MySQL Tutorial/Logic Operator/NOT

NOT: !

Logical NOT.

Return 1 if the operand is 0.

Return 0 if the operand is non-zero.

mysql>
mysql> SELECT NOT 10;
+--------+
| NOT 10 |
+--------+
|      0 |
+--------+
1 row in set (0.00 sec)
mysql> SELECT NOT 0;
+-------+
| NOT 0 |
+-------+
|     1 |
+-------+
1 row in set (0.00 sec)

SELECT NOT;

mysql>
mysql> SELECT NOT (1 - 1);
+-------------+
| NOT (1 - 1) |
+-------------+
|           1 |
+-------------+
1 row in set (0.00 sec)
mysql>

Using NOT with integer value

mysql>
mysql> SELECT ! (1+1);
+---------+
| ! (1+1) |
+---------+
|       0 |
+---------+
1 row in set (0.00 sec)
mysql> SELECT ! 1+1;
+-------+
| ! 1+1 |
+-------+
|     1 |
+-------+
1 row in set (0.00 sec)

Using NOT with NULL value

mysql>
mysql>
mysql> SELECT NOT NULL;
+----------+
| NOT NULL |
+----------+
|     NULL |
+----------+
1 row in set (0.00 sec)