APEX

Hello,
I'm having an issue with the "sort order" clause in the query builder tool when using a function on the same column.

I've build a simple query in the gui and the following statement is displayed in the SQL Window
select "DEMO_ORDER_ITEMS"."ORDER_ID" as "ORDER_ID",
sum(DEMO_ORDER_ITEMS.QUANTITY) as "QUANTITY"
from "DEMO_ORDER_ITEMS" "DEMO_ORDER_ITEMS"
group by DEMO_ORDER_ITEMS.ORDER_ID

and if I add a sort order of "1" on the quantity field, the following query is changed to
select "DEMO_ORDER_ITEMS"."ORDER_ID" as "ORDER_ID",
sum(DEMO_ORDER_ITEMS.QUANTITY) as "QUANTITY"
from "DEMO_ORDER_ITEMS" "DEMO_ORDER_ITEMS"
group by DEMO_ORDER_ITEMS.ORDER_ID
order by DEMO_ORDER_ITEMS.QUANTITY DESC

When running this query I get an error
failed to parse SQL query:
ORA-00979: not a GROUP BY expression

It is quite obvious what is wrong with the query but I don't know how to get the query builder tool to generate the correct statement. The order by clause should be order by sum(DEMO_ORDER_ITEMS.QUANTITY) DESC.

I've tried to do some searching and haven't found much documentation on this issue. Any assistance is appreciated.

Thanks,
Tony