Finding someone's age in SQL

Question

In a SQL Server database, I record people\'s date of birth. Is there an straight-forward method of working out the person\'s age on a given date using SQL only?

Usi

Answer 1

FWIW, Age can be computed in a straightforward manner without resorting to hacks (not that there's anything wrong with hacks!):

CREATE FUNCTION Age (@BirthDate DATETIME)
RETURNS INT
AS
BEGIN
    DECLARE @AgeOnBirthdayThisYear INT
    DECLARE @BirthdayThisYear DATETIME
    SET @AgeOnBirthdayThisYear = DATEDIFF(year, @BirthDate, GETDATE())
    SET @BirthdayThisYear = DATEADD(year, @AgeOnBirthdayThisYear, @BirthDate)
    RETURN
        @AgeOnBirthdayThisYear
        - CASE WHEN @BirthdayThisYear > GETDATE() THEN 1 ELSE 0 END
END