Get difference in years between two dates in MySQL as an integer

Question

I am trying to calculate how old is a person in a database.
Let\'s suppose to have this simple table:

student(id, birth_date);

Where

Answer 1

I'd suggest this:

DATE_FORMAT(NOW(),"%Y")
   -DATE_FORMAT(BirthDate,'%Y')
   -(
     IF(
      DATE_FORMAT(NOW(),"%m-%d") < DATE_FORMAT(BrthDate,'%m-%d'),
      1,
      0
     )
    ) as Age

This should work with leap-years very well ;-)