The following tables display how the AND, OR, NOT, and IS logical operators of SQL work in three-valued logic.
AND | TRUE | FALSE | UNKNOWN |
---|---|---|---|
TRUE | TRUE | FALSE | UNKNOWN |
FALSE | FALSE | FALSE | FALSE |
UNKNOWN | UNKNOWN | FALSE | UNKNOWN |
OR | TRUE | FALSE | UNKNOWN |
---|---|---|---|
TRUE | TRUE | TRUE | TRUE |
FALSE | TRUE | FALSE | UNKNOWN |
UNKNOWN | TRUE | UNKNOWN | UNKNOWN |
TRUE | FALSE | UNKNOWN |
---|---|---|
FALSE | TRUE | UNKNOWN |
IS | TRUE | FALSE | UNKNOWN |
---|---|---|---|
TRUE | TRUE | FALSE | FALSE |
FALSE | FALSE | TRUE | FALSE |
UNKNOWN | FALSE | FALSE | TRUE |
SQL/2008 Core feature. Truth value tests, such as IS UNKNOWN, comprise SQL language feature F571.
Discuss this page in DocCommentXchange.
|
Copyright © 2012, iAnywhere Solutions, Inc. - SQL Anywhere 12.0.1 |