Mysql IS NOT
From w3cyberlearnings
Contents |
MySQL IS NOT Function
This function tests an expr against a boolean value, where boolean_value can be TRUE, FALSE, or UNKNOWN.
Syntax IS NOT
expr to be tested against a boolean value.
expr IS NOT boolean_value
Example 1
mysql> SELECT 2 IS NOT UNKNOWN; +------------------+ | 2 IS NOT UNKNOWN | +------------------+ | 1 | +------------------+ 1 row in set (0.00 sec) mysql> SELECT 3 IS NOT FALSE; +----------------+ | 3 IS NOT FALSE | +----------------+ | 1 | +----------------+ 1 row in set (0.00 sec) mysql> SELECT 3 IS NOT TRUE; +---------------+ | 3 IS NOT TRUE | +---------------+ | 0 | +---------------+ 1 row in set (0.00 sec)
Example 2
mysql> SELECT * FROM myclient; +----+-------+------+---------------------------+ | id | name | age | email | +----+-------+------+---------------------------+ | 1 | Bob | 53 | [email protected] | | 2 | John | 53 | [email protected] | | 3 | Mark | NULL | [email protected] | | 4 | Janny | 40 | [email protected] | | 5 | Johma | 29 | NULL | +----+-------+------+---------------------------+ 5 rows in set (0.00 sec) mysql> SELECT * FROM myclient -> WHERE age IS NOT UNKNOWN; +----+-------+------+-------------------+ | id | name | age | email | +----+-------+------+-------------------+ | 1 | Bob | 53 | [email protected] | | 2 | John | 53 | [email protected] | | 4 | Janny | 40 | [email protected] | | 5 | Johma | 29 | NULL | +----+-------+------+-------------------+ 4 rows in set (0.00 sec)
