Create a primary key auto-increment table in Oracle

Oracle creates a primary key auto-increment table 1, creates a table www.2cto.com create table Test_Increase (userid number (10) not null primary key,/* primary key, automatically adding */username varchar2 (20 )); 2. CREATE an automatic growth sequence create sequence TestIncrease_Sequence increment by 1 -- add several start with 1 each time -- count NOMAXVALUE from 1 -- do not set the maximum value, set the maximum value: maxvalue 9999 NOCYCLE -- always accumulate, create trigger Test_Increase BEFOREinsert ON Test_Increase for each row/* checks whether each row is triggered */beginselect TestIncrease_Sequence.nextval into: New. userid from dual; end; // * exit sqlplus row edit */4, submit commit; 5. test insert into Test_Increase (Username) values ('test ');