#1

DATE_FORMAT( FROM_DAYS( TO_DAYS(CURDATE()) - TO_DAYS(@dob) ), '%Y' ) + 0 
YEAR(CURDATE()) - YEAR(@dob) - ( RIGHT(CURDATE(),5) < RIGHT(@dob,5) ) 

#2
ROUND((((YEAR(NOW()) - YEAR(@dob)))*12 + (((MONTH(NOW()) - MONTH(@dob)))))/12, 2)

Given a birthdate in @dob, here are two simple formulae for age in years :
(the second formulae is for age in years to two decimal places, ignoring day of month)

Age in Years for Given Birthdate

mysql

MySQL