If function in SQL

IF expression

IF( expr1 , expr2 , expr3 )

expr1 The value of is TRUE, The return value is expr2
expr1 The value of is FALSE, The return value is expr3

as follows ：

SELECT IF(TRUE,1+1,1+2);
-> 2

SELECT IF(FALSE,1+1,1+2);
-> 3

SELECT IF(STRCMP("111","222")," It's not equal "," equal ");
->  It's not equal