在oracle数据库里创建自增ID字段的步骤

在oracle里使用自增ID字段的步骤比较繁琐，总结如下：

-- 创建表

rush:sql;"> 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;