Syntax:
IF(condition,true_value,false_value)
If expr1 is TRUE (expr1 0 and expr1 NULL) then IF() returns expr2; otherwise it returns expr3.
expr1 is evaluated as an integer value.
mysql>
mysql> SELECT IF(1>2,2,3);
+-------------+
| IF(1>2,2,3) |
+-------------+
| 3 |
+-------------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT IF(1<2,'yes','no');
+--------------------+
| IF(1<2,'yes','no') |
+--------------------+
| yes |
+--------------------+
1 row in set (0.00 sec)
mysql>