IF
If expr1 is TRUE, IF() returns expr2. Otherwise, it returns expr3.
Syntax
IF(expr1,expr2,expr3)
Arguments
| Arguments | Description | 
|---|---|
| expr1 | The condition for evaluation that can be true or false. | 
| expr2 | The expression to return if condition is met. | 
| expr3 | The expression to return if condition is not met. | 
Return Type
The return type is determined by expr2 and expr3, they must have the lowest common type.
Examples
mysql> select if(number=0, true, false) from numbers(1);
+-------------------------------+
| if((number = 0), true, false) |
+-------------------------------+
|                             1 |
+-------------------------------+
1 row in set (0.01 sec)
mysql> SELECT if(number > 5, number*5, number+5 ) FROM numbers(10);
+----------------------------------------------+
| if((number > 5), (number * 5), (number + 5)) |
+----------------------------------------------+
|                                            5 |
|                                            6 |
|                                            7 |
|                                            8 |
|                                            9 |
|                                           10 |
|                                           30 |
|                                           35 |
|                                           40 |
|                                           45 |
+----------------------------------------------+