ทำไมคำสั่ง ExecuteNonQuery() ไม่ทำงานคะ เพราะพอ Copy code sql ไปวางใน sql server ก็ exec ได้

String strSQL1;
                strSQL1 = "UPDATE KPIperformance SET " +
                " Score = '" + lblMonth3.Text + "' " +
                    //" WHERE kpiID = '" + Request.QueryString["kpiID"] + "' AND MONTH(Date)=1 AND Round = '" + Session["Round"] + "')";
                " WHERE kpiID = '" + DataBinder.Eval(e.Item.DataItem, "kpiID") + "' AND MONTH(Date)=3 AND Round = '2012' AND empID = '51-2955'";

                objCmd = new SqlCommand();
                objCmd.Connection = objConn;
                objCmd.CommandText = strSQL1;
                objCmd.CommandType = CommandType.Text;

                try
                {
                    objCmd.ExecuteNonQuery();
                }
                catch (Exception ex)
                {
                    this.lblStatus.Text = strSQL1;
                }