Group By and aggregation as Sum in RunTime Query: Query query; QueryRun queryRun; QueryBuildDataSource ds; QueryBuildRange range1; CustAccount accountNum; CustTrans custTrans; query = new Query(); ds = query.addDataSource(tableNum(CustTrans)); ds.addGroupByField(fieldNum(CustTrans, AccountNum)); range1 = SysQuery::findOrCreateRange(ds, fieldNum(CustTrans, AccountNum)); range1.value(queryValue(accountNum)); ds.addSelectionField(fieldNum(CustTrans, AmountMST),SelectionField::Sum);