Syntax
------ 
IF(expr1,expr2,expr3)
 
Description
----------- 
If expr1 is TRUE (expr1  0 and expr1  NULL) then IF()
returns expr2; otherwise it returns expr3. IF() returns a
numeric
or string value, depending on the context in which it is
used.
 
Note: There is also an IF statement which differs from the
IF() function described here.
 
Examples
-------- 
SELECT IF(1>2,2,3);
+-------------+
| IF(1>2,2,3) |
+-------------+
| 3 |
+-------------+
 
SELECT IF(1

URL: https://mariadb.com/kb/en/if-function/