OR, ||
Logical OR
. 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
.
For this operator, short-circuit evaluation can be used.
In Oracle mode, ||
ignores null.
SELECT 1 || 1;
+--------+
| 1 || 1 |
+--------+
| 1 |
+--------+
SELECT 1 || 0;
+--------+
| 1 || 0 |
+--------+
| 1 |
+--------+
SELECT 0 || 0;
+--------+
| 0 || 0 |
+--------+
| 0 |
+--------+
SELECT 0 || NULL;
+-----------+
| 0 || NULL |
+-----------+
| NULL |
+-----------+
SELECT 1 || NULL;
+-----------+
| 1 || NULL |
+-----------+
| 1 |
+-----------+
In Oracle mode:
SELECT 0 || NULL;
+-----------+
| 0 || NULL |
+-----------+
| 0 |
+-----------+
This page is licensed: GPLv2, originally from fill_help_tables.sql