请教一个数据库(SQL Server)的问题!!!!!

来源:百度知道 编辑:UC知道 时间:2024/06/20 09:41:38
编写程序过程,返回所有读者的平均年龄
我的程序如下:
USE XSBOOK
IF EXISTS (SELECT name
FROM sysobjects
WHERE name = 'reader_age'
AND type = 'P')
DROP PROCEDURE reader_age
GO

CREATE PROCEDURE reader_age @age_avg int output
AS
select @age_avg=avg(year(getdate())-year(XS.出生时间))
from XS
go
可是无法输出结果,请哪位高手指点一下!

USE XSBOOK
IF EXISTS (SELECT name
FROM sysobjects
WHERE name = 'reader_age'
AND type = 'P')
DROP PROCEDURE reader_age
GO

CREATE PROCEDURE reader_age @age_avg int
AS
begin
select @age_avg=avg(year(getdate())-year(XS.出生时间))
from XS
end
go