The implementation process of Oracle database Auto-Growth column

1. Create a sequence

--Create sequence

Create sequence Innerid

MinValue 1

MaxValue 99999999999999

Start with 1

Increment by 1

Cache 20

Order

2.--innerid.currval refers to the current sequence

--innerid.nextval refers to the next sequence

Insert into admin values (innerid.nextval, ' a ');

Insert into admin values (innerid.nextval, ' B ');

Insert into admin values (innerid.nextval, ' C ');

Insert into admin values (innerid.nextval, ' d ');

CREATE TABLE Admin

(ID varchar2 (), name VARCHAR2 (10));

--constant insertion of the next value of the sequence.

3. Create a trigger (note: The default value for ID cannot be set here is Innerid.nextval)

CREATE OR REPLACE TRIGGER ADMIN_TG

Trigger for--admin ID

Before INSERT on admin for each ROW

BEGIN

SELECT Innerid. Nextval INTO:NEW.id from DUAL;

END;

The test statements are as follows:

Insert into admin (username) VALUES (' Zdz ');

If you successfully insert the data, and then look at the data, you can see that the ID has grown automatically and this problem is resolved!

The implementation process of Oracle database Auto-Growth column