You can create a lot of constraints … 

tested in 12.2 You can create a lot of constraints ... create table aa (bbb varchar2(10) not null); Table created. alter table aa add (check (bbb is not null) enable validate); Table altered. alter table aa add (check (bbb is not null) enable validate); Table altered. alter table aa add (check (bbb is not null) enable … Continue reading You can create a lot of constraints …