How to get an age from a D.O.B field in MySQL?

Question

I need to calculate the age of a \"customer\" from their date of birth.

I have tried to use the following:

DATEDIFF(year, customer.dob, \"2010

Answer 1

Depends on your needs - int and float functions provided.
- Your business rules may differ so adjust accordingly

DROP FUNCTION IF EXISTS `age`; 
CREATE FUNCTION `age` (
  `pdate_begin` DATE,
  `pdate_end` DATETIME
) RETURNS INT(11) UNSIGNED   
COMMENT 'Calc age between two dates as INT' 
DETERMINISTIC NO SQL SQL SECURITY DEFINER
RETURN floor(datediff(pdate_end, pdate_begin) / 365.25) ;

DROP FUNCTION IF EXISTS `age_strict`; 
CREATE FUNCTION `age_strict` (
  `pdate_begin` DATE,
  `pdate_end` DATETIME
) RETURNS decimal(10,4)
COMMENT 'Calc age between two dates as DECIMAL .4' 
DETERMINISTIC NO SQL SQL SECURITY DEFINER
RETURN round(datediff(pdate_end, pdate_begin) / 365.25, 4) ;

-- test harness
select 
    age(dob, now())        as age_int,
    age_strict(dob, now()) as age_dec
    from customer 
    where dob is not null 
    order by age(dob,now()) desc;

-- test results
dob,                  age_int,            age_dec
1981-01-01 00:00:00        33             33.9713
1987-01-09 00:00:00        27             27.9507
2014-11-25 00:00:00         0              0.0739