using Computed Field as a column in check for permission

[archywillhe]

Looks like right now only PGColumn is supported to be used as a column in check for permission. https://hasura.io/docs/1.0/graphql/core/auth/authorization/permission-rules.html

Will be nice if Computed Field is supported too. So say if a user is only allowed to insert at most N rows to a table we can restrict that using an insert check i.e. by having a Computed Field like this to get the count:

CREATE OR REPLACE FUNCTION public.get_app_count(user_row user)
 RETURNS integer
 LANGUAGE plpgsql
 STABLE
AS $function$
declare
   app_count integer;
begin
   select count(*) 
   into app_count
   from app_profile
   where app_profile.user.id = user.id;
   return app_count;
end;
$function$

related to - #4356

[tirumaraiselvan]

Closing this as a dupe of #5646

Would be great if you could comment with your use-case over there!