL. Otherwise, the value is FALSE.
For more information, see Three-valued logic.