SQLServer有返回值的标量值函数

USE [ZJPJTX]
GO
/****** Object:  UserDefinedFunction [dbo].[fun_GradeDiff]    Script Date: 05/18/2012 10:57:42 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [dbo].[fun_GradeDiff] (@sum decimal(10,4)) 
RETURNS char(1)
AS 
BEGIN
declare @returnValue char(1)
declare @temp table (startMoney decimal,endMoney decimal,flag char(4))
insert into @temp select startMoney,endMoney,flag from PjCorpOutS where isDel='F' and Flag between 'a' and 'g'
declare @countNum int
set @countNum =(select Count(*) from @temp)
if( @countNum>=1)
select @returnValue=flag from @temp where @sum>=startMoney and @sum<=endMoney
else
set @returnValue=''
return @returnValue
END