IS_NULL

Checks whether a value is NULL.

Syntax

IS_NULL( <expr> )

Arguments

Arguments	Description
<expr>	Any general expression which will be evaluated as the value.

Return Type

If x is NULL, IS_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_null(b);
+------+
| a    |
+------+
|    1 |
+------+