string sql2 = "select servername from serverconfig where sysname='测试'";
            string connctionstr = System.Configuration.ConfigurationManager.ConnectionStrings["TgNetVideo.Properties.Settings.shidevideoConnectionString"].ToString();
            MySqlConnection con = new MySqlConnection(connctionstr);
            MySqlDataAdapter dap = new MySqlDataAdapter(sql2, con);
            DataSet ds2 = new DataSet();
            dap.Fill(ds2);
            if (ds2.Tables[0].Rows.Count > 0)
                MessageBox.Show("成功");
            //DataSet ds2 = db2.SelectDs(sql2);
            foreach (DataTable tb in ds2.Tables)
            {
                foreach (DataRow row2 in tb.Rows)
                {
                    foreach (DataColumn column2 in tb.Columns)
                    {
                        string mss2 = String.Format("{0}", row2[column2]);
                        //groupNode = treeVideo1.AddGroup(mss2, rootNode);
                        MessageBox.Show(mss2);
                    }
                }
            }这样操作也没有结果啊!不知道是什么原因啊。不带Where操作能返回结果!!迷糊!