SQL Anywhere 10.0.1
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Three-valued logic
The following tables display how the AND, OR, NOT, and IS logical operators of SQL work in three-valued logic.
AND operator
| AND | TRUE | FALSE | UNKNOWN |
| TRUE | TRUE | FALSE | UNKNOWN |
| FALSE | FALSE | FALSE | FALSE |
| UNKNOWN | UNKNOWN | FALSE | UNKNOWN |
OR operator
| OR | TRUE | FALSE | UNKNOWN |
| TRUE | TRUE | TRUE | TRUE |
| FALSE | TRUE | FALSE | UNKNOWN |
| UNKNOWN | TRUE | UNKNOWN | UNKNOWN |
NOT operator
| TRUE | FALSE | UNKNOWN |
| FALSE | TRUE | UNKNOWN |
IS operator
| IS | TRUE | FALSE | UNKNOWN |
| TRUE | TRUE | FALSE | FALSE |
| FALSE | FALSE | TRUE | FALSE |
| UNKNOWN | FALSE | FALSE | TRUE |
