DjangoFilterConnectionField with coalescence in a resolver

[oharlem]

Hi,

Stumbled upon the following case:

1. DjangoFilterConnectionField won't allow me to use Coalese in a resolver's queryset throwing "Cannot resolve keyword u'display_or_updated_date' into field."
   Using DjangoConnectionField instead helps.

    qs = qs.annotate(display_or_updated_date=Coalesce('display_date', 'updated_at'))

2. At the same time, with DjangoConnectionField I cannot apply a slice (aka page size) to my query_set, getting "Cannot combine queries once a slice has been taken." + implement filtering, so would be great to find a solution for coalescence.

Any thoughts are appreciated!
Thank you!