USE [Vertragsverwaltung_20160404]
GO
/****** Object:  UserDefinedFunction [dbo].[Check_Date]    Script Date: 02.12.2016 09:08:53 ******/
DROP FUNCTION [dbo].[Check_Date]
GO
/****** Object:  UserDefinedFunction [dbo].[Check_Date]    Script Date: 02.12.2016 09:08:55 ******/
SET ANSI_NULLS OFF
GO
SET QUOTED_IDENTIFIER ON
GO

CREATE FUNCTION [dbo].[Check_Date]
(@datum datetime)
RETURNS datetime  

BEGIN 
declare @result datetime

if @datum is null set @datum='01.01.1900'
set @result=@datum

if year(@datum)=1900 set @result=null

return @result
END





GO