我有一个三列的表

MyDate : DateiIme
  MyBlob: blob
  Id: String

我想以Json的形式返回MyDate和MyBlob。表中可以有多条记录。

public class MyData
      {
          public  string? MyDate { get; set; };
          public  string? MyBlob { get; set; };
      }
  public async Task<string> GetQueryResult(string Id)
    {
        MyData data = new MyData();
        List<MyData> MyList = new List<MyData>();
        string sqlSelect = string.Format("Select MyDate, MyBlob from MyTablee WHERE Id = '{0}'", Id);
      
        try
        {
            MySqlCommand sqlcmd = new MySqlCommand();
            MySqlConnection connetcion = new MySqlConnection(connectionString);
            sqlcmd.Connection = connetcion;
            sqlcmd.CommandTimeout = 0;
            sqlcmd.CommandType = CommandType.Text;
            sqlcmd.CommandText = sqlSelect;
            connetcion.Open();
            using (connetcion)
            {
                int count = 0;
                using (MySqlDataReader reader = sqlcmd.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        data.MyDate = reader.GetString(0);
                        data.MyBlob = reader.GetString(1);
                        MyList.Add(data);
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        var json = JsonSerializer.Serialize(results);
        return json;
    }

Postman中的输出为：

"{\"MyDate\":\"1/30/2023 9:16:40 PM\",\"MyBlob\":\"@MyBlob\"}"

我不确定blob数据到JSON的转换是否正确。谢谢。