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 have not enough reputation to add comment to an answer by Rat-a-tat-a-tat Ratatouille to improve his code. Here is the better SQL-query:

SELECT IFNULL(TIMESTAMPDIFF(YEAR, birthdate, CURDATE()), YEAR(CURDATE()) - YEAR(birthdate)) AS age

This is better because sometimes "birthdate" may contain only year of birth, while day and month is 0. If TIMESTAMPDIFF() returns NULL, we can find rough age by subtracting the current year from the year of birth.