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.
Note that, if the PIPES_AS_CONCAT
SQL_MODE is set, ||
is used as a string concatenation operator. This means that a || b
is the same as CONCAT(a,b)
. See CONCAT()
for details.
In Oracle mode from MariaDB 10.3, ||
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, from MariaDB 10.3:
SELECT 0 || NULL; +-----------+ | 0 || NULL | +-----------+ | 0 | +-----------+
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Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/or/