Mega Code Archive
Logical XOR (XOR)
'a XOR b' is mathematically equal to (a AND (NOT b)) OR ((NOT a) and b).
Returns NULL if either operand is NULL.
For non-NULL operands, evaluates to 1 if an odd number of operands is non-zero, otherwise 0 is returned.
mysql>
mysql> SELECT 1 XOR 1;
+---------+
| 1 XOR 1 |
+---------+
| 0 |
+---------+
1 row in set (0.00 sec)
mysql> SELECT 1 XOR 0;
+---------+
| 1 XOR 0 |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)
mysql> SELECT 0 XOR 0;
+---------+
| 0 XOR 0 |
+---------+
| 0 |
+---------+
1 row in set (0.00 sec)
mysql> SELECT 1 XOR 1 XOR 1;
+---------------+
| 1 XOR 1 XOR 1 |
+---------------+
| 1 |
+---------------+
1 row in set (0.00 sec)