c#database选择然后插入.但是值为0

2023年6月12日 162次阅读

我试图选择然后从表1插入日期时间到表2.我已成功插入数据.但是,表2中显示的日期时间为00:00:00. Idk哪里出错.有人请帮我解决这个问题.我正在努力解决这个问题.这是SELECT然后插入的正确方法吗？ (从表1中选择然后插入表2)

 try
    {
        string myConnectionString;
        myConnectionString= "server=localhost;uid=root;pwd=root;database=medicloud;SslMode=None;charset=utf8";

        MySqlConnection connection = new MySqlConnection(myConnectionString);
        MySqlCommand cmd = new MySqlCommand();

        cmd.CommandType = CommandType.Text;

        EncodingProvider ppp;
        ppp = CodePagesEncodingProvider.Instance;
        Encoding.RegisterProvider(ppp);

        connection.Open();   

        string select = "Select time from assign where userId=@name";
        cmd.Parameters.AddWithValue("@name", txtValue.Text);                           
        cmd.CommandText = select;
        cmd.Connection = connection;


        MySqlDataReader selectAssign = cmd.ExecuteReader();
        selectAssign.Read();
        string assign = (selectAssign["time"].ToString());
        selectAssign.Close();


        cmd.CommandType = CommandType.Text;
        cmd.CommandText = "INSERT into bluetooth (userId,arm,armNumberDone,armNumber,comDate,assignDate,status) VALUES (@name, @stupid0, @stupid1, @stupid2, @stupid3, @stupid4, @stupid5)";
        cmd.Parameters.AddWithValue("@stupid0", databaseLine);
        cmd.Parameters.AddWithValue("@stupid1", counter);
        cmd.Parameters.AddWithValue("@stupid2", databaseValue);
        cmd.Parameters.AddWithValue("@stupid3", DateTime.Now);
        cmd.Parameters.AddWithValue("@stupid4", assign);
        cmd.Parameters.AddWithValue("@stupid5", complete);
        cmd.Connection = connection;


        cmd.ExecuteNonQuery();
        connection.Close();

    }

    catch (MySqlException ex)
    {
        txtExercise.Text = ex.ToString();
    }

最佳答案 请试试这个

try
{
      string myConnectionString;
      myConnectionString = "server=localhost;uid=root;pwd=root;database=medicloud;SslMode=None;charset=utf8";

      MySqlConnection connection = new 
           MySqlConnection(myConnectionString);
      MySqlCommand cmd = new MySqlCommand();

      cmd.CommandType = CommandType.Text;

      EncodingProvider ppp;
      ppp = CodePagesEncodingProvider.Instance;
      Encoding.RegisterProvider(ppp);

      connection.Open();

      string select = "Select time from assign where userId=@name";
      cmd.Parameters.AddWithValue("@name", txtValue.Text);
      cmd.CommandText = select;
      cmd.Connection = connection;

      MySqlDataReader selectAssign = cmd.ExecuteReader();
      selectAssign.Read();
      string assign = (selectAssign["time"].ToString());
      selectAssign.Close();

      DateTime assignDate = DateTime.Now;
      DateTime.TryParseExact(assign, out assignDate);

      cmd.CommandType = CommandType.Text;
      cmd.CommandText = "INSERT into bluetooth 
(userId,arm,armNumberDone,armNumber,comDate,assignDate,status) VALUES (@name, 
@stupid0, @stupid1, @stupid2, @stupid3, @stupid4, @stupid5)";
      cmd.Parameters.AddWithValue("@stupid0", databaseLine);
      cmd.Parameters.AddWithValue("@stupid1", counter);
      cmd.Parameters.AddWithValue("@stupid2", databaseValue);
      cmd.Parameters.AddWithValue("@stupid3", DateTime.Now);
      cmd.Parameters.AddWithValue("@stupid4", assignDate);
      cmd.Parameters.AddWithValue("@stupid5", complete);
      cmd.Connection = connection;

      cmd.ExecuteNonQuery();
      connection.Close();
   }
  catch (MySqlException ex)
  {
      txtExercise.Text = ex.ToString();
  }
}
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