IS_NOT_NULL
Checks whether a value is not NULL.
Syntax
IS_NOT_NULL( <expr> )
Arguments
| Arguments | Description | 
|---|---|
| <expr> | Any general expression which will be evaluated as the value. | 
Return Type
If x is not NULL, is_not_null() returns 1, otherwise it returns 0.
Examples
CREATE TABLE nullable_test (a INT NULL, b INT UNSIGNED NULL);
INSERT INTO nullable_test VALUES(1, NULL), (NULL, 2), (3, 3);
SELECT a FROM nullable_test WHERE is_not_null(a);
+------+
| a    |
+------+
|    1 |
|    3 |
+------+