function to get date from parts / Funktion um Datum aus Jahr/Monat/Tag zu erhalten in ms sql server 2008 and 2005

-- Description: like DateFromParts in sql server 2012
-- =============================================
ALTER FUNCTION [dbo].[MyDateFromParts]
(
@year int,
@month int,
@day int
)
RETURNS Datetime --nvarchar(20)--
AS
BEGIN
-- Declare the return variable here
declare @dateString as nvarchar(20) = convert(nvarchar(4),@year)+ dbo.AddLeading0(@month) +dbo.AddLeading0(@day)--dbo.AddLeading0(@year)--+
DECLARE @ret as DateTime=Convert(datetime, @dateString)

RETURN @ret

END

--depends on

-- Description: adds leading 0 if x in 0-9
-- =============================================
ALTER FUNCTION [dbo].[AddLeading0]
(
@x int
)
RETURNS Nvarchar(2)
AS
BEGIN
-- Declare the return variable here
DECLARE @ret as nvarchar(2) = convert(nvarchar(2),@x)
if (2>len(@ret)) set @ret='0'+@ret
RETURN @ret

END