| 8. 4. 1. Logical OR (OR( || )) |
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When both operands are non-NULL, the result is 1 if any operand is non-zero, and 0 otherwise. |
With a NULL operand, the result is 1 if the other operand is non-zero, and NULL otherwise. |
If both operands are NULL, the result is NULL. |
|
mysql>
mysql> SELECT 1 || 1;
+--------+
| 1 || 1 |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)
mysql> SELECT 1 || 0;
+--------+
| 1 || 0 |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)
mysql> SELECT 0 || 0;
+--------+
| 0 || 0 |
+--------+
| 0 |
+--------+
1 row in set (0.00 sec)
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