在oracle数据库里创建自增ID字段的步骤

CREATE TABLE ADVICE

(

ID INT NOT NULL ,

ACTIVE INT DEFAULT 1 NOT NULL ,

TYPE INT NOT NULL ,

MSG VARCHAR2(512) NOT NULL ,

ADVICE VARCHAR2(4000) NOT NULL ,

PRIMARY KEY (ID),

CONSTRAINT ADVICE_UNI UNIQUE (TYPE,MSG)

)TABLESPACE MYDB;

--创建自增ID，名称为：表名_字段名_SEQ

CREATE SEQUENCE ADVICE_ID_SEQ MINVALUE 1 NOMAXVALUE INCREMENT BY 1 START WITH 1 NOCACHE;

-- 为Insert操作创建触发器，无需在SQL语句里写NEXTVAL，名称为表名_INS_TRG

CREATE OR REPLACE TRIGGER ADVICE_INS_TRG BEFORE INSERT ON ADVICE FOR EACH ROW WHEN (NEW.ID IS NULL )

BEGIN

SELECT ADVICE_ID_SEQ.NEXTVAL INTO :NEW.ID FROM DUAL;

END ;