Query query = new Query();
            QueryBuildDataSource qbds , qbdsCheck;
            SysTableLookup _sysTableLookup = SysTableLookup::newParameters(tableNum(PurchReqTable),This);

            qbds= query.addDataSource(tableNum(PurchReqTable));

            qbds.addRange(fieldNum(PurchReqTable , RequisitionStatus)).value(enum2Str(PurchReqRequisitionStatus::Approved));
            qbds.addRange(fieldNum(PurchReqTable , NW_RequestCategory)).value(enum2Str(NW_RequestCategory::RFP_RFQ));

            qbdsCheck = qbds.addDataSource(tableNum(PurchRFQCaseTable));
            qbdsCheck.addLink(fieldNum(PurchReqTable , PurchReqId) ,fieldNum(PurchRFQCaseTable , PurchReqId));
            qbdsCheck.joinMode(JoinMode::NoExistsJoin);
           

            _sysTableLookup.parmQuery(query);
            _sysTableLookup.addLookupfield(fieldNum(PurchReqTable, PurchReqId));
            _sysTableLookup.addLookupfield(fieldNum(PurchReqTable, PurchReqName ));

            _sysTableLookup.performFormLookup();