在oracle數(shù)據(jù)庫里創(chuàng)建自增ID字段的步驟

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;

--創(chuàng)建自增ID，名稱為：表名_字段名_SEQ
CREATE SEQUENCE ADVICE_ID_SEQ MINVALUE 1 NOMAXVALUE INCREMENT BY 1 START WITH 1 NOCACHE;


-- 為Insert操作創(chuàng)建觸發(fā)器，無需在SQL語句里寫NEXTVAL，名稱為表名_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;