IF(expr1,expr2,expr3)

##</code><code>##

CASE 
 WHEN condition THEN result 
 [ WHEN condition THEN result ]... 
 [ ELSE result ] 
END 

##</code><code>##

CASE expression 
 WHEN value THEN result 
 [ WHEN value THEN result ]... 
 [ ELSE result ] 
END