以下是几个符合文章内容的英文问答类标题： * Why Am I Unable to Retrieve Data from a MySQL Database Through SSH.NET? * Troubleshooting MySQL Connection Issues with SSH.NET: A Case Study * How to Correctly Connect to a Rem

使用 SSH.NET 库从 .NET 连接到 MySQL

问题：

An ASP.NET/C# 网页尝试使用 Renci.SshNet 和 mysql-connector-net 库通过 SSH 连接查询远程服务器上的 MySQL 数据库。但是，代码并未从数据库中检索任何数据。

代码片段：

C# 代码尝试建立 SSH 连接、转发端口和然后连接MySQL数据库。但是，它无法从数据库中检索任何数据。

<code class="csharp">using(var client = new SshClient("ssh server id", "sshuser", "sshpassword")) // establishing ssh connection to server where MySql is hosted
{
    client.Connect();
    if (client.IsConnected)
    {
        var portForwarded = new ForwardedPortLocal("127.0.0.1", 3306, "127.0.0.1", 3306);
        client.AddForwardedPort(portForwarded);
        portForwarded.Start();
        using (MySqlConnection con = new MySqlConnection("SERVER=127.0.0.1;PORT=3306;UID=someuser;PASSWORD=somepass;DATABASE=Dbname"))
        {
            using (MySqlCommand com = new MySqlCommand("SELECT * FROM cities", con))
            {
                com.CommandType = CommandType.CommandText;
                DataSet ds = new DataSet();
                MySqlDataAdapter da = new MySqlDataAdapter(com);
                da.Fill(ds);
                foreach (DataRow drow in ds.Tables[0].Rows)
                {
                    Console.WriteLine("From MySql: " + drow[1].ToString());
                }
            }
        }
        client.Disconnect();
    }
    else
    {
        Console.WriteLine("Client cannot be reached...");
    }
}</code>

解决方案：

要解决此问题，可以对代码进行以下修改：

1. 用于连接 MySQL 数据库的连接字符串语法不正确。将连接字符串更改为以下内容：

MySqlConnectionStringBuilder connBuilder = new MySqlConnectionStringBuilder();
connBuilder.AllowBatch = true;
connBuilder.Server = "portal.RemoteServer.edu";
connBuilder.Port = 3306;
connBuilder.UserID = "RemoteServerUsername";
connBuilder.Password = "RemoteServerPassword";
connBuilder.Database = "DatabaseName";

2. 未正确建立 SSH 连接。确保SSH连接参数正确，并且客户端能够成功连接远程服务器。

修改代码：

<code class="csharp">using(var client = new SshClient("portal.RemoteServer.edu", "RemoteServerUsername", "RemoteServerPassword")) // establishing ssh connection to server where MySql is hosted
{
    client.Connect();
    if (client.IsConnected)
    {
        var portForwarded = new ForwardedPortLocal("127.0.0.1", 3306, "127.0.0.1", 3306);
        client.AddForwardedPort(portForwarded);
        portForwarded.Start();
        using (MySqlConnection con = new MySqlConnection(connBuilder.ConnectionString))
        {
            using (MySqlCommand com = new MySqlCommand("SELECT * FROM Clients", con))
            {
                com.CommandType = CommandType.CommandText;
                DataSet ds = new DataSet();
                MySqlDataAdapter da = new MySqlDataAdapter(com);
                da.Fill(ds);
                foreach (DataRow drow in ds.Tables[0].Rows)
                {
                    Console.WriteLine("From MySql: " + drow[1].ToString());
                }
            }
        }
        client.Disconnect();
    }
    else
    {
        Console.WriteLine("Client cannot be reached...");
    }
}</code>

以上是以下是几个符合文章内容的英文问答类标题： * Why Am I Unable to Retrieve Data from a MySQL Database Through SSH.NET? * Troubleshooting MySQL Connection Issues with SSH.NET: A Case Study * How to Correctly Connect to a Rem的详细内容。更多信息请关注PHP中文网其他相关文章！