Ilmu Sql

create function [dbo].[umur](@tanggallahir datetime, @tipe as tinyint)
   RETURNS varchar(100)
   with ENCRYPTION
   --select dbo.umur('12/17/1982', 1)
AS
Begin
DECLARE @thisYearBirthDay datetime
DECLARE @years int, @months int, @days int
Declare @hasil as varchar(30)
   
    set @thisYearBirthDay = DATEADD(year, DATEDIFF(year, @tanggallahir, getdate()), @tanggallahir)
    set @years = DATEDIFF(year, @tanggallahir, getdate()) - (CASE WHEN @thisYearBirthDay > getdate() THEN 1 ELSE 0 END)
    set @months = MONTH(getdate() - @thisYearBirthDay) - 1
    set @days = DAY(getdate() - @thisYearBirthDay) - 1
   
    if @tipe=1--full
    begin       
        set @hasil = cast(@years as varchar(2)) + ' tahun, ' + cast(@months as varchar(2)) + ' bulan, ' + cast(@days as varchar(3)) + ' hari'
    end
    else if @tipe=2--Tahun bulan
    begin
        set @hasil = cast(@years as varchar(2)) + ' tahun, ' + cast(@months as varchar(2)) + ' bulan'
    end
    else if @tipe=3--Tahun aja
    begin
        set @hasil = cast(@years as varchar(2))
    end
    else if @tipe=4--bulan aja
    begin
        set @hasil = cast(@months as varchar(2))
    end
    else if @tipe=5--hari aja
    begin
        set @hasil = cast(@days as varchar(3))
    end
   
    return @hasil
end

select birthdate, dbo.umur(birthdate,1) umur from employees where birthdate is not null