Oracle Set PRIMARY key auto-increment

There is no self-increment field in Oracle, which can be implemented indirectly via sequence + trigger, Sqlplus login in cmd and run directly. It usually takes a few steps:

1 Creating a data sheet

CREATE TABLE Test_increase (
UserID Number PRIMARY KEY,/* primary key, auto increment */
Username VARCHAR2 (20)
);

2 Creating an auto-grow sequence

CREATE SEQUENCE testincrease_sequence
INCREMENT by 1--add a few each time
Start with 1-counting starting from 1
Nomaxvalue--Do not set the maximum value
Nocycle--keep accumulating, not looping
CACHE 10;

3 Creating a Trigger

CREATE TRIGGER Test_increase before
Insert on Test_increase for each ROW
Begin
Select Testincrease_sequence.nextval Into:New.userid from dual;

End

4 Submit

Commit

5 Testing

Execute the following statement repeatedly:

Insert into Test_increase (Username) VALUES (' Test ')

6 View Insert Results:

UserID username

1 Test
2 Test
3 Test
4 test
5 test
6 test
7 Test
8 test
9 test

Turn: Http://blog.163.com/[email protected]/blog/static/165190577201082910371842/

Oracle Set PRIMARY key auto-increment