Implementing a self-increment ID in Oracle

In some databases (for example, MySQL), implement the self-increment ID as long as you specify it when you build the table,

But in Oracle, with sequence to implement the self-increment ID,

There are several ways to use the self-increment ID:

1. Use sequence's nextval directly in the INSERT statement.

2. Set default for the field when building the table, which I haven't tested yet.

3. Use a trigger, about the way the trigger, from someone else that got an example, for the moment to paste here as a memo. I think that if the default mode is available, it will be simpler than using a trigger.

Here is the code for how the trigger is Related:

CREATE TABLE STUDENT
(
ID INT not NULL,
NAME VARCHAR2 (4000) is not NULL,
PRIMARY KEY (ID)
)
Tablespace MYDB;

--Create a self-increment ID named: Table name _ Field name _seq
CREATE SEQUENCE student_id_seq MINVALUE 1 nomaxvalue INCREMENT by 1 START with 1 NOCACHE;


--Create a trigger for the insert operation without having to write nextval in the SQL statement, name is table name _INS_TRG
CREATE OR REPLACE TRIGGER student_ins_trg before INSERT on STUDENT for each ROW if (New.id is NULL)
BEGIN
SELECT Student_id_seq. Nextval INTO:NEW.ID from DUAL;
END;

Not to be continued

Implementing a self-increment ID in Oracle