How to calculate age in T-SQL with years, months, and days

Question

What would be the best way to calculate someone\'s age in years, months, and days in T-SQL (SQL Server 2000)?

The datediff function doesn\'t handle year

Answer 1

Try this...

SELECT CASE WHEN
 (DATEADD(year,DATEDIFF(year, @datestart  ,@dateend) , @datestart) > @dateend)
THEN DATEDIFF(year, @datestart  ,@dateend) -1
ELSE DATEDIFF(year, @datestart  ,@dateend)
END

Basically the "DateDiff( year...", gives you the age the person will turn this year, so i have just add a case statement to say, if they have not had a birthday yet this year, then subtract 1 year, else return the value.