Question

I have a script below – I dont know if it will produce the same effect as auto increment. When i begin inserting rows into my database, i dont want to insert the id. I want the database to generate and insert them automatically when i insert non-id rows.

CREATE TABLE myschema.mytable
(id NUMBER PRIMARY KEY NOT NULL,
name VARCHAR2(30));

CREATE SEQUENCE myschema.test1_sequence
START WITH 1
INCREMENT BY 1;

create or replace trigger myschema.auto_increment
before insert on myschema.mytable
for each row
begin
select test1_sequence.nextval into :new.id from dual;
end;
/

Answer 1

Yes it will work, except that you don’t have to use

id NUMBER PRIMARY KEY NOT NULL

because PRIMARY KEY already contains the NOT NULL constraint, so

id NUMBER PRIMARY KEY

is enough.