Question

provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接

代码如下：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 _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}

public void getData()
{
SqlConnection cn = new SqlConnection("server=localhost;database=Northwind;user=da;password=da");
SqlCommand cmd = new SqlCommand("select * form Customers", cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "Customers");//在这里出现问题
this.GridView2.DataSource = ds.Tables[0].DefaultView;
this.DataBind();

}
protected void Button1_Click(object sender, EventArgs e)
{
getData();
}
}

Answer 1

Sql Server->配置工具->sql server外围应用配置器->服务和连接的外围应用配置器->打开MSSQLSERVER节点下的Database Engine 节点,先择"远程连接",接下建议选择"同时使用TCP/IP和named pipes",确定后,重启数据库服务就可以了.

如果还出现错误的话 那么请你检查一下所写的代码connectionString中的Data Source这个属性填写的值是否正确 本机默认填写.\SQLEXPRESS 或者换成 计算机名\SQLEXPRESS ...

Answer 2

cn .open();