find age in year from date of birth from current date using sql query in sql server2005?

Question

find age in year from date of birth from current date using sql query?

Answer 1

You may want to refer to a well known solution developed by Steve Kass which accounts for a number of edge cases including leap years. Here it is for reference:

DECLARE @birthdate SMALLDATETIME, @endDate SMALLDATETIME 
SET @birthdate = '19791204' 
SET @endDate = GETDATE() 
 
SELECT DATEDIFF 
( 
    YEAR, 
    @birthdate, 
    @endDate 
) - CASE 
    WHEN 100 * MONTH(@endDate) + DAY(@endDate) 
    < 100 * MONTH(@birthdate) + DAY(@birthdate) 
    THEN 1 ELSE 0 END 

Answer 2

Drop table Bird;

CREATE TABLE Bird (
    name VARCHAR(20), 
    owner VARCHAR(20),
    species VARCHAR(20), 
    sex CHAR(1), 
    birth DATE, 
    death DATE
);



INSERT INTO  Bird VALUES ('BlueBird','Joe','Car','f','1999-03-30',NULL);
INSERT INTO  Bird VALUES ('RedBird','Yin','Bus','m','1979-04-30',NULL);
INSERT INTO  Bird VALUES ('RedBird','Yin','Bus','m','1998-01-30',NULL);



SELECT name, birth, CURDATE(),
       (YEAR(CURDATE())-YEAR(birth))
        - (RIGHT(CURDATE(),5)<RIGHT(birth,5))
       AS age
       FROM Bird;

Answer 3

DECLARE
@dob DATETIME
BEGIN
SET @dob = '19791204' -- set your birthday in datetime..
SELECT DATEDIFF(YEAR,@dob,GETDATE()) AS AGE
-- if you do it reverse :  DATEDIFF(YEAR,GETDATE(),@dob,) you will get negative
-- refer : http://msdn.microsoft.com/en-us/library/ms189794.aspx
END