CREATE FUNCTION dbo.CustomUnitNumConversion(@cnvNumber decimal(23,6) ,@coefficient int) 
RETURNS decimal(23,6) --返回返回值的数据类型
as
BEGIN
declare @result decimal(23,6)
select @result = (CASE @coefficient 
			WHEN 0
			THEN @cnvNumber ELSE (@cnvNumber/@coefficient)
		END)
RETURN @result
END