Question

我正在开发一个网页（ASP.NET / C＃），它通过SSH在远程服务器上查询（MySQL）数据库。我正在使用这两个库（mysql-connector-net-6.9.7）和（Renci.SshNet.dll）。

我可以通过SSH连接在远程服务器上使用MySQL Workbench访问MySQL数据库：
“ portal.RemoteServer.edu:22 ”使用“ RemoteServerUsername ”和
“的 RemoteServerPassword ”。

这是我的C＃代码，它不会从远程服务器上的Clients表返回任何数据：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using MySql.Data.MySqlClient;
using Renci.SshNet;
using Renci.SshNet.Common;
namespace WebApplication1
{
    public partial class About : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            MySqlConnection conn = null;
            SshClient client = null;
            ForwardedPortLocal port = null;

            MySqlConnectionStringBuilder connBuilder = new MySqlConnectionStringBuilder();
            connBuilder.AllowBatch = true;
            connBuilder.Server = "127.0.0.1";
            connBuilder.Port = 3306;
            connBuilder.UserID = "LocalHostUserID";
            connBuilder.Password = "LocalHostPassword";
            connBuilder.Database = "DatabaseName";

            ConnectionInfo conInfo = new ConnectionInfo("portal.RemoteServer.edu", "RemoteServerUsername", new PasswordAuthenticationMethod("RemoteServerUsername", "RemoteServerPassword"));

            using (client = new SshClient(conInfo))
            {
                try
                {
                    port = new ForwardedPortLocal("127.0.0.1", 0, "127.0.0.1", 22);
                    client.Connect();
                    client.AddForwardedPort(port);
                    port.Start();
                    conn = new MySqlConnection(connBuilder.ConnectionString);
                    conn.Open();
                    conn.ChangeDatabase(connBuilder.Database);

                    using (MySqlCommand cmd = new MySqlCommand("SELECT * FROM DatabaseName.Clients LIMIT 10"))
                    {
                        using (MySqlDataAdapter sda = new MySqlDataAdapter())
                        {
                            cmd.Connection = conn;
                            sda.SelectCommand = cmd;
                            using (DataTable dt = new DataTable())
                            {
                                sda.Fill(dt);
                                GridView1.DataSource = dt;
                                GridView1.DataBind();
                            }
                        }
                    }
                }
                catch (Exception ex) {}
            }
        }
    }
}

在@Martin Prikryl的答案中应用建议之后的代码，但它仍无效。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using MySql.Data.MySqlClient;
using Renci.SshNet;
using Renci.SshNet.Common;
namespace WebApplication1
{
    public partial class About : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            MySqlConnection conn = null;
            SshClient client = null;
            ForwardedPortLocal port = null;

            MySqlConnectionStringBuilder connBuilder = new MySqlConnectionStringBuilder();
            connBuilder.AllowBatch = true;
                        connBuilder.Server = "127.0.0.1";
        connBuilder.Port = 3306;
        connBuilder.UserID = "remoteUsername";
        connBuilder.Password = "remotePassword";
        connBuilder.Database = "databasename";

        ConnectionInfo conInfo = new ConnectionInfo("portal.remoteserver.edu", 22, "remoteUsername", new PasswordAuthenticationMethod("remoteUsername", "remotePassword"));

        using (client = new SshClient(conInfo))
        {
            try
            {
                port = new ForwardedPortLocal(0, "127.0.0.1", 3306);
                client.Connect();
                client.AddForwardedPort(port);
                port.Start();
                connBuilder.Port = port.BoundPort;
                    conn = new MySqlConnection(connBuilder.ConnectionString);
                    conn.Open();
                    conn.ChangeDatabase(connBuilder.Database);

                    using (MySqlCommand cmd = new MySqlCommand("SELECT * FROM DatabaseName.Clients LIMIT 10"))
                    {
                        using (MySqlDataAdapter sda = new MySqlDataAdapter())
                        {
                            cmd.Connection = conn;
                            sda.SelectCommand = cmd;
                            using (DataTable dt = new DataTable())
                            {
                                sda.Fill(dt);
                                GridView1.DataSource = dt;
                                GridView1.DataBind();
                            }
                        }
                    }
                }
                catch (Exception ex) {}
            }
        }
    }
}

Answer 1

您必须将本地端口转发到远程MySQL端口（3306），而不是SSH端口22（这将创建一个循环）。
您正在将0传递给boundPort的{{1}}参数。这意味着操作系统会自动选择端口号。然而，您正尝试通过固定端口ForwardedPortLocal连接到MySQL。
- 将固定端口3306传递给3306
```
ForwardedPortLocal
```
  如果本地MySQL数据库已使用本地3306端口，则无法工作。您当然可以使用任何其他本地端口（远程端口必须是3306）。
- 或port = new ForwardedPortLocal("127.0.0.1", 3306, "127.0.0.1", 3306);使用port.BoundPort值（在致电port.Start()后）{/ 1}}。
```
connBuilder.Port
```
  确保您拥有最新版本的SSH.NET库。 .BoundPort was not updated in the old versions。
请注意，第一个port.Start(); connBuilder.Port = port.BoundPort; conn = new MySqlConnection(connBuilder.ConnectionString);指的是本地计算机（相对于本地计算机的IP地址），而第二个指的是服务器（IP地址相对于服务器计算机）。您通常可以省略第一个参数。

使用SSH.NET库从.NET连接到MySQL

1 个答案: