CDS Custom Entity not working with Multilevel Expand

[catalinfeidi]

Hi there,

We have been experimenting CDS Custom Entity in order to keep the legacy code clean but we do have a corner case to load full BO which custom entity is not supporting.

We need to retrieve parent entity -> children entity -> grandchildren entity, all together as follows:

Parent(entity: parent)

-Child1(entity:_children)

--GrandChild1forChild1(entity: _grandchildren)

--GrandChild2forChild2(entity: _grandchildren)

Child2(entity:_children)

--GrandChild1forChild2(entity: _grandchildren)

--GrandChild2forChild2(entity: _grandchildren)

Our OData call:

/parent?$filter=((key1 eq 'something1')and(key2 eq 'something2'))&$expand=_child($expand=_grandchildren)

When we want to get the navigation keys inside of _grandchildren query implementation class as doing get_filter()->get_as_ranges(), it is short-dumping when method is being called, because there are 2 children for the Parent(Child1 and Child2). It doesn't work with multiple parents for that respective entity.

This seems to be a limitation of Custom Entity, not supporting the expand of associations on entities that have more entries.

[dominik_ee]

As mentioned in the documentation, it is not possible to express all types of filters as ranges:

https://help.sap.com/docs/btp/sap-abap-restful-application-programming-model/implementing-filtering-...

and

https://help.sap.com/docs/btp/sap-abap-restful-application-programming-model/interface-if-rap-query-...