Syntax
IF(expr1,expr2,expr3)
Purpose
If the value of expr1 is TRUE, which means that expr1 <> 0 and expr1 <> NULL, the returned result is expr2. Otherwise, the returned result is expr3.
The returned result of IF() can be a numeric or string value. This depends on the arguments of the function.
If only one of expr2 and expr3 is NULL, the result of IF() is an non-NULL expression.
Examples
obclient> SELECT IF(5>6, 'T','F'), IF (5>6, 1, 0), IF(NULL, 'TRUE', 'FALSE'), IF(0, 'TRUE', 'FALSE')\G
*************************** 1. row ***************************
IF(5>6, 'T','F'): F
IF (5>6, 1, 0): 0
IF(NULL, 'TRUE', 'FALSE'): FALSE
IF(0, 'TRUE', 'FALSE'): FALSE
1 row in set