How to select aggregate fields using query?

Query query;
QueryBuildDataSource qbds;
QueryBuildRange qbr;
QueryRun queryrun;

date fromDate = systemDateGet();
date toDate = (systemDateGet() + 25);
query          = new Query();
qbds           = query.addDataSource(tableNum(MyTable));
qbds.addGroupByField(fieldNum(MyTable, DateField));
qbds.addGroupByField(fieldNum(MyTable, CurrencyNameField));
qbds.addSelectionField(fieldNum(MyTable, DateField));
qbds.addSelectionField(fieldNum(MyTable, CurrencyNameField));
qbds.addSelectionField(fieldNum(MyTable, EURAmountField), SelectionField::Sum);
qbds.addSelectionField(fieldNum(MyTable, USDAmountField), SelectionField::Sum);
qbr            = qbds.addRange(fieldNum(MyTable, DateField));
qbr.value(queryRange(fromDate, toDate));

queryRun       = new QueryRun(query);