SET @birthday = CAST('1980-05-01' AS DATE);
SET @today = CURRENT_DATE();
SELECT YEAR(@today) - YEAR(@birthday) -
(CASE WHEN
MONTH(@birthday) > MONTH(@today) OR
(MONTH(@birthday) = MONTH(@today) AND DAY(@birthday) > DAY(@today))
THEN 1
ELSE 0
END);
It returns this year - birth year (how old the person will be this year after the birthday) and adjusts based on whether the person has had the birthday yet this year.
It doesn't suffer from the rounding errors of other methods presented here.
drop function if exists getIdade;
delimiter |
create function getIdade( data_nascimento datetime )
returns int
begin
declare idade int;
declare ano_atual int;
declare mes_atual int;
declare dia_atual int;
declare ano int;
declare mes int;
declare dia int;
set ano_atual = year(curdate());
set mes_atual = month( curdate());
set dia_atual = day( curdate());
set ano = year( data_nascimento );
set mes = month( data_nascimento );
set dia = day( data_nascimento );
set idade = ano_atual - ano;
if( mes > mes_atual ) then
set idade = idade - 1;
end if;
if( mes = mes_atual and dia > dia_atual ) then
set idade = idade - 1;
end if;
return idade;
end|
delimiter ;
Now, you can get the age from a date:
select getIdade('1983-09-16');
If you date is in format Y-m-d H:i:s, you can do this:
DELIMITER $$ DROP FUNCTION IF EXISTS `db`.`F_AGE` $$
CREATE FUNCTION `F_AGE`(in_dob datetime) RETURNS int(11)
NO SQL
BEGIN
DECLARE l_age INT;
IF DATE_FORMAT(NOW( ),'00-%m-%d') >= DATE_FORMAT(in_dob,'00-%m-%d') THEN
-- This person has had a birthday this year
SET l_age=DATE_FORMAT(NOW( ),'%Y')-DATE_FORMAT(in_dob,'%Y');
ELSE
-- Yet to have a birthday this year
SET l_age=DATE_FORMAT(NOW( ),'%Y')-DATE_FORMAT(in_dob,'%Y')-1;
END IF;
RETURN(l_age);
END $$
DELIMITER ;
Since the question is being tagged for mysql, I have the following implementation that works for me and I hope similar alternatives would be there for other RDBMS's. Here's the sql:
select YEAR(now()) - YEAR(dob) - ( DAYOFYEAR(now()) < DAYOFYEAR(dob) ) as age
from table
where ...