This is a read-only copy of the MariaDB Knowledgebase generated on 2024-11-14. For the latest, interactive version please visit https://mariadb.com/kb/.

IS

Syntax

IS boolean_value

Description

Tests a value against a boolean value, where boolean_value can be TRUE, FALSE, or UNKNOWN.

There is an important difference between using IS TRUE or comparing a value with TRUE using =. When using =, only 1 equals to TRUE. But when using IS TRUE, all values which are logically true (like a number > 1) return TRUE.

Examples

SELECT 1 IS TRUE, 0 IS FALSE, NULL IS UNKNOWN;
+-----------+------------+-----------------+
| 1 IS TRUE | 0 IS FALSE | NULL IS UNKNOWN |
+-----------+------------+-----------------+
|         1 |          1 |               1 |
+-----------+------------+-----------------+

Difference between = and IS TRUE:

SELECT 2 = TRUE, 2 IS TRUE;
+----------+-----------+
| 2 = TRUE | 2 IS TRUE |
+----------+-----------+
|        0 |         1 |
+----------+-----------+

See Also

Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.