domain_registrations
id | attached_to_hoster
1  | null
2  | null

select * from `domain_registrations` where 'attached_to_hoster' != 1;
select * from `domain_registrations` where `attached_to_hoster` <> 1;

$oDomainRegistrations = DomainRegistrations::where('attached_to_hoster', '<>', '1')->get();

select * from domain_registrations
 where attached_to_hoster != 1 and not attached_to_hoster is null;
select * from domain_registrations
 where attached_to_hoster != 1 or attached_to_hoster is null;

DomainRegistrations::where('attached_to_hoster', '<>', '1')