oracle 主键自增

注意：new后面的和主键对应

CREATE TABLE item (
  iid  INT ,
  title VARCHAR2(50),
  CONSTRAINT pk_iid PRIMARY KEY (iid)
);
CREATE TABLE news (
  nid     INT ,
  title   VARCHAR2(50),
  pubdate  DATE,
  content  LONG,
  iid     INT,
  CONSTRAINT pk_nid PRIMARY KEY (nid),
  CONSTRAINT fk_iid FOREIGN KEY (iid) REFERENCES item (iid)
    ON DELETE SET NULL
);
-- 测试数据


--create   sequence customer_id_seq increment by 1 start with 1 ;


create or replace
trigger trg_item before insert on item for each row 
begin 
select CUSTOMER_ID_SEQ.nextval into :new.iid from dual; 
end;
/
create or replace
trigger trg_news before insert on news for each row 
begin 
select CUSTOMER_ID_SEQ.nextval into :new.nid from dual; 
end;

/

INSERT INTO item (title) VALUES ('aaa');
INSERT INTO item (title) VALUES ('体育新闻');
INSERT INTO item (title) VALUES ('娱乐新闻');
INSERT INTO item (title) VALUES ('财经新闻');
INSERT INTO item (title) VALUES ('科技新闻');