sum ใน crystal report ผิดผลรวมกลายเป็น count ตอนรันโปรแกรม ก่อนรันโปรแกรมถูก??

                CrpRec1 crprec2 = new CrpRec1();
                DataSet ds = new DataSet();

                strSQL = "SELECT quotation.*,CONCAT(cus_id,'   ',cus_name) AS quo_customer,cus_sales AS quo_saleman FROM quotation,customers WHERE quo_id = '" + _quoid + "' AND quotation.quo_cusid = customers.cus_id";
                dtAdapter = new MySqlDataAdapter(strSQL, hm.objConn());
                dtAdapter.Fill(ds, "dsquotation");
                crprec2.Database.Tables["quotation"].SetDataSource(ds.Tables["dsquotation"]);

                strSQL = "SELECT quotation2.*,product.pro_name AS quo2_proname,product.pro_unit AS quo2_prounit FROM quotation2,product WHERE quo2_quoid = '" + _quoid + "' AND product.pro_id = quotation2.quo2_proid ORDER BY quo2_quoid";
                dtAdapter = new MySqlDataAdapter(strSQL, hm.objConn());
                dtAdapter.Fill(ds, "dsquotation2");
                crprec2.Database.Tables["quotation2"].SetDataSource(ds.Tables["dsquotation2"]);
                crystalReportViewer1.ReportSource = crprec2;