Oracle 18c

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table myprojects ( startdate date, enddate date, profit  number);
insert into myprojects (startdate, enddate,profit ) values(to_date('1/5/2019','mm/dd/yyyy'),to_date('5/1/2019','mm/dd/yyyy'),100);
1 rows affected

insert into myprojects (startdate, enddate,profit ) values(to_date('1/6/2019','mm/dd/yyyy'),to_date('2/10/2019','mm/dd/yyyy'),50);
1 rows affected

alter table myprojects add ( projectid number generated always as identity);
select * from myprojects;


STARTDATE
ENDDATE
PROFIT
PROJECTID


05-JAN-19
01-MAY-19
100
1

06-JAN-19
10-FEB-19
50
2