以下是幾本符合文章內容的英文問答類標題： * 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 庫從.NET 連接到MySQL

問題：

An ASP.NET/C# 網頁嘗試使用Renci.SshNet 和mysql-connector-net 函式庫透過SSH 連線查詢遠端伺服器上的MySQL 資料庫。但是，程式碼並未從資料庫中檢索任何資料。

程式碼片段：

C# 程式碼嘗試建立 SSH 連線、轉送連接埠和然後連接MySQL資料庫。但是，它無法從資料庫中檢索任何資料。

<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>

解決方案：

要解決此問題，可以對程式碼進行以下修改：

1. 用於連接MySQL 資料庫的連接字串語法不正確。將連接字串變更為以下內容：

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. 未正確建立 SSH 連線。確保SSH連線參數正確，且用戶端能夠成功連接遠端伺服器。

修改程式碼：

<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>

以上是以下是幾本符合文章內容的英文問答類標題： * 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的詳細內容。更多資訊請關注PHP中文網其他相關文章！