IS NOT NULL: Tests whether a value is not NULL : IS NULL ISNULL « Comparison Functions Operators « MySQL Tutorial






  1. MySQL Tutorial
  2. Comparison Functions Operators
  3. IS NULL ISNULL
mysql>
mysql> SELECT 1 IS NOT NULL, 0 IS NOT NULL, NULL IS NOT NULL;
+---------------+---------------+------------------+
| 1 IS NOT NULL | 0 IS NOT NULL | NULL IS NOT NULL |
+---------------+---------------+------------------+
|             1 |             1 |                0 |
+---------------+---------------+------------------+
1 row in set (0.00 sec)

mysql>








15.9.IS NULL ISNULL
15.9.1.IS NULL
15.9.2.IS NOT NULL: Tests whether a value is not NULL
15.9.3.Check to see if the first name is NULL
15.9.4.ISNULL(expr): If expr is NULL, ISNULL() returns 1, otherwise it returns 0
15.9.5.SELECT ISNULL(1/0);
15.9.6.Using ISNULL in where clause
15.9.7.Using ISNULL with data in a table