SELECT ISNULL(1/0); : IS NULL ISNULL « Comparison Functions Operators « MySQL Tutorial






  1. MySQL Tutorial
  2. Comparison Functions Operators
  3. IS NULL ISNULL
mysql>
mysql> SELECT ISNULL(1/0);
+-------------+
| ISNULL(1/0) |
+-------------+
|           1 |
+-------------+
1 row in set (0.00 sec)

mysql>
mysql>
ISNULL() can be used instead of = to test whether a value is NULL.
Comparing a value to NULL using = always yields false.
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