sql 自定义函数

create function dbo.fun(@inputid as varchar(40))
returns int
as
begin
declare @counts int
select @counts=COUNT(*) from Stu_Infor
return @counts
end

declare @input varchar(40)
set @input='2'
select dbo.fun(@input)

自己写个小例子

http://www.cnblogs.com/no7dw/archive/2010/07/08/1773495.html

很详细