c#调用SQL的存储过程session2

//存储过程

create proc [dbo].[select_proc]
(
@uid char,
@output char(20) output
)
as
select * from test_table where id>@uid
set @output='记录总数: '+convert(char(20),(select count(*)from test_table))

//代码

 

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class Default2 : System.Web.UI.Page
...{
    protected void Page_Load(object sender, EventArgs e)
    ...{
        //一个连接一个命令
        SqlConnection conn = new SqlConnection(@"data source=.sqlexpress;initial catalog=mytest;user id=sa;password=test");
        SqlCommand com = new SqlCommand("select_proc", conn);            
        com.CommandType = CommandType.StoredProcedure;  
        //输入参数         
        com.Parameters.Add("@uid",SqlDbType.Char,10).Value=0;
        //输出参数
        SqlParameter sp = com.Parameters.Add("@output",SqlDbType.Char,20); 
        sp.Direction = ParameterDirection.Output; 
        //适配器 数据集 填充 赋值 绑定
        SqlDataAdapter da = new SqlDataAdapter(com);                       
        DataSet ds=new DataSet();                                         
        da.Fill(ds);                                                       
        GridView1.DataSource = ds;
        GridView1.DataBind();
        Response.Write("存储过程的返回值   "+com.Parameters["@output"].Value.ToString());

    }
}