Mysql NULLIF
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Contents |
MySQL NULLIF Function
This operator uses to check two expression.
Syntax NULLIF
When expr1=expr2 returns NULL, otherwise returns expr1.
NULLIF(expr1,expr2)
Example 1
mysql> SELECT NULLIF('ab','ab');
+-------------------+
| NULLIF('ab','ab') |
+-------------------+
| NULL |
+-------------------+
1 row in set (0.00 sec)
Example 2
mysql> SELECT NULLIF(2,3),NULLIF(5,5),NULLIF('good','bad');
+-------------+-------------+----------------------+
| NULLIF(2,3) | NULLIF(5,5) | NULLIF('good','bad') |
+-------------+-------------+----------------------+
| 2 | NULL | good |
+-------------+-------------+----------------------+
1 row in set (0.00 sec)
