Sequence as default value for table columns

Oracle 12c allows to use sequence as default value for column value. This video shows the behavior in pre-12C & 12C version onwards.



-- Behaviour from 12c onwards ( USAGE OF SEQUENCE FOR DEFAULT VALUE )

drop table stu_details;
create sequence stu_id_seq;

CREATE TABLE stu_details (
    stu_id         NUMBER DEFAULT stu_id_seq.nextval,
    stu_name       VARCHAR2(30),
    date_of_join   DATE DEFAULT sysdate
);

insert into stu_details(stu_name,date_of_join) values('RAGU',sysdate);
insert into stu_details(stu_id,stu_name,date_of_join) values(201,'SCOTT',sysdate);
insert into stu_details(stu_id,stu_name,date_of_join) values(NULL,'SMITH',sysdate);

select * 
from stu_details;

-- Behaviour from 12c onwards ( USAGE OF "DEFAULT ON NULL" )
drop table stu_details;
drop sequence stu_id_seq;
create sequence stu_id_seq;

CREATE TABLE stu_details (
    stu_id         NUMBER DEFAULT ON NULL stu_id_seq.nextval,
    stu_name       VARCHAR2(30),
    date_of_join   DATE DEFAULT sysdate
);

insert into stu_details(stu_name,date_of_join) values('RAGU',sysdate);
insert into stu_details(stu_id,stu_name,date_of_join) values(100,'SCOTT',sysdate);
insert into stu_details(stu_id,stu_name,date_of_join) values(NULL,'SMITH',sysdate);

select * 
from stu_details;