IS NOT

Grammar Description

The IS NOT operator is used to test whether the value is a Boolean value. If it is not a Boolean value, the result is true. where boolean_value can be TRUE, FALSE or UNKNOWN.

Grammar Structure

> IS NOT boolean_value

Example

mysql> SELECT 1 IS NOT TRUE, 0 IS NOT FALSE, NULL IS NOT UNKNOWN;
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 1 is not true | 0 is not false | null is not unknown |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| false | false | false |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 row in set (0.01 sec)