Laravel backpack crud Group除了零值之外的一切

Question

I want to group by my collection by a shared_id but if it has a NULL value it groups all of my null values.

I thought I will fix it with a RAW query but backpack isn't allowing me to do that..

I tested this SQL line in Heidi SQL and it works fine:

select * from `themes` group by shared_id, case when shared_id is null then id else 0 end

Hope you guys can help me out ;)