How to create a PLSQL table with an auto-increment ID?

 

create table tbl_product(
    product_id number(10) NOT NULL,
    product_title varchar2(100) NOT NULL,
    product_description varchar2(255) NOT NULL,
    category_id number(10) NOT NULL
);

alter table tbl_product ADD CONSTRAINT pk_product_id PRIMARY KEY(product_id);

CREATE SEQUENCE seq_product_id
START WITH 1
INCREMENT BY 1
NOCACHE
NOCYCLE;

CREATE OR REPLACE TRIGGER trg_tbl_product
BEFORE INSERT
ON tbl_product
FOR EACH ROW
BEGIN
:new.product_id:=seq_product_id.nextval;
END;